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HomeMy WebLinkAbout1.0 Applicationencana Encana Oil & Gas (USA) Inc. 143 Diamond Avenue Parachute, Colorado 81635 LIMITED IMPACT REVIEW APPLICATION K19NE Storage Facility (Laydown Yard) Garfield County, Colorado February 2015 Prepared by: Olsson Associates 760 Horizon Drive, Suite 102 Grand Junction, Colorado 81506 TEL 970.263.7800 1 FAX 970.263.7456 www.olssonassociates.com O\OLSSON ASSOCIATES Index Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OAProject No. 014-2797 Article Topic 4-101.A Preapplication Conference Summary 4-118, 4-202 Waiver Requests 4-203.B.1 General Application Materials 4-203.6.2 Deeds, Easements and Agreements 4-203.6.3 Adjacent Land Owners and Mineral Rights Owners Information 4-203.6.4 Project Description 4-203.0 Vicinity Map 4-203.D Site Plan 4-203.E Grading and Drainage Plan 4-203.E.16 Stormwater Management Permit and Plan 4-203.E.18 Reclamation Plan 4-203.G Impact Analysis 4-203.G.3 NRCS Soils Report 4-203.G.4 Geologic and Soils Hazard Report 4-203.G.6 Wildlife and Vegetation Impact Analysis 4-203.G.7 Fugitive Dust Control Plan 4-203.L Traffic Study 4-203.M Water Supply and Distribution Plan 4-203.N Wastewater Management and System Plan 7 Standards Analysis 7-107 Roadway Assessment 7-202.C.3 Noxious Weed Plan 7-1003.0 Emergency Response Plan Figures Article 4-101.A Preapplication Conference Summary Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OAProject No. 014-2797 Garfield County Community Development Department 108 8th Street, Suite 401 Glenwood Springs, CO 81601 (970) 945-8212 www.garfield-county.com PRE -APPLICATION CONFERENCE SUMMARY TAX PARCEL NUMBER: 2179-193-00-128 DATE: 8/28/14 APPLICANT'S PLANNER: Lorne Prescott, Olsson Associates PROJECT: Encana K19NE Storage Yard OWNER: Encana Oil and Gas (USA) Inc. REPRESENTATIVE: Jason Eckman, Encana Oil and Gas (USA) Inc. PRACTICAL LOCATION: Approximately 1mile southeast of the Rifle City Limits, south of the Garfield County Airport, on private roads off of County Road 333, and generally located in Section 19, T6S, R92W. ZONING: Rural TYPE OF APPLICATION: Limited Impact Review for a Storage Facility I. GENERAL PROJECT DESCRIPTION The Applicant proposes the creation of a storage facility on an existing well pad. The site is fully developed with several wells in active production on the site. The proposal is to utilize the existing disturbed area with the potential to expand the storage area up to a total of 5.172 acres. The site is located on an overall parcel of approximately 88 acres. The existing well pad and disturbed area covers approximately half of the proposed 5.1 acres. Additional grading and related improvements will be required to expand the site. The site is currently covered by existing COGCC permits/forms with reclamation covered by an existing bond. Access roads to the site are in place and are gated. The potential for security fencing is still being considered and may be implemented for the site. The Applicant represents that the site is not located in a subdivision and given the location compatibility with adjacent land uses may be an important consideration. Existing improvements on the site include a tank area, pipelines, separator units, a communication tower and 6 well heads. Compatibility with the existing uses will need to be addressed in the storage facility application submittal. No water or sanitation facilities are anticipated and the proposal is to operate as an unmanned facility. Staff will access the site only intermittently to pick up equipment. The Rural Zoning for the property requires a Limited Impact Review Land Use Change Permit for the proposal. II. REGULATORY PROVISIONS APPLICANT IS REQURED TO ADDRESS • Garfield County Comprehensive Plan 2030 • Garfield County Land Use and Development Code, as amended o Section 4-101, Common Review Procedures o Section 4-104, Limited Impact Review o Table 4--102, Common Review Procedures and Required Notice o Table 4-201, Application Submittal Requirements o Section 4-203, Description of Submittal Requirements o Table 3-403, Use Table — Storage o Section 7-1001, Industrial Use Standards o Article 15, Definitions, Storage o Section 4-118 (Waiver of Standards), Section 4-202 (Waiver of Submittal Requirements o Article VII, Standards — Divisions 1 and 2 and 3 as applicable -- including roadway standards • Colorado Department of Public Health and Environment Regulations Pertaining to Storm Water and Air Quality (site disturbance, construction, dust). • Safety provisions pertaining to emergency procedures. • Regulations on Noise and Nuisances • COGCC Reclamation and Re -vegetation Requirements • Demonstration of compliance with Section 7-107 Access and Roadway Standards including the Policy (01-14) related to submittal requirements and demonstration of compliance with Waiver Criteria for Roadway Waivers. III. REVIEW PROCESS 1. Pre -application Conference. 2. Preparation and Submittal of the Application. 3. Determination of Completeness — Provision of Additional Application Copies, and Distribution of Referrals. 4. Schedule Date for Board of County Commissioner's Public Hearing 5. Completion of Public Notice Requirements. 6. Staff Review -- Preparation of Staff Report 7. Board of County Commissioner's Public Hearing 8. Documentation of the Board's Action by Resolution - Approval, Approval with Conditions, or Denial 9. Applicant addresses any Conditions of Approval within one year of the Board's Decision. 10. Preparation of Land Use Change Permit as Appropriate. IV. APPLICABILITY OF STANDARDS AND WAIVER REQUESTS Should the Applicant chose to request waivers from submittal requirements or standards the Application submittals will need to clearly address the review criteria contained in Sections 4-118 and 2-202 in justifying the requests. The Applicant should consult with the Roadway Standards and Waiver Policy 01-14 regarding roadway and access issues (see attached) In lieu of waiver requests the Applicant should submit Water Supply Plans and Waste Water Plans to demonstrate the lack of demand for these services associated with the unmanned facility. Where waiver's from completion of fully developed plans are the intent of the waiver request the Application should still contain general information appropriate to demonstrate compliance with the waiver review criteria. The Application andlor waiver requests need to address screening requirements V. SUBMITTAL REQUIREMENTS An Application for an Administrative Review will also need to provide all standard application forms, agreement to pay form, a listing of all property owners (with addresses) within 200 ft., an excerpt from the Assessor's Office mapping showing the ownerships, a listing of any mineral rights owners on the subject property (with addresses), authorization to represent statements/letters, evidence of ownership such as a deed and/or lease agreements for the site. Other key elements of the submittal include vicinity map, site plan including details on the existing conditions and proposed use, grading and drainage plans, impact analysis, geologic hazards information, and traffic study. The areas of the site proposed for expansion will need to be addressed in the submittals including site plan and technical details (i.e. grading and drainage plans). VI. APPLICATION REVIEW a. Review by: Staff for completeness recommendation and referral agencies for additional technical review b. Public Hearing: c. Referral Agencies: _ Director's Decision (with notice) Planning Commission X Board of County Commissioners Board of Adjustment May include but not limited to Garfield County Road and Bridge Department, Fire Protection Districts, Garfield County Environmental Health Manager, Garfield County Vegetation Manager, Garfield County Consulting Engineer, CDPHE, COGCC, and City of Rifle. VII. APPLICATION REVIEW FEES a. Planning Review Fees: $ 400 b. Referral Agency Fees: $ TBD — consulting engineer/civil engineer fees c. Total Deposit: $ 400 (additional hours are billed at $40.50 /hour) General Application Processing Planner reviews case for completeness and sends to referral agencies for comments. Case planner contacts applicant and sets up a site visit. Staff reviews application to determine if it meets standards of review. Case planner makes a recommendation of approval, approval with conditions, or denial to the appropriate hearing body. Disclaimer The foregoing summary is advisory in nature only and is not binding on the County. The summary is based on current zoning, which is subject to change in the future, and upon factual representations that may or may not be accurate. This summary does not create a legal or vested right. Pre -application Summary Prepared by: /2/L - Glenn Hartmann, Senior Planner Da Policy 01-14 Waivers for Roads and Demonstration of Compliance March 3, 2014 Section 7-107, Access and Roadways, of the Garfield County Land Use and Development Code (LUDC) requires all roads to be designed to provide for "adequate and safe access" and reviewed by the designated County Engineer. The LUDC defines "road" as "a County road, State highway, public road, street or alley, or private thoroughfare which affords primary access to abutting property, excluding a driveway accessing a single property." The LUDC defines "private road" as "a right-of-way constructed, established, owned, and maintained by a private party for access exclusively to private property." Many of the roads in Garfield County are private roads in that they are gated and do not serve the general public and they pre-existed the design currently required by the County's Road Standards as defined in Table 7-107. The LUDC allows for the waiver of specific standards provided that the following criteria have been met: 1) an alternative design achieves the intent of the subject standard to the same or better degree and 2) the proposed alternative will impose no greater impacts on adjacent properties than would occur through compliance with the specific standard (Section 4-118). In applications that include roads that do not meet current County road standards as outlined in Table 7-107, the County has asked that Applicants request a waiver of Section 7-107.F, Design Standards, and include in the Application submittal sufficient information, prepared by a professional qualified in the specific discipline, to demonstrate that they meet the criteria outlined in Section 4-118 for granting a waiver. In doing so, the application must include: A Statement of Adequacy - The evaluation of the existing roadway and waiver will need to include a clear statement that finds that the road will be adequate for the proposed use. This statement must be signed by a professional engineer qualified in traffic engineering and licensed by the State of Colorado. To support this evaluation, the following information will be required to be provided: Geometry of the road A description of how the private road does/does not meet the design standards in Table 7-107. This should include a chart that compares the private road design to those standards in Table 7-107, as well as a map that shows the existing road design and highlights those areas that deviate from the standards. A narrative may also be helpful in describing the characteristics of the road as they compare to Table 7-107 design standards. Unless available, this is not intended to imply construction - level drawings. Safety/Structural Issues A description of obvious safety and/or structural issues observed and a statement about how these issues will be addressed. Maintenance A description of how the road is and/or will be maintained. This should be supported with the submittal of any existing or proposed maintenance agreements for the road sections. Travel Demand An accurate count of the existing peak travel demand as well as the Average Daily Traffic on the road. This should also include the types of vehicles that currently use the road as well as the additional amount and type of traffic that the proposed use will generate through all phases of its development. Other Evidence of Compliance. In addition, Sections 7-I07.A, B, C, D, and E are required to be addressed, which includes documentation about legal access. Sufficient evidence will be required to be submitted to demonstrate compliance with these sections of the Code. A. Section 4-104 Limited Impact Approximately 3 months if s PC Garfield County Limited Impact Review Process (Section 4-104) Step 1. Pre -application Conference •Applicant has 6 months to submit application Step 2: Application Submittal Step i Completeness Review •20 business days to review •If incomplete, 60 days to remedy deficiencies Step 9: Schedule i -fed ri "i; ;acid Pravide Nui'c • Published, posted, and mailed to adjacent property owners within 200 feetand mineral owners at least 30 days but no more than 60 days prior to BOCC public hearing Step 5: Referral • 21 day comment period Step 6: Evalution by Director Step 7:i BOCC- Decision • Applicant has 1 year to meet any conditions of approval Article 4-118, 4-202 Waiver Requests Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OA Project No. 014-2797 OLSSON ASSOCIATES Waiver Requests Encana Oil & Gas (USA) Inc. K19NE Storage Facility SECTION 4-118 WAIVER OF STANDARDS Pursuant to Section 4-118 of the Garfield County Land Use and Development Code, Encana requests a waiver for the following Access and Road Design Standards for the K19NE Storage Facility. Section 7-107 Access & Roadways F. Design Standards. A waiver of standards request shall be considered based on the following criteria: 1. Achieves the intent of the subject standard to the same and better degree than the subject standard: Response: The intent of the design standards is to provide safe access to the project site. This road was designed for the exclusive use of Encana to access its natural gas operations. It is not designed for public use. Given the average daily traffic that this road services, it should most closely correspond to the Primitive/Driveway road standard. The private access road does not meet the design standards for road grade, cross slope, or ditches. See Road Assessment report for more information. The area of the road that has a grade of more than 12% is a short distance. The road has been designed to follow the natural topography of the area with minimal change to the natural grade. The road is graveled. Emergency vehicles will be able to negotiate the grade, if necessary. The cross slope varies from 0.6% to 7.3% along the road. In some places, the road slopes toward the side of the road without a ditch, including some areas where the road is crowned. The road geometry changes occasionally with maintenance activities. While ponding may occur in areas of shallow cross slope, the road is inspected on a regular basis for maintenance issues, which are addressed in a timely manner. Speeds are low to promote safety and reduce road damage. Some areas of the road do not have ditches present on either side. Where ditches are present, they range in width from 2.0 to 7.5 feet. They are fairly shallow. The road is inspected on a regular basis for maintenance issues, which are addressed in a timely manner. 760 Horizon Dr., Suite 102 TEL 970.263.7800 Grand Junction, CO 81506 FAX 970.263.7456 www.olssonassociates.com Encana Energy Inc. K19NE Storage Facility 2. Imposes no greater impacts on adjacent properties than would occur through compliance with the specific requirements of this Code. Response: This private road does not provide access to residential uses nor is it used by the general public on a regular basis. The waiver of this standard will not create greater impacts on adjacent properties than would occur if it was in full compliance. SECTION 4-202 WAIVER OF SUBMISSION REQUIREMENTS Pursuant to Section 4-202 of the Garfield County Land Use and Development Code, Encana Oil & Gas (USA) Inc. (Encana) requests a waiver for the submittal requirement of a Development Agreement and Improvements Agreement for the K19NE Storage Facility. Section 4-203.J. Development Agreement A waiver request shall be considered based on the following criteria: 1. The Applicant shows good cause for the requested waiver; Response: Encana wishes to neither propose a phasing schedule nor extend establishment of vested property rights. 2. The project size, complexity, anticipated impacts, or other factors support a waiver; Response: The facility is largely constructed and does not require additional improvements to operate as a storage facility. 3. The waiver does not compromise a proper and complete review; and Response: The request can be properly and completely reviewed without a development agreement. 4. The information is not material to describing the proposal or demonstrating compliance with approval criteria. Response: A development agreement is not material to describing the purpose, operation and maintenance of the facility or demonstrating compliance with applicable approval criteria. Section 4-203.K. Improvements Agreement A waiver request shall be considered based on the following criteria: 1. The Applicant shows good cause for the requested waiver; Response: No public improvements are being proposed that would warrant the creation of an improvements agreement. 2. The project size, complexity, anticipated impacts, or other factors support a waiver; Response: As stated above no public improvements are being proposed with this request. Waiver Requests Page 2 Encana Energy Inc. K19NE Storage Facility 3. The waiver does not compromise a proper and complete review; and Response: The application can be properly and completely reviewed without an improvements agreement. 4. The information is not material to describing the proposal or demonstrating compliance with approval criteria. Response: An improvements agreement is not material to describing the purpose, operation and maintenance of the facility or demonstrating compliance with applicable approval criteria. Waiver Requests Page 3 Encana Energy Inc. K19NE Storage Facility THIS PAGE LEFT BLANK FOR TWO-SIDED DUPLICATION. Waiver Requests Page 4 Article 4-203.6.1 General Application Materials Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OAProject No. 014-2797 Nimor Garfield County Community Development Department 108 8th Street, Suite 401 Glenwood Springs, CO 81601 (970) 945-8212 www.garfield-countv.com LAND USE CHANGE PERMIT APPLICATION FORM TYPE OF APPLICATION • Administrative Review • Development in 100 -Year Floodplain Limited Impact Review • Development in 100 -Year Floodplain Variance • Major Impact Review 0 0 Code Text Amendment • Amendments to an Approved LUCP ❑ LIR ❑MIR 0 SUP Rezoning ❑ Zone District]] PUD ■ PUD Amendment • Minor Temporary Housing Facility • Administrative Interpretation • Vacation of a County Road/Public ROW 0 Appeal of Administrative Interpretation • Location and Extent Review • Areas and Activities of State Interest ■ Comprehensive Plan Amendment ❑ Major ❑ Minor 0 Accommodation Pursuant to Fair Housing Act ❑ Pipeline Development • Variance • Time Extension (also check type of original application) INVOLVED PARTIES Owner/Applicant Name: Encana Oil & Gas (USA) Inc Mailing Address: 143 Diamond Ave Phone: ( 970 ) 285.2656 City: Parachute State: CO Zip Code: 81635 I: -mail: jason.eckman@encana.com Representative (Authorization Required) Name: Lorne Prescott Mailing Address: 760 Horizon Drive, Suite 102 Phone: ( 970 ) 263.6014 City, Grand Junction State: CO Zip Code: 81506 I: -mail: Iprescott@oissonassociates.com PROJECT NAME AND LOCATION Project Name: K19NE Laydown Yard Assessor's Parcel Number: 2179 _ 193 _ 00 _ 128 Physical/Street Address: Legal Description: Lot 3, Section 19, Township 6 South, Range 92 West, 6th PM Zone District: Rural Property Size (acres): °88.5 PROTECT DESCRIPTION Existing Use: Natural gas well pad Proposed Use (From Use Table 3-403): Storage Description of Project: provide a centralized location to store equipment and supplies in support of Encana's natural gas drilling and production activities in the area. REQUEST FOR WAIVERS Submission Requirements 13 The Applicant requesting a Waiver of Submission Requirements per Section 4-202. List: Section: 4-203.J Development Agreement Section: Section: 4-203.K Improvements Agreement Section: Waiver of Standards The Applicant is requesting a Waiver of Standards per Section 4-118. List: Section: 7-107.F Access & Roadways Design Standards Section: Section: Section: 1 have read the statements above and have provided the required attached information which is correct and accurate to the best of my knowledge. Si ture of Property Owner Date OFFICIAL USE ONLY File Number: Fee Paid: $ Garfield County PAYMENT AGREEMENT FORM GARFIELD COUNTY ("COUNTY") and Property Owner ("APPLICANT") Encana Oil & Gas (USA) Inc agree as follows: 1. The Applicant has submitted to the County an application for the following Project: K19NE Storage Facility (Laydown Yard) 2. The Applicant understands and agrees that Garfield County Resolution No. 2014-60, as amended, establishes a fee schedule for each type application, and the guidelines for the administration of the fee structure. 3. The Applicant and the County agree that because of the size, nature or scope of the proposed project, it is not possible at this time to ascertain the full extent of the costs involved in processing the application. The Applicant agrees to make payment of the Base Fee, established for the Project, and to thereafter permit additional costs to be billed to the Applicant. The Applicant agrees to make additional payments upon notification by the County, when they are necessary, as costs are incurred. 4. The Base Fee shall be in addition to and exclusive of any cost for publication or cost of consulting service determined necessary by the Board of County Commissioners for the consideration of an application or additional County staff time or expense not covered by the Base Fee. If actual recorded costs exceed the initial Base Fee, the Applicant shall pay additional billings to the County to reimburse the County for the processing of the Project. The Applicant acknowledges that all billing shall be paid prior to the final consideration by the County of any Land Use Change or Division of Land. I hereby agree to pay all fees related to this application: Billing Contact Person: J1ASOn1 Phone: 076) Z6 - Z -' 1O Billing Contact Address: ( y 3 � onf r�tJ City: PA Cat- State: CO Zip Code: Silo 36 - Billing Contact Email: J0.50.A . Printed Name of Person Authorized to Sign: \fit Sono .a4 -t -L (Signature) (Date) 11111' 11,1Pyid .rill.111,1 i1r,WWI 11111 Receptfan#: 821766 07/24/2012 03:04:72 pm Jean Albertoo 1 of 1 Roo Fe$$11.00 Doo Fee:0.00 CARFI€LD COUNTY CO STATEMENT OP AUTHORITY CONFORMED COPY Pursuant to C.R.S. §38-30-172, the undersigned executes this Statement of Authority on behalf of Encano OiI k Gas (USA) Inc, a corporation (corporation, limited liability company, general partnership, registered limited liability partnership, registered limited liability limited partnership, limited partnership association, government agency, trust or other), an entity other than an individual, capable of holding title to real property (the "Entity"), and states as follows: The name of the Entity is Encana Oil & Gas (USS,) and is formed under the laws of th t t o The mailing address for the Entity is 37017th Street, Suite 3700 Denver, CO 8202 The name and/or position of the person authorized to execute instruments conveying, encumbering, or otherwise affecting title to real property on behalf of the Entity is Renata Busch, Jason Eckman, Mike Herndon and Chris Putnam The limitations upon the authority of the person named above or holding the position described above to bind the Entity are as fol lows : sign permit applications and permits issued by Garfield County (ii: no limitations, insert "None") Other matters concerning the manner in which the Entity deals with any interest in real property are (if no other matter, leave this section blank) EXECUTED this day et , 2 i2•, Signature: Name hyped or printed: barrin J. Henke STATE OF Colorado COUNTY OF Denver 11/08 Title(if any} : Vice -President } }55. The foregoing inatrumant was acknowled ed before me this 1'-3 day of 11,441ne i 201. by barna J, Henke , on behalf of . a . jawariKgERiEt gn - - Witness my hand and official seal. My commission expires: DITH B SISNEROS NOTARY PUBLIC STATE OF COLORADO My Commission Expires 01712018 (Notary Public) encana December 8, 2014 Mr. Fred Jarman, Community Development Director Garfield County Community Development Department 108 8th Street, Suite 401 Glenwood Springs, CO 81601 RE: Agent Authorization Dear Mr. Jarman, Encana Oil and Gas (USA) Inc. (Encana) authorizes Lorne Prescott and Tilda Evans, and Olsson Associates to act on behalf of and represent Encana in all matters related to land use permitting in Garfield County. Please contact me if you have any questions. Sincerely, date)-(9-,t_k_ Jason Eckman Senior Regulatory Analyst Encana Oil & Gas (USA) Inc. 143 Diamond Avenue Parachute„ CO 81635 t 970.285.2656 f 970.285.2691 www.encana.com Article 4-203.6.2 Deeds, Easements and Agreements Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OAProject No. 014-2796 Filed Tor record the day of Rema wn 110. dr ,A.D. . ac o,cfockM. per, Rs' aP.1::7LY. WARRANTY DEED THIS DEED. Nada on dolt day of Aprii 01, 7004 berween AIRPORT LAND PARTNERS LIMITED. A COLOAADD LIM1TTD PARTNERSHIP of the Cawrty- or GARFIELD ENCANA OIL 14 asiosAiNc. ewd Scare ok Colorado ere Grantor 1a1. and *rase legal address is : 930 ITTH ST $T X660 i II VER, CO $O at thr County or DEMI ud state of Colorado . tee Gramme la): WITNESS. mit rhe Gra:eorrs). Tor and tri cmanderatarn of she sea or t 1224.000.40 1 Two Hundred Twenty Thrlusand and 00/100 . DOLLARS the receipt and su"f darty or which to orrery aca:nerled)ci, has granted. tergained, sold and mrvsyed. and ty these presents does grant, k+azsgatn, sell. convey aid cretins ouzo ire Grantee Isl, his heirs and assigns forever, all the real grepe_ty, together wish nota, if any. elevate. tying and hetng in the Comny of GARFIELD and state of Luloaada. de__crUed as Tvilwa. LILT 3 ANC) TIFF. NW 1f•]SEI/4 OF SECTION 19. TOWNSHIP 6 SOUTH, RANCE 22 WEST OF THE 6TH P.M. COUNTY OF GARFIELD STATE OF COLORADO afar/ knees as ~areae umber SECTION 19. TOWNSHIP 6 SOUTH. RANGE S2 WEST TOGETHER with all and singular anti tercd[Las its and aaurtenantres uaareto 1xLxi3L3. or ler aerywix a71ertairdm and the manakin and rerers1 zu. radish -ear and rem freers. rams, xsnres end profits fresco": and all the stage. right tide inrerrer, claim and deaur3 wiveTver of ire G an.=1s). either in law of expiry. of. +r1 and co cre above hatga red pxemises, with the rewardcatrents and appucesw1cga: TO HAVE AND TO HOLD the said premises ahave hae90111ed aqd deice Lred with aFpwrtenanoea, =ra ch0 Gtanteefel his lairs and assigns loreour. the GYanror101 . for rusise1f. his (tells and peraa'iat repregerratners, dams tUvrsraerr, gent. bargain. and agree ro and with the Graoteelaltua tad's and aasigee. that dt the cine of the enae.l:ing and delivery of these presents, he ,.s well seized or tre pre -uses above tear jed. has grad. sure. raciest, ahaoluce and irehfosesble estate of sruer1caser. in lar. in for %male, are has 920d nate. toil rawer and lawLt+l avcharicy co gam. bargain, sell and coney chi gone lei nartlez and Lunn as aforesaid, ane _hat the Fane are Ecce and cleave from all tomer ani [cher Or name waver. SE}BOECT To GENERAL TAX FOR taxes, YEAR 2004. ANO�ENT RESERVATIand ONS. RESTRof ICTIONS COVENANTS AND RIGHTS OF WAY OF RECORD. TF ANY: AND DISTRIBUTION UTILITY EASEMENTS: AND 'HATTERS NOT SHOWN BY THE PLIBLIC RECORDS HMO! WHICH GRANTEE HAS ACTUAL KNOWLEDGE: AND INCLUSION OF THE PROPERTY WITHIN ANY SPECIAL TAXING DISTRICT. AND THE BENEFITS AND BURDENS OF ANY DECLARAT1ON AND PARTY WALL AGREEMENTS. 1F ANY. We Grantor. 1w1 aha! I and rr t 1 SCAPAir]' AtO FgHEVHt tiona0 the arae hargatned xerr see In TY quiet and peecsable possessicr of the Cranteeter. fug false 6/6± asl¢71i, against all and a,nsay person or penscris lawfully cLaireirg rhe tanle of any parr theleof I1 singular ranter shall Include the plural. and the plural Che nlpgulat. orad t2* 10e el any gender shall be applicable to nil garelers. IN WiT'NESS WHEREOF the Grantor lel has executed psis 'deed al the Cate set forth derive. 6T161E OP Colorado Cdcmcy n! GARFIELD t ra�..t, f .,: 1 i_ei-="0 S.n.eatrers. rod raokn7w1ect0ed be6ore re oar this day of A 6 67 2004 ;.1.1;? L }1E BARP DENT OF AIRPORT BUSINESS PAR C h RLP I RT ��.,Ryr.,' 7 -Ac - kT J ., p�y. 4,,.aomi erajai:agii re6 a%'../ 5. cues any h r 1 and otticial seal. Payr and s b AIRPORT LAND ARTNERS LIMITED, A COLORADO LIMITED PARTNERSHIP BY AIRPORTIUS1NESS PARK COIF' RATION : ROB R A. '' ARD. ' ' - raxat� E4A, Rue= Qpat ug Partly Cheated Legal fescrrptxo:l 1 39. 35.106 5. C.A.S,I 4iYn¢,575 ;T¢t1eel ,,LW2.13575 Fotm fb. 931 REV 1 91. MAMMY L'1e20 1Phoawraddc Record km) i an Rp;comed Return to. fs[7.11)% 7[1. t CFS ILEA) UK, 950 L7711 SP Sre 2600 rano-# m mnanf 111111111!11111111111!111111! rfii!ilii! !!I !ilii i!1! !ij] 149881 04/09/2004 0340P 81576 P207 0 81110 F 1 of 1 R 6.00 0 22.00 1RRFIE..D COUNTY CO Producers BB—Rev. 1988 Rocky Mountain (Colo. CBM) REC D. AT /0 12-1: O'CLOCK /—' RECk'409298 rILDRED ALSD GARFIELD COUN1' OIL AND GAS LEASE ri. JAN 2 2 1990 Fr COUNTY CLERK fr COLORADO R.f1:K 71 p'_r't`' 61 AGREEMENT, made and entered into Ips 7th* tl December j9 89 Dorothy Dever, formerly Dorothy Dever Fuller, now a single woman 99 South Downing Street, #1502 Denver, CO 80209 by and between Richard Thompson Dever, a single man P.O..Box 636 Glenwood Springs, CO 81602 and Party of the fed part, hereinafter called lessor (whether one or morel and Pioneer 011 Park Center, Suite 145, Midvale, Utah 84047 & Gas, a Utah corporation. 6925 Union Party of the second part. hereinafter called lessee WITNFSSETI{, that the said lessor, for and in consideration of Ten and More ($10.00 & More) Dullars cash in hand paid, receipt of which n hereby aeknnwtedged and dale covenantsard agreements hereinafter unstained on the ran of the lessee to b• part, kept and performed. has grandest. Jetnivd. leased. and let and by these presents doesgrant, demise, lase, and let exclusively unti r the said luso., its successors and a Signs, for the xde and only putperws of surveying, by geologieaI. geophy se a I. and all other methal, exploring. mining and operating for. and producing oil, gas, and other hydh..arbns. and all other minerals or sulucinccs. whether simdat en dissimilar. including. but not limned to. coalbed methane. helium. nun/gem carbon dioxide, and all substances produced in association IhercwiIh from out -bean in for mations of elsewhoe, that maw he prod uc d f,nm any well dr idled by testi on UP:leased premises hereinafter described, andfayingpipelines,andpuddingtanks.powerstationsandstructurestheremtopnduex, awe:in sakel'Jle1.I.aidprsJueiall[hatcerviinIracytillandI.seehe'...ohanyreyeni•.nary.rsmaimke•rman - and sponging es ecutuuy rights theei n..situate in.ihe County of_ . era rf i p1 r1 — -Same o1. rolararin -described as tedious. to wmt Township 6 South, Range 92 West, 6th PM Township 6 South, Ran&e 93 West, 6th PM Sec. 17: SW1/4NW1/4, WSW` Sec. 25: SE1/4NW1/4 Sec. 18: S'INE1/4, N1/2SE1/4, SW1/4SE1/4 Sec. 26: W'SE' Sec. 19: NW1/4SE1/4, Lot 3 (48.42 a.) Sec. 35: SLISE1/4, NINE -1 Sec. 36: WISW1/4 Township 7 South, Range 93 West, 6th PM Sec. 1: Lot 2, (24.00 a.) W1/2SW1/4, NE1/4SW1/4, WNW1/4SE1/4 Sec. 2: Lot 1, (23.65 a.) ElISE1/4 together "thall snips,orparcels ofland. (not.however. u Ise construed to include parcels crimprising a regular 40-aere lepl subdivision or lot of approximately cormapanding suel adjoining or e, nitiguouslo the above descnbrxi land and owned or claimed by Lessor. and containing 1036.07 acro, more or Ica I Without reference w the commencement. prowl:Lawn or ccs ai.on al any time of drilling or other development operations and/or to the discovery. development or cessation at any time of prtduetion of oil. gas or other hydrocarbons Including coalbed methane or other minerals or substances envered hereby (herein o die to cry referred to as"oil or gas") en either or any of them. acct i.ln ut furtlpei In,vmcncs ocher than [heroyalties herein providedand notwithstanding anything herein conuincxltothe contra contrary. seve:i• )-""'�+�''•years from the dale hereof. and as long thereafter as oil and gas, or c,eher err any of them, is per d uud from said lands cur premise pooled t hcrew iI h or dntling operations are ontinuewl as heremifter provided by the haste, its sin favors and assigns. During the term of this lase, lover agrees nor to enter into any od and gas lease with any other pany orvcnng any lands ursn,d by this' lease ; r ' • '-r - 2. Thu is a PAID-UP LEASE. In consideration id the cash down payment lee. agrees that 11:7011: shall not h' obligated. exeepl a- other wise pros Wed hetero ro eon menex err e7rnmuc any operations during the primary term. Lessee may at any time or timesduring or after the primary term surrender This lease as Io all ..r any Armon of said land and as les any sirau or srlatuni by eklver ng w lesser car by filing for record a release or releases, and be relieved of all obligation thereafter accruing as to the acreage surrendered • 3. In consideration of the premises the said Lessee emsenants and agreees ep f r - First. The lessee shalldelis'eriothecrednofInsorasrnya!'y,freeofcostinthepilxfmctowhichlesseemayconnetn.well.,-the equal one-eIghth(I/8lhlpart nfalludprrducedand sae nllrnmtheleual premises, or at lessee's option. lessee may buy or sell such one-eighth 11/8110 royally and pay lessor the M3I once for oil like grade and gravity prevailing in the Field "in [he diystichtadsruncolapipelinesor into storage tanks. % .I- • • . - Second. To pay tenor one-eighth( I e8thlof the net proceedsar the well from the proceeds rexeised for gas sold from each u ell where gasonly is found, or the market vilue at the %sell ofsuch gas usol off the premises. Third. To pay lessor one-eighth f 1/801) of the market value at the 'well helps produced from any oil well and need of the premises: in for the manufacture of casing -head gasoline or dry commercial gas Founh. Tu pay lessor one-eighth (f/8lhlofthe proevolsremhW from the ule ...limy substance. coverol by his lease. oth,1 than crel and gas and the products ihereot. which lessee may prikiuce. sas e. and markel from the leased premises. 4 If at the expiration of the primary term of this leas•, oil or gas is not being produced on the leased premises or on acreage pexmked therewith but lessee is then engaged In drilling or re -working operations thereon, then this tease shall continue in force so long as oevrations are bring continuously prosecuted an the leased premises or on acreage paled Iherewoh. and operations shall he considered to be continuously prosecuted If non more than ninety (901 day's shall elapse between the completion or abandonment of one welt and the beginning of operations for the drilling of a subsequent well 1 f after discos ery of rid or gason said [and or on acreage pooled therewith. the production thereof should cine (rum any cause after the primary term, Ihu leaser shall nut terminate if lessee commences additional drilling u: re-wor:'ing _within ninety (90) days from dale of ceese. r.rn of produclor, or from ;ate or, on:pkbon Well v. hole-. If oil or gas shall I4• distusercl and produced as a result of such operannns al or after 'he expirateon of die primary term of Ihcs lease, this lease shall continue In force so long as od or gas is prulucul from the leaved premises ur on acreage pooled therewith. ▪ -- : '' "'adjJ,. 5. If a well capable ofprrductngoiltargas islocated onsaidland and isshut-in before. pnaluctioneummrmss,oratany limethereafter. rheslease shall continueineffectfrom It.edlleklehuell is but -in until the anniserury date (herein called "said anniversary date`) e d this lease next ensuing after the expiration of ninety (90)days form the dale sac h wc•II a shut -,n. Lasser may dh:ivae; p ay.ur tender tel then ri royal[}. on or before card anniversary date, an amount of $100 00 per well per year, and if such pre mens or lender is made. sue h u rLI shall continue this lease in eflect for a further -Pe Wei ufone year from slid drain:esary date. and In hie manner and upon like payments ur tenders annually made on or before the anniversary dale hereof, this (ease shall continue in efleer for sueccysive prircds u' is. cr.e.(I 2 hrprrnthSlach. Notwithstanding any other provision to the contrary. "his lease shall not terminale because of a fail ure to propriety or timely make a shut -,n well payment unless less r ;hai_has a gra er leime w, wen such failure to properly or timely makesuch shoe in well payment and lessee shall have faded tar a rawer.] of then}' 1301 days after receipt of such notice to tender such pavm: nitn for proper amount. usgethe .with i Lute or improper payment penally of SI0000. a . • G ;+� -r �' = 6. If said lessor ou ns a less interest in the above decnbed land than the entire and undivided fee simple note thereto, then the royalties herein provided shall he paid rhe Issof imly in the mot -union which hie interest bears to the whole and undivided fee Any interest in the production from the abo.c described land to which the marred of lessor may be subject shall he dedeoid fn.m 1h. royalticc pros Wed for tic; cm. 7. Lessee shall have rhe nghl ro use, free of oust tad or gas and water produced on said land lin its operations thereon, except water from 'welts of lesser. Lessee ;Pall flaw the right al any time to remove all machinery and fixtures placed on said preens', including the right to draw and remose casing. /;- + • - 8 Lessee shall pay for damagesausod by its operations ingrowing crops on said lands. When requested by the loam. lessee shall bury his pipelines below plow Jrpth.'No A di shall rednIled'lean ./ than 200 far to the house or barn now on said premise, without written consent of the lessor. 9 Lessee. at its option, is hereby given the right and power at any rime and from time to time as a recurring right. either hefnrc or after production as wall or any pan of the ▪ lams & senbd her cm and as w any one or more oldie formations hereunder. Io poo[ or unicue the leasehold estate and the mins-ral wale coveted by rho lease ea it h other land lease or leases in the immediate s .:miry for the pnduetian of oil or gas. or both, when in lessee's judgment it is newury of advisable dodo so, and ure.pecive of sehether authority similar to the execs with resp et to such other land. lease nr leases Likewise, anus prey r.rusly formed to include Samaritans not producing oil or gas. may be reformed to exclude such non -producing formations. The forming or reforming of any unit shall he au. mmpltshed by lessee executing and filing of record a declarautan of such uniLnrion or reformation, which declaration shall Jescrub• rhe unit Any unit may include land upon x hich a well has Ihereurtme been completed or upon which op rations Inti drilling has theretofore leen commenced. Production. drilling or reworking operations. or a s el I shut in a nyw here on a unit which includes all or pan of this ]case shall he heated as It n were production. dnlling or reworking operations. or a well shut in under this Lease. In lieu of the royalties elsewhere herein specified. excluding shut -,n royalties, lessor shall reverse on pr.aluctian from the umr sea pooled royalties nnly un the portmn of su-h production allocated to rho lease: such allocation shall he that proportion (lithe unit prialuetion that the local number of surfau acro Levered by this (ease and includes] in the unit ban to the total numbrer of rurface acres in such unit. In additim to the foregoing, lessee shall have the right to uni[iie. pad, or combine all or any pan of the above desertbrd ]ands as to our or mule olthe formations thereunder with other lands in the same general area by entering into a catperati re or unit plan of development or operation approved by any governmental authority and. fri rm time les rime. with ]eke appro.. al, Se. modify, change or terminate any such plan or agreement and. In such event. the terms conditions and provisions of this lease shall he deemed modified to conform lo the terms. conditions. and provisions of such approved cooperative or unit plan of development or operation and, particularly, all dnlling and development requirements of lhls lease. express ur implied. shall be strolled by compliance with the dnlling and dcselopmcnt requirements of such plan or agreement. and this lease shall not terminate or expire during the Ile of such plan or agreement. In the event that seed above Jsacribed lands or any part thereof: shall hcrraher bK operated under any such cooperative or unu plan of development or operation u hereby the production therefrom res allocated to different portions of the land cos era! by said plan. then the production allocated to anv particular tract of land shall, for rhe purpose of computing the royalua ru he furl hereunder to lessor, be regarded a., having teen produced Irom the panicular tract o1 Land In w hich u es allocated and nor toany other tract of land: and the royalty payments an be made hereunder tar lessen shall lr base.) upon production only as sea ailr. aced I ...soot skull formally espies, les,.a's consent to any coo/math e tar unit plan of development or operation adopted by lessee and approsnl by any governmental agency by executing the same upon 'equal of ksxe. 10. If the estate of either pany hereto es assigned or sublet, and the pn.ilege of assigning or suhlrmng en whole or in pan u expressly allowed, the express and implied covenants here -id shall extend W the suhlnsees. sucansors, and assigns of the parties. and in the even) of an assignment or sublrmng by lessee lessee shall be reliesed and discharged as to the leasehold rights so assigned or sublet Irom any liability res lessor thereafter accruing upon any of the cosenanu or cnndruons of the lust. other enprss or implied No change in the ownership of the land tar royalties, howrscr accomplished, shall nperare to enlarge the; obligations or diminish the nghts of lessee or require separate measunng or installation of separate unks by lessee. Notwithstanding any actual or constructive kno'wledge of or notice to lessee. nu change in the ou nershrp of said land or oldie right to receive royalties hereunder, or of any mrereso therein. whether by reason of death, con seyance, or any other matter. shall be binding on lesser (except at lure's option In any particular easel until si ery (60) days after lessee has been furnshed with either the ongtna I recorded instrument of conveyance ora duly certified copy thereof or a unified copy of the will u( any daJtascd taw nee and of the probate thereof, or unified atpy of the proceeding showing appointment of an administrator for the estate of any deceased owner. w hn•hescr is appropriate. together -wish all original ro ord.'J instruments of conseyance or duly unified copies thereof necessary in showing a complete chain of tale tuck In Iessurto the full inre+r el_imal, and al] advance payments of shut-in royalties made hereunder beforereteiptofsaiddocumensshallFiebindingonanydirrclorindimatass:gnee.grmlec dcsisce•adm'inseralor.esuutor.orheiroflessor.ItaherebyagreedtnsheeventIhsleaseshallbeassignedasboapanor. reart, rf rhe also. a ducnbul Ia.4s atim thee assignee or assigners of such pan tar pans shall fail or stake default in [he payment til the proportionate pan til the shut •in royalties due from him or them. sue h default shall nor operate to defeat or affect this lease insofar as 11 coven a part or parts of said lands upon which the cod lesser or any assignee thereof shall make due payment of said shut-in royalties 11 All pros'seons hereof, express or implied, shall be subject lo all applicable laws, governmental order, rules and regulations This lease shall not be terminated ,n whole or in part nor lessee held [table in damages. because of a cessation of production or of dnlling operations doe to the applicator .n of such laws. governmental orders. rules and regulations or breakdown of equipment or the repairing of a well or seeds or because of such a ccsssuon ora failure to comply with any of the express or implied provisions of the lease if such cessation or failure is the result of the exerese of governmental authority. u ar. lack of market, an of Gee'. stnke, fire explosion, flood, or any other cause reasonably beyond the control of lessee If lessee shall he prevented during the last sex months of the pnmary term hereof from dnllinga well hereunder by the order of any csnstrtuted authority having jurisdiction thereover, or If lesser should be unahlr during said period to dull a well hereunder due to equipment necessary in rhe dnlling thereof nut bring asadahle on account of any cause beyond the control of Tessa, rhe primary term orf chs lease shall continue until six months after said order is suspended and/or said equipment asadable. 12. In the event lessor considers that the lessee has failed to comply with act obligati. is hereunder, express or impliai, lessor shall notify lessee In writing. specifyingin what respect lessor claims lessee has bleached the lease. Lessee shall [hen have sixty [601 days after receipt of said noose within which to meet or commence to meet all or any pan of the preaches alleged by lessor. The service glued nolo: shall he precedent Io the tin nging of any action by lessor on said lease for any cause. and no such act i, n shall bre brought until I he !ache of six iv l 60I days after sea ice of such notice on lessee. Neither the x•tser til said nuti.e nor the doing of any acs by lessee aimed ler meat an or any of the alleged breaches shall hi deemed an admission or presumption that leasee has failed to prrlurm all its obligations hereunder 13. Lessor hereby rekas s and relinquishes any nght of homestead dower or curtsy they err either of them may has(' en or to the leased land. 1� ;• BOOK 771 PeGE465 14. Lessor hereby warrants and agrees to defend the tide to the lands herein described. and agrees that the lessee shall have the right at any time to redeem for lessor, by payment, any mortgage. taxes, or other liens err the above described lands in the event of default of payment by lessor, and be subrogaled to the rights of the holder thereof, and such payments may be deducted from any royalties which may be payable to lessor hereunder. • - - - 15. This lease and all its terms. conditions, and stipulations binds each executing lessor and shall extend to and be binding on his assigns, heirs, devisees and successors. and those of rhe lessee, though unsigned by other lessors named herein. IN WITNESS WHEREOF, We sign the day and year first above written. By: Richard Thompson Dever (S.S. 1521-60-5425) STATE of COLORADO ) ) COUNTY OF GARFIELD ) ss. By Doth ory ever, formerly Doroth h Fuller S.S. #522-48-6139) ever the6w, BEFORE ME, she undersigned authority, on this day personally appeared Richard Thompson Dever, a single man known to merobe the person_ whose name is subscribed to the foregoing instrument and acknowledged to me that _he_ executed the same for the purposes and consideration therein expressed. GIVEN UNDER MY HAND AND SEAL OF OFFICE THIS My�`�drprhission txpucs� .MY £?mm stIon pirc acarnbo; 19, 1989. :9b1 rpr;d Co'ernve -Glllr.L534140; s s.e Q e1601rir // cif day of December 198 9 TJ 4,1 44 Notary Public 1 .,f- COLORADO STATE OF • ) --77-couxrf.9F.DENVER '-_ ) — .- _ r ." .- - -•i'a-�. `ti �'t�.t,.r1if now a single woman 'itEFQitil.[ tf in -de {fin authority,onthisdaypersonallyappeared Dorothy Dever, formerly Dorothy Dever Fuller kno+sntomelobe �e ~'' t low, Isubsl abed to the foregoing instrument and acknowledged to me that b Pte'. � i Rrt"�e �� j g g the— executed the same for the purposes and consideration therein expressed cG.1fri NDE 4W4 ND AND _FAL OFOFFICE THIS r -1 -:-- day of December 1989 .may s� \T7 `!}}a�►►►4' sori l i nr Iri�;ca:nritiss:Qn expip:,:f .` ..,1*/£01hmtvgaEffiires Nov. 4, I991 STATE OF - - 'COUNTY OF ) Notary Public _ BEFORE ME. rhe undersigned authority, on this day personally appeared known to me ro be the person whose name is subscribed to the foregoing instrument as of a corporation, and acknowledged to me that esecuted the same for the purposes and consideration therein expressed. in the capacity stated, and as the act and deed of said corporation. GIVEN UNDER MY HAND AND SEAL OF OFFICE THIS — day of --°'` - --- 198 - My commission expires: Noury Public :RETURN TO: Pioneer Oil & Gas, 6925 Union Park Center, #145, Midvale, UT 84047 Dp Contract Documents 111111111111111111111111111111111111111111111111111111111 Contract Number: Document Date: OCR.c,4. 3 State: Contract File/Contract Document Types: Co ■ Contract ❑ Area of Mutual Interest ❑ Communitization Agreement ❑ Development Contract ❑ Divestiture O Encumbrance Documents ❑ Environmental Contract ❑ Exchange Agreement O Farmout ❑ Farmout Option ❑ Joint Operating Agreement ❑ Joint Exploration Agreement ❑ Letter Agreement ❑ Participating Area ❑ Participation Agreement ■ Pooling Agreement ❑ Purchase & Sale Agreement O Segregation Agreement ❑ Unit Agreement ❑ Unit Operating Agreement ❑ Misc. Submitted by:, o General ❑ Amendment ❑ Assignment ❑ BLM Notification ❑ Contract Brief ❑ Correspondence ❑ Data Sheet ❑ Draft Agreements ❑ Due Diligence Documentation ❑ Paying Well Determination ❑ Plan of Development ❑ Ratification/Joinders ❑ Termination/Release Documentation ❑ Title Opinion 1111 !Pi ,1141'1011'1#7STIP ItI Reception#: 837408 07101!2013 02:29:30 PM Jean Plberico 1 of 5 Rec Fee,$31.00 Doc Fee -0.00 GARFIELD COUNTY CO DECLARATION OF POOLING K19CNE UNIT (305.25 ACRE POOLED UNIT) STATE OF COLORADO COUNTY OF GARFIELD WHEREAS, Encana Oil & Gas (USA) Inc., a Delaware corporation, whose address is 370 17n1 Street, Suite 1700, Deriver, CO 80202 (hereinafter referred to as "Lessee"), is the owner of the oil, gas and mineral leases, as extended and/or amended, and ratifications thereto described in Exhibit "A" (the "Leases"), which cover certain lands in Garfield County, Colorado, as depicted on a plat marked as Exhibit "B"; said Exhibits "A" and "B" are attached hereto and made a part hereof for all purposes; and WHEREAS, each of the Leases provides the Lessee the right to unitize or pool the Leases and the lands covered thereby, in whole or in part, so as to create a unit or pool as may or may not be required to conform with applicable rules and orders of the Colorado Oil and Gas Conservation Commission. WHEREAS, in the judgment of the Lessee, it is necessary and desirable to pool and combine the Leases described in Exhibit "A," insofar as such Leases extend to and cover the lands depicted in Exhibit "B," in order to promote conservation and properly develop and operate those lands for the production of oil and/or gas, condensate, and all other hydrocarbons. NOW THEREFORE, in consideration of the premises, Lessee, acting under and by virtue of the power and authority granted to it by the terms and provisions of the Leases, does hereby pool and combine the Leases described in Exhibit "A," and the leasehold rights, mineral and royalty interests therein, as well as all other interests which may be covered by any agreement or amendment affecting said lands now held by Lessee, or which Lessee may hereinafter acquire, insofar and only insofar, as such Leases, rights, and interests extend to and cover the lands depicted in Exhibit "B" (the "Unit Area"), and further, insofar, and only insofar, as said Leases, rights and interest cover the depths from the surface down to one hundred feet (100') below the base of the stratigraphic equivalent of the Mesa Verde Formation, for the purpose of forming and creating a pooled unit for the drilling for, development of, and production of oil and/or gas, condensate and all other hydrocarbons. The pooled unit created hereby shall be known as the "K19CNE Unit," containing 305.25 acres, more or less. The production of oil, gas, condensate, and all other hydrocarbons (after any authorized deductions) shall be allocated on a pro rata acreage basis to and among separate tracts within the Unit Area having any difference in mineral or royalty ownership; that is, the percentage of production allocated to each tract shall be equal to the percentage the tract's surface acreage comprises of the overall surface acreage of the Unit Area, and all working interests, royalties, overriding royalties, or other interest in the oil and/or gas, condensate, and all other hydrocarbons produced from such pooled unit shall be computed and paid on the basis of their respective interest in the pooled substances allocated to the tract or tracts in which they own and interest. Lessee reserves the continuing right to amend, correct, or alter this instrument and the pooled unit created hereby to the extent permitted by law and the authority granted in the Leases, including, without limitation, the power to (i) change the size, area, and formations covered by the pooled unit; (ii) to successively amend, reform, divide, alter, or revise the configuration of or rearrange any then existing Unit Area, to diminish or expand any Unit Area, and or to dissolve and terminate any then existing unit and create another unit or several units; (iii) to include in the pooled unit designated herein any subsequent oil, gas and mineral leases, amendments, extensions and/or ratifications thereof, covering interest in the Unit Area; and (iv) to include in the pooled unit any undivided interest in the Unit Area which is not otherwise included herein by the respective owner of such undivided interest. Further, by execution of this Declaration of Pooling ("Declaration"), Lessee does not exhaust its right to pool the Leases and lands hereinabove described with other leases and lands as to any other horizon, strata, or substances covered thereby and not pooled herein. Any amendment to this Declaration shall be in writing, signed by Lessee, or its successors in interest or title, filed for record in the office of the Clerk and Recorder of Garfield County, Colorado. Page 1 of 2 5 ®lit litre maim! Nix iiroiclorialoui 11111 Reception#: 837408 07!01!2013 02:29:30 PM Jean Rlberico 2 of 5 Rea- Fee:$31.00 Doo Fee q,00 GARFIELD COUNTY CO This pooled unit shall be effective as of the date set forth below and shall remain in full force and effect as long as oil and/or gas, condensate or other hydrocarbons are being produced from the pooled unit, drilling or reworking operations are being conducted, delay rentals or shut-in payments are being paid to maintain the Leases or any other provisions of the Leases are being satisfied to maintain the Leases in full force and effect. The terms of this instrument shall inure to the benefit of and be binding upon the respective parties hereto, the owners or royalty or other interests upon whose behalf the parties are acting, and their heirs, successors, legal representative, and assigns. IN WITNESS WHEREOF, this instrument is dated and effective the 1 day of Mat, 2013. ENCANA OIL & GAS (USA) INC. Helen M. Capps Attorney -in -Fact ACKNOWLEDGEMENT STATE OF COLORADO CITYAND COUNTY OF DENVER On this 4-'1- day of , 2013, before me personally appeared Helen M. Capps, known to me to be an Attorney -in -Fact for Encana Oil & Gas (USA) Inc. and that she executed the within and foregoing instrument, and acknowledged the said instrument to be the free and voluntary act and deed of said corporation, for the uses and purposes therein set forth. WITNESS my hand and official seal. My Commission Expires: APRIL JACKSON NOTARY PUBLIC STATE OF COLORADO NOTARY ID # 20094010281 MY COMMISSION EXPIRES MARCH 25, 2017 CipAi Notary Vublic Page 2 of 2 1111 ': iI !ILIV' liffrogiretlibilli 11111 Reception#: 837408 07101/2013 02:29:30 PM .lean R1,herico 3 of 5 Rec Fee:$31.00 Doc Fee:0.003 GARFIELD COUNTY CO EXHIBIT "A" Attached to and made a part of that certain Declaration of Pooling for the K19CNE Unit, containing 305.25 acres, more or less, and dated Ms y--\ , 2013. INSOFAR AND ONLY INSOFAR AS TO LOTS 2, 3, 4, AND THE N/2NE/4, SW/4NE/4 AND NW/4SE/4 OF SECTION 19, TOWNSHIP 6 SOUTH, RANGE 92 WEST, 6TH P.M., CONTAINING 305.25 ACRES, MORE OR LESS GARFIELD COUNTY, COLORADO Lessor: Original Lessee: Present Lessee: Lease Date: Recorded: Description of Lands: Lessor: Original Lessee: Present Lessee: Lease Date: Recorded: Description of Lands: Catherine Sweeny, a/k/a Catherine J. Sweeny, Individually and As Attorney in Fact for Alfred Sweeny, a/k/a Alfred A. Sweeny, her husband, under that certain P -0-A, dated April 1988, and recorded in Bk. 754, Pg. 757 of the records of Garfield County, Colorado Mobil Oil Corporation Encana Oil & Gas (USA) Inc. July 14, 1989 Book 779, Page 726, Garfield County, Colorado Township 6 South, Range 92 West, 6th P.M. Section 8: SE/4SW/4 Section 16: SW/4SW/4, W/2NW/4NE/4, Westerly 30 feet of the E/2NW/4NE/4, NE/4NW/4, less and except that portion lying Northerly of the Rising Sun Ditch. Section 17: SW/4NE/4, E/2NW/4, E/2SW/4, SE/4 Section 18: SE/4SE/4 Section 19: Lot 2 (SW/4NW/4 48.48 ac), N/2NE/4, SW/4NE/4 Also Section 8: SW/4SW/4 and Section 17: NW/4NW/4, less and except that part conveyed to George Yule recorded in Bk. 32, Pg. 425 of the offices of County Clerk, Garfield County, Colorado, containing 56.75 acres, more or less. Township 7 South, Range 92 West, 6th P.M. Section 17: W/2NW/4, NW/4SW/4 Section 18: NE/4SE/4 Garfield County, Colorado, containing 891.73 acres. J. Gentry and Carol L. Gentry, husband and wife Mobil Oil Corporation Encana Oil & Gas (USA) Inc. May 9, 1989 Book 779, Page 765, Garfield County, Colorado Township 6 South. Range 92 West, 6th P.M. Section 8: SE/4SW/4 Section 16: Section 17: Section 18: Section 19: SW/4NE/4 Also Section 8: SW/4SW/4 and Section 17: NW/4NW/4, less and except that part conveyed to George Yule recorded in Bk. 32, Pg. 425 of the offices of County Clerk, Garfield County, Colorado, containing 56.75 acres, more or less. Township 7 South. Range 92 West, 6th P.M. Section 17: W/2NW/4, NW/4SW/4 Section 1S: NE/4SE/4 Garfield County, Colorado, containing 831.73 acres. SW/4SW/4 SW/4NE/4, E/2NW/4, E/2SW/4, SE/4 SE/4SE/4 Lot 2 (SW/4NW/4 48.48 ac), N/2NE/4, Page A-1 of A-2 11111111'''.6N MITE Mk 4Yir.«714 «1130f141Nui 11!11 Reception#1: 837408 07/01/2013 02:29.30 PM Jean Alberico 4 of 5 Rec Fee:$31.00 Doc Fee:0.00 GARFIELD COUNTY GO Lessor: Original Lessee: Present Lessee: Lease Date: Recorded: Description of Lands: Lessor: Original Lessee: Present Lessee: Lease Date: Recorded: Description of Lands: Richard Thompson Dever, a single man, and Dorothy Dever, formerly Dorothy Dever Fuller, now a single woman Pioneer Oil & Gas, a Utah corporation Encana Oil & Gas (USA) Inc. December 7, 1989 Book 771, Page 464, Garfield County, Colorado Township 6 South= Range 92 West, 6th P.M. Section 17: SW/4NW/4, S/2SW/4 Section 18: S/2NE/4, N/2SE/4, SW/4SE/4 Section 19: NW/4SE/4, Lot 3 (48.42 a.) Township 7 South, Range 93 West. 6th P.M. Section 1: Lot 2 (24.00 a.), W/2SW/4, NE/4SW/4, W/2NW/4SE/4 Section 2: Lot 1 (23.65 a.), E/2SE/4 Township 6 South, Range 93 West, 6th P.M. Section 25: SE/4NW/4 Section 26: W/2SE/4 Section 35: S/2SE/4, N/2NE/4 Section 36: N/2SW/4 Garfield County, Colorado, containing 1036.07 acres, more or less. Larry R. Wiskirchen, aka Lawrence R. Wiskirchen, a married man dealing in his sole and separate property Ballard Petroleum LLC Encana Oil & Gas (USA) Inc. May 4, 1999 Book 1136, Page 763, Garfield County, Colorado Township 6 South, Range 92 West, 6th P.M. Section 19: Lot 4 Section 30: Lot 1, Lot 2 Garfield County, Colorado, containing 144.93 acres, more or less. Page A-2 of A2 IM Receptionl#: 837408 07/0112013 02,29:30 PM Jean Alberic❑ 5 of 6 Rec Fee -$31.00 Doc Fee:0.00 GRRFTELD COUNTY CO Exhibit "B" Attached to and made part of that certain Declaration of Pooling for K19CNE Unit, containing 305.25 acres, more or Tess, and dated 3j ft < `1.�, , 2013. 13 18 6S93W 24 K'1�9:C.N_E Unit fac.res;, mli 17 19 6 20 92W 25 encana 30 29 ©2013 Encana Oil & Gas (USA), Inc. - Leslie Forbes I IIIIII Illll 111111111111 III 111111111111 111 1111111111111 553t9 84/16/2p64 03:17P 61576 P319 i1 t1LS00RF 1 of 6 R 31 00 0 0.00 GARFIELD Cot ry CO EASEMENT AND RIGHT-OF-WAY AGREEMENT THIS EASEMENT AND RIGHT-OF-WAY AGREEMENT, dated effective./1, 2004, is made h, and between Airport Land Partners Limited, located at 312 Aspen Airport Business Center, Suite A, Aspen, CO 81611-2568 ("GRANTOR") and EnCana Oil & Gas (USA) Inc , located at 950 17'h Street, Suite 2600, Denver, Colorado 80202 ("GRANTEE"). WITNESSETH • For and in consideration of the sum of Ten Dollars (S1000) in hand paid, and other valuable consideration, the receipt and sufficiency of which is hereby acknowledged, Grantor does hereby grant, bargain, convey and confirm unto Grantee, the following, A. ACCESS EASEMENT: A non-exclusive easement and nght-of-way to construct, maintain, and remove an access road for ingress and egress across the lands identified on Exhibit "A" attached hereto and made a part hereof for the purpose of dnlling and completing one or more wells on leasehold owned by Grantee Said access easement shall be approximately forty feet (45') in width, with a sixteen (16') foot travel surface Grantee has the nght to use an additional thirty fcet (30') of land its temporary workspace as Grantee determines necessary to the exercise of the nghts granted herein 13 PIPELINE RIGHT-OF-WAY. An easement and right-of-way to construct, lay, maintain operate, alter, replace remove one gas pipeline and one water pipeline including but not limited to valves, regulators, meters, separators, punficanon equipment and pipeline with fittings, appliances, and appurtenant facilities. The pipeline shall be used for the transportation and processing of oil, natural gas, petroleum products or any other liquids, gases or substances which can be transported through a pipeline and for other purpose, The approximate pipeline route is depicted ori Exhibit "13", attached hereto and made a part hereof Said easement and right of way shall be fifteen feet (15') in width, being seven and one half feet (7 5') on each side of a anter line of the right-of-way. During the penod of pipeline construction, Grantee shall have the right to use an additional strip of land forty feet (40') in width along and on either side of the easement and right of way described in this paragraph, except where Grantee's activities will interfere with imgatton ditches, streams or creeks Grantee shall bury the pipeline with a minimum of 36 inches (36") of soil from the top of the pipeline to the normal surface of the ground, The affected areas shall be recontoured and reseeded with species which are consistent to adjacent, undisturbed areas upon completion of pipeline construction to prevent erosion Grantee shell be permitted to cut all undergrowth and other obstructions that may injure, endanger or interfere with the use of said pipeline The lands that arc the subject of the above described access easement pipeline easement and nght-of- way are hereinafter referred to as "Subject Lands " Grantor reserves the right to the full use and enjoyment ofthe Subject Lands except for the purposes herein granted The foregoing rights and pnvileges ofGrantee are further conditioned upon the following 111111111111111111111111111111111111111 ! !11111111111111 6S631S D4/16/ZBB4 e3:17P B177a P366 M ALSDORF 2 of O R 31.ee 6 e.ee GARFIELD COUNTY CO 1, DAMAGES Grantee shall either repair andtor pay Grantor for demos (if any) caused by its operations on the Subject Lands relative to growing crops, buildings, ditches. fences and livestock of Grantor or Grantor's surface lessees; Grantee shat not alter the natrral flow of any credos, strums, or irrigation ditches relative to the Subject Lands 2 MAINTENANCE The eccass road shal be maintained by Grantee in accordance with Bureau of Land Management standards. 3 GRANTOR'S DUTIES AND OBLIGATIONS Grantor shal have the right to use and enjoy the above-described prarisea, subpct to the rights herein granted Grantor shall not interfere with or =par or permt others to interfere with or impair m any way theexdrvise of the nets herein granted to Grantee, andGnator aha; notbuild, construct, or permit to be buil or constructed, any structure or obstruction, or impound water or other substance, or charge the grade on or over said road, provided, however, at such time as Grantor undertakes development of the property adjrce nt to and including the Subject Lands, Grantor shall have the nght, at Grantor's e%pmse, to provide Grantee with an alternate legal access, equivalent m grade and surface, m which evert the accas providod in this Agreement shalt be abandoned 4 LIABILITY OF THEPARTIES. Grantee covenants and agrees to fully defend, protect. indanrufy, and hold harmless Grantor, its partners, empbyees and agents, from and against each and every clam,, demand or cause of actin and liability, cost andbr expaue (including but not hinted to reasonable attorney's fee and costa Metered in defame of Grantor, as officers, directors, employees andbr agents), for danusp or loss in connection therewith, which may be made or assorted by Grantee, Grantee's partner, employees andbr agrees, or whids may be assorted by any third party, on account of personal injury or death or property damage caused by, arising out of, or m any way incidental to, or in connection with Grantee's meat the Subject Limb or the nets grated hereunder, except to the event such damage or injury results from the actin of Grantor, its partners, anpbyeec, contractors. or age is Whae personal injury, death, or loss of or damage to ply is therrsdt of thcjoir* actions of Grantor or its partners, employees, contractors, agents and Grantee, Grantee's duty of indamufiraion shal be in proportaonta as allocable share of such act on 5 DRUGS, ALCOHOL AND FIREARMS: Grantee shall not allow the use or possession of illegal drugsor other unlawful substances or alcohol or firearms by Grantee or its contractors, sub- contractors, agate, business invitees or other victors while on the Subject Lands or adjacent lanes. 6 HUNTING AND FISHING: No hunting trapping or fishing is permtted on the Subject Lands or adjacent lands and no such rights are granted by this Agreement 7 GOVERNING LAW: This Agreement and all matters pertaenrnghereto, including, but not lusted to, matters of performance, non-performance, breach, remedies, procedures, nets, duties and interpretation or oonstrudnon, shall be governed and detammed by the laws of the State of Colorado 8 MISCELLANEOUS: This Agreement contains the entre agreement between; Grantor and Grantee and any pnor oral representations or understanding concernmg this Agreement or its subject matter shal be of no force and effect 111111111111 IlUhl 111111 II1111111111111 III Illi111111111 660315 04/16/2e84 8317P 51576 P391 M ALSOORF 3 of 6 R 31.08 D a.ee GARFIELD COUNTY CO This Agreement is subject to all contracts, leases, liens, easements and encumbrances or clams of title which may affect the Subject Lands and nothing contained herein shall be construed as a covenant or warranty agars5t the existence nce of any thereof The terns and provisions of this Agrennent shall uloid to and be binding upon the parties and thcr successors and assigns IN WITNESS WHEREOF. the parties haveexearted this Easement and Right -of -Way Agreement the day and year indicated below but effective on thedate first set forth abort. GRANTOR. Airport Land Partners Limied By Airport Busaiess Parr Corporation General Partner Date; 1/11-/q GRANTEE ENCANA OIL& GAS(USA) INC. By Date lFoel S Fox Attorney -m-Fact 16#11151101141 1III1I 11111 IIIIII Il1III 11111111111111111 I111111E01 6�e315 e4/16/2004 s3.1W 81578 P392 4 of 6 R 31.@0 D 0.00 GARFIELD COUNTY CO ACKNOWLEDGFMENTS STATE OF COLORADO p, fes,., COUNTY OF GOARELD Theforegonginstrument was acknowledged before me on this pi day of ff 2044 by Robert A. Howard; kr silent ofAirpoR Busuess Pads Corporation, the general partn of Arport Land Pumas Limted0d'nbehalf ofsaidlurutedpartnership. e A r1 44 , tlAes: 7A/tr.", STATE OF COLORADO ) CIT YAND COUNTY OF DENVER ) The foregong urstrument was adasowledfird before me on this 3o Il. day of + lcip.. ,. 2044 by Joel S. Fox Attorney -Ln -Fact for ENGNA OIL& GAS (LISA) Inc, aDelaware corporation, on behalf of said corporation Nbtary Pub Notary Public My Commission Expucs t4,zo./_ =1 . rj EXHIBIT A 1111111111111111l111A1111111111! 1111111111111111111111 65e315 94/16/289 9317P 81'178 P393 N DOR* 5 of 6R 31. OS D 8.00 GARFIELD COUNTY CO y 1 " 1'� r r ... ,, l» r„ e _ ZNCARA OIL & CAS (USA) INC Sec 24 .il I b,1�. r „per - -- I - PROPOSED ROAD RIGHT- OF- FY AY R 6 j4 461..... sr. r. •. 3^ •.�. i For Well Fad (A79NE) 1.1..,4•11 -Pr M.,it A /17 I 9 9 t.• y. t 27 d., 54. r.• J l.nr¢[,d In 3 i 2 r 0 - S,ctlon 19, TGS R92ir 6th PX 1.r<=4 4!•51 to Src[lon 24 TSS 09316 Bth Fir 1 �% ."=11 ,lalW Pe+i •5467. LTO 3.,. .-- I ,! -= 4O'a Cerf541d Cvelnty. Colorado :t77'..!�r 2174wr Aar T{ Lam P.rLner. LTO ••i 3/11 1 ��.�4 1446 11..:7014.....ww.,J10 17I 4".ROAD RICHT-Dr-MAY Ms:m.1nm .4 I/• 2( JN r 0)5[740$50 11040 111/.1- r- .. L0 4ITO W .1 K I/• 74 1/4 7- -_.-e`,11010..4 1.5113.641.1. .LSD 1.LOl 1x1(510'.11 MPTOr KA1111�T MGIC; I'^{ -115. 6I2e 4111 P4 U1r4LO 402.111 main)* 1.f [11tH[ 6..+•R r. Frrr/ .. 04... 1 5 ! _t • .447.1�-�P SAO 1rNT-D/-5451 4645 1441[ 1a.5[u •151 a,c..t0 *S ..w..w.n.1/1.Ah a1aR1orr416 a\41111.41151all M ryl�rl (707141 . 1IOI-.0 5l • 74[01 F. -.S .c 1/. 5C I/a R SECTOR 2a '65. ly, S. =J41••J, aal i1 r / •13w aim 14 ►HC4 15415 453,0 JS w 1107 74 ntW P[ 1 Y ` i ; r. �a.1•i• `70 17 r� 5,111[451 C(R!(. Or Sae 47500 Mac a 1461 C.e LS •5646) .'1111... ) 11 1.1-IF� 455451(7! 675 5171[[ 4-467-7%[ 1*i75 454(0(( A ' f • : - 1 III�-�-1617 .77412•r37% 11149 MKi Sln:7:t 461 66 1+(.C[ ,` t ; i - b6•"57r 3.4'7 ,1 ..M 1.4.t �P.^ 51437703 6151 P411C1141175713 1755..11. 5 10 4 00..1 IN M \\ f 1,115 --k: - ->f / 4651 L..[ Sr 14 7/ I/1 Ti.465Cc1P• If 7.S +911 5154 11 4. 454[54 „4Y 1J ,• • 1 e[.0 %CC5I 5.-I 1xk ,a MI1 •1f 4171 1 .4 ce..lF 0 SAO �7 ti �.;4 i � % r „ r YCei. 15 147(• 14T SSa4t Iy.1L x117]713 701,1 _ _ _ _•/.f •w.a. _.•1 / J""-' 7 • � •a'r - 11CI.Cc 51,,/62 1110 4411.(1 x4513163 C 7c 1w71cF /C1 Conlod•oo of Proloomd ll Rood R919 -c/ -may F ROAD RI .T-OF-1eAY LENCTSI$ PM / 641045 1- /- ro, ■wo uorr-.s-4617 Su 1.0e \Ns 41a 1741 lyllti i•rp.r1 :And hrin.ra ('0 sr 4 146• j1 L -e. L•+ - wao. t1 14.1. dm' 14.714.1 77014 P7027701 LTD SEC110N 24 - 915,65 Arpa1 tend Pv[nr6 LTD SECDOH 19 • 172955' ,DIAL R/W 541190TH • 2 945 3D' .h: M7 / 7rnw. I • � o R 5755[ LEGEND C.,2-14/45 • 0411 Cr 141117077.04 74 ;Il • 64:441: 0. 5[0,041.8 6 . 1.74.•4•-7-4.Fr • 1 0.1• 117 t . .416 •t 133 6051 54144c[ 4,4n6.4.4 L N 16 I74(4CI 444).310. 54 50 111wx .70']4 mil', 7a 44 1.11•(5 133,0 .5 t 474 53 1144:1 4415. 433 •4 74 1.4+a 51111 31+ 61 .4 04405 4,5-2 1,-L- 05 ...Dec( 17:4.76317.6 +•V{C 147W 013 14731 451.4 510'15751"! 70`5 14.,5 :`•l 1750 7 4. •_( .4_sl'P7 1115 T2C,CC 41302 54[4r 1.44» S4..f+3: 1011 .[.C(5 55355 if 1111 ID 4 .'}.1 15 .O1 a 140 577111+ 11 97174•. 6'.474 422111) 5 145617 1111 141 749 14.51 1/4 Cl[*24DI 2257 Me 11 44515 7 2.114.57 1 1.[ 4751 7670 Or 5.4 5541 14 1/4 7 5[71174 16 461.14.5 16.5, r2* 40,44 703757174115 SS'(L54 c 245[1041/}46 174 5[70 .004655-• l .1A31Ar0 2251*._1 Cr 959135 .5+•""'511416 COIlrl ��fi4f R[ -- J- 5 -t /74.7.440,9•441 9.441 '* I.) • 1-1.510..• 15451..1.1 H5,•.,5w I MI SLOW ‘111 !;[�Ao 1 Ir [03. b1' LCL01 5(174,4 77 K'0 •1 Ir.. 75.3: _ 141.440 L{r ! • 370 2+Z / 04-0071 Art" State nd Survey*ny !7.r \(4_15, 7747-2501 60.2454 107.0 4174 5114. *14. 54,19 C7� Ne 1 1 EXHIBIT B 161510131511111e141/111211411101311111 IIl11I 111111111 Millis!!! 7P 815745 P394 !t ALSDDRF 6 of 6 R 31.00 D 0.00 ti1RFIELD COUNTY CO Sec 24 4,4 Ir. . PBend liar ▪ .1L( P,}.r '514 ran '119.1 rlr.ar7n rrrr� MGM O.In, o.min 5,:71 r1 1 3.4111. 37200 :6 16U.- . 17 37740 5711 1 71 V 6 ll(`i 7 13 '.11710 5779 r7 an IPI 4 6.764 5611• .'17' 5575.E 141 1•078 . 1 11.13 43 3474 4 12 1 117. l • I 1 11.615! 14231 64 41.1 E1 1 11.55.r 56614 4. £77 r, , 71.6566 5611 n , 16G1T-OF-WAT LENGTHS AIRPORT VNO PMSN€A5, LIO SECTION 24 - E142.94 AIRPORT LAND PARTNERS. LID SECTION 19 - 2,50210• TOTAL AIGHT-OF-WAY LENGTH - 2.18506' R/W 01111'3 BOX s74,134n [171 0i 49021 of C.a I7'l.rr C7r+1Mr1. It •14710 r .111Alr641r0 Lood 3 ., - 1 Allrmm ►rumor P4rr7..r7 [TD p S 119E 001 L . P. r.•rr •18.1 Vr r,. Sr 1/. 6 :d\j 6,«h W/ • cr*( - 7:Sr. . 3:201 7Y3+ _'`, 7+'116 \` - _6 ..:;-'L- -,...H":.;-,3T-1",,r5 [1.tHneW .w. Y _t fa...,... . e :Co� O / 6611141P 4rANNE i w. 11.141 19'4 P..P ..r1 '.RP131!3r 11, u 5 -7"7..."..r.'.: - ''r.4 644 R ENCANA CATILERINU SERVICES (EISA) INC. / PROPOSED BURIED PIPELINE /l .1 RICHT--OF--WAY Sec. 19 \\ For Vett Pad (A79NE) De OF r7 4 21610.'1 rl1 32 32+ S2101 31 30 Lir v 1.q 35 tom ted M r Srct on 21, 7'6S, R931( 6th PW Alsn, I 1n Seciwon 19, T65, R921 6111. P /4 Garfield County, Colorado ,677346.1 1......2 1 ••• Partner. LTD ' I I ..0 i �- 1 r.," 31 Y 1-•e 318 1'.816, trr,�•' ,. ✓.1018.'- 8 1 µ� .. 5.11V 45T 0Si37. 66,- 91 3"''''''`''45.1..7-.reg 8'4. 45.1..7 -.re be R 3 / 06....1/. C••.. ... Orb Il n 0 .. W. 0,11.1.- 1119 - lmi PIPELINE RICHT-pF-WAY DESCRIPTION s c ... L A 7774,7. 17847 -118 -*7l torART 14 ilf 5C t/. Cr X0707, 14 65 5939 61. 7 Y 111 4 001 S or 4Ec1CA l hPropos-gra' Ppd.,. 9 115 117• 4 . v. r.APIrt D C01R.7Y C01.(r40[ 11,0 CENIra tit G 540 06.4'-Or_R4t 901.0 7104( Mp15t-of-SPoy 1AR1.LL.4Nt1 10(31.71110 45 70...3613 ..=6•144. 4 a WI'+ n '..0 1.1 Y. I/4 0' •'0103 2. Ns. .11S. G. 9V '7134 a 4.1. 71117.5.52'• 1'4+47 64047 . .4...1.......,a .4.466 -. 1A. 74.01..'.£. 1421.,,. ...t.C fr i 4P.1.3, 1*1101.3117*it 144... •-10191 .1711270 1 `66 11077.. 5777573r 40339 1-.0100 344.55r5 V. 33 10100 77Y17.77 4.7 . 0 1 7Orr. N .... R5- LrC 0' -.4 5. Il. IR 1'014. +1 715. 59-"77 611, PM .1.4714 1141r5 7476.36 54 • 11'073 7407 NC 13.113-74.5 04541 5 5.44 450194 It 1.(40£ 4663141 7 2343, 77.4:7400 4114 01.1 - ` 5. sr .1'CL 447724 320 113 79 144...15( 01 1.75,-E 343 .r 7.400 7467'+.55-F •4737 le •5 a 111011111 4 .01 '1 jam 3 a 5+7 5.6-,44. 13 .•.,r^ 4(3.43 552.745'_ 15,3.74 '1571 56 4151 1/4 calla or 540 26444 14 40-.40, 4 507 6701, 3 545-4 a Ra417.65 4 814 1.87 a, 51 UK 07 nC 59 1/. Lar 5:0-191 19 we.. 11 •4409 ,q4 4'111_ ••50 04147, 541. 110 OBSITNA141i 7C 10.4 .141rYTX1 4 4C 4.37.41117 1.71r44CC Cr 75µ2r :, T. 1 LEGEND 1 116' - Mc Ls. ...Y4nra'a 1 /4 6i - •'3A' 67 14-¢45[1,70 1 1 .• • .w., c4 YR. 77. 1.4 {/R • Orr' -V 1 • 1,11C-1.--13:- r 11711 ,TALI • • F. - - 10101.5~" .74 - - - 13113457 4 3 724 .,x11n14hl„fi W,J ST/r ..O '$- - 1 3131.8. IV.~3 r'-.]'- 41* .es .cx, a 3636, 5334' LAMA n+rr•7ew•• k4...1• . 1 10 RF.YO 3-d -Y Dr 7 Cr .1.741 • M ' VIAL ..[v++.. to •••• 1.w 1••4742 5i.1rK0 .1' 3 ORA.' er •19 0.1" +_ I h s..� . •.c `'4'5% 78'-1572 Ort 04-0078J..1.1 I.6,•+ Vt.!4.( 51_74.41 316, 11017 Tri State Lund Sorveyeney Mc Article 4-203.6.3 Adjacent Land Owners and Mineral Rights Owners Information Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OAProject No. 014-2797 217724100476 BOARD OF COUN COMMISSIONERS 0 GARFIELD COUN 17919100511 ILDSON, SC & LINDA 217919300128 ENCANA OIL'& GAB(USA) INC'" 217725100546 AIRPORT LAND PARTNERS LIMITED 217930100522/ BRYNILDSON, SCOTT W & LINDA S r Subject Parcel 92W O K19NE Storage Yard =I Parcels K19NE Storage Yard Boundary Subject Parcel Perennial Stream WE PROJECT NO: 014-2797 DRAWN BY: JWH DATE: 11/25/2014 ADJACENT LAND OWNERS MAP K19NE STORAGE YARD ENCANA OIL & GAS (USA) INC. GARFIELD COUNTY, COLORADO O\OLSSON ASSOCIATES 760 HORIZON DR., SUITE 102 GRAND JUNCTION, CO 81506 TEL 970.263.7800 FAX 970.263.7456 FIGURE ALO -1 Adjacent Land Owners and Mineral Rights Owners Encana Oil & Gas (USA) Inc. K19NE Storage Facility (Laydown Yard) January 13, 2015 Adjacent Land Owners Parcel Number: 217724100476 Board of County Commissioners Garfield County 108 8th Street, Suite 213 Glenwood Springs, CO 81601 Parcel Number: 217725100546 Airport Land Partners Limited 312 AABC, Suite A Aspen, CO 81611-2568 Parcel Number: 217919100511 Scott W & Linda S Brynildson 1831 Railroad Avenue Rifle, CO 81650-3203 Parcel Number: 217919300128 Encana Oil & Gas (USA) Inc c/o Merit Appraisal & Tax Consulting PO Box 330 Gainesville, TX 76241 Parcel Number: 217930100522 Scott W & Linda S Brynildson 1831 Railroad Avenue Rifle, CO 81650-3203 Mineral Rights Owners Richard Thompson Dever PO Box 636 Glenwood Springs, CO 81602 Dorothy Dever 99 S Downing Street, #502 Denver, CO 80209 Page 1 Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) THIS PAGE LEFT BLANK FOR TWO-SIDED DUPLICATION. Adjacent Land Owners Page 2 Article 4-203.6.4 Project Description Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OA Project No. 014-2797 OLSSON ASSOCIATES Project Description Encana Oil & Gas (USA) Inc. K19NE Storage Facility (Laydown Yard) As detailed in this application, Encana Oil & Gas (USA) Inc. (Encana) is requesting a Limited Impact Review (LIR) to allow a Storage Facility (Laydown Yard). The property is zoned Rural by Garfield County. Table 3-403 of the Garfield County Land Use and Development Code identifies storage use as requiring a Limited Impact Review (LIR) in this zone. The facility will be at an elevation of approximately 5,689 feet. The proposed project area is in a location that provides convenient field access for Encana operations. In addition, this land use will take advantage of a previously permitted surface disturbance and stay within the boundaries of the existing disturbance. The project site is located is approximately one mile south of the Garfield County Regional Airport in Lot 3 of Section 19, Township 6 South, Range 92 West of the 6th Prime Meridian in Garfield County. The total project area is approximately 5.17 acres. The proposed laydown yard will utilize an existing disturbance. The current use is a Colorado Oil and Gas Conservation Commission (COGCC) approved natural gas well pad. The proposed additional use is intended to accommodate storage of equipment and supplies on-site for convenient access related to Encana's natural gas drilling and production activities. The proposed use is compatible with surrounding properties which are similar and are host to natural gas operations. This property is located within the Rural (R) zone district and is not within a platted subdivision. Storage Areas are an allowed use in the subject zone district provided the LIR is approved. The proposed facility meets all applicable standards for the Rural zoning district. The adjacent properties are primarily undergoing oil and gas development and have limited residential and agricultural operations. Due to the location of the facility, the proposed use will have minimal impact, if any, to the surrounding area. Project activities will generate little or no noise impacts, thus sound impacts will be easily accommodated by the Garfield County and Colorado Revised Statue noise standards. The site is covered by Encana's Mamm Creek Unit Stormwater Management Plan (SWMP), which details the use of site-specific Best Management Practices (BMPs). Implementation of the SWMP will ensure that activities conducted at the site comply with stormwater management regulations as required by Garfield County, the State of Colorado, and the United States Environmental Protection Agency. Through this plan, disturbed soils will be reseeded to regain stability as soon as practical and BMPs will be utilized to mitigate sediment erosion and transportation. Implementation of these plans also ensures that installation and operation of this facility will not impact surface runoff, stream flow, or groundwater. 760 Horizon Drive, Suite 102 TEL 970.263.7800 Grand Junction, CO 81506 FAX 970.263.7456 www.olssonassociates.com K19NE Storage Area Encana Oil & Gas (USA) Inc. This site is not covered by a Spill Prevention Control and Countermeasures (SPCC) Plan. Nothing will be stored on site that requires an SPCC. This facility will be in operation for approximately thirty (30) years, the expected lifespan of the associated gas wells in the area. When the facility is no longer needed to support operation of the wells in the area, this site will be reclaimed by removing all surface equipment and structures, grading to restore original contours, replacing any topsoil that may have been removed, and revegetating the reclaimed area with the applicable seed mix. See Reclamation Plan for further information. Hazardous materials will not be stored at this location. The proposed use may require minor additional surface disturbance to accommodate the Grading and Drainage Plan. Encana employees and contractors will be on-site for short intervals picking up or dropping off supplies. Sanitation facilities, potable water and office space are not proposed. Portable toilets are provided throughout the area for use by field employees. The site will not be fenced. Access to the laydown yard is via Garfield County Road (CR) 315 (Mamm Creek Road) for approximately 4 miles from 1-70 exit 94 to CR 333 (Hunter Mesa Road) for approximately 2.8 miles to a private access road (see Access Road Map). The K19NE Laydown Yard location is approximately 0.5 miles east of CR 333 on this private access road. There is no historic public access through the proposed site. See Traffic Analysis for further information. A secondary access route uses CR 346 (Rifle -Silt Rd) west for approximately 2 miles from 1-70 exit 94 to CR 352 (Airport Road). Vehicles will then head east for approximately 1.3 miles to CR 333, then head south for approximately 0.8 miles to the private access road. No significant natural or geological hazards are found at the project site. Because this is a previously disturbed location with minor additional disturbance anticipated, impacts on wildlife and native vegetation will be negligible. No smoke, vibration, heat, radiation or fumes will be produced as a result of the operation of this facility. Adjacent properties will not be affected by the operations. A public nuisance or hazard will not be created. Traffic impacts to public roads will be minimal and will not require additional improvements or permits. Potential impacts to wildlife, natural environment, and the surrounding properties are expected to be minimal, if any. The proposed facility will be located on an existing disturbed area. The topography surrounding the facility acts as a visual and sound barrier in most directions. The facility may be partially visible from surrounding properties and public roads. The following table summarizes the required permitting for this facility. Project Description Page 2 K19NE Storage Area Encana Oil & Gas (USA) Inc. Table 1: Permits Required Permit Required Responsible Regulatory Agency Status Land Use Change Permit — Limited Impact Review Garfield County Application submitted TBD Stormwater Permit CDPHE Permit COR034840 issued 7/1/2002, renewed 6/20/2007, and administratively continued 6/21/2012, included in this permit application. Air Quality CDPHE Not Required Access/Driveway Permit Garfield County Permit GRB05-D-38 included in this permit application. Project Description Page 3 K19NE Storage Area Encana Oil & Gas (USA) Inc. This page left blank for two-sided printing. Project Description Page 4 Article 4-203.0 Vicinity Map Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OA Project No. 014-2797 Subject Parcel 0 K19NE Storage Yard Parcels 3 Mile Buffer Perennial Stream PROJECT NO: 014-2797 DRAWN BY: DATE: JWH 11/25/2014 VICINITY MAP K19NE STORAGE YARD ENCANA OIL & GAS (USA) INC. GARFIELD COUNTY, COLORADO CAOLSSON ASSOCIATES 760 HORIZON DR., SUITE 102 GRAND JUNCTION, CO 81506 TEL 9702617800 FAX 970.263.7456 FIGURE V-1 Article 4-203.D Site Plan Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OA Project No. 014-2797 50' 0' 50' SCALE: 1" = 50' CONTOUR INTERVAL = 2' WEST 1/4 COR. SECTION 19 ORIGINAL STONE N00°58'32"W N co CERTIFICATE OF SURVEYOR I, TED T. TAGGART OF FRUITA, COLORADO HEREBY CERTIFY THAT THIS MAP WAS MADE FROM NOTES TAKEN DURING AN ACTUAL SURVEY MADE BY ME OR UNDER MY DIRECTION FOR ENCANA OIL & GAS (USA) INC. AND THAT THE RESULTS OF WHICH ARE CORRECTLY SHOWN HEREON. INFORMATION TABLE TOTAL SITE AREA: 5.172 ACRES ZONING: RURAL FLOOD ZONE DESIGNATION: UNDETERMINED BY FEMA TOTAL AREA OF EXISTING BUILDINGS = 0 SQ. FT. NO PROPOSED BUILDINGS WASTE WATER SYSTEM: NONE CULINARY WATER SUPPLY: NONE GENERAL NOTES THE SITE SURFACE IS GRADED NATIVE SOIL OR GRAVEL. NO PLANNED SURFACE GRADING NO RECORDED EASEMENTS WERE FOUND N53°19'19"E, 80.65' \ �s o\ N89°01'28"E, 1258.35' \ SOUTHWEST COR. SECTION 19 1981 BRASS CAP PLS 15846 4 � I O ti \ \ V/ / / N Section 19, T6S-R92W z,. Point of Beginning BARRICADE \S66, — -- 5666- - — — S83°39'12''E, 5666- S83°39'12'E, 262.78' ■■■... -5670- N81 °10'46"E 39.50' / — 3 EXISTING TOPOGRAPHY S79°29'23"E 37.93' O,c os� RBFo ..�..��� �" PIP�I Inlr — ` BARRICADE METER LLI SEP. BARRICADE L. J J 0 rn d J O O EDGE OF STORAGE AREA W J J rn C3, d J TANK ♦ ♦ AREA A �� COMM. TOWER •` \ • • 1 1 1 1 1 J 3 / 1 gRFq 66 Is 30 , S�,F 6? J 56j2 0 • • • • • • ■ ■ \ 0 ("1 .0_) /VS6S 1107 >, /w. ry '9 O 40. 5680- - Lot 3 —56 74 -5676_ EDGE OF EXISTING DISTURBED AREA N84°39'53»W ■■■■■■'■. 260.99' - - -5682- 1/4 1/4 SECTION LINE PROJECT LOCA TION DESCRIPTION A TRACT OF LAND LOCATED IN LOT 3 AND THE NW1/4 SE1/4 OF SECTION 19, T6S, R92W, 6th P.M., GARFIELD COUNTY, COLORADO, SAID TRACT BEING MORE PARTICULARLY DESCRIBED AS FOLLOWS: COMMENCING AT THE SOUTHWEST CORNER OF SAID SECTION 19 AND RUNNING THENCE NOO°58'32"W, 1844.27 FEET ALONG THE WEST LINE THEREOF; THENCE N89°01'28"E, 1258.35 FEET TO THE POINT OF BEGINNING; THENCE N5319'19"E, 80.65 FEET; THENCE S83°39'12"E, 262.78 FEET; THENCE N81 °10'46"E, 39.50 FEET; THENCE S79°29'23"E, 37.93 FEET; THENCE S59°58'35"E, 162.34 FEET; THENCE S54°56'54"E, 60.76 FEET; THENCE S12°15'16"W, 316.15 FEET; THENCE S88°32'58"W, 160.64 FEET; THENCE N84°39'53"W, 260.99 FEET; THENCE N56°54'01 "W, 80.81 FEET; THENCE N16°23'57"W, 103.62 FEET; THENCE N01°52'46"W, 243.20 FEET TO THE POINT OF BEGINNING. SAID TRACT CONTAINING 5.172 ACRES, MORE OR LESS. THE BASIS OF BEARING FOR THIS SURVEY IS N00°58'32"W, 2598.53 FEET BETWEEN FOUND MONUMENTS AT THE SOUTHWEST CORNER AND THE WEST ONE-QUARTER CORNER OF SECTION 19, T6S, R92W, 6TH P.M. / • • • ofz x S88°3258W, 160.64' EXISTING FENCE X \ \ NW1/4 SE\1/4 ■ • • • • • •I • I •I • \ s O\ 1/4 1/4 SECTION LINE Source Map: U. S. G. S. Quadrangle Silt, Colorado / ys :0r_ _ - 08,; 09 A 1-70 ENCANA OIL & GAS (USA) INC PARCEL NO. 217919300 128 KI9NE STORAGE YARD SITE LOCATION 333 'r3 0 0.5 1 SCALE (IN MILES) MAP LEGEND = PUBLIC LAND SURVEY CORNER • = SITE BOUNDARY CORNER = EXISTING PIPELINE EDGE OF EXISTING DISTURBANCE SITE BOUNDARY LINE 0 Issued for Preliminary Review 8 20 14 REFERENCES USGS QUADRANGLE: SILT, CO. PREPARED FOR: Encana Oil & Gas (USA) Inc. PREPARED BY: WSURV�SATCH EYING �ssATc�t Wasatch Surveying Associates 906 Main Street Evanston, Wyoming 82930 Phone No. (307) 789-4545 TITLE: K19NE Storage Yard Existing Site Plan Located in Lot 3 and the NW1/4 SE1/4 of Section 19 T6S, R92W, 6th P.M. Garfield County, Colorado DATE: 8/20/14 SCALE: 1" = 50' PROJECT NO.: 14-04-12 DRAWING NAME: Site Plan SHEET NO.: 1 of 1 1 1 1 1 1 1 Article 4-203.E Grading and Drainage Plan Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OA Project No. 014-2797 FINAL DRAINAGE REPORT FINAL DRAINAGE REPORT ENCANA OIL AND GAS - K19NE STORAGE YARD GARFIELD COUNTY, COLORADO PREPARED FOR: ENCANA OIL AND GAS 143 DIAMOND AVENUE PARACHUTE, CO 81635 PH: (970) 285-2600 CONTACT: JASON ECKMAN PREPARED BY: OLSSON ASSOCIATES 760 HORIZON DRIVE, SUITE 102 GRAND JUNCTION, CO 81506 PH: (970) 263-7800 CONTACT: LORNE C. PRESCOTT WYATT E. POPP, PE, LEED AP JANUARY 16, 2015 OLSSON ASSOCIATES PROJECT No. 014-2797 FINAL DRAINAGE REPORT THIS PAGE LEFT BLANK FOR TWO-SIDED DUPLICATION. FINAL DRAINAGE REPORT ENGINEER'S STATEMENT I hereby certify that this Final Drainage Report for the design of Encana Oil and Gas, K19NE Storage Yard was prepared by me, or under my direct supervision, in accordance with sound engineering practices for the owners thereof. I understand that Garfield County does not and will not assume liability for drainage facilities designed by others. Wyatt E. Popp, PE Registered Professional Engin State of Colorado No. 38514 OWNER'S STATEMENT /1013P Date 1, , hereby certify that the drainage facilities for Encana Oil and Gas, K19NE Storage Yard shall be constructed according to the design presented in this report. I understand that Garfield County does not and will not assume liability for the drainage facilities designed and/or certified by my engineer. I understand that Garfield County reviews drainage plans but cannot, on behalf of Encana Oil and Gas, K19NE Storage Yard, guarantee that final drainage design review will absolve and/or their successors and/or assigns of future liability for improper design. I further understand that approval of the Final Plat and/or Final Development Plan does not imply approval of my engineer's drainage design. Owner/Developer Authorized Signature Date Encana Oil and Gas - K19NE Storage Yard Garfield County, CO 014-2797 FINAL DRAINAGE REPORT THIS PAGE LEFT BLANK FOR TWO-SIDED DUPLICATION. Encana Oil and Gas - K19NE Storage Yard Garfield County, CO 014-2797 FINAL DRAINAGE REPORT TABLE OF CONTENTS I. INTRODUCTION 1 A. Background 1 B. Project Location 1 C. Property Description 1 D. Previous Investigations 1 II. DRAINAGE SYSTEM DESCRIPTION 1 A. Existing Drainage Conditions 1 B. Master Drainage Plan 2 C. Offsite Tributary Area 2 D. Proposed Drainage System Description 2 E. Drainage Facility Maintenance 3 III. DRAINAGE ANALYSIS AND DESIGN CRITERIA 3 A. Regulations 3 B. Development Criteria 3 C. Hydrologic Criteria 3 D. Hydraulic Criteria 4 E. Variance from Criteria 4 IV. POST -CONSTRUCTION STORMWATER MANAGEMENT 4 A. Stormwater Quality Control Measures 4 B. Calculations 4 V. CONCLUSIONS 4 A. Compliance with Manual 4 B. Compliance with Colorado Oil and Gas Conservation Commission Criteria 4 C. Design Effectiveness 5 D. Areas in Flood Hazard Zone 5 E. Variance from Manual 5 VI. REFERENCES 5 APPENDIX A: MAPS AND EXHIBITS APPENDIX B: HYDROLOGIC CALCULATIONS APPENDIX C: HYDRAULIC CALCULATIONS Encana Oil and Gas - K19NE Storage Yard Garfield County, CO 014-2797 i FINAL DRAINAGE REPORT THIS PAGE LEFT BLANK FOR TWO-SIDED DUPLICATION. Encana Oil and Gas - K19NE Storage Yard Garfield County, CO 014-2797 ii FINAL DRAINAGE REPORT I. INTRODUCTION A. Background This Final Drainage Report has been prepared for Encana Oil and Gas, K19NE Storage Yard (the SITE) by Olsson Associates. This report evaluates the SITE's drainage patterns, analyzes the change in stormwater quantity/quality associated with existing development, and provides design to alleviate the impacts of stormwater runoff due to the proposed use. B. Project Location The SITE is located in Lot 3 and the NW1/4 of the SE1/4 of Section 19, Township 6 South, Range 92 West of the Sixth Principal Meridian, County of Garfield, State of Colorado. Refer to Appendix A for the General Project Map. The SITE is approximately 4.3 miles southeast of the City of Rifle, Colorado. The SITE is located on County Road 333 approximately 0.8 miles south of Airport Road. C. Property Description The SITE consists of a modification to a previously developed well pad of approximately 1.73 acres. Prior to the initial development, the SITE was covered by native vegetation, and sheet - flowed from south to north. The existing site pad is a gravel surface. According to the NRCS Web Soil Survey, soils in the area of the SITE consist of Potts loam on 3 to 6% slopes, which is classified as hydrologic group Type C. A soil map and description of NRCS soil groups from NRCS is included within Appendix A. D. Previous Investigations To the best of our knowledge, no previous drainage investigations have been conducted in regards to this site II. DRAINAGE SYSTEM DESCRIPTION A. Existing Drainage Conditions The SITE drains to an unnamed tributary to the northeast which eventually empties into Mamm Creek to the north. Refer to the General Location Map in Appendix A for the SITE location relative to major tributary drainage ways. The SITE generally slopes from south to north at approximately 3%. The SITE generally drains via overland flow to an unnamed tributary mentioned above. Refer to the Drainage Plan Exhibit in Appendix B for the SITE's historic drainage conditions. The Rational Method for determining runoff has been applied resulting in site peak flow rates listed in Table 1, and calculations of each flow rate are presented in Appendix B — Hydrologic Calculations. Encana Oil and Gas - K19NE Storage Yard Garfield County, CO 014-2797 1 FINAL DRAINAGE REPORT Table 1: Site Peak Runoff Drainage Basin Area (Ac) 10 -YR Peak Flow (cfs) 100 -YR Peak Flow (cfs) OS -1 — Offsite Run -On 1.52 0.70 2.35 OS -2 — Offsite Run -On 2.99 0.97 3.28 A - SITE Storage Yard 1.73 0.66 1.60 B. Master Drainage Plan To our knowledge, no master drainage studies have analyzed the SITE. C. Offsite Tributary Area The SITE will not be adversely affected by stormwater from adjacent land. The offsite run-on will be diverted around the site by existing grass lined drainage swales. For the purposes of this study, all adjacent land was assumed to remain undeveloped in the foreseeable future. During construction, runoff from the SITE storage yard should be treated prior to leaving the SITE using methods described in Vol. 3 of the Urban Drainage and Flood Control District's Urban Storm Drainage Criteria Manual, including use of straw bales and/or other methods to provide temporary water quality. D. Proposed Drainage System Description The site consists of three drainage basins, Basin A, Basin OS -1, and Basin OS -2. Refer to the Drainage Plan Exhibit in Appendix B. Drainage Basin A comprises 1.73 acres of an existing pad and drains via sheet flow and pad perimeter swales into a detention basin located in the northwest corner of the pad. The pad as it exists does not provide enough slope to drain into the proposed detention basin. The proposed changes to the pad will not change the dimensions of the existing pad but will only modify the grades to provide positive drainage to the detention basin. The grades within the secondary containment of the existing tanks on the pad will not be modified. Drainage Basin OS -1 consists of 1.52 acres of undeveloped area on the south side of the existing pad. This basin drains via sheet flow towards the pad and will be conveyed around the pad using an existing swale and discharged to the east of the pad towards an existing natural drainage way. The swales that are currently in place will be sufficient to intercept the offsite flow anticipated. Drainage Basin OS -2 consists of 2.99 acres of undeveloped area on the west side of the existing pad. This basin drains via sheet flow and a natural drainage way parallel to the pad and will be conveyed around the detention basin by a swale formed by the detention basin itself. The swale will discharge to the north of the detention basin into the existing road ditch. The existing road ditch will need to be modified slightly to convey the offsite runoff to convey any emergency overflow from the detention basin released through the proposed weir. Encana Oil and Gas - K19NE Storage Yard Garfield County, CO 014-2797 2 FINAL DRAINAGE REPORT The proposed detention basin will replace an existing basin that is undersized for the drainage requirements. The proposed detention basin will be an ellipse 57 feet long and 41 wide with 3:1 slopes and a depth of 4.5'. The proposed detention basin outlet will replace an existing culvert under the existing access road with a new culvert graded for appropriate outflow into an existing natural drainage way. The release rates from the proposed detention basin are calculated based on common engineering practices and are detailed below. Mesa County Storm Water Management Manual Table 1402 - Allowable Release Rates for Detention Ponds (cfs/acre CONTROL FREQUENCY SOIL GROUP A B C/D 10 -year 0.05 0.09 0.12 100 -year 0.25 0.43 0.50 For soil group C, the allowable release rate for the 10 -year event in Basin A is 0.12 cfs/acre x 1.73 acres = 0.21 cfs and the allowable release rate for the 100 -year event in Basin A is 0.50 cfs/acre x 1.73 acres = 0.87 cfs. These release rates are reflected in the Hydraulics Calculations in Appendix C. Refer to Appendix B for Hydrologic Calculations and Appendix C for Hydraulic Calculations. E. Drainage Facility Maintenance The owner shall be responsible for maintaining all on-site drainage facilities. A minor amount of continuous maintenance will be necessary to keep vegetation established and stormwater structures working at their original designed capacity. The detention pond bottom should be scraped and regraded at least once every 1-3 years to remove sediment build-up. The detention pond and outlet structure should be examined after any significant rainfall event to ensure proper functionality. III. DRAINAGE ANALYSIS AND DESIGN CRITERIA A. Regulations This report has been prepared in accordance with common engineering practices, Mesa County's Storm Water Management Manual, the Urban Drainage and Flood Control District's Urban Storm Drainage Criteria Manual, and Garfield County Standards. B. Development Criteria There are no known constraints placed on the SITE due to floodplain studies, master studies or adjacent property drainage studies. Flows from upstream land will be diverted around the SITE. C. Hydrologic Criteria Hydrologic calculations have been prepared in accordance with common engineering practices and criteria set forth in Mesa County's Storm Water Management Manual and Urban Encana Oil and Gas - K19NE Storage Yard Garfield County, CO 014-2797 3 FINAL DRAINAGE REPORT Drainage and Flood Control District's Urban Storm Drainage Criteria Manual. Rainfall intensities used are sourced from the NOAA Atlas 14, Volume 8, Version 2. Refer to Appendix B for all hydrologic calculations. D. Hydraulic Criteria Hydraulic calculations have been prepared in accordance with criteria set forth in Mesa County's Storm Water Management Manual, the Urban Drainage and Flood Control District's Urban Storm Drainage Criteria Manual, and Garfield County Land Use and Development Code, Article 7, Section 204. Refer to Appendix C for all hydraulic calculations. E. Variance from Criteria No variances from criteria set forth in the above noted regulations are requested at this time. IV. POST -CONSTRUCTION STORMWATER MANAGEMENT A. Stormwater Quality Control Measures The existing grass lined drainage swale will provide a means for offsite run-on stormwater to be routed around the SITE during all post -construction storm events. The proposed detention pond will temporarily detain and slowly release the runoff from a 100 -year precipitation event from the SITE storage yard area to allow sediment to settle to the bottom of the pond, therefore providing stormwater quality for the SITE. B. Calculations All Hydrologic Calculations can be found in Appendix B. All Hydraulic Calculations can be found in Appendix C. V. CONCLUSIONS A. Compliance with Manual This report has been prepared in accordance with common engineering practices and the criteria set forth in Mesa County's Storm Water Management Manual and the Urban Drainage and Flood Control District's Urban Storm Drainage Criteria Manual, and Garfield County Land Use and Development Code, Article 7, Section 204. B. Compliance with Colorado Oil and Gas Conservation Commission Criteria 100 -Year Run-on Diversions Along the south and west sides of the SITE, existing swales will convey the run-on flow. The swale on the south side will discharge into an existing natural drainage way. The swale on the west side will be routed around the detention basin and discharged into the existing road ditch. Encana Oil and Gas - K19NE Storage Yard Garfield County, CO 014-2797 4 FINAL DRAINAGE REPORT 25 -Year Runoff Control Runoff from the site will be captured in a detention pond at the northwest corner of the SITE which was designed to capture the 100 year runoff for the SITE. C. Design Effectiveness Proper implementation of the proposed measures outlined in this report will alleviate the direct impacts of stormwater runoff on adjacent, downstream lands. The quantity of stormwater released from the SITE will not exceed the current conditions. A registered licensed engineer in the state of Colorado has been consulted for the preparation of construction plans related to the recommendations outlined within this report. D. Areas in Flood Hazard Zone The SITE is within FEMA Panel 0802051360B, which has not been printed. Based on the relative elevation above the nearest major river (approximately 200 feet), the flood risk has been determined to be minimal. Refer to Appendix A for the FEMA map information. E. Variance from Manual No variances from the criteria set forth in the references listed below are requested at this time. VI. REFERENCES 1) Stormwater Management Manual, City of Grand Junction and Mesa County 2) Urban Drainage and Flood Control District Urban Storm Drainage and Criteria Manual, Vols. 1-3 3) Garfield County Land Use and Development Code, Article 7, Section 204 4) NRCE Web Soil Survey - http://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx 5) FEMA Flood Map Service Center - https://msc.fema.gov/portal Encana Oil and Gas - K19NE Storage Yard Garfield County, CO 014-2797 5 FINAL DRAINAGE REPORT THIS PAGE LEFT BLANK FOR TWO-SIDED DUPLICATION. Encana Oil and Gas - K19NE Storage Yard Garfield County, CO 014-2797 6 FINAL DRAINAGE REPORT APPENDIX A: MAPS AND EXHIBITS Encana Oil and Gas - K19NE Storage Yard Garfield County, CO 014-2797 FINAL DRAINAGE REPORT THIS PAGE LEFT BLANK FOR TWO-SIDED DUPLICATION. Encana Oil and Gas - K19NE Storage Yard Garfield County, CO 014-2797 —nt I Inn, n —, n I , swi stopo,;ancl eoEye, i` -cubed, Earthstar Geographics, USG; AEX, Getmapping, Aerogrid, IGN. !GP. User Community DISCLAIMER This Geographic Information System (GIS) and its components are designed as a source of reference for answering inquiries, for planning and for modeling. GIS is not intended, nor does it replace legal description information in the chain of title and other information contained in official government records such as the County Clerk and Recorders office or the courts. In addition, the representations of locations in this GIS cannot be substituted for actual legal surveys. N A Project Number: 014-279 Drawn By: ABL Revision Date: 1/14/2015 General Location Map Encana Oil and Gas K19NE Storage Facility Garfield County, CO Lot 3, Sec 19, T6S, R92W, 6th PM 760 Horizon Drive, Suite 0/1* OLSSON 1GranP:9700tio6n3.7 0015062 ASSOCIATES F: 970.263.7456 Figure 1 39° 30' 41" N 39° 30' 21" N 266850 Hydrologic Soil Group—Rifle Area, Colorado, Parts of Garfield and Mesa Counties (Encana K19NE) 266930 267010 267090 267170 267250 n O O / / M n CO O / n 1 1 1 1 I 266850 266930 267010 267090 267170 267250 Map Scale: 1:3,100 if printed on A portrait (8.5" x 11") sheet. Meters 0 45 90 180 270 Feet 0 150 300 600 900 Map projection: Web Mercator Comer coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 USDA Natural Resources Web Soil Survey 12/17/2014 Conservation Service Natinnal Cnnnerative Snil Siirvav Pane 1 of 4 You created this PDF from an application that is not licensed to print to novaPDF printer (http://www.novapdf.com) 39° 30' 41" N 39° 30' 21" N N a) .O O U co a) 2 D m D a) CO (7 0 ms U1 az - O) o � Y `o c O U 0 2 w a) a) o- 0 (3 U 0) 0 O D T 2 MAP INFORMATION MAP LEGEND The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. 0 0 0 0 Not rated or not available ■ ■ ■ o Water Features Streams and Canals a) 0 O O co a) N Ul a) © O O O_ iE .— O 6) p a) N U 6 U -6 L() i N - Ul a) p (6 Cll -C(6 6) 2i C 0 O) p L a) 0 N W N O O o- E N U -O a) a) O .O (6 a) 0 f .N = 0 a) a) N O C E E (n Ul a) 'O w E E i p — 7 - w - (6 (0 — p a) C 7 — a) Ul!7 a) n N N U N O) (OA fl O (6 C co a) (6 Ul U) O E O a) o N a) L >, c? c o- (n = 0 (n v Q s : ,- a) a) CD OL O O'O O 7 O_ C N a) -O .2 z Ul '6• D O N d a) 'O Ul - t co E U.—(n w N o a -o N O L (6 Ul N O O_ L N (n (6 N N C W p N0 a) U N O `) 0 O w D O O O O Q -0 a) 7 2 U O U .�.. O - N O O (n U O N-0 O N o a) w-. '� 6) E U ao - o E :Dim a) 0 a) O U a) E O N W N Q n = a) O a) O w O_ N ul '0 6s a) N (� 6sN6s �_ .o Q `o o ai a) - a) EU (6Ul 7 . O NO- .2 U w >a)UlZ OQU N —a)ocoT N tl) N �...iu a) co w to O C a) Ul U N -O O) a) O (6 N E O O p C N U)to o > -O - O -o < 6) .J 6) 0 O_ _a >' N (n a) 0 0 7 C 7 0 �+ N O O- RS •Ul • E c co O a) O p 'O C a) 7 O O C O U a) O O N 3 .0 T co O N Q co Ul ".&_(:, (n U O,_ O O- a) U) -E-Ht.) E 2) O .O- 0 0 (6 0 5 fl o o- .a? cu a) U ul > — 3— m °? a) E E d E c�50 2 0'3< o H -c u)0 u) u) `o aNN H co).- o C Transportation A ce Interstate Highways US Routes 0 0 0 2 Q rn Q a m m 0 U 0 c c R '62[ ogf❑❑❑❑❑❑❑❑ g Local Roads Not rated or not available 0 0) R Aerial Photography 1 N C J 0 0 0 rn a a m m 0 0 0 c }111111 0 Not rated or not available ti Soil Rating Points 0 0 a a mEa 0 0 0 0 You created this PDF from an application that is not licensed to print to novaPDF printer (http://www.novapdf.com) Natural Resources Conservation Service Hydrologic Soil Group—Rifle Area, Colorado, Parts of Garfield and Mesa Counties Encana K19NE Hydrologic Soil Group Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long -duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink -swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. USi)A Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey You created this PDF from an application that is not licensed to print to novaPDF printer (http://www.novapdf.com) 12/17/2014 Page 3 of 4 Hydrologic Soil Group— Summary by Map Unit — Rifle Area, Colorado, Parts of Garfield and Mesa Counties (C0683) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 55 Potts loam, 3 to 6 percent slopes C 35.5 69.3% 58 Potts-Ildefonso complex, 12 to 25 percent slopes C 2.1 4.1 % 67 Torriorthents-Rock outcrop complex, steep D 13.6 26.6% Totals for Area of Interest 51.2 100.0% Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long -duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink -swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. USi)A Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey You created this PDF from an application that is not licensed to print to novaPDF printer (http://www.novapdf.com) 12/17/2014 Page 3 of 4 Hydrologic Soil Group—Rifle Area, Colorado, Parts of Garfield and Mesa Counties Encana K19NE Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher USDA Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey You created this PDF from an application that is not licensed to print to novaPDF printer (http://www.novapdf.com) 12/17/2014 Page 4 of 4 I, C, kttE • J fr i1 h• Nath ! *PANEL NOT PRINTED - AREA IN ZONE D *PANEL NOT PRINTED -THIS AREA IS SHOWN O[1 080205 1885 8 IS SHO' ,' v; I i n �f Cr` �.c`h n n�fnc��0950-B. *080205 q� *O ' C b n *080205 p� IIII NATIONAL FLOOD 1N5URANC <' ROONAM :. 15 0925 B 0950-B._ rr if le 1000 13).--z' N. I• :' •i : I' :� I s 'I I ; �,.:.:,. FIRM FL000 INSURANCE GARFIELD �;-::�' •;, ... COLORAD i ::'.IS) IVIAP NDEX PANELS P 5s. 964, 965. 1015, 1043, 104 54, 1431, 1432, 1434, 144 1 53, 1-0v 70. 1705, 1855, 1856-1$59, 1870. 1886 AHEL NUMBERS o 05 0001-1900 MAI' REVISED: JANUARY 3, 1986 _ ency Management Agency 'v C3 ,4' $ 9 ,4 off` *q0 Town of Silt City of AREA NOT New Castle ]OEO \•, 0'r 69 City of Rifle --____INCL AREA NOT INCLUDED _ ^d N. Hubbard ti , Gulch py paoti �' ... Oh �a - Q'_ �-_ •..., Co --,_.y_" �� L.. :,::, .�.=d:�::a: a.-.:�u�' {VeY Colorado cls •\ ` THIS AR h iQ• t V &RA .mow.__-...` tip. 0 / - Helmer;y -- Gulch �p'V a • ___' qhs pati p �J *080205 1400 B ON PANE(UNINCORPORAT �..-..._-. .._....-.. *08020 ,01370-2151-350-13, 1 Ramsayf U r „_ ��� izt ,�C3 4, *.o `, Nei' 4� oeyq •`�+ �7 White River ='i qcb C '{ * Natioltai Forest , µ N.CO 47 Oeg, .Yi ab +a U ,�� N '� .-- _._. _� '�F a j �_ ` _ �'' L- ' � - :- i a ' �i I 4_ �w _ 1�� _+ k-st` Q t -.. -Divide _-"--"� � 4'080205,* os�zo5 175�.�B,, � � ��� B o8oz051$00 a * 08020 1 _._ Q f1�' Cb * C3 _ .7'� - Grand Mesa National - �_.....Y.-- ..__ _ _ _ _. ForestN. _ _ ____ __ .__ ___ _ _ This is an official copy of a portion of the above referenced flood map. 11 was extracted using F -MIT On -Line. This map does not reflect changes or amendments which may have been made subsequent to the date on the title block. For the latest product information about National Flood Insurance Program flood maps check the FEMA Flood Map Store at www.msc.fema.gov 0 W 0 IQ 0 0 7 7 5 7 7 7 7 7 5 5 5 5 5 5 5 2 5 I i i \\---5665 — 7 7 5670------\ 7 .._—mNEamme ■ ---- - 2 \II I\ II 5 1 \ 1 1 1 5 5 5 5 \. 1 5 5 1 \\ 1 1 1 1\ 1 1 \ 1 1 1 1 1 1 1 2 1 \� 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11 11 11 1 1 11 1 1 1 1 1 5 5 5 X r — — / --\ 5 2 2 1 22 2 2 2 5 5 2 5 X 7 1 2 2 7 2 \ 5 2 52 \ 2 2 2 2 2 2 2 7 / 1 1 1 1 2 5 2 2 5 2 2 \ 7- 7- 7- 7- 7- 7 xa'EM—MEN 2 5 5 7 7 7 7 5 7 \ v--5675-- \ \ 7 / / / / i 7- 5 1 2 / / • • • • ♦ 56g0 7 7 7 i 7- 1 -' / 1 aft NM WI SIN NMI INN MI WE WI NM INN alit INN MIN INN • • • ♦/ • • • • • 1 1 1 1 _-------; 1 /OS 1 26 7 - MIR 11■11 NW WI - - - - - - _ - _ .51 -56 75- - / 7 7- 7- I --- II \ •I \ — 5 • I / 5 • .2/ I I • I II I k< •\ 7- ---maV x �v ��� SII v 5 v 2 \ \ \ \ \ 7\ 7 \ �\ I \\ss XN \ 5 \ \ 80 \ \ 1 N I I\ I I Ns N 7 \ I \ N I v 7v \ I v 2 \ X \V A I7 v vv 2 5 \ I \ 2 \ \ \ III \ 2 2 2 \\ 1 V \ \ \ II \\ \ \ \ \ x 2 7- \ 7 — — 7- 7 7 7- 2 2 2 s 0 -x-� 2 2 2 \ 7- 2 2 2 5 SCALE IN FEET mmmmmm DRAINAGE BOUNDARY —5670— PROPOSED MAJOR CONTOUR 5666 PROPOSED MAJOR CONTOUR - - 5670- - PROPOSED MAJOR CONTOUR PROPOSED MAJOR CONTOUR PROPOSED DRAINAGE FLOW DIRECTION BASIN DESIGNATION 10 -YR RUNOFF COEFF. 100 -YR RUNOFF COEFF. BASIN AREA IN AC. Z 1-w es% a 1/41 tn 0 ti) stt 0 CD o co co co 0 o CN o Lo NOTE THIS DOCUMENT HAS BEEN RELEASED BY OLSSON ASSOCIATES ONLY FOR REVIEW BY REGULATORY AGENCIES AND OTHER PROFESSIONALS, AND IS SUBJECT TO CHANGE. THIS DOCUMENT IS NOT TO BE USED FOR CONSTRUCTION. OLSSON ASSOCIATES ASSUMES NO RESPONSIBILITY FOR EXISTING UTILITY LOCATIONS (HORIZONTAL OR VERTICAL). THE EXISTING UTILITIES SHOWN ON THIS DRAWING HAVE BEEN PLOTTED FROM THE BEST AVAILABLE INFORMATION. IT IS HOWEVER THE RESPONSIBILITY OF THE CONTRACTOR TO FIELD VERIFY THE LOCATION OF ALL UTILITIES PRIOR TO THE COMMENCEMENT OF ANY CONSTRUCTION ACTIVITIES. Know what's below, Cail before you dig. CALL 811 SEVENTY-TWO HOURS PRIOR TO DIGGING, GRADING OR EXCAVATING FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES REVISIONS DESCRIPTION REVISIONS ENCANA K19NE STORAGE YARD LOT 3, SECTION 19, T6S, R92W, 6TH P.M. DRAINAGE PLAN SHEET ENCANA K19NE STORAGE YARD 10 GARFIELD COUNTY, COLORADO drawn by: checked by: approved by: QA/QC by: project no.: drawing no.: date: ABL WEP WEP WEP 014-2797 01-16-2015 SHEET 1 1 1 1 1 1 0 N 0 O ww (n O X N -0 I o. Z O 0 O 0, 0 O) O N O h N (n O0 o cis o Ew / w X 0 w E r, N I 0-) (7) Ln o N 0 o� a / p c 1- 1— < CI 00 \ \ \ / ---?> /// 7/7 7/7 // % _ ---__N N /- 7 \ \////////Z' /H \77\ ////// V H 7 \ / — — '1///////////// I H\v I V i///i /////// // / \ \ / y vHv / \ \ 7 7 / / REMOVE EXISTING CULVERT TYPE VL RIPRAP RUNDOWN 5' BEYOND TOE OF SLOPE 3' WIDE OVERFLOW, 7 CREST EL=5670.00 7 SEE DETAILS, THIS SHEET OUTLET STRUCTURE SEE DETAILS, THIS SHEET BOTTOM OF DETENTION POND 7 30'X14' EL=5666.00 1' WIDE TOP OF POND EL=5670.50 7 7 C \ \ \ EXISTING PIPE LINE EXISTING RIGHT—OR—WAY 7 7 7 7 7 7 7 - X 0' 15' 30' SCALE IN FEET 60' 7 /\V' 100YR WSEL, f /c• \ / 0.34' — 7 7 7 7 7 \ i 7 7 7 \ 7 7 \ 7 / FINISHED GRADE A EXISTING GRADE SECTIO\ A—A NOT TO SCALE 7 7 7 7 v \ // \ I/ / 7 \ MATCH PROPOSED 12" CMP CULVERT 89 L.F. @ —1.1% INVERT OUT EL = 5665.00 7 7 7 7 7 7 TYPE VL RIPRAP 5'x5' PAD 7 7 7 7 ADDITIONAL FILL REQUIRED _ FOR PIPE COVER 7 MATCH PROPOSED BERM TO KEEP — — — SITE STORMWATER ON PAD \ — — 7 7 7 7 / / / / / / X 7 7 \ \ 7 7 \ \ \ 7 7 7 7 / 7 i i /EXISTING EQUIPMENT 1 / \ 7 7 7 7 / 7 7 / �7. / 7 7 7 7 \ 1 1 1 1 1 II 7 q I II I II /// // / /. 7 7 \ FINISHED GRADE 100YR WSEL— — EXISTING GRADE v. Q. \./ H,c-v 0.23' SECTIO\ S— NOT TO SCALE 3 7 i 1' i 41' 7 7 7 7 EL=5670.5 100YR WSEL A 1r1' 0.39' 100YR WSEL FINISHED GRADE EXISTING GRADE J 14' -s-] EL=5669.5 EL=5668.5 EL=5666.0 SECTIO\ C—C NOT TO SCALE L \ CHH \7 _ FINISHED GRADE J 2.5' ^5/ 3' 7 EXISTING GRADE — SECTIO\ D—D NOT TO SCALE / 7 7 TOP OF POND EL=5670.50 WEIR CREST EL=5670.00 7 TYPE VL RIPRAP 5'x5' PAD 3.12 r cy DiTAIL NOT TO SCALE GRADING LEGEND EXISTING PROPERTY LINE MAJOR CONTOURS MINOR CONTOURS BREAKLINE FENCE SPOT ELEVATIONS WATER SURFACE ELEVATION EXCAVATION QUANTITIES SITE QUANTITIES CUT: 935 CY FILL: 565 CY NET: 370 CY (CUT) PROPOSED 5670 5666 THE ABOVE ESTIMATES OF EARTHWORK QUANTITIES ARE NET QUANTITIES ONLY FOR THE PURPOSES OF PERMITTING AND ARE NOT TO BE USED FOR PAY QUANTITIES. THE EARTHWORK CONTRACTOR SHALL DETERMINE HIS OWN QUANTITIES FOR BIDDING PURPOSES. x—ELEV WSEL 41'' THICK RESTRICTOR PLATE — WIDE ENOUGH TO COVER CULVERT 41" THICK RESTRICTOR PLATE — WIDE ENOUGH TO COVER CULVERT — 0.50' 3.92' RECESS FOR GRATING 0.50' r 0.33' 0.25' 0.50' 3.92' 0.50' — TOP VIEW 12" CMP CULVERT RECESS FOR GRATING 1% SLOPE 0.16' 3.00' 0.50' MATCH BOTTOM OF POND ELEVATION = 5666.00 OUTLET CULVERT INVERT EL = 5665.97 SIDE VIEW NOTES: 1. CONCRETE STRUCTURE DESIGN ADOPTED FROM CDOT INLET TYPE C (M-604-10). 2. REFER TO CDOT INLET TYPE C FOR STEEL GRATE DETAILS — STADARD INLET GRATE. 3. REFER TO CDOT INLET TYPE C FOR REINFORCING BAR DETAILS. STLCTLR NOT TO SCALE ETAIL V) 0 tn 0 71. TEL 970.461.7733 PT En co LE 0 Lo Lo NOTE THIS DOCUMENT HAS BEEN RELEASED BY OLSSON ASSOCIATES ONLY FOR REVIEW BY REGULATORY AGENCIES AND OTHER PROFESSIONALS, AND IS SUBJECT TO CHANGE. THIS DOCUMENT IS NOT TO BE USED FOR CONSTRUCTION. OLSSON ASSOCIATES ASSUMES NO RESPONSIBILITY FOR EXISTING UTILITY LOCATIONS (HORIZONTAL OR VERTICAL). THE EXISTING UTILITIES SHOWN ON THIS DRAWING HAVE BEEN PLOTTED FROM THE BEST AVAILABLE INFORMATION. IT IS HOWEVER THE RESPONSIBILITY OF THE CONTRACTOR TO FIELD VERIFY THE LOCATION OF ALL UTILITIES PRIOR TO THE COMMENCEMENT OF ANY CONSTRUCTION ACTIVITIES. Know what's below. Can before you dig. CALL 811 SEVENTY-TWO HOURS PRIOR TO DIGGING, GRADING OR EXCAVATING FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES REVISIONS DESCRIPTION REVISIONS ENCANA K19NE STORAGE YARD LOT 3, SECTION 19, T6S, R92W, 6TH P.M. ENCANA K19NE STORAGE YARD GRADING PLAN SHEET 10 C\J GARFIELD COUNTY, COLORADO drawn by: checked by: approved by: QA/QC by: project no.: ABL WEP WEP WEP 014-2797 drawing no.:014-2797 GRADING.dwg date: 01-16-2015 SHEET ELEVATION DEPTH AREA INCREMENTAL VOLUME (CUBIC FEET) TOTAL VOLUME (CUBIC FEET) 5666 329 5667 1.0 566 443 443 5668 2.0 856 707 1150 5669 3.0 1206 1028 2178 5670 4.0 1612 1405 3583 5670.5 4.5 1836 861 4444 41'' THICK RESTRICTOR PLATE — WIDE ENOUGH TO COVER CULVERT 41" THICK RESTRICTOR PLATE — WIDE ENOUGH TO COVER CULVERT — 0.50' 3.92' RECESS FOR GRATING 0.50' r 0.33' 0.25' 0.50' 3.92' 0.50' — TOP VIEW 12" CMP CULVERT RECESS FOR GRATING 1% SLOPE 0.16' 3.00' 0.50' MATCH BOTTOM OF POND ELEVATION = 5666.00 OUTLET CULVERT INVERT EL = 5665.97 SIDE VIEW NOTES: 1. CONCRETE STRUCTURE DESIGN ADOPTED FROM CDOT INLET TYPE C (M-604-10). 2. REFER TO CDOT INLET TYPE C FOR STEEL GRATE DETAILS — STADARD INLET GRATE. 3. REFER TO CDOT INLET TYPE C FOR REINFORCING BAR DETAILS. STLCTLR NOT TO SCALE ETAIL V) 0 tn 0 71. TEL 970.461.7733 PT En co LE 0 Lo Lo NOTE THIS DOCUMENT HAS BEEN RELEASED BY OLSSON ASSOCIATES ONLY FOR REVIEW BY REGULATORY AGENCIES AND OTHER PROFESSIONALS, AND IS SUBJECT TO CHANGE. THIS DOCUMENT IS NOT TO BE USED FOR CONSTRUCTION. OLSSON ASSOCIATES ASSUMES NO RESPONSIBILITY FOR EXISTING UTILITY LOCATIONS (HORIZONTAL OR VERTICAL). THE EXISTING UTILITIES SHOWN ON THIS DRAWING HAVE BEEN PLOTTED FROM THE BEST AVAILABLE INFORMATION. IT IS HOWEVER THE RESPONSIBILITY OF THE CONTRACTOR TO FIELD VERIFY THE LOCATION OF ALL UTILITIES PRIOR TO THE COMMENCEMENT OF ANY CONSTRUCTION ACTIVITIES. Know what's below. Can before you dig. CALL 811 SEVENTY-TWO HOURS PRIOR TO DIGGING, GRADING OR EXCAVATING FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES REVISIONS DESCRIPTION REVISIONS ENCANA K19NE STORAGE YARD LOT 3, SECTION 19, T6S, R92W, 6TH P.M. ENCANA K19NE STORAGE YARD GRADING PLAN SHEET 10 C\J GARFIELD COUNTY, COLORADO drawn by: checked by: approved by: QA/QC by: project no.: ABL WEP WEP WEP 014-2797 drawing no.:014-2797 GRADING.dwg date: 01-16-2015 SHEET 1 1 1 1 1 1 r►A 10' 0" r SYMMETRICAL ABOUT q_ 41PARALLEL o ROADWAY SLOPE SHALL MATCH MEDIAN SLOPE ,1E11 - - r I A 1'4 INLET WITH DITCH PAVING EARTHWORK ASSOCIATED WITH DIKE INCLUDED IN THE COST OF THE INLET 10:1 MAX. - 10:1 MEDALLION STEEL GRATE QUANTITIES NO. PIECES DESCRIPTION LENGTH LBS PER FT. WEIGHT (LBS.) 4 S4 x 7.7 BEAM 40" 7.70 103 2 31/2" x 1/4" FLAT 26%" 2.98 13 2 3" x I/4" FLAT 26%" 2.55 12 TOTAL LBS. - 128 B 'I IL CROSS PIPE B SECTION VIEW SLOPE TO FIT DIKE NORMAL MEDIAN DITCH GRADE LENGTH OF CONNECTING PIPE SHOWN ON PLAN DETAIL SECTION B -B INLET CONNECTED TO A CROSS PIPE 1'-0" HEIGHT OF DIKE SLOPE 1/2" PER FT. MAX. 4'-0" -•.1 l- 41_0" THIS SLOPE SHALL BE SHOWN ON THE PLANS CONNECTING PIPE IN CASES OF SKEWED PIPE, THIS DIMENSION SHALL BE SHOWN SKEW ON THE PLANS ANGLE CL OF MEDIAN OR DITCH CONNECTING PIPE r ♦ • 1 6" STEEL (LBS.) 4" MIN. _'_ _ _I STEPI _ 1 i 'BOLTS' QI i ? ' 35" 4 3'-0" GRATING 1 1 litiFOR 1 0 171/2 1.2 96 L i - - ir -- i- - -i - J 6" PLAN 41" t 12" MIN 7402 1. #40 '' / .1_ 1 '1 -12" CENTER'il 1 (TYP-)402- I- Y - -I, 1 � I -� -1 -402- i- ,-F -r I p p , 1 \� o a. L 4% `+t i / 4A -J j " i -I - i -402-i- y 6" -►{ 6" I� 3511_„...I6�I F 47" ELEVATION CONCRETE INLET H 11AX MAX. 4" CONCRETE SLOPE AND DITCH PAVING (REINFORCED) (REQUIRES 1.3 CU. YD.) SECTION A -A INLET ON GRADE (FLOW FROM ONE DIRECTION) SLOPE %2" PER FT. MAX. *4" CONCRETE SLOPE AND DITCH PAVING INLET (REINFORCED) (REQUIRES 1.3 CU. YD.) INLET CONNECTED TO A SKEWED CROSS PIPE MEDIAN DITCH GRADE SLOPE I/z" PER FT. MAX. 4" I~ 4'-0" SECTION A -A *CONCRETE SLOPE AND DITCH PAVING WILL BE REQUIRED WHEN SHOWN ON THE PLANS. INLET AT BOTTOM OF VERTICAL CURVE (FLOW FROM TWO DIRECTIONS) 3/6 N 3/611 V 3' x 1/4" FLAT SECTION D -D D 31/ZNx1/411 FLAT 311 x /4" FLAT S4 x 7.7 BEAMS 40/2" (±1/411) 135/6" (±1/8") - it -r 1 JL JL 41/4" OPEN SLOT ---►JL FACILITATE 8'1 -f (TOG T GALVANIZING) CTRS-. STANDARD INLET GRATE GRATE 6" 1/2 II1.111 -__ 1ii11 SAMMA-',ter, WASHER 'S/6" CLR. 4yz 3" -2N OFFSET 5/8"x8" BOLT 3�1 INLET WALL GRATE INSTALLATION DETAIL II 3/g" R. 3" x 1/4" FLAT SLOT DETAIL II/16" x 1" SLOTTED HOLE ALTERNATE SLOT AND HOLD DOWN PLATE DETAIL GENERAL NOTES 1. INLET TYPE C IS NOT HS -20 RATED AND SHALL NOT BE PLACED IN PAVED ROADWAYS. THIS INLET SHALL BE USED ONLY OUTSIDE PAVED ROADWAYS. 2. CONCRETE SHALL BE CLASS B. INLET MAY BE CAST -IN-PLACE OR PRECAST. 3. REINFORCING BARS SHALL BE EPDXY COATED AND DEFORMED #4, AND SHALL HAVE A MINIMUM 2 IN. CLEARANCE. CUT OR BEND AROUND PIPES AS REQUIRED. 4. CONCRETE SLOPE AND DITCH PAVING SHALL BE IN ACCORDANCE WITH SECTION 507. REINFORCEMENT FOR CONCRETE SLOPE PAVING SHALL BE 6 X 6 - W1.4 X W1.4 OR 6 X 6 - W2.1 X W2.1. 5. STRUCTURAL STEEL FOR GRATES AND GRATE INSTALLATION HARDWARE SHALL BE GALVANIZED, AND SHALL BE IN ACCORDANCE WITH SUBSECTION 712.06. 6. THE STANDARD INLET GRATES SHALL BE USED ON ALL TYPE C INLETS UNLESS CLOSE MESH GRATES ARE SPECIFIED ON THE PLANS. 7. CLOSE MESH GRATES ARE RECOMMENDED WHERE FOOT TRAFFIC OR BICYCLE ROUTES ARE IN CLOSE PROXIMITY TO GRATE. THIS GRATE IS NOT ADA COMPLIANT OR BICYCLE FRIENDLY AND SHALL NOT BE PLACED DIRECTLY IN SIDEWALKS, CROSSWALKS OR BIKE PATHS. 8. STEPS SHALL BE PROVIDED WHEN INLET DIMENSION "H" IS EQUAL TO OR GREATER THAN 3 FT. - 6 IN., AND SHALL CONFORM TO AASHTO M 199. 9. SEE STANDARD PLAN M-604-11, FOR REINFORCEMENT AROUND THE PIPE OPENING. 10. ALL INLETS SHALL HAVE A 4 IN. DIA. METAL MEDALLION WITH A "NO DUMPING DRAINS TO STREAM" MESSAGE ON IT. THE MEDALLION SHALL HAVE A FISH SYMBOL WITH A BLUE BACKGROUND. IT SHALL BE FIRMLY ATTACHED TO THE TOP OF THE INLET WITH A PERMANENT FASTENER. QUANTITIES FOR ONE INLET H CONCRETE (CU. YDS.) STEEL (LBS.) NO STEPS REQ'D. 2'-6" 0.9 75 0 3'-0" 1.0 80 0 3'-6" 1.2 96 0 4'-0" 1.3 101 1 4'-6" 1.4 116 2 5'-0" 1.5 122 2 5'-6" 1.7 137 2 6'-0" 1.8 142 3 6'-6" 1.9 158 3 7'-0" 2.0 163 3 7'-6" 2.2 179 4 8'-0" 2.3 184 4 8'-6" 2.4 199 4 9'-0" 2.5 205 5 9'-6" 2.7 220 5 10'-0" 3.0 235 6 11'-6" 3.4 251 6 • PIPE INSIDE DIAMETER SHALL BE 30 IN. OR LESS. CONCRETE AND STEEL QUANTITIES ARE FOR ONE ENTIRE INLET BEFORE DEDUCTION FOR VOLUME OCCUPIED BY PIPE. WEIGHT OF STEEL INCLUDES A RING FOR THE MAXIMUM PIPE DIAMETER. BAR LIST FOR H = 2 FT. -6 IN. AND BENDING DIAGRAM CENTERLINE OF GRATE PARALLEL TO CENTERLINE OF ROADWAY 26%" (±'/4") 311/2;''►`�` 40/4"\ 4" x %" BAR 3A" TYPICAL HEX. ROUND OR TWISTED CROSS BARS AT 8 IN. CTRS. WELDED TO 4" x %" BEARING BARS SPACED AT 2%" CTRS. 3�/z" x 1/4" FLAT 3/6 N 3"x1/4"FLAT SECTION E -E �\� E CLOSE MESH GRATE 3" x 1/" FLAT 4'/4" MARK REQ;D HEIGHT LENGTH 401 2 2'-3" 7'-11" 401 6 2'-7" 8'-7" 402 3 "U' 15'-0" "U" 6 IN. OF NO. 401 �3-51�� INCREASE DIMENSION FOR EACH 6 "H" ABOVE 7 I,u, V IN. INCREASE 2 FT. -6 IN. 3'-6" - - L 12" 6" N0.402 ` 1 f ADD ONE BAR FOR EACH FT. INCREASE OF "H" ABOVE 2 FT. - 6 IN. 402 BARS SHALL BE EQUALLY SPACED FROM EACH OTHER. SLOT DETAIL IN 31/2" x /4" FLATS SAME AS IN STANDARD INLET GRATE Computer File Information Creation Date: 07/04/12 Initials: DD Last Modification Date: 07/04/12 Initials: LTA Full Path:www.coloradodot.info/business/designsupport Drawing File Name: 6040100101.dgn CAD Ver.: MicroStation V8 Scale: Not to Scale Units: English (R -X) (R -X) (R -X) (R -X) Sheet Revisions Date: Comments Colorado Department of Transportation DEPARTMENT Of TRANSPORTATION 4201 East Arkansas Avenue Denver, Colorado 80222 Phone: (303) 757-9083 Fax: (303) 757-9820 Project Development Branch DD/LTA INLET, TYPE C STANDARD PLAN NO. M-604-10 Issued By: Project Development Branch July 4, 2012 Sheet No. 1 of 1 FINAL DRAINAGE REPORT APPENDIX B: HYDROLOGIC CALCULATIONS Encana Oil and Gas - K19NE Storage Yard Garfield County, CO 014-2797 FINAL DRAINAGE REPORT THIS PAGE LEFT BLANK FOR TWO-SIDED DUPLICATION. Encana Oil and Gas - K19NE Storage Yard Garfield County, CO 014-2797 Precipitation Frequency Data Server Page 1 of 3 NOAA Atlas 14, Volume 8, Version 2 Location name: Rifle, Colorado, US* Latitude: 39.5104°, Longitude: -107.7098° Elevation: 5669 ft* * source: Google Maps POINT PRECIPITATION FREQUENCY ESTIMATES rUFNH Sanja Perica, Deborah Martin, Sandra Pavlovic, Ishani Roy, Michael St. Laurent, Carl Trypaluk, Dale Unruh, Michael Yekta, Geoffery Bonnin NOAA, National Weather Service, Silver Spring, Maryland PF tabular 1 PF graphical 1 Maps & aerials PF tabular PDS -based point precipitation frequency estimates with 90% confidence intervals (in inches/hour)1 Duration Average recurrence interval (years) 1 2 5 10 25 50 100 200 500 1000 5 -min 1.38 (1.08-1.74) 1.74 (1.36-2.20) 2.38 (1.85-3.02) 2.96 (2.29-3.79) 3.86 (2.92-5.24) 4.61 (3.38-6.35) 5.42 (3.84-7.68) 6.30 (4.28-9.20) 7.55 (4.92-11.4) 8.56 (5.41-13.0) 10 -min 1.01 (0.786-1.28) 1.27 (0.990-1.61) 1.74 (1.36-2.21) 2.17 (1.68-2.78) 2.83 (2.14-3.84) 3.38 (2.48-4.64) 3.97 (2.81-5.62) 4.61 (3.13-6.74) 5.52 (3.61-8.33) 6.26 (3.97-9.55) 15 -min 0.820 (0.640-1.04) 1.03 (0.804-1.31) 1.42 (1.10-1.80) 1.76 (1.36-2.26) 2.30 (1.74-3.12) 2.74 (2.02-3.78) 3.22 (2.29-4.57) 3.75 (2.55-5.48) 4.49 (2.93-6.78) 5.09 (3.22-7.76) 30 -min 0.530 (0.414-0.672) 0.682 (0.532-0.864) 0.944 (0.734-1.20) 1.18 (0.912-1.51) 1.53 (1.15-2.07) 1.82 (1.33-2.49) 2.12 (1.50-3.00) 2.45 (1.66-3.58) 2.91 (1.90-4.39) 3.28 (2.08-5.00) 60 -min 0.345 (0.270-0.437) 0.429 (0.335-0.544) 0.576 (0.448-0.733) 0.707 (0.546-0.904) 0.900 (0.677-1.21) 1.06 (0.775-1.45) 1.23 (0.867-1.73) 1.41 (0.953-2.05) 1.66 (1.08-2.49) 1.86 (1.18-2.83) 2 -hr 0.212 (0.168-0.267) 0.259 (0.204-0.326) 0.340 (0.266-0.429) 0.412 (0.321-0.522) 0.518 (0.392-0.690) 0.604 (0.446-0.816) 0.695 (0.496-0.967) 0.792 (0.542-1.14) 0.928 (0.610-1.37) 1.04 (0.662-1.55) 3 -hr 0.164 (0.130-0.205) 0.194 (0.153-0.242) 0.245 (0.193-0.308) 0.291 (0.228-0.368) 0.360 (0.275-0.477) 0.417 (0.310-0.559) 0.477 (0.342-0.658) 0.541 (0.373-0.771) 0.631 (0.418-0.928) 0.704 (0.453-1.05) 6 -hr 0.102 (0.081-0.126) 0.118 (0.094-0.146) 0.146 (0.116-0.181) 0.170 (0.134-0.212) 0.204 (0.157-0.266) 0.232 (0.174-0.307) 0.262 (0.189-0.355) 0.292 (0.203-0.409) 0.335 (0.224-0.483) 0.369 (0.240-0.539) 12 -hr 0.061 (0.049-0.075) 0.071 (0.057-0.087) 0.087 (0.070-0.107) 0.101 (0.080-0.125) 0.120 (0.093-0.155) 0.136 (0.103-0.177) 0.152 (0.111-0.204) 0.169 (0.118-0.233) 0.192 (0.130-0.273) 0.210 (0.138-0.302) 24 -hr 0.037 (0.030-0.045) 0.042 (0.034-0.051) 0.051 (0.042-0.063) 0.059 (0.048-0.073) 0.071 (0.055-0.090) 0.080 (0.061-0.103) 0.089 (0.066-0.118) 0.099 (0.070-0.135) 0.113 (0.077-0.158) 0.123 (0.082-0.175) 2 -day 0.021 (0.017-0.026) 0.024 (0.020-0.029) 0.030 (0.024-0.036) 0.034 (0.028-0.041) 0.041 (0.032-0.051) 0.046 (0.035-0.058) 0.051 (0.038-0.067) 0.057 (0.041-0.076) 0.064 (0.044-0.089) 0.070 (0.047-0.098) 3 -day 0.015 (0.012-0.018) 0.018 (0.014-0.021) 0.022 (0.018-0.026) 0.025 (0.020-0.030) 0.030 (0.024-0.037) 0.034 (0.026-0.043) 0.038 (0.028-0.049) 0.042 (0.030-0.055) 0.047 (0.032-0.064) 0.051 (0.035-0.070) 4 -day 0.012 (0.010-0.014) 0.014 (0.012-0.017) 0.017 (0.014-0.021) 0.020 (0.016-0.024) 0.024 (0.019-0.030) 0.027 (0.021-0.034) 0.030 (0.022-0.038) 0.033 (0.024-0.043) 0.037 (0.026-0.050) 0.040 (0.027-0.055) 7 -day 0.008 (0.007-0.010) 0.009 (0.008-0.011) 0.011 (0.009-0.013) 0.013 (0.011-0.015) 0.015 (0.012-0.019) 0.017 (0.013-0.021) 0.019 (0.014-0.024) 0.020 (0.015-0.027) 0.023 (0.016-0.030) 0.025 (0.017-0.033) 10 -day 0.006 (0.005-0.008) 0.007 (0.006-0.009) 0.009 (0.007-0.010) 0.010 (0.008-0.012) 0.011 (0.009-0.014) 0.013 (0.010-0.016) 0.014 (0.010-0.017) 0.015 (0.011-0.019) 0.017 (0.012-0.022) 0.018 (0.012-0.024) 20 -day 0.004 (0.004-0.005) 0.005 (0.004-0.005) 0.005 (0.005-0.006) 0.006 (0.005-0.007) 0.007 (0.006-0.008) 0.008 (0.006-0.009) 0.008 (0.006-0.010) 0.009 (0.007-0.011) 0.010 (0.007-0.013) 0.011 (0.007-0.014) 30 -day 0.003 (0.003-0.004) 0.004 (0.003-0.004) 0.004 (0.004-0.005) 0.005 (0.004-0.006) 0.005 (0.004-0.007) 0.006 (0.005-0.007) 0.006 (0.005-0.008) 0.007 (0.005-0.009) 0.008 (0.005-0.010) 0.008 (0.006-0.010) 45 -day 0.003 (0.002-0.003) 0.003 (0.003-0.003) 0.003 (0.003-0.004) 0.004 (0.003-0.005) 0.004 (0.004-0.005) 0.005 (0.004-0.006) 0.005 (0.004-0.006) 0.006 (0.004-0.007) 0.006 (0.004-0.008) 0.006 (0.004-0.008) 60 -day 0.002 (0.002-0.003) 0.003 (0.002-0.003) 0.003 (0.003-0.004) 0.003 (0.003-0.004) 0.004 (0.003-0.005) 0.004 (0.003-0.005) 0.004 (0.003-0.005) 0.005 (0.004-0.006) 0.005 (0.004-0.007) 0.005 (0.004-0.007) ' Precipitat on frequency (PF) estimates in this table are based on frequency analysis o partial duration series (PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given dura ion and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top PF graphical http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=3 9.5 1 04&lon=- 1 07. 7098&dat... 1/1 5/201 5 Pueblo 0 Map dat 2961a ldovkp 5,101) Precipitation Frequency Data Server 1.000 Precipitation intensity finlhrl Precipitation intensity {inlhr} 0.100 0.010 0.001 c E E E 10.000 1.000 0.100 0.010 A Duration A - re m re ro re re re re re � v v -o 7 rs 4'?p fv r d•i 4 r 6 6 A'1 L �O 2 5 10 25 50 'Sack 1004 200 Average recurrence interval {rs! Top ur Maps&a OrriSr). Thu Jan 15 16.33.39 2015 NOAA Atlas 14. Volume 8, Version 2 500 1000 Small scale terrain Page 2 of 3 Average recurrence interval (years) — 1 2 — 5 — 10 — 25 — 50 — 100 — 200 — 500 — 1000 Duration — 5 -min 2-09y — 10-inrr1 — 3 -clay 15 -min --- 4 -clay - 30 -mm — T-0ay — 60 -nom — 10 -Clay — 2411 — 20 -day - 3411 — 30-oay - 6-nr — 45 -nay — 12 -hr — 60 --day 24 -hr AS1rie1 ^Ja!ic!ri rrel +Boit CWWIins Greeley vEland° ° a4 L• 4n gm°nt o ▪ pEtoulder `,4.Denver St-- '. L ittleton° 0 ,;.Centenni a I �rry� b Colorado Springs San rs+b& Nationa7'Forest ' ! J Ga non Cily Uncompahgre rfari°na! Forest `SQ Large scale terrain http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=3 9.5104&ton=-107.7098&dat... 1/1 5/201 5 Precipitation Frequency Data Server Page 3 of 3 Hire Y i ff: 1,1 : r Sill '1--- f"' ). _ 3' ' Regwnal A9rpprt� �+` Ae — =1 Ela 0 r. lana.. cct .k; Bil 13191 2 km 1 Silt Egi Large scale aerial Map datirktafiiaPeogie Back to Top US Department of Commerce National Oceanic and Atmospheric Administration National Weather Service Office of Hydrologic Development 1325 East West Highway Silver Spring, MD 20910 Questions?: HDSC.Questions(anoaa.gov Disclaimer http://hdsc.nws.noaa.gov/hdsc/pfds/pfdsprintpage.html?lat=3 9.5104&lon=-107.7098&dat... 1 /1 5/201 5 0.35 0.42 CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: Catchment ID: Encana K19NE Storage Yard A I. Catchment Hydrologic Data Catchment ID = Area = Percent Imperviousness = NRCS Soil Type = A 1.73 40.00 C Acres A, B, C, or D II. Rainfall Information I (inch/hr) = Cl * P1 /(C2 + Td)AC3 Design Storm Return Period, Tr = 01 = C2= C3= P1= 10 28.90 10.00 0.786 0.71 years (input return period for design storm) (input the value of 01) (input the value of C2) (input the value of C3) inches (input one -hr precipitation --see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = Overide Runoff Coefficient, C = 5 -yr. Runoff Coefficient, C-5 = Overide 5 -yr. Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration NRCS Land Type Heavy Meadow Tillage/ Field Short Pasture/ Lawns Nearly Bare Ground Grassed Swales/ Waterways Paved Areas & Shallow Paved Swales (Sheet Flow) Conveyance 2.5 5 7 10 15 20 Calculations: I Overland Slope S ft/ft input 0.0020 1 1 0.0020 Length L ft input 5 -yr Runoff Coeff C-5 output 300 NRCS Convey- ance input Flow Velocity V fps output Flow Time Tf minutes output 0.351 N/A 1 0.13 39.96 57 2 3 4 5 Sum 357 IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = Rainfall Intensity at Regional Tc, I = Rainfall Intensity at User -Defined Tc, I = 0.92 1.81 0.92 10.00 1 0.45 2.12 Computed Tc = Regional Tc = User -Entered Tc = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = 42.08 11.98 42.08 0.66 1.30 0.66 cfs cfs cfs UD -Rational v1.02a - BASIN A 10YR, Tc and PeakQ 1/15/2015, 9:30 AM 0.35 0.58 CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: Catchment ID: Encana K19NE Storage Yard A I. Catchment Hydrologic Data Catchment ID = Area = Percent Imperviousness = NRCS Soil Type = A 1.73 40.00 C Acres A, B, C, or D II. Rainfall Information I (inch/hr) = Cl * P1 /(C2 + Td)AC3 Design Storm Return Period, Tr = C1 = C2= C3= P1= 100 28.90 10.00 0.786 1.23 years (input return period for design storm) (input the value of C1) (input the value of C2) (input the value of C3) inches (input one -hr precipitation --see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = Overide Runoff Coefficient, C = 5 -yr. Runoff Coefficient, C-5 = Overide 5 -yr. Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration NRCS Land Type Heavy Meadow Tillage/ Field Short Pasture/ Lawns Nearly Bare Ground Grassed Swales/ Waterways Paved Areas & Shallow Paved Swales (Sheet Flow) Conveyance 2.5 5 7 10 15 20 Calculations: I Overland Slope S ft/ft input 0.0020 1 1 0.0020 Length L ft input 5 -yr Runoff Coeff C-5 output 300 NRCS Convey- ance input Flow Velocity V fps output Flow Time Tf minutes output 0.351 N/A 1 0.13 39.96 57 2 3 4 5 Sum 357 IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = Rainfall Intensity at Regional Tc, I = Rainfall Intensity at User -Defined Tc, I = 1.59 3.13 1.59 10.00 1 0.45 2.12 Computed Tc = Regional Tc = User -Entered Tc = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = 42.08 11.98 42.08 1.60 3.16 1.60 cfs cfs cfs UD -Rational v1.02a - BASIN A 100YR, Tc and PeakQ 1/15/2015, 9:30 AM 0.16 0.26 CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: Catchment ID: Encana K19NE Storage Yard OS -1 I. Catchment Hydrologic Data Catchment ID = Area = Percent Imperviousness = NRCS Soil Type = OS -1 1.52 2.00 C Acres A, B, C, or D II. Rainfall Information I (inch/hr) = Cl * P1 /(C2 + Td)AC3 Design Storm Return Period, Tr = 01 = C2= C3= P1= 10 28.90 10.00 0.786 0.71 years (input return period for design storm) (input the value of 01) (input the value of C2) (input the value of C3) inches (input one -hr precipitation --see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = Overide Runoff Coefficient, C = 5 -yr. Runoff Coefficient, C-5 = Overide 5 -yr. Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration NRCS Land Type Heavy Meadow Tillage/ Field Short Pasture/ Lawns Nearly Bare Ground Grassed Swales/ Waterways Paved Areas & Shallow Paved Swales (Sheet Flow) Conveyance 2.5 5 7 10 15 20 Calculations: I Overland Slope S ft/ft input 0.0270 1 1 0.0780 Length L ft input 5 -yr Runoff Coeff C-5 output NRCS Convey- ance input Flow Velocity V fps output Flow Time Tf minutes output 300 0.16 0.24 21.11 2 1 0.0150 3 1 0.0030 40 60 100 4 5 Sum 500 IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = Rainfall Intensity at Regional Tc, I = Rainfall Intensity at User -Defined Tc, I = 1.25 1.76 1.76 10.00 10.00 10.00 2.79 1.22 0.55 0.24 0.82 3.04 Computed Tc = Regional Tc = User -Entered Tc = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = 25.21 12.78 12.78 0.50 0.70 0.70 cfs cfs cfs UD -Rational v1.02a - BASIN OS -1 10YR, Tc and PeakQ 1/15/2015, 9:29 AM 0.16 0.51 CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: Catchment ID: Encana K19NE Storage Yard OS -1 I. Catchment Hydrologic Data Catchment ID = Area = Percent Imperviousness = NRCS Soil Type = OS -1 1.52 2.00 C Acres A, B, C, or D II. Rainfall Information I (inch/hr) = Cl * P1 /(C2 + Td)AC3 Design Storm Return Period, Tr = C1 = C2= C3= P1= 100 28.90 10.00 0.786 1.23 years (input return period for design storm) (input the value of C1) (input the value of C2) (input the value of C3) inches (input one -hr precipitation --see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = Overide Runoff Coefficient, C = 5 -yr. Runoff Coefficient, C-5 = Overide 5 -yr. Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration NRCS Land Type Heavy Meadow Tillage/ Field Short Pasture/ Lawns Nearly Bare Ground Grassed Swales/ Waterways Paved Areas & Shallow Paved Swales (Sheet Flow) Conveyance 2.5 5 7 10 15 20 Calculations: I Overland Slope S ft/ft input 0.0270 1 1 0.0780 Length L ft input 5 -yr Runoff Coeff C-5 output NRCS Convey- ance input Flow Velocity V fps output Flow Time Tf minutes output 300 0.16 0.24 21.11 2 1 0.0150 3 1 0.0030 40 60 100 4 5 Sum 500 IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = Rainfall Intensity at Regional Tc, I = Rainfall Intensity at User -Defined Tc, I = 2.16 3.05 3.05 10.00 10.00 10.00 2.79 1.22 0.55 0.24 0.82 3.04 Computed Tc = Regional Tc = User -Entered Tc = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = 25.21 12.78 12.78 1.67 2.35 2.35 cfs cfs cfs UD -Rational v1.02a - BASIN 05-1 100YR, Tc and PeakQ 1/15/2015, 9:28 AM 0.16 0.26 CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: Catchment ID: Encana K19NE Storage Yard OS -2 I. Catchment Hydrologic Data Catchment ID = Area = Percent Imperviousness = NRCS Soil Type = OS -2 2.99 2.00 C Acres A, B, C, or D II. Rainfall Information I (inch/hr) = Cl * P1 /(C2 + Td)AC3 Design Storm Return Period, Tr = 01 = C2= C3= P1= 10 28.90 10.00 0.786 0.71 years (input return period for design storm) (input the value of 01) (input the value of C2) (input the value of C3) inches (input one -hr precipitation --see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = Overide Runoff Coefficient, C = 5 -yr. Runoff Coefficient, C-5 = Overide 5 -yr. Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration NRCS Land Type Heavy Meadow Tillage/ Field Short Pasture/ Lawns Nearly Bare Ground Grassed Swales/ Waterways Paved Areas & Shallow Paved Swales (Sheet Flow) Conveyance 2.5 5 7 10 15 20 Calculations: I Overland Slope S ft/ft input 0.0240 1 1 0.0270 Length L ft input 5 -yr Runoff Coeff C-5 output 300 NRCS Convey- ance input Flow Velocity V fps output Flow Time Tf minutes output 0.161 N/A 1 0.23 21.95 330 2 3 4 5 Sum 630 IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = Rainfall Intensity at Regional Tc, I = Rainfall Intensity at User -Defined Tc, I = 1.25 1.72 1.25 10.00 1 1.64 3.35 Computed Tc = Regional Tc = User -Entered Tc = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = 25.29 13.50 25.29 0.97 1.34 0.97 cfs cfs cfs UD -Rational v1.02a - BASIN OS -2 10YR, Tc and PeakQ 1/15/2015, 9:26 AM 0.16 0.51 CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: Catchment ID: Encana K19NE Storage Yard OS -2 I. Catchment Hydrologic Data Catchment ID = Area = Percent Imperviousness = NRCS Soil Type = OS -2 2.99 2.00 C Acres A, B, C, or D II. Rainfall Information I (inch/hr) = Cl * P1 /(C2 + Td)AC3 Design Storm Return Period, Tr = C1 = C2= C3= P1= 100 28.90 10.00 0.786 1.23 years (input return period for design storm) (input the value of C1) (input the value of C2) (input the value of C3) inches (input one -hr precipitation --see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = Overide Runoff Coefficient, C = 5 -yr. Runoff Coefficient, C-5 = Overide 5 -yr. Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration NRCS Land Type Heavy Meadow Tillage/ Field Short Pasture/ Lawns Nearly Bare Ground Grassed Swales/ Waterways Paved Areas & Shallow Paved Swales (Sheet Flow) Conveyance 2.5 5 7 10 15 20 Calculations: I Overland Slope S ft/ft input 0.0240 1 1 0.0270 Length L ft input 5 -yr Runoff Coeff C-5 output 300 NRCS Convey- ance input Flow Velocity V fps output Flow Time Tf minutes output 0.161 N/A 1 0.23 21.95 330 2 3 4 5 Sum 630 IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = Rainfall Intensity at Regional Tc, I = Rainfall Intensity at User -Defined Tc, I = 2.16 2.97 2.16 10.00 1 1.64 3.35 Computed Tc = Regional Tc = User -Entered Tc = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = inch/hr Peak Flowrate, Qp = 25.29 13.50 25.29 3.28 4.51 3.28 cfs cfs cfs UD -Rational v1.02a - BASIN OS -2 100YR, Tc and PeakQ 1/15/2015, 9:26 AM FINAL DRAINAGE REPORT APPENDIX C: HYDRAULIC CALCULATIONS Encana Oil and Gas - K19NE Storage Yard Garfield County, CO 014-2797 FINAL DRAINAGE REPORT THIS PAGE LEFT BLANK FOR TWO-SIDED DUPLICATION. Encana Oil and Gas - K19NE Storage Yard Garfield County, CO 014-2797 DETENTION VOLUME BY THE MODIFIED FAA METHOD Project: Encana K19NE Basin ID: A (For catchments less than 160 acres only. For larger catchments, use hydrograph routing method) (NOTE: for catchments larger than 90 acres, CUHP hydrograph and routing are recommended) Determination of MINOR Detention Volume Using Modified FAA Method Determination of MAJOR Detention Volume Using Modified FAA Method Design Information (Input): I,= A = Type = T = Tc = q = Pr = Cr = Cr = C3= percent acres A, B, C, or D years (2, 5, 10, 25, 50, or 100) Design Information (Input): I,= A = Type = T =1 Tc = q = Pr = Cr= Cr = C3= 40.00 percent acres A, B, C, or D (years (2, 5, 10, 25, 50, or 100) minutes cfs/acre inches Catchment Drainage Imperviousness Catchment Drainage Area Predevelopment NRCS Soil Group Return Period for Detention Control Time of Concentration of Watershed Allowable Unit Release Rate One-hour Precipitation Design Rainfall IDF Formula 1=Cr*P.,/(Cr+Tc)^C3 Coefficient One Coefficient Two Coefficient Three 40.00 Catchment Drainage Imperviousness Catchment Drainage Area Predevelopment NRCS Soil Group Return Period for Detention Control Time of Concentration of Watershed Allowable Unit Release Rate One-hour Precipitation Design Rainfall IDF Formula 1=C"Pr/(Cr+Tr)^C3 Coefficient One Coefficient Two Coefficient Three 1.730 1.730 C C 10 100 12 minutes cfs/acre inches 12 0.12 0.50 0.71 1.23 28.50 28.50 10 10 0.789 0.789 Determination of Average Outflow from the Basin (Calculated): cfs cfs cubic feet acre -ft 5 -Minutes) Determination of Average Outflow from the Basin (Calculated): cfs cfs cubic feet acre -ft Runoff Coefficient Inflow Peak Runoff Allowable Peak C = Qp-in = Outflow Rate Qp-out = Mod. FAA Minor Storage Volume= Mod. FAA Minor Storage Volume= <- Enter Rainfall Duration Incremental Increase Value 0.42 Runoff Coefficient C = Inflow Peak Runoff Qp-in = Allowable Peak Outflow Rate Qp-out = Mod. FAA Major Storage Volume= Mod. FAA Major Storage Volume= 0.58 1.28 3.07 0.21 0.87 1,465 2,570 0.034 0.059 5 Here (e.g. 5 for Rainfall Duration minutes (input) Rainfall Intensity inches / hr (output) Inflow Volume acre-feet (output) Adjustment Factor "m" (output) Average Outflow cfs (output) Outflow Volume acre-feet (output) Storage Volume acre-feet (output) Rainfall Duration minutes (input) Rainfall Intensity inches / hr (output) Inflow Volume acre-feet (output) Adjustment Factor "m" (output) Average Outflow cfs (output) Outflow Volume acre-feet (output) Storage Volume acre-feet (output) 0 0.00 0.000 0.00 0.00 0.000 0.000 0 0.00 0.000 0.00 0.00 0.87 0.87 0.78 0.000 0.000 5 2.39 0,012 1.00 021 0.001 0.011 5 4.14 0.029 1.00 0.006 0.023 10 1.90 0.019 1.00 0.21 0.003 0.016 10 3.30 0.046 1.00 0.012 0.034 15 1.60 0,024 0.90 0.19 0.004 0.020 15 2.77 0.057 0.90 0.016 0.041 20 1.38 0.028 0.80 0.17 0.005 0.023 20 2.39 0.066 0.80 0.69 0.019 0.047 25 1.22 0,031 0.74 0.15 0.005 0.025 25 2.12 0.073 0.74 0.64 0.022 0.051 30 1.10 0.033 0.70 0.15 0.006 0.027 30 1.91 0.079 0.70 0.61 0.025 0.054 35 1.00 0.035 0,67 0.14 0.007 0.028 35 1.74 0.084 0.67 0.58 0.028 0.056 40 0.92 0.037 0.65 0.13 0.007 0.030 40 1.60 0.088 0.65 0.56 0.031 0.058 45 0.88 0.039 0,63 0.13 0.008 0.030 45 1.48 0.092 0.63 0.55 0.034 0.058 50 0.80 0.040 0.62 0.13 0.009 0.031 50 1.39 0.096 0.62 0.54 0.037 0.059 55 0.75 0.041 0,61 0.13 0.010 0.032 55 1.30 0.099 0.61 0.53 0.040 0.059 60 0.71 0.043 0.60 0.12 0.010 0.032 60 123 0.102 0.60 0.52 0.043 0.059 65 0.67 0.044 0.59 0.12 0.011 0.033 65 1.16 0.104 0.59 0.51 0.046 0.059 70 0.64 0.045 0.59 0.12 0.012 0.033 70 1.10 0.107 0.59 0.51 0.049 0.058 75 0.61 0.046 0.58 0.12 0.012 0.033 75 1.05 0.109 0.58 0.50 0.052 0.057 80 0.58 0.047 0.58 0.12 0.013 0.033 0.033 0.034 0.034 80 1.01 0.111 0.58 0.50 0.055 0.056 85 90 0.58 0.047 0.57 0.12 0.014 85 0.96 0.113 0.57 0.49 0.058 0.056 0.53 0.048 0.57 0.12 0.015 90 0.93 0.115 0.57 0.49 0.061 0.054 95 0.51 0.049 0.56 0.12 0.015 95 0.89 0.117 0.56 0.49 0.064 0.053 100 0.50 0.050 0.56 0.12 0.016 0.034 100 0.86 0.119 0.56 048 0.067 0.052 105 0.48 0.050 0.56 0.12 0.017 0.034 105 0.83 0.120 0.56 0.48 0.070 0.051 110 0.46 0.051 0.55 0.12 0.017 0.034 110 0.80 0.122 0.55 048 0.073 0.049 115 0.45 0.052 0.55 0.11 0.018 0.033 115 0.78 0.123 0.55 0.48 0.076 0.048 120 0.43 0.052 0.55 0.11 0.019 0.033 120 0.75 0.125 0.55 048 0.079 0.048 125 0.42 0.053 0.55 0.11 0.020 0.033 125 0.73 0.126 0.55 0.47 0.082 0.045 130 0.41 0.053 0.55 0.11 0.020 0.033 130 0.71 0.128 0.55 0.47 0.085 0.043 135 0.40 0.054 0.54 0.11 _ 0.021 0.033 135 0.69 0.129 0.54 0.47 0.088 0.041 140 0.39 0.054 0.54 0.11 0.022 0.033 140 0.67 0.130 0.54 0.47 0.091 0.040 145 0.38 0.055 0.54 0.11 _ 0.022 0.032 145 0.66 0.131 0.54 0.47 0.094 0.038 150 0.37 0.055 0.54 0.11 0.023 0.032 150 0.64 0.133 0.54 0.47 0.097 0.038 155 0.38 0.056 0.54 0.11 _ 0.024 0.032 155 0.62 0.134 0.54 0.47 0.099 0.034 160 0.35 0.056 0.54 0.11 0.025 0.032 160 0.61 0.135 0.54 0.46 0.102 0.032 165 0.34 0.057 0.54 0.11 _ 0.025 0.031 165 0.60 0.136 0.54 0.46 0.105 0.030 170 0.34 0.057 0.54 0.11 0.026 0.031 170 0.58 0.137 0.54 0.46 0.108 0.028 175 0.33 0.058 0.53 0.11 _ 0.027 0.031 175 0.57 0.138 0.53 0.46 0.111 0.026 180 0.32 0.058 0.53 0.11 0.027 0.031 180 0.56 0.139 0.53 0.46 0.114 0.024 185 0.32 0.058 0.53 0.11 _ 0.028 0.030 185 0.55 0.140 0.53 0.46 0.117 0.022 190 0.31 0.059 0.53 0.11 0.029 0.030 190 0.54 0.141 0.53 0.46 0.120 0.020 195 0.30 0.059 0.53 0.11 _ 0.030 0.030 195 0.53 0.142 0.53 0.46 0.123 0.018 200 0.30 0.060 0.53 0.11 0.030 0.029 200 0.52 0.143 0.53 0.46 0.126 0.016 205 029 0.060 0.53 0.11 _ 0.031 0.029 205 0.51 0.143 0.53 0.46 0.129 0.014 210 0.29 0.060 0.53 0.11 0.032 0.029 210 0.50 0.144 0.53 0.46 0.132 0.012 215 028 0.061 0.53 0.11 _ 0.032 0.028 215 0.49 0.145 0.53 0.46 0.135 0.010 220 0.28 0.061 0.53 0.11 0.033 0.028 220 0.48 0.146 0.53 0.46 0.138 0.008 225 027 0.061 0.53 0.11 _ 0.034 0.027 225 0.47 0.147 0.53 0.46 0.141 0.006 230 0.27 0.062 0.53 0.11 0.035 0.027 230 0.46 0.148 0.53 0.46 0.144 0.003 235 0.28 0.062 0.53 0.11 _ 0.035 0.027 235 0.46 0.148 0.53 0.45 0.147 0.001 240 0.26 0.062 0.53 0.11 0.036 0.026 240 0.45 0.149 0.53 0.45 0.45 0.150 -0.001 245 0.28 0.063 0.52 0.11 _ 0.037 0.026 245 0.44 0.150 0.52 0.153 -0.003 250 0.25 0.063 0.52 0.11 0.037 0.025 250 0.44 0.151 0.52 0.45 0.45 0.156 -0.005 255 025 0.063 0.52 0.11 _ 0.038 0.025 255 0.43 0.151 0.52 0.159 -0.008_ 260 0.24 0.064 0.52 0.11 _ 0.039 0.025 260 0.42 0.152 0.52 0.45 0.162 -0.010 -0.012_ 265 024 0.064 0.52 0.11 0.040 0.024 265 0.42 0.153 0.52 0.45 0.165 270 0.24 0.064 0.52 0.11 0.040 0.024 270 0.41 0.153 0.52 045 0.168 -0.015 -0.017_ 275 0.23 0.064 0.52 0.11 0.041 0.023 275 0.41 0.154 0.52 0.45 0.171 280 0.23 0.065 0.52 0.11 0.042 0.023 280 0.40 0.155 0.52 045 0.174 -0.019 -0.022 285 023 0.065 0.52 0.11 0.042 0.022 285 0.39 0.155 0.52 0.45 0.177 290 0.22 0.065 0.52 0.11 0.043 0.022 290 0.39 0.156 0.52 045 0.180 -0.024 295 022 0.065 0.52 0.11 0.044 0.022 295 0.38 0.157 0.52 0.45 0.183 -0.028 300 0.22 0.066 0.52 0.11 0.045 0.021 300 0.38 0.157 0.52 0.45 0.186 -0.029 UD -Detention v2.34 BASIN A - OVAL, Modified FAA Mod. FAA Minor Storage Volume (cubic ft.)= 1,465 Mod. FAA Major Storage Volume (cubic ft.)= 2,570 Mod. FAA Minor Storage Volume (acre -ft.)= 0.0336 Mod. FAA Major Storage Volume (acre -ft.). 0.0590 UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.34, Released November 2013 1/15/2015, 9:22 AM J DETENTION VOLUME BY THE MODIFIED FAA METHOD Project: Encana K19NE Basin ID: A Volume (acre-feet) 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 0 Inflow and Outflow Volumes vs. Rainfall Duration 50 100 150 200 Duration (Minutes) 250 300 •Minor Storm Inflow Volume - Minor Storm Outflow Volume o Minor Storm Storage Volume •neMajor Storm Inflow Volume +Major Storm Outflow Volume • Major Storm Storage Volume 350 UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.34, Released November 2013 UD -Detention v2.34 BASIN A - OVAL, Modified FAA 1/15/2015, 9:22 AM • • • •• tho • sOO O 000000OOOOOOOOOOOO •• pEei•O::- BOO _ - oo OOpp OOO 0000000 50 100 150 200 Duration (Minutes) 250 300 •Minor Storm Inflow Volume - Minor Storm Outflow Volume o Minor Storm Storage Volume •neMajor Storm Inflow Volume +Major Storm Outflow Volume • Major Storm Storage Volume 350 UDFCD DETENTION BASIN VOLUME ESTIMATING WORKBOOK Version 2.34, Released November 2013 UD -Detention v2.34 BASIN A - OVAL, Modified FAA 1/15/2015, 9:22 AM STAGE -STORAGE SIZING FOR DETENTION BASINS Project: Encana K19NE Storage Yard Basin ID: A Design Information (Input): Width of Basin Bottom, W = Length of Basin Bottom, L = Dam Side -slope (H:V), Zd = Stage -Storage Relationship: 14.00 30.00 3.00 Side Slope Z ft ft ftJft Side Slope Z Check Basin Shape Right Triangle OR... Isosceles Triangle OR... Rectangle OR... Circle / Ellipse X OR... Irregular (Use Overide values in cells G32:G52) Storage Requirement from Sheet 'Modified FAA': Storage Requirement from Sheet 'Hydrograph': Storage Requirement from Sheet 'Fu l -Spectrum': MINOR MAJOR 0.03 0.06 acre -ft. acre -ft. acre -ft. Labels for WQCV, Minor, & Major Storage Stages (input) Water Surface Elevation ft (input) Side Slope (H:V) ft/ft Below El. (input) Basin Width at Stage ft (output) Basin Length at Stage ft (output) Surface Area at Stage ft2 (output) Surface Area at Stage ft2 User Overide Volume Below Stage ft' (output) Surface Area at Stage acres (output) Volume Below Stage acre -ft (output) Target Volumes for WQCV, Minor, & Major Storage Volumes (for goal seek) 5666.00 14.00 30.00 329.9 0.008 0.000 5666.25 3.00 15.50 31.50 383.5 89 0.009 0.002 5666.50 3.00 17.00 33.00 440.6 192 0.010 0.004 5666.75 3.00 18.50 34.50 501.3 310 0.012 0.007 5667.00 3.00 20.00 36.00 565.5 443 0.013 0.010 5667.25 3.00 21.50 37.50 633.2 593 0.015 0.014 5667.50 3.00 23.00 39.00 704.5 760 0.016 0.017 5667.75 3.00 24.50 40.50 779.3 946 0.018 0.022 5668.00 3.00 26.00 42.00 857.7 1,150 0.020 0.026 MINOR 5668.25 3.00 27.50 43.50 939.5 1,375 0.022 0.032 5668.50 3.00 29.00 45.00 1,024.9 1,621 0.024 0.037 5668.75 3.00 30.50 46.50 1,113.9 1,888 0.026 0.043 5669.00 3.00 32.00 48.00 1,206.4 2,178 0.028 0.050 5669.25 3.00 33.50 49.50 1,302.4 2,492 0.030 0.057 MAJOR 5669.50 3.00 35.00 51.00 1,401.9 2,830 0.032 0.065 5669.75 3.00 36.50 52.50 1,505.0 3,193 0.035 0.073 WEIR CREST 5670.00 3.00 38.00 54.00 1,611.6 3,583 0.037 0.082 5670.25 3.00 39.50 55.50 1,721.8 3,999 0.040 0.092 TOP 5670.50 3.00 41.00 57.00 1,835.5 4,444 0.042 0.102 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #NIA #N/A #NIA #N/A #NIA #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A UD -Detention v2.34 BASIN A - OVAL, Basin 1/15/2015, 9:23 AM STAGE -STORAGE SIZING FOR DETENTION BASINS Project: Basin ID: 5671.00 STAGE -STORAGE CURVE FOR THE POND 5670.50 5670.00 5669.50 5669.00 > w TD 6 5668.50 d En t4 r� 5668.00 5667.50 5667.00 5666.50 5666.00 0.00 0.02 0.04 0.06 0.08 0.10 0.12 Storage (acre-feet) UD -Detention v2.34 BASIN A - OVAL, Basin 1/15/2015, 9:23 AM RESTRICTOR PLATE SIZING FOR CIRCULAR VERTICAL ORIFICES Project: Encana K19NE Storage Yard Basin ID: A - 100 YR RELEASE RATE CULVERT FROM POND STRUCTURE X Dla� To Sizing the Restrictor Plate for Circular Vertical Orifices or Pipes (Input) Water Surface Elevation at Design Depth PipeNertical Orifice Entrance Invert Elevation Required Peak Flow through Orifice at Design Depth PipeNertical Orifice Diameter (inches) Orifice Coefficient Full -flow Capacity (Calculated) Full -flow area Half Central Angle in Radians Full -flow capacity Calculation of Orifice Flow Condition Half Central Angle (0<Theta<3.1416) Flow area Top width of Orifice (inches) Height from Invert of Orifice to Bottom of Plate (feet) Elevation of Bottom of Plate Resultant Peak Flow Through Orifice at Design Depth Width of Equivalent Rectangular Vertical Orifice 0 Elev: WS = Elev: Invert = Q= Dia = Co = Af = Theta = Qf = Percent of Design Flow = Theta = Ao = To = Yo = Elev Plate Bottom Edge = Q. = #1 Vertical Orifice #2 Vertical Orifice 5,670.00 5,666.00 0.87 12.0 0.65 0.79 3.14 7.7 880% 0.84 0.08 8.90 0.16 5,666.16 0.9 Equivalent Width = 0.50 feet feet cfs inches sq ft rad cfs rad sq ft inches feet feet cfs feet UD-Detention_v2.34 BASIN A - OVAL, Restrictor Plate 1/15/2015, 9:23 AM STAGE -DISCHARGE SIZING OF THE SPILLWAY Project: Encana K19NE Basin ID: A angk +ebglu0 IS Or f1EIR CREST a�elF.t' w�a. Design Information (input): Bottom Length of Weir Angle of Side Slope Weir Elev. for Weir Crest Coef. for Rectangular Weir Coef. for Trapezoidal Weir Calculation of Spillway Capacity (output): L= Angle = EL. Crest = Cw = C= 3.00 14.04 5,670.00 3.34 3.34 Water Surface Elevation ft. (linked) Rect. Weir Flowrate cfs (output) Triangle Weir Flowrate cfs (output) Total Spillway Release cfs (output) Total Pond Release cfs (output) 5666.00 0.00 0.00 0.00 #N/A 5666.25 0.00 0.00 0.00 #N/A 5666.50 0.00 0.00 0.00 #N/A 5666.75 0.00 0.00 0.00 #N/A 5667.00 0.00 0.00 0.00 #N/A 5667.25 0.00 0.00 0.00 #N/A 5667.50 0.00 0.00 0.00 #N/A 5667.75 0.00 0.00 0.00 #N/A 5668.00 0.00 0.00 0.00 #N/A 5668.25 0.00 0.00 0.00 #N/A 5668.50 0.00 0.00 0.00 #N/A 5668.75 0.00 0.00 0.00 #N/A 5669.00 0.00 0.00 0.00 #N/A 5669.25 0.00 0.00 0.00 #N/A 5669.50 0.00 0.00 0.00 #N/A 5669.75 0.00 0.00 0.00 #N/A 5670.00 0.00 0.00 0.00 #N/A 5670.25 1.25 0.03 1.28 #N/A 5670.50 3.54 0.15 3.69 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #NIA #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #NIA #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #NIA #N/A #N/A #NIA #N/A #N/A #NIA #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #NIA #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #NIA #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A feet degrees feet UD-Detention_v2.34 BASIN A - OVAL, Spillway 1/15/2015, 9:24 AM RESTRICTOR PLATE SIZING FOR CIRCULAR VERTICAL ORIFICES Project: Encana K19NE Storage Yard Basin ID: A X Dla� To Sizing the Restrictor Plate for Circular Vertical Orifices or Pipes (Input) Water Surface Elevation at Design Depth Pipe/Vertical Orifice Entrance Invert Elevation Required Peak Flow through Orifice at Design Depth PipeNertical Orifice Diameter (inches) Orifice Coefficient Full -flow Capacity (Calculated) Full -flow area Half Central Angle in Radians Full -flow capacity Calculation of Orifice Flow Condition Half Central Angle (0<Theta<3.1416) Flow area Top width of Orifice (inches) Height from Invert of Orifice to Bottom of Plate (feet) Elevation of Bottom of Plate Resultant Peak Flow Through Orifice at Design Depth Width of Equivalent Rectangular Vertical Orifice 0 Elev: WS = Elev: Invert = Q= Dia = Co = Af = Theta = Qf = Percent of Design Flow = Theta = Ao = To = Yo = Elev Plate Bottom Edge = Q. = #1 Vertical Orifice #2 Vertical Orifice 5,668.50 5,666.00 0.21 4.0 0.65 0.09 3.14 0.7 333% 1.24 0.03 3.78 0.11 5,666.11 0.2 Equivalent Width = 0.27 feet feet cfs inches sq ft rad cfs rad sq ft inches feet feet cfs feet UD-Detention_v2.34 BASIN A - OVAL 10YR ORIFICE CALC, Restrictor Plate 1/15/2015, 9:20 AM SECTION A -A RUN-ON BERM Project Description Friction Method Solve For Manning Formula Normal Depth Input Data Roughness Coefficient 0.030 Channel Slope 0,00150 ft/ft Left Side Slope 2.4D ft/ft (H:V) Right Side Slope 67.00 ft/ft (H:V) Discharge 2.35 ft3/s Resu Its Normal Depth 0.34 ft Flow Area 4.00 ft2 Wetted Perimeter 23.64 ft Hydraulic Radius 0.17 ft Top Width 23.57 ft Critical Depth 0.20 ft Critical Slope 0.02859 f fft Velocity 0.59 ftjs Velocity Head 0.01 ft Specific Energy 0.34 ft Froude Number 0.25 Flow Type Subcritical GVF Input Data Downstream Depth Length Number Of Steps 0.00 ft 0.00 ft 0 GVF Output Data Upstream Depth Profile Description Profile Headloss Downstream Velocity Upstream Velocity Normal Depth Critical Depth Channel Slope Critical Slope 0.00 ft 0.00 ft Infinity ft/s Infinity ft/s 0.34 ft 0.20 ft 0.00150 ft/ft 0.02859 ft/ft Bentley Systems, Inc. Haestad Methods Solditimill9pfftewMaster V8i (SELECTseries 1) [08.11.01.03] 11812015 8:09:50 AM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 SECTION B -B PAD BERM Project Description Friction Method Manning Formula Solve For Normal Depth Input Data Roughness Coefficient 0.033 Channel Slope 0.00300 ft/ft Left Side Slope 200.00 ft/ft (H:V) Right Side Slope 2.30 ft/ft (H:V) Discharge 3.16 ft'/s Results Normal Depth 0.23 ft Flow Area 5.40 ft2 Wetted Perimeter 46.78 ft Hydraulic Radius 0.12 ft Top Width 46.73 ft Critical Depth 0.14 ft Critical Slope 0.03823 ft/ft Velocity 0.59 ft/s Velocity Head 0.01 ft Specific Energy 0.24 ft Fronde Number 0.30 Flow Type Subcritical GVF Input Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Downstream Velocity Infinity ftls Upstream Velocity Infinity ftls Normal Depth 0.23 ft Critical Depth 0.14 ft Channel Slope 0.00300 ft/ft Critical Slope 0.03823 ft/ft Bentley Systems, Inc. Haestad Methods Solitl€efftewMaster V8i (SELECTseries 1) [08.11.01.031 118/2015 8:10:11 AM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 SECTION C -C RUN-ON BERM Project Description Friction Method Manning Formula Solve For Normal Depth Input Data Roughness Coefficient 0.030 Channel Slope 0.00500 ftift Left Side Slope 3.00 ft/ft (H:V) Right Side Slope 33.00 ft/ft (H:V) Discharge 3.28 ft'Is Results Normal Depth 0.39 ft Flow Area 2.78 ft2 Wetted Perimeter 14.22 ft Hydraulic Radius 0.20 ft Top Width 14.15 ft Critical Depth 0.29 ft Critical Slope 0.02512 ft/ft Velocity 1.18 ft!s Velocity Head 0.02 ft Specific Energy 0.41 ft Fronde Number 0.47 Flow Type Subcritical GVF Input Data Downstream Depth Length Number Of Steps 0.00 ft 0.00 ft 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Downstream Velocity Infinity ft/s Upstream Velocity Infinity ftis Normal Depth 0.39 ft Critical Depth 0.29 ft Channel Slope 0.00500 ft/ft Critical Slope 0.02512 ftlft Bentley Systems, Inc. Haestad Methods SoldittortlepFtewMaster V81 (SELECTseries 1) (08.11.01.03] 1/712015 1:19:20 PM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 SECTION D -D SWALE TO POND Project Description Friction Method Solve For Manning Formula Normal Depth Input Data Roughness Coefficient 0.030 Channel Slope 0.01500 ft/ft Left Side Slope 3.00 ft/ft (H:V) Right Side Slope 3.00 ft/ft (H:V) Bottom Width 3.00 ft Discharge 3.16 fts/s Results Normal Depth 0.33 ft Flow Area 1.29 ft2 Wetted Perimeter 5.06 ft Hydraulic Radius 0.26 ft Top Width 4.95 ft Critical Depth 0.29 ft Critical Slope 0.02169 ft/ft Velocity 2.44 ft/s Velocity Head 0.09 ft Specific Energy 0.42 ft Froude Number 0.84 Flow Type Subcriticai GVF Input Data Downstream Depth Length Number Of Steps 0.00 ft 0.00 ft 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s Normal Depth 0.33 ft Critical Depth 0.29 ft Channel Slope 0.01500 fitft Bentley Systems, Inc. Haestad Methods SohRertlep61ewMaster V8i {SELECTseries 1) [08.11.01.03] 118/2015 8:08:53 AM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2 SECTION D -D SWALE TO POND GVF Output Data Critical Slope 0.02169 ft/ft 11812015 8:08:53 AM Bentley Systems, Inc, Haestad Methods SoI2 itl jefitewMaster V8i (SELECTseries 1) 108.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 2 of 2 DETENTION POND OUTLET WEIR Project Description Solve For Discharge Input Data Headwater Elevation 1.00 ft Crest Elevation 0.50 ft Tailwater Elevation 0.00 ft Weir Coefficient 3.34 US Crest Length 3.00 ft Results Discharge 3.54 ft°/s Headwater Height Above Crest 0.50 ft Tailwater Height Above Crest -0.50 ft Equal Side Slopes 0.25 ft/ft (H:V) Flow Area 1.56 ft2 Velocity 2.27 ft/s Wetted Perimeter 4.03 ft Top Width 3.25 ft Bentley Systems, Inc. Haestad Methods Soh$entlapfitewMaster V8i ISELECTseries 1) [08.11.01.03] 1/8/2015 8:09:28 AM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 Article 4-203.E.16 Stormwater Management Permit and Plan Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OAProject No. 014-2797 STATE OF COLORADO John W. Hickenlooper, Governor Christopher E. Urbina, MD, MPH Executive Director and Chief Medical Officer Dedicated to protecting and improving the health and environment of the people of Colorado 4300 Cherry Creek Dr. 5. Denver. Colorado 60246-1530 Phone (303) 692-2000 Located in Glendale, Colorado http://www.cdpha state ,co.us June 21, 2012 Laboratory Services Division 8100 Lowry Blvd, Denver, Colorado 80230-6928 (303) 692-3090 Cindy Allen, EHS Team Lead Encana Oil & Gas (USA) Inc 370 17 St Ste 1700 Denver, CO 80202 RE: Renewal of Permit/Certification Administrative Continuation For: Mamm Creek Located at: See Map In File, Uninc, Garfield County Permit No.: C0R034840 Dear Mr. Allen; Colorado Department of Public Health and Environment The Division has received an application to renew the above perfrtiticertificatian. It has been determined that there is sufficient information to make this permit/certification eligible for renewal. More information may be requested by the Division as progress is made in developing a new permit/certification for the above listed facility. This informationmust be made available to the Division when requested to complete the permit process. The Division is currently in the process of developing a new permit or master general permit and associated certification for the above permitted facility. The development and review procedures required by law have not yet been completed. When the discharge permit issued to you for your facility expired on June 30, 2012 your permit is administratively continued and remains in effect udder Section 104(7) of the Administrative Procedures Act, C.R.S. 1973, 24-4-101, etsept. (1982 repl. vol... 10) until the new permit/certification is issued and effective. All effluent permit terms and conditions in your current permit will remain in effect anti] your new permit/certification is issued and effective. PLEASE KEEP THIS LETTER WITH YOUR PERMIT AND SWMP TO SHOW CONTINUATION OF PERMIT COVERAGE. Sincerely, Debbie Jessop Permits Section WATER QUALITY CONTROL DIVISION xc: Permit File encana.. natural gas Master Stormwater Management Plan Mamm Creek Volume 1 COR -034840 encana. gas Permit Area Mamm Creek Permit Number COR -034840 SWMP REVISIONS Date Description Initials 11/24/2010 Update Legal and Local Contacts KK 11/24/2010 Updated company name from EnCana to Encana KK 11/24/2010 Inserted Oil and Gas Construction Field Permit Certification NOTICE OF AMENDMENT OF PERMIT COVERAGE in the place of the Final Stabilization Certification - Appendix F KK Prepared by: EnCana Oil & Gas (USA) Inc. Parachute, Colorado Volume 1 Master Stormwater Management Mamm Creek`� COR -034840 �` EnCana Oil & Gas (USA Inc. Updated June 2009 Prepared by: EnCana Oil & Gas (USA) Inc. Parachute, Colorado Volume 1 Master Stormwater Management Plan r Mamm Creek COR -034840 Prepared : c Env 8,� ental Field Coordinator Reviewed By Ryan Meath, Environmental Field Coordinator EnCana Oil & Gas (USA) Inc. Updated June 2009 Contents 1.0 Introduction 1-1 1.1 Site Specific Records 1-1 1.2 SWMP Administrator 1-2 2.0 Narrative Description of Master SWMP Permit Coverage Area 2-1 2.1 Sequence of Major Activities 2-1 2.1.1 Well Pads and Roads 2-1 2.1.2 Pipelines 2-2 2.1.3 Compressor Stations, Treatment Facilities, or Other Facilities. 2-4 2.2 Area Estimates 2-6 2.3 Description of Existing Topography and Soils 2-6 2.4 Description of Existing Vegetation 2-6 2.5 Identification of Potential Pollution Sources 2-9 2.6 Allowable Sources of Non-Stormwater Dischar 2-11 2.7 Receiving Water 2-11 2.8 Master SWMP Permit Area Map and Individual Stprmw Sit- s 2-11 3.0 Best Management Practices (BMPs) 3-1 3.1 Erosion, Drainage, and Sediment Control BMPs 3-1 3.2 Non-Stormwater Control BMPs 3-1 3.2.1 Materials Delivery and Storage 3-2 3.2.2 Material Handling and Spill Prevention 3-2 3.2.3 Vehicle Cleaning, Fueling, Maintenance, and Tracking Controls 3-2 3.2.4 Waste Management and Disposal 3-3 3.2.5 Dewatering 3-3 3.3 Stormwater Manual of BMPs 3-4 3.4 Phased BMP Implementation 3-5 4.0 Interim Reclamation and Final Stabilization 4-1 5.0 Inspection and Maintenance 5-1 5.1 Inspection Schedule 5-1 5.1.1 Minimum Inspection Schedule for active sites 5-1 5.1.2 Post -Storm Event Inspections at Temporarily Idle Sites 5-1 5.1.3 Completed Sites 5-1 5.1.4 Winter Conditions Inspections Exclusion 5-2 5.2 Performing Inspections 5-2 F:\Projects\014-2797\Documents\Operational I Updated June 2009 Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 5.3 Maintenance 5-2 5.4 Documenting Inspections and Maintenance 5-3 6.0 Plan Revisions and Retention 6-1 7.0 Inactivation Notice 7-1 8.0 Signature 8-1 9.0 References 9-1 List of Appendices Appendix A General Permit Application Appendix B Revegetation Manual Appendix C Existing Soil and Vegetation Data Appendix D Master SWMP Permit Area Map Appendix E Stormwater Manual of Best Management Practices (BMPs) Appendix F Oil and Gas Construction Field Permit Certification NOTICE OF AMENDMENT OF PERMIT COVERAGE and/or Final Stabilization Certification Appendix G Inspection and Maintenance Report Form Appendix H Inactivatio F:\Projects\014-2797\Documents\Operational ii Updated June 2009 Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 1.0 Introduction This Master Stormwater Management Plan (Master SWMP) satisfies the Colorado Department of Public Health and Environment (CDPHE) Water Quality Control Division (WQCD) General Permit No. COR -030000 issued on May 31, 2007 for Stormwater Discharges Associated with Construction Activities (the Stormwater Construction Permit). EnCana Oil & Gas (USA) Inc. (EnCana) has submitted a General Permit Application to WQCD, a copy of which is provided as Appendix A. This Master SWMP has been prepared in compliance with CDPHE WQCD, the Federal Clean Water Act (CWA), and the National Pollutant Discharge Elimination Permit (NPDES) regulations found in 40 CFR, Part 122.26 for stormwater discharges. The objectives of this Master SWMP are to: 1. Identify all potential sources of pollution which may reasony be xper ed fo • - quality of stormwater discharges associated with construction activity within this =ster S • it area at each project site; 2. Describe the practices to be used to reduce the pollutants in stormw discharges associated with construction activity within this Master SWMP permit area at each proj -t site (also known as Best Management Practices (BMPs)); and ensure the practices are selected and described in accordance with good engineering practices, including the installation, implementation and maintenance requirements; 3. Be properly prepared and updated to ensure compliance with the terms and conditions of the Stormwater Construction Permit; 4. Work hand in hand with the Site Specific Records, as described in the following section; and 5. Serve as an education tool and comprehensive reference/guide to stormwater management for inspectors, surveyors, engineers, and EnCana employees and contractors. EnCana construction activities fall under one of two types. Exploration and Production (E&P) sites involve the construction of well pads, roads, and other facilities. Midstream Services (also referred to as Gas Gathering) sites involve the construction of pipelines and compressor, treatment, and other facilities. This Master SWMP is intended to address stormwater management for any and all of these sites within this Master SWMP's Permit Coverage Area. 1.1 Site Specific Records While Volume 1 of the Master SWMP contains all of the general permit area information, Volume 2 of the Master SWMP contains all of the Site Specific Records including all Individual Stormwater Site Plans (Site Plans), as discussed in Section 2.8, and all Inspection and Maintenance Reports (discussed in Section 5.4). These Site Specific Records contain information specific to each site (each well pad, compressor station, section of road/pipeline, etc.), including information on areas of disturbance, ecosystems and vegetation, soil types, percent pre -disturbance vegetation, etc. Any changes to the design of individual sites or the BMPs used at those sites will be noted on the Site Plans as those changes occur, and kept with the Site Specific Records. The Site Specific Records (Volume 2 of the Master SWMP) are bound separately from the body of this Master SWMP; however, both are readily available during any inspection. Both the body of this SWMP (Volume 1) and the Site Specific Records (Volume 2) comprise the entire SWMP, and go hand in hand in keeping EnCana in compliance with stormwater regulations. The Site Specific Records will be kept at the EnCana field office in F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 1-1 Updated June 2009 Parachute during active construction and site inspections to ensure accurate implementation, inspections, and maintenance of BMPs, as well as timely revisions to the Site Specific Records. 1.2 SWMP Administrator The SWMP Administrator is responsible for the process of developing, implementing, maintaining, and revising this SWMP as well as serving as the comprehensive point of contact for all aspects of the facility's SWMP. SWMP Administrators: • Local Contact: • Legal Contact: Kathy Kiloh, Surface Management Lead 2717 County Road 215, Suite 100, Parachute, CO 81635 (970) 285-2626 Brant Gimmeson, Group Lead EH&S South Rockies 370 17th St. Suite 1700, Denver, CO 80202 (720) 876-5030 Illigb \'' \r F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 1-2 Updated June 2009 2.0 Narrative Description of Master SWMP Permit Coverage Area Name of Permit Coverage Area: Mamm Creek Unit Permit Number: COR -034840 Location of the Permit Coverage Area: • County: Garfield and Mesa County. • City: Located in Colorado approximately 1 mile south of Rifle and south of the the southern portion of the Piceance Basin. • Township/Section/Range: Township 6S, 7S, & 8S, Range 92W, 93W, & 94W, sections, Sixth Principal Meridian. Activities at the Permit Coverage Area will likely involve the construction of: • Well pads • Access roads • Pipelines • Compressor stations • Water Treatment Facility • Fresh Water Storage Pond • Evaporation Facility 1' Colorado River within portions or all of 113 The above construction activities are only typical andie ay vary once construction begins. Up-to-date information on the construction of well pa roads, lines, etc. will be kept with the Site Specific Records (Volume 2 of the Master SWMP). 2.1 Sequence of Major Activities Site specific, scheduling, surface use agreements, and/or other constraints can and/or may dictate changes in construction sequences. Significant sequence changes are addressed in the Site Specific Records (Volume 2 of the Master SWMP). Specific details on the construction and maintenance of BMPs mentioned below are provided in the Stormwater Manual of Best Management Practices (BMP Manual) as discussed in Section 3.3. 1 2.1.1 Well Pads and Roads Construction activities for well pads and roads are generally completed in the following sequence: Preconstruction: 1. Surveys. Topographic, vegetation, wildlife and archeology, as dictated. 2. Temporary BMP's. Where physical access is available, installation of terminal perimeter and temporary sediment controls, such as wattles, silt fence and/or other as necessary. Actual BMPs used for each site are shown on the Site Plans (discussed in Section 2.8) and kept with the Site Specific Records (Volume 2 of the Master SWMP). Construction: F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 2-1 Updated June 2009 3. Vegetation Clearing. Vegetation will be cleared/grubbed and placed along the perimeter at the terminal discharge edges/points in a windrow and/or dam beyond the edge of excavation and at any run -on -protection discharge points, and/or chipped or other depending on landowner requirements. 4. Diversions and Retention Reservoirs. After vegetation clearing and prior to topsoil stockpiling, diversions are to be placed for run -on -protection (ROP) to prevent the greater landscape from discharging onto the planned disturbance. Temporary sediment control BMPs shall be placed at the discharge points of the ROP until permanent erosion controls can be installed along the entire length of the ROP. Diversions are to be installed along the terminal discharge edge inside of the vegetation windrows to convey site water/sediment to terminal discharge points where rough retention reservoirs are to be installed. The retention reservoir outlets are to receive temporary sediment control BMPs until permanent retention reservoirs and erosion, drainage, and sediment BMPs can be installed. 5. Topsoil Stripping/Conservation. All ACCESSIBLE TOPSOIL is to be removed from areas that are to be excavated, covered in subsoils, or turned into stabilized unpaved surfaces. If initial topsoil stockpile areas are insufficient to accommodate the quantities of topsoil being generated, the excess is to be placed at either end of the subsoil stockpile and segregated as much as possible. After major earthwork, grading, and erosion/drainage/sediment controls are complete, any areas that can be identified for immediate interim reclamation shall receive topsoil. 6. General Rough Grading. The site location will be graded tillprovide suitable surfaces for vehicle traffic and/or building sites, and may be graded to establish urace drainage patterns, such as berms or roadside ditches as necessary. 7. Facility Specific Grading. Individual facilities may require additional excavation to allow for construction of foundations. Excess soil will typically be used in general site grading. 8. Foundation Construction. To support facilities (such as tanks, processing equipment, etc), foundations will be constructed. Foundations may consist of select backfill, concrete spread footings, or piles. Finished support elevations are to be installed twelve to eighteen inches (12-18") above finished grade or the lowest point of the facility. 9. Facility Construction. Tanks, processing equipment, etc. will be constructed. Interim Reclamation: 10. Gravel Surfacing. Areas used for access, parking, or materials staging will typically be gravel surfaced. 11. Reclamation of Unused Areas. Areas not needed for facilities, roads, parking, or materials staging will generally be reclaimed. Salvaged topsoil will be spread and the vegetative seed mix will be applied 12. Application of Erosion Stabilization. Depending on terrain (e.g. steep slopes and drainage crossings) additional measures may be applied to increase stability of the reclaimed area. Final Reclamation: 13. Reclamation of Post -Operation Areas. When operation of well pad or road is no longer necessary, the area will be decommissioned and all newly disturbed areas will be reclaimed. Any remaining topsoil will be spread and the vegetative seed mix will be applied. This may occur after termination of this permit and under the coverage of a new construction permit. 2.1.2 Pipelines Construction activities for pipelines are generally completed in the following sequence: Preconstruction: 1. Surveys. Topographic, vegetation, wildlife and archeology, as dictated. F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 2-2 Updated June 2009 2. Mark Right -Of -Way. The construction right-of-way (ROW) will be marked prior to construction with laths and/or flagging. Laths/flagging will be maintained throughout construction and will not be removed until after reclamation activities have been completed. 3. Temporary BMPs. EnCana's stormwater inspectors will determine locations to install preconstruction temporary erosion control devices, per site specific BMP installation plans and as necessary. EnCana's contractor will maintain the erosion control structures as directed by the stormwater inspectors throughout all phases of construction, or until permanent erosion control measures are installed. Actual BMPs used for each site are shown on the Site Plans, which are kept with the Site Specific Records (Volume 2 of the Master SWMP). Construction: 4. Vegetation Clearing. If necessary, vegetation will be cleared and placed in a windrow at the edge of the work area to be used later in reclamation activities, removed from the construction site, or burned/chipped depending on landowner requirements. Details for windrows are provided within the Stockpiling BMP of the BMP Manual (discussed in Section 3.3). 5. Topsoil Stripping. All ACCESSIBLE TOPSOIL (from the entire width of the right-of-way) will be removed and temporarily stockpiled along the up -hill side of the right-of-way (if terrain grades will allow) for later use in reclamation activities. 6. General Grading. For pipeline segments that occur in relatively rough terrain, general grading will be conducted to create a safe and workable ground surface. This is generally done to form a relatively level work surface on steep cross slopes and to reduce slopes in undulating terrain (arroyo and wash crossings). The site location will be gr ed to provide suitable surfaceNor vehicle traffic and/or building sites, and may be graded to e blish surface drainage patterns, such as berms or roadside ditches as necessary. 7. Trench Excavation. The trench ne for p4eline install*n is most always off -set in the ROW. The surveyors may indicate the locatiof the trench on their pipeline lateral. Generally, the trench will be located in the first third of the RO . The remaining two thirds of the ROW will be used for working space. The trench depth and width will vary with the number of pipes to be installed and the pipe diameter. Generally, a 4 -foot deep trench will be excavated by track -mounted excavators. The ditch will be excavated and sloped in accordance with OSHA specifications. The cover from top of pipe to ground level will be a minimum of 36 inches. Where rock is encountered, tractor -mounted mechanical rippers or rock trenching equipment may be used to facilitate excavation. The trench will be excavated and subsoil material stockpiled within the confines of the approved right-of-way limits. Trench spoil will be stored in a separate location from the previously segregated topsoil. 8. Pipe Installation. Pipe installation will include stringing, bending for horizontal or vertical angles in the alignment, welding the pipe segments together, coating the joint areas to prevent corrosion, and then lowering -in and padding. 9. Stringing. Pipe will be hauled by truck to the pipeline ROW. Each joint of pipe will be unloaded and placed parallel to the ditch. 10. Bending. After the joints of pipe are strung along the ditch, individual joints of pipe may need to be bent to accommodate horizontal and vertical changes in direction. Field bends will be made utilizing a hydraulically operated bending machine. Where the deflection of a bend exceeds the allowable limits for a field -bent pipe, factory (induction) bends will be installed. 11. Welding. After the pipe joints are bent, the pipe is lined up end-to-end and clamped into position. The pipe is then welded in conformance with 49 CFR Part 192, Subpart E. "Welding of Steel Pipelines" and API 1104, "Standard for Welding Pipelines and Related Facilities". 12. Welding Inspection. Welds will be visually inspected by a qualified inspector. Any defects will be repaired or cut out as required under the specified regulations and standards. 13. Coating. To prevent corrosion, the pipe will be externally coated with fusion bonded epoxy coating prior to delivery. After welding, field joints will be coated with fusion bond epoxy coating, tape and F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 2-3 Updated June 2009 primer, or shrink sleeves. Before the pipe is lowered into the ditch, the pipeline coating will be visually inspected and tested with an electronic detector, and any faults or scratches will be repaired. 14. Lowering -In and Padding. Once the pipe coating operation has been completed, a section of the pipe will be lowered into the ditch. Side -boom tractors may be used to simultaneously lift the pipe, position it over the ditch, and lower it in place. Inspection will be conducted to verify: that minimum cover is provided; the trench bottom is free of rocks, debris, etc.; external pipe coating is not damaged; and the pipe is properly fitted and installed into the ditch. Specialized padding machines will be used to sift soil fines from the excavated subsoil to provide rock -free pipeline padding and bedding. In rocky areas, padding material or a rock shield will be used to protect the pipe. Topsoil will not be used to pad the pipe. At the completion of lowering -in and padding activities the contractor may install trench breakers around the pipelines to minimize subsurface water flow. Details for trench breakers are provided within the BMP Manual (discussed in Section 3.3). 15. Backfilling. Backfilling will begin after a section of the pipe has been successfully placed in the ditch and final inspection has been completed. Backfilling will be conducted using a bulldozer, rotary auger backfill, padding machine or other suitable equipment. Backfilling the trench will use the subsoil previously excavated from the trench. Backfill will be graded and compacted, where necessary for ground stability, by being tamped or walked in with a wheeled or track vehicle. Compaction will be performed to the extent that there are no voids in the trench. Any excavated materials or materials unfit for backfill will be utilized or properly disposed of in conformance with applicable laws or regulations. 16. General Grading. If general grading was conducted to facilitate pipeline construction, these materials will be replaced and graded to recreate the preconstruction topography. Final Reclamation: 17. Cleanup. Cleanup activities will be initiated as soon as practicable after backfilling activities have been completed. All construction -related debris will be removed and disposed of at an approved disposal facility. 18. Subsoil and Topsoil Placement. Subsoil will be evenly re-contoured across the right-of-way to pre -construction conditions. After the subsoil has been re -spread the contractor will spread the previously segregated topsoil back across the right-of-way. The topsoil will be evenly spread to original contours. 19. Vegetation. After any remaining topsoil is spread, the vegetative seed mix will be applied. The area will be revegetated according to private landowner Surface Use Agreements and/or according to the BLM/Forest Service reclamation requirements. Details for revegetation are provided within the BMP Manual (discussed in Section 3.3) and the Revegetation Manual (provided as Appendix B). 20. Application of Erosion Stabilization. Depending on terrain (e.g. steep slopes and drainage crossings) additional measures may be applied to increase stability of the reclaimed area. Possible erosion stabilization methods are provided within the BMP Manual (discussed in Section 3.3). Actual locations and measures used are shown on the Site Plans, which are kept with the Site Specific Records (Volume 2 of the Master SWMP). 2.1.3 Compressor Stations, Treatment Facilities, or Other Facilities. Construction activities for compressor stations, treatment facilities, and other facilities are generally completed in the following sequence: Preconstruction: 1. Surveys. Topographic, vegetation, wildlife and archeology, as dictated. 2. Temporary BMP's. Where physical access is available, installation of terminal perimeter and temporary sediment controls, such as wattles, silt fence and/or other as necessary. Actual BMPs F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 2-4 Updated June 2009 used for each site are shown on the Site Plans, which are kept with the Site Specific Records (Volume 2 of the Master SWMP). Construction: 3. Vegetation Clearing. Vegetation will be cleared/grubbed and placed along the perimeter at the terminal discharge edges/points in a windrow and/or dam beyond the edge of excavation and at any run -on -protection discharge points, and/or chipped or other depending on landowner requirements. 4. Diversions and Retention Reservoirs. After vegetation clearing and prior to topsoil stockpiling, diversion are to be placed for ROP to prevent the greater landscape from discharging onto the planned disturbance. Temporary sediment control BMP's shall be placed at the discharge points of the ROP until permanent erosion controls can be installed along the entire length of the ROP. Diversions are to be installed along the terminal discharge edge inside of the vegetation windrows to convey site water/sediment to terminal discharge points where rough retention reservoirs are to be installed. The retention reservoir outlets are to receive temporary sediment control BMP's until permanent retention reservoirs and erosion, drainage, and sediment BMP's can be installed. 5. Topsoil Stripping/Conservation. All ACCESSIBLE TOPSOIL is to be removed from areas that are to be excavated, covered in subsoils, or turned into stabilized unpaved surfaces. If initial topsoil stockpile areas are insufficient to accommodate the quantities of topsoil being generated, the excess is to be placed at either end of the subsoil stockpile and segregated as much as possible. After major earthwork, grading, and erosion/drainage/sediment control are'pmplete, any areas that can be identified for immediate interim reclamation shall receive topsoil 6. General Rough Grading. The site location will be graded to prove ssurfaces for building sites and vehicle traffic, and may be g ed to establish surface drainage atterns, such as berms or roadside ditches as necessary. 7. Excavation. Soil will be excavated to allow for the construction of foundations. Trenches will be excavated for all underground piping and conduit. Excess soil will typically be used in general site grading. 8. Foundation Construction. Foundations will be constructed to support facility buildings. Foundations may consist of select backfill, concrete spread footings, piles, etc. Finished support elevations are to be installed twelve to eighteen inches (12-18") above finished grade or the lowest point of the facility. 9. Facility Construction. Buildings, tanks, processing equipment, etc. will be constructed. Utilities will be installed. Interim Reclamation: 10. Landscaping. If necessary, certain areas will be spread with topsoil and landscaped. 11. Gravel Surfacing. Areas used for access, parking, or materials staging will typically be gravel surfaced. 12. Reclamation of Unused Areas. Areas not needed for facilities, roads, parking, or materials staging will generally be reclaimed. Salvaged topsoil will be spread and the vegetative seed mix will be applied. 13. Application of Erosion Stabilization. Depending on terrain (e.g. steep slopes and drainage crossings) additional measures may be applied to increase stability of the reclaimed area. Possible erosion stabilization methods are provided within the BMP Manual (discussed in Section 3.3). Actual locations and measures used are shown on the Site Plans, which are kept with the Site Specific Records (Volume 2 of the Master SWMP). Final Reclamation: 14. Reclamation of Closed Facilities. When facilities are no longer necessary, the buildings may be demolished, according to approved procedures. All construction materials will be removed and the newly disturbed areas will be reclaimed. Any remaining topsoil will be spread and the vegetative seed F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 2-5 Updated June 2009 mix will be applied. This may occur after termination of this permit and under the coverage of a new construction permit. 2.2 Area Estimates The Permit Coverage Area encompasses portions or all of 113 sections of surface land (approximately 72,273 acres) in Township 6, 7, and 8 South, Range 92, 93, and 94 West. Development of the natural gas resource and related facilities within the area is estimated to result in a total disturbance area of 999+ acres. Because the area will vary over time, these are only approximate estimates. This information is used to help determine the extent of control measures (BMPs) needed. 2.3 Description of Existing Topography and Soils The Permit Coverage Area consists of relatively flat mesas and ridge crests, alluvial terraces, steep slopes, mountainsides, intermittent drainage swells, and valley bottoms. The Mamm Creek Unit is located south of the Colorado River, within the southern portion of the Piceance Basin. The Piceance Basin is a broad, asymmetric, southeast -northwest trending structural basin that contains sedimentary rocks up to 20,000 feet thick and lies between the White River uplift to the northeast, the Gunnison uplift to the south, and the Uncompahgre swell to the west (George 1927; Weiner and Haun 1960). Elevations within the Permit Coverage Area range from approximately 5,000 feet above mean sea level (amsl) along the Colorado River to 8,900 feet on Grass Mesa near the western edge of the unit area. Annual precipitation within the Permit Coverage Area ranges from 10 to 40 inches. Soils surrounding the Permit Coverage Area are distributed according to the major soil forming factors including climate (effective moisture and temperature), parent material, topographic position, and slope. The soils table within Appendix C provides a summary of the soil types found within the Permit Coverage Area (including permeability, available water capacity, surface runoff, erosion hazard, and others). Most of these soil types are considered to possess moderate to very severe potential for water erosion. 2.4 Description of Existing Vegetation The existing percent vegetative ground cover for each well pad, section of roadway/pipeline, etc. within the Permit Coverage Area is estimated on each inspection and maintenance report form (discussed in Section 5.4), which are kept with the Site Specific Records (Volume 2 of the Master SWMP). A map indicating the existing ecosystem types ,ithin the Permit Coverage Area is provided in Appendix C. A description of the exis pg' etation within each ecosystem (Mutel, 1992) is as follows: 1. Grasslands a. Plains Gr#lands: Plaigrasslands are dominated by a mixture of blue grama (Chondrosum gracile) and buffalograss (Buchloe dactyloides). Interspersed are occasional shrubs and bright flowered forbs, most of which are members of the pea and sunflower families. Taller grass species cover 10 to 25 percent of the ground of little -grazed, moist sites. Most are perennial bunch -grasses up to three feet tall. Needle -and -thread (Stipa comata), sand dropseed (Sporobolus cryptandrus), side -oats grama (Bouteloua curtipendula), western wheatgrass (Pascopyrum smithii), Junegrass (Koeleria macrantha), and red three -awn (Aristida purpurea) are other common species. Common forbs consist of prickly pear (Opuntia polyacantha), pasture sage (Artemisia frigida), and yucca (Yucca glauca). b. Mountain Grasslands and Meadows. Natural wet meadows and fens are dominated by moisture -loving species, primarily members of the sedge and rush families. Spike-rush (Eleocharis palustris), sedges, Canadian reedgrass (Calamagrostis canadensis), and tufted hairgrass (Deschampsia cespitosa) are common. Natural dry meadows are filled with members of the grass family. Bunchgrasses dominate at low elevations. Needle -and -thread, mountain muhly (Muhlenbergia montana), Junegrass, blue grama, and species of wheatgrass and bluegrass are common. Successional meadows contain a combination of weedy, introduced plants and plants F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 2-6 Updated June 2009 typical of dry, rocky slopes, such as common dandelion (Taraxacum officinale), golden banner (Thermopsis divaricarpa), Colorado locoweed (Oxytropic sericea), mountain pussytoes (Antennaria parvifolia), showy daisies (Erigeron speciosus), stonecrop (Sedum lanceolatum), and some sedges (Carex ssp.). Mountain grasslands, where Thurber fescue (Festuca thurberi) and mountain muhly were once the dominant grasses, are now largely dominated by blue grama, Canada bluegrass (Poa compressa), foxtail barley (Critesion jubatum), and other species as a result of grazing. 2. Riparian Ecosystems a. Lowland Riparian Ecosystems. The lowland riparian ecosystem is dominated by the plains cottonwood (Populus deltoidea ssp. occidentalis), the valley cottonwood (Populus deltoidea ssp. wislizenii) and the peach -leaved willow (Salix amygdaloides). Common shrubs and herbaceous plants include snowberry (Symphoricarpos occidentalis), sandbar willow (Salix exigua), bulrush (Schoenoplectus lacustris), broad-leaved cat -tail (Typha latifolia), prairie cord -grass (Spartina pectinata), and western wheatgrass. b. Mountain Riparian Ecosystems. The mountain riparian ecosystem is dominated by quaking aspen (Populus tremuloides), lanceleaf cottonwood (Populus X acuminata), narrowleaf cottonwood (Populus angustifolia), and Colorado blue spruce (Picea pungens). Common shrubs include alder (Alnus incana), river birch (Betula fontinalis), chokecherry (Padus virginiana), common gooseberry (Ribes inerme), bush honeysuckle (Distegia involucrata), and mountain maple (Acer glabrum). The lush riparian herbaceous understory includes forbs, grasses, sedges, rushes, climbing vines, mosses, lichens, and liverworts. Weedy invaders are also common. 3. Shrublands. Shrub communities include semidesert shrublands found in dry lowlands, sagebrush shrublands that occupy a wide range of elevation from the Colorado Plateau to high mountain valleys, and montane shrublands other than sagebrush, characteristic of foothills and mountain regions. a. Semidesert Shrublands. Common shrubs include Great Basin big sagebrush (Seriphidium tridentatum), greasewood (Sarcdbatus vermiculatus), rabbitbrush (Chrysothamnus), four -winged saltbush (Atriplex canescens)„,and shadscale (Atriplex confertifolia). Common grasses and forbs include galletagrass (Hilaria jarnesii), blue grama, alkali sacaton (Sporobolus airoides), nodding eriogonum (Eriogonum cernuum), copper mallow (Sphaeralcea coccinea), and prince's plume (Stanleya pinnata). b. Sagebrush Shrublands. Common shrubs include Great Basin big sagebrush, mountain big sagebrush (Seriphidium vaseyanum), rabbitbrush, and serviceberry (Amelanchier alnifolia). Common grasses and forbs include nodding eriogonum, copper mallow, and Indian Paintbrush (Castilleja spp.). c. Montane Shrublands. Common shrubs include mountain mahogany (Cercocarpus), Gamble oak (Quercus gambelii), rabbitbrush, serviceberry, and skunkbrush (Rhus aromatica). Common grasses and forbs include needle -and -thread, western wheatgrass, copper mallow, and Indian Paintbrush. 4. Pinyon -Juniper Woodlands. Pinyon -juniper woodlands consist of scattered Utah juniper interspersed with big sagebrush. Pinyon pine is a minor component. Several other shrub species also occur in this community, including snowberry, bitterbrush (Purshia tridentata), snakeweed (Gutierrezia sarothrae), and serviceberry. In general, the sparse herbaceous layer consists of graminoids such as cheatgrass (Anisantha tectorum), Kentucky bluegrass (Poa pratensis), western wheatgrass, Indian ricegrass (Oryzopsis hymenoides), and squirreltail (Elymus elymoides). Forbs include Tracy's thistle (Cirsium tracyi), mariposa lily (Calochortus nuttallii), western wallflower (Erysimum capitatum), tapertip onion (Allium acuminatum), yarrow (Achillea lanulosa), stemless four - nerve daisy (Tetraneuris acaulis), and sharpleaf twinpod (Physaria acutifolia). All of these are native species, except for cheatgrass (an invasive, non-native annual species) and Kentucky bluegrass (a widely naturalized non-native perennial species). F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 2-7 Updated June 2009 5. Montane Forests a. Ponderosa Pine Forests. These forests are dominated by the ponderosa pine (Pinus ponderosa) and the Rocky Mountain juniper (Savina scopulorum). Common shrubs and herbaceous plants include the wax currant (Ribes cereum), blue grama, side -oats grama, Junegrass, needle -and -thread, spike fescue (Leucopoa kingii), and sulphur flower (Eriogonum umbellatum). b. Douglas Fir Forests. These forests are dominated by the Douglas fir (Pseudotsuga menziesii). Common shrubs and herbaceous plants include common juniper (Juniperus communis), kinnikinnik (Arctostaphylos), mountain maple (Acer glabrum), mountain lover (Paxistima myrsinites), heart -leaved arnica (Arnica cordifolia), and false Solomon's seal (Maianthemum spp.) c. Aspen forests. Quaking aspen generally occur on north -facing slopes, and along drainage swales. The aspen forest generally has an understory of Wood's rose (Rosa woodsii), Colorado blue columbine (Aquilegia caerulea), showy daisy, Thurber fescue, white geranium (Geranium richardsonii), common lupine (Lupinus argenteus), Fendler meadowrue (Thalictrum fendleri), and American vetch (Vicia americana). d. Lodgepole Pine Forests. These forests are dominateby the lodgepile pine (Pinus contorta). Common shrubs and herbaceous plants include broom huckleberry (Vaccinium scoparium), common juniper, kinnikinnik, sticky -laurel (Ceanothus velutinus), and heart -leaved arnica. 6. Subalpine Forests a. Engelmann Spruce and Subalpine Fir. Engelmann spruce (Picea engelmannii) and subalpine fir (Abies bifolia) trees are the dominant species in this type of forest, however lodgepole pine, aspen, and sedge -bluegrass have been known to invade in areas which have been severely burned. Understory growth is patchy and consists primarily of dense, low -growing blueberry (Vaccinium myrtillus) and broom huckleberry bushes. Moisture -loving shrubs and herbs such as broad-leaved arnica (Arnica latifolia) and heart -leaved arnica, Jacob's ladder (Polemonium pulcherrimum), curled lousewort (Pedicularis racemosa), elk sedge (Carex geyen), and lesser wintergreen (PPa minor) are interspersed among the huckleberry. b. Limber and Bristlecone Pine Woodlands. Limber pine (Pinus flexilis) and bristlecone pine (Pinus aristata) trees are the only tree species that can invade this harsh ecosystem. Common species among the sparse understory consist of common juniper, kinnikinnik, sticky -laurel, Junegrass, stonecrop, Colorado locoweed, and whitlow -wort (Draba spp.). Lichens cover exposed rock surfaces. 7. Alpine Tundra. Tundra vegetation consists of a low growth of shrubs, cushion plants, and small forbs with brilliantly colored flowers, and of lush meadows of narrow -leaved sedges and grasses. These plants cover gentle slopes and rock crevices filled with soil. Rock surfaces are partially covered with more primitive plants — lichens and mosses. Shrubs consist of arctic willow (Salix arctica), barrenground (Salix brachycarpa), planeleaf (Salix planifolia), and snow (Salix reticulate ssp. nivalis). Common grasses are alpine bluegrass (Poa arctica), tufted hairgrass (Deschampsia cespitosa), and kobresia (Kobresia myosuroides). The most common forbs are alpine avens (Acomastylis rossii), American bistort (Bistorta bistortoides), marsh marigold (Psychrophila Ieptosepala), old -man -on -the - mountain (Rydbergia grandiflora), moss pink (Silene acualis), rock selaginella (Selaginella densa), and alpine sandwort (Lidia obtusiloba). All plant species are slow-growing perennials except for the rare annual koenigia, a tiny member of the buckwheat family. 8. Urban Areas. Urban areas contain an increased density of human -created structures in comparison to the areas surrounding it. Depending on the area, vegetation may account for anywhere between 20 and 70 percent of the total land cover, with the remaining portion being constructed materials. Types of vegetation within urban areas may be any combination of the above ecosystems, and may include areas of blue grass yards and parks. F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 2-8 Updated June 2009 9. Cropland. Cropland vegetation may consist of wheat, corn, soybeans, or a variety of many other crops. Cropland may either lie fallow (bare of any crops) or contain crops at any stage of growth from seedlings to mature plants. Detailed Description of Existing Vegetation The existing percent vegetative ground cover for each well pad, section of roadway/pipeline, etc. within the Permit Coverage Area is estimated on each inspection and maintenance report form (discussed in Section 5.4), which are kept with the Site Specific Records (Volume 2 of the Master SWMP). The primary vegetation types in the Mamm Creek Unit are sagebrush shrublands (Artemisia tridentata), pinyon -juniper woodlands (Pinus edulis-Juniperus osteosperma), and Gambel oak shrublands (Quercus gambelii). A small amount of aspen is present at the southern and eastern edge of the Project Area. The riparian vegetation includes narrowleaf cottonwood (Populus angustifolia), mountain maple (Acer glabrum), river birch (Betula occidentalis), alder (Alnus incana spp. tenuifolia), dogwood (Cornus sereciea), and Woods' rose (Rosa woodsii). Snowberry occurs in the shrublayer, and orange sneezeweed (Dugaidia hoopesii), tailcup lupine (Lupinus caudatus), field horsetail (Equisetum arvense), American vetch (Vicia americana), orchardgrass (Dactylis gloverata), northern bedstraw, geranium (Geranium caespitosum), and yarrow (Achillea lanulosa) occur in the understory. Further to the southwest, numerous blue spruce (Picea pungens) occur along the creek (BLM 2005). Vegetation within the Grass Mesa area primarily consists of hillsides dominated by pinyon -juniper woodlands (Juniperus osteosperma and Pinus edulis) and the mesa top dominated by mixed mountain shrubs, mostly big sagebrush (Artemisia tridentata), Gambel oak (Quercus gambelii), and serviceberry (Amelanchier alnifolia). Several of the proposed locations fall within areas dominated by sagebrush -steppe. Herbaceous and succulent species commonly found in the project area include arrow -leaf balsamroot (Balsamorhiza sagittata), prickly pear cactus (Opuntia polyacantha), prairie lupine (Lupinus wyethii), orange globemallow (Sphaeralcea munroana), and several species of penstemon (Penstemon spp.) and paintbrush (Castilleja spp.) (BLM 2004). The entire Mamm Creek Unit has, to some extent, been affected by cheatgrass (downy brome) (Bromus tectorum) (see Invasive, Non -Native Species). It is often associated with sagebrush communities and disturbed areas, especiallu two -track roads. In the pinyon/juniper woodlands, this species may be found as the understory. Stressed by the recent drought, many pinyon pine trees in the Colorado Plateau have succumbed to an engraver beetle (Ips confusus) infestation. However, in the Mamm Creek Unit, the scattered pinyon pine trees have shown few signs of infestation. 2.5 Identification of Potential Pollution Sources Potential sources of pollution are associated with all phases of the project from the start of construction though interim reclamation and up until final stabilization has occurred. Final stabilization occurs when construction activities have been completed and all disturbed areas have been either built on, paved, or a uniform vegetative cover has been established with a density of at least 70 percent of pre -disturbance levels, or equivalent permanent, physical erosion reduction methods have been employed. The most common source of pollution during construction is sediment resulting from the erosion of recently cleared and/or graded areas, such as cut/fill slopes and soil stockpiles. However, there may be many potential pollution sources at any given site. The following types of conditions that might affect the potential for a pollutant source to contribute pollutants to stormwater (CDPHE, 2007B) shall be evaluated: F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 2-9 Updated June 2009 • The frequency of the activity (i.e., does it occur every day or just once a month? can it be scheduled to occur only during dry weather?); • Characteristics of the area where the activity takes place (i.e., surface type (pavement, gravel, vegetation, etc.), physical characteristics [site gradients, slope lengths, etc.]); • Ability of primary and secondary containment (fuel tanks, drum storage, etc.) at product storage and loading/unloading facilities to prevent and contain spills and leaks; • Proximity of product storage and loading/unloading facilities to waterways or drainage facilities; • Concentration and toxicity of materials which may to be found in the site's stormwater runoff; and • Contamination of storage facilities/containment with stored materials (i.e., used oil drums or tanks coated with spilled oil). The following items are potential sources of pollutants at the Mamm Creek Unit. Each of the potential sources of pollutants will be controlled using one or more of the following types of BMPs: Erosion Controls, Drainage Controls, Sediment Controls or Non-Stormwater Controls. Descriptions and details for each of these types of BMPs are provided in the BMP Manual (discussed in Section 3.3). Actual BMPs used at each site are shown on the Site Plans (discussed in Section 5.4). Construction: • All Disturbed and Stored Soils: Erosion Controls, Drainage Controls, Sediment Controls. • Vehicle Tracking of Sediments: Sediment Controls, Non-Stormwater Controls. • Management of Contaminated Soils: Non-Stormwater Control • Loading and Unloading Operations: Non-Stormwater C • Outdoor Storage Activities (Building Materials, Fertilizers, icals, etc.): Non-Stormwater Controls. • Vehicle and Equipment Maintenance and F ieling: Non-Strmwater Controls. • Significant Dust or Particulate Generat[ng Processes: Non-Stormwater Controls. • Routine Maintenance Activities Involving Fertilizers, Pesticides, Detergents, Fuels, Solvents, Oils, etc.: Non-Stormwater Controls. • On -Site Waste Management Practices (Waste Piles, Liquid Wastes, Dumpsters, etc.): Non-Stormwater Controls. VVI • Concrete Truck/Equipment ing, Including the Concrete Truck Chute and Associated Fixtures and Equipment: Non-Stormwater Controls. • Dedicated Asphalt and Concrete Batch Plants: There will be no asphalt or concrete batch plants located within the Permit Coverage Area of this SWMP. • Non -Industrial Waste Sources Such as Worker Trash and Portable Toilets: Non-Stormwater Controls. Interim/Final Reclamation: • All Disturbed and Stored Soils: Erosion Controls, Drainage Controls, Sediment Controls. • Vehicle Tracking of Sediments: Sediment Controls, Non-Stormwater Controls. • Vehicle and Equipment Maintenance and Fueling: Non-Stormwater Controls. • Significant Dust or Particulate Generating Processes: Non-Stormwater Controls. • Non -Industrial Waste Sources such as Worker Trash and Portable Toilets: Non-Stormwater Controls. F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 2-10 Updated June 2009 2.6 Allowable Sources of Non-Stormwater Discharge Allowable sources of non-stormwater discharge within the Permit Coverage Area include the following: • Uncontaminated Springs. Although there are several springs within the Permit Coverage Areas, none of these springs are currently located in areas where soil disturbance will occur. If this changes in the future, the controls used at any such location will be noted with the Site Specific Records. • Landscape Irrigation Return Flow. There are several locations where pipelines cross through irrigated fields. These locations will be treated similarly to any water crossing with the use of an appropriate control which will be noted in the Site Specific Records. • Construction Dewatering. Construction dewatering is described and discussed in Section 3.2.5. • Concrete Washout. Concrete washout is described and discussed in Section 3.2.4. • Emergency Fire Fighting Water. Water used to put out any type of fire is considered an allowable source of non-stormwater discharge. No other non-stormwater discharges are allowed under the Stormwater Construction Permit. Other types of non-stormwater discharges must be addressed in a separate permit issued for that discharge. 2.7 Receiving Water Runoff from disturbed areas during construction will be controlled and/or routed through the use of one or more BMPs, as described later in this plan, prior to being discharged to receiving waters. However, it may be expected that runoff from certain areas will into the earth and is not expected to contribute to receiving waters. All streams in the Mamm Creek Unit are tribiTfary to the Colorado River. The project area is located in the Mamm Creek watershed, and drained by Gant Gulch, Middle Mamm Creek, and an unnamed tributary to Middle Mamm Creek. Gant Gulch is tributary to West Mamm Creek. These drainages flow to the northeast into the mainstream portion of Mamm Creek. Mamm Creek is a perennial tributary to the Colorado River. Floodplain habitat occurs along Middle Mamm Creek and East Mamm Creek, which are perennial streams within the Gant Gulch Area. Dry Hollow Creek is also within the Project Area. Riparian habitat is found along the banks of these streams. The riparian vegetation along Middle Mamm creek extends up to 100 feet on either side of the creek. The riparian habitats associated with Middle Mamm, East Mamm and Dry Hollow Creeks, have been determined to be "non-functional" or "functioning at risk" (M. Kinser, BLM, personal communication, September 2005) (BLM 2005). The Grass Mesa area is located within the watersheds of Dry Creek and Ramsey Gulch. Both of these creeks are tributaries to the Colorado River. Stream flows in the drainages within the Grass Mesa area are generally ephemeral and dependent on seasonal storm and snowmelt runoff. Floodplain habitats occur along the intermittent drainages within Dry Creek and Ramsey Gulch but no floodplain habitat would be impacted by the proposed action. Intermittent drainages occur along Dry Creek and Ramsey Gulch. However, no wetland habitats or riparian vegetation have been documented along these drainages (BLM 2004) 2.8 Master SWMP Permit Area Map and Individual Stormwater Site Plans An overall Master SWMP Permit Area Map is provided as Appendix D. This map is likely to change constantly and will be updated at least annually. The Master SWMP Permit Area Map includes: • Contours and elevations (topography) with existing drainage patterns; F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 2-11 Updated June 2009 • Locations and names of major surface waters such as streams, wetlands, irrigation ditches, canals, etc., • Master SWMP permit area boundaries; • Construction area locations including roads, pipelines, well pads, compressor station facilities, treatment facilities, water parks, and all other facilities. Individual Stormwater Site Plans (Site Plans) of each site (well pad, access road, section of pipeline, etc.) are provided with the Site Specific Records (Volume 2 of the Master SWMP) Separate Site Plans will be developed for each phase of construction: preconstruction, construction, interim reclamation (if applicable), final stabilization (if applicable) and final reclamation (if applicable). These Site Plans include: • Construction site boundaries (this is the area expected to be disturbed by clearing, excavating, grading, or other construction activities); • Contours and elevations (topography) with existing and propos drainage patterns; • Limits of well pads and locations of reserve pits and well h (i pplible); • All areas of ground surface disturbance, including areas of cut fill; • Locations of all potential pollutant sources listed in Section 2.5 (including areas used for vehicle fueling, the storage of materials, equipment, soil, or waste, etc...); • Locations of all minor surface waters and all anticipated allowable sources of non-stormwater discharge (including springs, dewatering, concrete washout, etc...); • Locations of all existing and planned BMP#Ohcludingerosion, drainage, and sediment controls); i • Locations, names, distances to wetlaids, irrigation ditches, canals, other surface waters, etc; • The size, type and location of any ouffall(s). If the stormwater discharge is to a municipal separate stormwater system, name that system, the location of the storm sewer discharge, and the ultimate receiving water(s). Figures showing typical BMP locations along roadways and pipelines are provided as part of the BMP Manual (discussed in Section 3.3). F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 2-12 Updated June 2009 3.0 Best Management Practices (BMPs) A key component of this Master SWMP is employing BMPs to improve stormwater quality. Local factors will be evaluated to determine what BMPs are suitable and practical at different locations. BMPs will be employed in different combinations during construction activities and phases as conditions warrant. Due to the fact that this Master SWMP is likely to cover more than one ecosystem (as described in Section 2.4), the selection of BMPs (including type, quantity, sequence/combination, etc.) will vary at each site within the Master SWMP Permit Area. Specific BMPs to be employed at each well pad, road, pipeline, or other facility are identified on the Site Plans, which are kept with the Site Specific Records (Volume 2 of the Master SWMP). 3.1 Erosion, Drainage, and Sediment Control BMPs The primary method for controlling erosion, drainage, and sediment transport consists of minimizing initial disturbance of the soil and ground cover. However, many other methods can also be used. All stormwater- related BMPs will fall under at least one of the following three types of controls: • Erosion Control. Any source control practice that protects the soil surface and/or strengthens the subsurface in order to prevent soil particles from being detached by rain or wind, thus controlling raindrop, sheet, and/or rill erosion. • Runoff Control. Any practice that reduces or eliminates gully, channel, and stream erosion by minimizing, diverting, or conveying runoff. • Sediment Control. Any practice that traps the soil particles after they have been detached and moved by wind or water. Sediment control measures are usually passive systems that rely on filtering or settling the particles out of the water or wind that is transporting them prior to leaving the site boundary. BMPs may also be classified as either structural or non-structural controls: • Structural Control. Handles sediment -laden stormwater prior to it leaving each site. Structural BMPs are used to delay, capture, store, treat, or infiltrate stormwater runoff. Some examples of structural BMPs include sediment traps, diversions, and silt fences. Most Runoff Controls and Sediment Controls can also be classified as Structural Controls. • Non-structural Control. Reduces the generation and accumulation of pollutants, including sediment, from a construction site by stabilizing disturbed areas and preventing the occurrence of erosion. Some examples of non-structural BMPs include revegetation, mulching, and surface roughening. These types of stabilization techniques are not only the most effective method for reducing soil loss, but they are also normally the most cost effective due to low initial cost and reduced maintenance requirements. Most, but not all, Erosion Controls can also be classified as Non-structural Controls. The Site Plans, as mentioned previously and kept with the Site Specific Records (Volume 2 of the Master SWMP), show the proposed locations of all erosion, drainage, and sediment control BMPs (both structural and non-structural). Detailed descriptions, design criteria, construction specifications, and maintenance information for all BMPs are provided in the BMP Manual (discussed in Section 3.3). 3.2 Non-Stormwater Control BMPs Non-stormwater controls include general site and materials management measures that indirectly aid in the minimization of water pollution. Types of pollution sources include, but are not limited to, litter, oil and grease, hazardous material spills, and sediment. F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 3-1 Updated June 2009 3.2.1 Materials Delivery and Storage The good housekeeping practices listed below will be followed on site during construction and operation: • An effort will be made to store only enough product required for task completion. • All materials stored on site will be stored in a neat and orderly manner in appropriate containers and, where possible, under a roof or other enclosure, and/or within secondary containment areas to avoid contact with stormwater. • Products will be kept in their original containers with the original manufacturer's label. • Substances will not be mixed with one another unless recommended by the manufacturer. • Whenever possible, all of the product will be used before disposing of the container. • Manufacturer's recommendations for proper use and disposal will be followed. Additional information on material delivery and storage is available in the BMP Manual (discussed in Section 3.3). 3.2.2 Material Handling and Spill Prevention In addition to the material storage practices (listed in the previous section) that will be used to reduce the risk of spills or other accidental exposure of materials and substance, the BMP Manual (discussed in Section 3.3) will provide more detailed information on spill prevention and control. Furthermore, the Spill Prevention, Control and Countermeasure (SPCC) Plan will be followed for the control of hydrocarbons. In general, spill prevention and response procedures will include notification (CDPHE 24-hour spill reporting line — 877-518- 5608), clean-up with the use of spill kits and absorbents, and ensuring that materials and wash water can not discharge from the site, and never into a storm drain system or stream. 3.2.3 Vehicle Cleaning, Fueling, Maintenance, and Tracking Controls As required by EnCana Oil & Gas (USA), Inc. master service agreement(s) and drilling contract(s), contracting companies and/or vendors are required to service all vehicles and equipment prior to entering EnCana facilities. However, in the event maintenance procedures are required at EnCana facilities, all fluids transferred must utilize secondary containment and drip pans to minimize a release of materials and properly dispose or recycle spent materials in compliance with local, state, and federal guidelines. While on site, equipment will be parked, serviced, and fueled within designated areas. Equipment fueling on pipeline rights-of-way will be mobile during active construction. Periodic inspections of equipment and control procedures will be implemented. Selected equipment may be fueled in place using fuel trucks. When necessary, equipment and machinery will be decontaminated at an on-site decontamination area prior to removal from the construction area. Areas will be provided with adequate waste disposal receptacles for liquid as well as solid waste. Vehicle tracking of sediments is not expected to be a problem due to construction scheduling. Construction vehicles will remain on site throughout earth -moving activities. All other vehicles remain in stabilized areas and do not enter the construction area until that area is stabilized. However, applicable BMPs (such as scheduling (to minimize site access), stabilized construction entrances, vehicle cleaning, etc.) will be utilized if sediment tracking does become a problem. In addition to the typical practices listed above, the BMP Manual (discussed in Section 3.3) provides more detailed information on vehicle cleaning, fueling, maintenance, and tracking controls. F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 3-2 Updated June 2009 3.2.4 Waste Management and Disposal As required by EnCana Oil & Gas (USA), Inc. master service agreement(s) and drilling contract(s), contracting companies and/or vendors are required to manage all waste generated by their activities at EnCana facilities in compliance with local, state, and federal guidelines. EnCana Oil & Gas (USA) utilizes a periodic inspection program to ensure waste management requirements are fulfilled and inspections are documented. A few of the waste management procedures that will be followed include the following: • Proper bins will be provided for trash collection and disposal in compliance with local, state, and federal guidelines. • Contaminated soils will be placed into a lined and bermed area. Samples of the impacted soil will be collected and a complete characterization analysis will be performed. When applicable, the impacted soil will be sent to a licensed disposal facility. • The contractor will provide portable toilets. Sanitary waste will be regularly collected by a licensed sanitary waste management contractor and disposed of in an approved manner. • In the event that sediment is inadvertently transported off the construction site, it will be collected and returned to the site and placed on the soil stockpile or spread over the construction pad area and compacted. On well pads and access roads concrete washout is used as an interior conductor pipe ballast. Concrete washout water can NOT be discharged to surface waters or to storm sewer systems without separate permit coverage. However, discharge to the ground of concrete washout water from washing of tools and concrete mixer chutes may be authorized by this permit, provided that (CDPHE, 2007a): 1. The source is identified in the SWMP; 2. BMPs are included in the SWMP to prevent pollution of groundwater; and 3. These discharges do not leave the site as surface runoff or to surface waters. Locations where concrete washout activities take place are shown on the Site Plans. Additional waste management proceduincluding solid waste, hazardous waste, contaminated soil, concrete washout, and septic and sanitary waste, are included in the BMP Manual (discussed in Section 3.3). 3.2.5 Dewatering Dewatering refers to the mechanical removal of water from an excavation or other structure. Both groundwater and stormwater may require dewatering during construction. Dewatering of pipelines at the completion of hydrostatic testing will be required for most pipeline installations. 3.2.5.1 Groundwater Dewatering Groundwater is very rarely encountered during the construction activities associated with either E&P sites or Midstream Services sites. If groundwater is encountered, it is typically during construction of a pipeline across a stream crossing. These pipelines are either bored under the stream or a flume is utilized. Non-stormwater construction dewatering of groundwater can NOT be discharged to surface waters or to storm sewer systems without separate permit coverage. However, discharges to the ground of water from construction dewatering activities may be authorized by this permit, provided that (CDPHE, 2007a): F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 3-3 Updated June 2009 1. The source is groundwater and/or groundwater combined with stormwater that does not contain pollutants in concentrations exceeding the State groundwater standards in Regulations 5 CCR 1002-41 and 42; 2. The source is identified in the SWMP; 3. BMPs are included in the SWMP; and 4. These discharges do not leave the site as surface runoff or to surface waters. Dewatered groundwater shall be pumped or diverted to a sediment control BMP prior to discharge to the ground. Locations of groundwater dewatering, as well as any BMPs utilized, will be noted on the Site Plans as soon as such dewatering occurs. Additional information on groundwater dewatering is provided in the BMP Manual, discussed in Section 3.3. 3.2.5.2 Stormwater Dewatering The discharge of pumped stormwater (not including groundwater or other non-stormwater sources) from excavations, ponds, depressions, etc., to surface water, or to a municipal separate storm -sewer system is allowed by the Stormwater Construction Permit, as long as the dewatering activity and associated BMPs are identified in the SWMP (including location of the activity), and BMPs are implemented in accordance with the BMP Manual, discussed in Section 3.3 (CDPHE, 2007c). Stormwater that collects in open depressions or trenches during constrtctio s will be dewatered into an existing sediment control, such as a detention pond, a sediment trap, or,, im a well -vegetated area to percolate into the ground and catch suspended sediment. The quality, source, an location of dewatering, as well as any BMPs utilized, will be noted on the Site Plans as soon as such dewatering occurs. Additional information on stormwater dewatering is provided in the BMP Manual, discussed in Section 3.3. 3.2.5.3 Pipeline Dewatering New Department of Transportation (DOT) pipelines are hydrostatically tested with water upon completion of construction. Once the hydrostatic testing has been completed, dewatering of the pipeline must occur. This will involve the insertion of a displacer, commonly referred to as a pig, in the pipeline. The discharge rate will be regulated, and energy dissipation devices, and/or sediment controls will be used, as necessary, to prevent erosion, streambed scour, suspension of sediments, or excessive streamflow. Locations on pipeline dewatering, as well as any BMPs utilized, will be noted on the Site Plans as soon as such dewatering occurs. Additional information on stormwater dewatering is provided in the BMP Manual, discussed in Section 3.3. 3.3 Stormwater Vulikof BMPs A Stormwater Manual of Best Anagement Practices (BMP Manual) is provided as Appendix E. The BMP Manual has been prepared to provide EnCana personnel, contractors, and subcontractors with information on the proper selection, design, installation, and maintenance of BMPs to manage oil and gas related stormwater and to meet federal and state SWMP implementation requirements. The main objectives of the BMP manual are to: • Serve as an easy-to-use guide for selecting, designing, installing, and maintaining BMPs. • Function as a reference for construction plans and specifications. • Ultimately lead to the avoidance of any net increase in off-site erosion and sedimentation of waters of the U.S. The BMPs within this BMP Manual are organized into four main types of controls for easy reference: Erosion Controls, Runoff Controls, Sediment Controls, and Non-stormwater Controls. Each of these types of controls has been discussed earlier in this section of the SWMP. F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 3-4 Updated June 2009 3.4 Phased BMP Implementation Various BMPs will be implemented and maintained during different phases of the project. A description of each phase is as follows: • Preconstruction. The preconstruction phase involves the installation of BMPs (temporary and/or permanent) around each site perimeter and at discharge points (such as vegetation buffers (no installation required for this BMP), slash, wattles, diversions, sediment basins and reservoirs, etc...). • Construction. The construction phase involves the stripping and stockpiling of topsoil, the excavation and backfill for access roads, pipelines, and well pads, and the installation of additional BMPs (preferably permanent BMPs) to control erosion and sedimentation (such as tracking topsoil piles and the installation of roadside channels, culverts, diversions, etc...). • Interim Reclamation. The interim reclamation phase primarily involves seeding of all disturbed areas not needed during operation of the well pads. However, this phase also involves the installation of any additional permanent BMPs that may be needed, as well as the continued maintenance and inspections of all BMPs until final stabilization occurs. Final stabilization occurs once all surfaces are built on, paved or graveled, and/or a uniform stabilized vegetative cover with a density of 70 percent of pre -disturbance levels has been established or when an equivalent permanent, physical erosion reduction method has been employed. A further explanation of final stabilization is provided as section 4 of this plan. • Final Reclamation. For pipelines, this phase involves seeding of all disturbed areas, and the installation of any additional permanent BMPs that may be needed, as well as the continued maintenance and inspections of all BMPs until final stabilization occurs. For other areas (roads, well pads, facilities, etc...), this phase (which may occur after termination of this permit and under the coverage of a new construction permit) occurs when operation of the area is no longer necessary. In these cases, this phase will include the installation of any additional BMPs required during facility decommissioning as well as the spreading of any remaining topsoil, the application of seed, and the inspection/maintenance of all BMPs until final stabilization occurs. Temporary controls, such as silt fencing, may be used to control sediment and erosion during preconstruction and construction activities. Permanent controls, such as diversions and sediment traps, may also be used during the initial phases of the project. However, only permanent controls will be used during interim reclamation and final stabilization. Temporary controls may be converted into permanent controls (such as revegetating a diversion) if needed. The primary control used during interim and final stabilization will be revegetation. Seeding will occur as soon as possible after disturbance of an area is complete. If the seeding is not successful, the area will either be eseeded or other controls will be put in place until reseeding can occur. ir 0 F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 3-5 Updated June 2009 4.0 Interim Reclamation and Final Stabilization As soon as practicable after construction activities have been completed in a disturbed area, interim (for well pads, or other facilities) or final (for roads and pipelines) reclamation will be started to prevent further erosion of soil from that area. This typically occurs immediately upon completion of earthwork activities. All disturbed areas (except for the surface of dirt roads, those portions covered by pavement or a structure, and those areas used during operation of a well) will be stabilized with permanent controls. The most common measure used to achieve final stabilization is revegetation. Mulching, erosion control blankets, surfacing with gravel or slash, and/or other methods may also be used. Structural controls (such as diversions, berms, and sediment traps) may be revegetated and used as permanent measures to control pollutants in stormwater discharges that will occur after construction operations have been completed. Appendix E includes detailed information on each of the previously discussed BMPs. In addition, a revegetation manual is provided as Appendix B, which provides guidance as to possible methods and materials needed to accomplish revegetation on differing site conditions. The specific BMPs used at each site are shown on the Site Plans wh. kept with the Site Specific Records (Volume 2 of the Master SWMP). Final stabilization means that all ground surface disturbing ties at the site have been completed, and all disturbed areas have been either built on, paved, or a uniform vegetative cover has been established with an individual plant density of at least 70 percent of pre -disturbance levels, or equivalent permanent, physical erosion reduction methods have been employed. For purposes of this permit, establishment of a vegetative cover capable of providing erosion control equivalent to pre-existing conditions at the site will be considered final stabilization. Areas developed as stabilized unpaved surfaces as needed for operation of the facility after interim reclamation, will also qualify as "finally stabilized." This includes dirt road surfaces and the portions of the well pad surfaces that cannot be revegetated due to operational necessity, but does not include slopes, ditches, and other areas where revegetation is necessary. Stabilized unpaved surfaces will be prepared in such a way as to prevent ongoing erosion issues. Coverage under the Stormwater Construction Permit may be inactivated for any individual site or a portion/section of that site (i.e. the access road to a well pad) when the area has attained final stabilization and all temporary erosion and sediment control measures associated with that area have been removed. An area will be considered finally stabilized when construction and interim reclamation is complete and when the above final stabilization criteria Ave been met, even though the site may be disturbed again in the future for final reclamation. However, fu e land disturbances that follow final stabilization and result in disturbance of one acre or greater (such as a lamation) will require new permit coverage at that time. Upon final stabilization of any site i i °.n/section of a site, Oil and Gas Construction Field Permit Certification NOTICE OF AMENDMENT OF PERMIT COVERAGE and/or Final Stabilization Certification (provided in Appendix F) will be placed into the Site Specific Records binder to replace the Site Plans and the inspection and maintenance records for that area. However, the Site Plans and inspection reports shall be retained in a separate location for a period of three years following final stabilization of the Permit Coverage Area. These documents will be made available to WQCD or EPA upon request and at the time of inspection. F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 4-1 Updated June 2009 5.0 Inspection and Maintenance Inspections and maintenance is an extremely important part of the Stormwater Construction Permit. The Construction Manager will ensure that all stormwater management controls are constructed or applied in accordance with governing specifications or good engineering practices. Experienced teams will be used for construction. A first inspection will occur upon installation of the controls. In addition, all workers on the site will be trained as to the location and use of the controls, especially those controls that will be disturbed as construction proceeds across the site. The goal is to minimize the potential for inadvertent removal or disturbance of BMPs and to prevent the off site transport of sediment and other pollutants. 5.1 Inspection Schedule Inspections are required as soon as the first soil disturbance occurs at the site. Once final stabilization of the site has occurred and the EnCana inspector has filled out the final stabilization certification sheet (see Section 4), inspections are no longer necessary. Specific information regarding inspection schedules are provided in the following sections. 5.1.1 Minimum Inspection Schedule for active sites The minimum inspection schedule applies to those sites under active construction, which includes the period from when the ground is initially disturbed to when construction activity is completed, and also includes the preparation of areas that will be revegetated for interim reclamation. During the Active Site period, a thorough inspection of the site stormwater management system (which includes all utilized BMPs) must be conducted at least every 14 calendar days. Also, post -storm event inspections must be conducted within 24 hours after the end of any precipitation or snowmelt event that causes surface erosion. There are three exceptions to the minimum in'pection schedule which are described in detail within the next three sections: post -storm event inspectiogs at temporarily idle sites (inspections required within 72 hours after a storm), inspections at corlreted sites (inspections required monthly), and inspections during certain winter conditions (inspections may not be required). Any use of an exception is temporary, and does not eliminate the requirement to perform routine maintenance due to the effects of a storm event or other conditions that may impact BMP performance, including maintaining vehicle tracking controls and removing sediment from impervious areas. Inspections, as described above, are required at all other times. 5.1.2 Post -Storm Event Inspections at Temporarily Idle Sites Temporarily idle sites are those where there are no construction activities occurring following a storm event. At such sites, post -storm event inspections must be conducted prior to restarting construction activities at the site, but no later than 72 hours following the storm event, and the delay noted in the inspection report. Routine inspections still must be conducted at least every 14 calendar days. 5.1.3 Completed Sites Once construction is completed and the site has been prepared for interim or final stabilization (including completion of appropriate soil preparation, amendments and stabilization practices), the site (or portion of the site) is considered a Completed Site (for purposes of the stormwater permit). Note: only construction activities that result in a disturbance of the ground surface must be completed. Construction activities that can be conducted without disturbance of the ground surface, such as certain well completion activities, would not prohibit a site from otherwise qualifying as a Completed Site. (Completed Sites still require permit coverage until the final stabilization criteria have been met) Completed Sites qualify for a reduced inspection schedule, as the potential for pollution is reduced if the site has been adequately prepared and/or seeded. However, because slopes and other disturbed areas may not F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 5-1 Updated June 2009 be fully vegetated, erosion in these areas still occurs which requires maintenance activities such as regrading and seeding of problem areas. As such, inspections must continue in order to address these situations. During the Completed Site period, a thorough inspection of the site stormwater management system (which included all utilized BMPs) is required at least once every month. The SWMP must be amended to indicate those areas that will be inspected at this reduced frequency. 5.1.4 Winter Conditions Inspections Exclusion Inspections are not required at sites where construction activities are temporarily halted, snow cover exists over the entire site for an extended period, and melting conditions posing a risk of soil erosion do not exist. This temporary exclusion is applicable only during the period where melting conditions do not exist, and applies to the routine 14 -day and monthly inspections, as well as the post -storm -event inspections. It is typical that when snow cover exists, even at a Completed Site, significant potential for erosion and BMP failure exists when melting does finally occur. Therefore, the site should prepared prior to snow cover to ensure it is as stabilized as possible, and be prepared to perform site maintenance when melt -off occurs, to alleviate any potential problems. Inspection records (see Section 5.4) will document that winter conditions exist and that inspections will be excluded. 5.2 Performing Inspections Inspections will be conducted by qualified personnel on the followinQars: • All vegetated areas until 70% of pre -disturbance vegetation legs A reac. . • All BMP measures identified in this document. • Construction site perimeter and discharge points. • All disturbed areas. • Areas used for storage of material/waste that are exposed to precipitation. • Other areas determined to have a significant potential for stormwater pollution, such as demolition areas or concrete washout locations, or locations where vehicles enter or exit the site. These areas will be inspected to determine if there is evidence of, or the potential for, pollutants leaving the construction site boundaries, entering the stormwater drainage system, or discharging to state waters. All BMPs will be evaluated to determine if they still meet the design and operational criteria in the SWMP and if they continue to adequately control pollutants at the site. Any BMPs not operating in accordance with Appendix E of this SWMP will be addressed as soon as possible, immediately in most cases, to minimize the discharge of pollutants, rago the Site Specific Records will be updated. 5.3 Maintenance Maintenance activities will ensure that all control measures are functioning at optimum levels and that all procedures and techniques will be in proper working order during a runoff event or spill condition. Any maintenance, repairs, or replacements deemed necessary after required inspections will be corrected as soon as possible (if not immediately), to minimize the discharge of pollutants. Certain maintenance procedures may take a short period of time to make sure that all the proper safety precautions are in place, such as a "one call" for utilities, if the maintenance involves excavation of sediment located above a buried pipeline. Maintenance will include, but is not limited to: • Pickup or otherwise prevention of litter, construction debris, and construction chemicals from becoming a pollutant source prior to anticipated storm events. • Removal of sediment from silt fences, sediment traps, and other sediment controls. F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 5-2 Updated June 2009 • Reseeding of any bare spots where vegetation has failed to establish. • Repairs and/or adjustments to any erosion and sediment control that is deteriorating or found to be performing inadequately. Detailed maintenance requirements for each BMP are identified in Appendix E. When maintenance is required, the following process will typically be followed: 1. Perform inspections according to the minimum inspection schedule discussed in Section 5.1. 2. Note the need for maintenance on the inspection and maintenance report form. 3. If necessary, collect the additional materials and/or resources needed to perform the maintenance activity. 4. Perform maintenance and note the date performed on the inspection and maintenance report form. 5. Re -inspect the area to ensure compliance. 5.4 Documenting Inspections and Maintenance The permittee must document inspection results, maintenance activities, and maintain a record of the results for a period of 3 years following expiration or inactivation of permit coverage. A typical inspection and maintenance report form is provided in Appendix G. Although the site may have a phased construction schedule, all construction areas may be inspected at the same time and on one form. Each well pad, road, pipeline, or other facility which is inspected shall be clearly written on the inspection form. Inspection reports will include the following: • Date of inspection, name of inspector, and title of inspector ,% • The area inspected (Site ID), type of area (well pad, acces9road, pipeline, etc.), phase of construction (preconstruction, construction, etc.), and type of inspection (active, completed, etc.) • Site specific information including disturbed area, soil type(s), ecosystem/vegetation type(s), receiving waters, etc. • Vegetation observations including the percent pre -disturbance vegetation and whether or not vegetation growth has reached 70% of pre -disturbance levels • Specific inspection requirements (all BMPs and areas of potential pollutant sources) • Observed conditions including: Location(s) of discharges of sediment or other pollutants from the site — Location(s) of BMPs that need to be maintained Location(s) of BMPs that failed to operate as designed or proved inadequate for a particular location — Location(s) where additional BMPs are needed that were not in place at the time of inspection • Description and date(s) of corrective action(s) taken, and measures taken to prevent future violations • Changes necessary to the SWMP A hand drawn Site Plan shall be included, if necessary, to show the location(s) of any observed condition (as listed above). F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 5-3 Updated June 2009 After adequate corrective action(s) has been taken and recorded, or where a report does not identify any incidents requiring corrective action, the report will contain a signed statement indicating the site is in compliance with the permit to the best of the signer's knowledge and belief. All completed inspection and maintenance report forms (a blank copy of which is included in Appendix G) are kept with the Site Specific Records (Volume 2 of the Master SWMP). F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 5-4 Updated June 2009 6.0 Plan Revisions and Retention When BMPs or site conditions change, the Master SWMP (Volume 1) and/or the Site Specific Records (Volume 2) will be amended to accurately reflect the actual field conditions. Examples include, but are not limited to, removal of BMPs, identification of new potential pollutant sources, addition of BMPs, modification of BMP installation/implementation specifications or maintenance procedures, and changes in items included in the Site Plans. Changes to the Master SWMP (Volume 1) shall be noted on the SWMP Revisions log at the front of this plan. Changes to individual site conditions will be noted in the Site Specific Records (Volume 2) on the applicable inspection and maintenance report form. All changes in Volume 1 and Volume 2 shall be made prior to actual changes in the site conditions, except for responsive SWMP changes, which shall be made immediately after changes are made in the field or as soon as practical, but in no case more than 72 hours after the change(s) in BMP installation and/or implementation occur at the site that require development of materials to modify the SWMP. At a minimum, the Master SWMP will be updated annually. The Master SWMP and the Site Specific Records will be retained at the EnCana field office in Parachute during active construction and site inspections to ensure accurate implementation and maintenance of BMPs, and required revisions. These documents will be retained for a period of three years following final stabilization of the Permit Coverage Area. These reports will be made available to WQCD or EPA upon request and at the time of inspection. F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 6-1 Updated June 2009 7.0 Inactivation Notice When all disturbed areas associated with the Stormwater Construction Permit have reached "final stabilization" (as described in Section 4), all temporary erosion and sediment control measures have been removed, and all components of the SWMP are complete, the area no longer requires coverage under the permit terms. At that time, EnCana will submit an Inactivation Notice that closes this permit to the WQCD upon final stabilization of all areas covered by the permit. A blank copy of this form is included in Appendix H of this document. Upon receipt of the Inactivation Notice, the WQCD will provide written confirmation that coverage under this permit has been terminated. This historical documentation will be maintained at the EnCana field office in Parachute for a period of at least three years following termination of permit coverage. F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 7-1 Updated June 2009 8.0 Signature The signature page will not be signed unless the SWMP is requested by an agency as a legal document. At that time, the supervisor will review the most updated version of the SWMP and sign it before submitting to an agency. "I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted, to the best of my knowledge and belief, is true, accurate, and complete. 1 am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment or knowing violations." Printed name Ti Signature Printed name Signature e F:\Projects\014-2797\Documents\Operational 8-1 Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc Updated June 2009 9.0 References CDPHE, 2007a. CDPS General Permit, Authorization to Discharge under the Colorado Discharge Permit System. Colorado Department of Public Health and Environment. Water Quality Control Division. Issued May 31, 2007. http://www.cdphe.state.co.us/wq/PermitsUnit/stormwater/SWConstructionPermit.pdf CDPHE, 2007b. General Permit Application and Stormwater Management Plan Preparation Guidance. Colorado Department of Public Health and Environment. Water Quality Control Division. Revised July, 2007. http://www.cdphe.state.co.us/wq/PermitsUnit/stormwater/SWConstructionApplication.pdf CDPHE, 2007c. Rationale. Colorado Department of Public Health and Environment. Water Quality Control Division. 2007. http://www.cdphe.state.co.us/wq/PermitsUnit/stormwater/SWConstructionRationale.pdf CDPHE, 2007d. Stormwater Fact Sheet — Construction at Qil nd Gas Facilities. Colorado Department of Public Health and Environment. Water Quality Control Division. Revised July, 2007. http://www.cdphe.state.co.us/wq/PermitsUnit/stormwater/OGfactsheet. pdf George, R.D. 1927. Geology and Natural Resources of Colorado. University of C ado, Boulder, CO. Mute!, C.F., and Emerick, J.C., 1992. From Grassland to Glacier - The Natura istory of Colorado and the Surrounding Region. 40 U.S. Department of Interior, Bureau of Land Management. 2004. Environmental Assessment of the Grass Mesa Geographic Area Plan. EA# 00140-2004-081 EA. Glenwood Springs Energy Office, Colorado. Online version available at: http://www.blm.qov/co/st/en/fo/gsfo/GSFO MasterPlansOfDevelopment.print.html U.S. Department of Interior, Bureau of Land Management. 2005. Environmental Assessment of the Gant Gulch Geographic Area Plan. EA# C0140-2005-134EA. Glenwood Springs Energy Office, Colorado. Online version available at: http://www.blm.qov/co/st/en/fo/gsfo/GSFO MasterPlansOfDevelopment.print.html USEPA, 1990. NPDES Stormwater Regulations, 40 CFR Parts 122.26. U.S. Environmental Protection Agency. Weiner, R.J., J.D. Haun. 1960. Guide to the Geology of Colorado. Geological Society of America. F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc 9-1 Updated June 2009 Appendix A General Permit Application F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc Updated February 2008 STATE OF COLORADO Bill Ritter, Jr., Governor James B. Martin, Executive Director Dedicated to protecting and improving the health and environment of the people of Colorado 4300 Cherry Creek Dr. S. Denver, Colorado 80246-1530 Phone (303) 692-2000 TOD Line (303) 691-7700 Located in Glendale, Colorado htlioliwww,cdphe.state.co.us June 20, 2007 Laboratory Services Division 8100 Lowry Blvd. Denver, Colorado 80230-6928 (303) 692-3090 Terry C. Gosney, Envir. Coord. EnCana Oil & Gas (USA) Inc., 2717 County Road 215 Ste. 100 Parachute, CO 81635 9701285-2687 RE: Final Permit, Colorado Discharge Permit System — Stormwater Certification No: COR -034840 Mama Creek Garfield County Local Contact: Terry Gosney, Envir. Coordinator 970/309-8155 Dear Sir or Madam: Colorado Department of Public Health and Environment Enclosed please find a copy of the new permit and certification which have been re -issued to you under the Colorado Water Quality Control Act. Your old permit expires on June 30, 2007. This is a renewal to the permit, and replaces the old one. See page 2 of the Rationale (the pages in italics) for a summary of the changes to the permit. Your Certification under the permit requires that specific actions be performed at designated tunes. You are legally obligated to comply with all terms and conditions of the permit. Please read the permit and certification. If you have any questions please visit our website at : www.cdphe.state.co.uslwq/perm_itsunitlstormwater or contact Matt Czahor at (303) 692-3517. Sincerely, r' �F Kathryn Dolan Stormwater Program Coordinator Permits Unit WATER QUALITY CONTROL DIVISION xc: Regional Council of Governments Local County Health Department District Engineer, Technical Services, WQCD Permit File STATE OF COLORADO COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT WATER QUALITY CONTROL DIVISION TELEPHONE: (303) 692-3500 CERTIFICATION TO DISCHARGE UNDER CDPS GENERAL PERMIT COR -030000 STORMWATER DISCHARGES ASSOCIATED WITH CONSTRUCTION Certification Number C0R034840 This Certification to Discharge specifically authorizes: EnCana Oil & Gas (USA) Inc. LEGAL CONTACT: Terry C GU.sney, L:ivir. C oord. EnCana Oil & Gas (USA) Inc. 2717 Count' Road 215 Nie_ 100 Parachute, CO 81635 Phone # 970/285-2687 terry.gosney@encana.com LOCAL CONTACT: Terry Gosney, Envir. Coordinator, Phone # 970/309-8155 ter rg ocneyaen Cana. cam During the Construction Activity: Gas/Oil Field Exploration and/or Development to discharge stormwater from the facility identified as Mamm Creek (44 which is located at: Various locations Various locations, Co 81 650 Latitude 39/25100, Longitude 107/50/00 In Garfield County to: -- Colorado River Anticipated Activity begins 07/01/2002 continuing through 06/30/2010 On 999 acres (999 acres disturbed) Certification is effective: 07/01/2007 Certification Expires: 06/30/2012 Annual Fee: $245.00 (DO NOT PAY NOW — A prorated bill will be sent shortly.) Page 1 of 22 Appendix B Revegetation Manual 4*1Agil* F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc Updated February 2008 EnCana Oil & Gas (USA), Inc. Revegetation Manual Table of Contents INTRODUCTION 2 1.0 Fertilization 2 2.0 Soil Preparation 2 2a. Disking 2 2b. Chisel Plowing 3 2c. Subsoiling 3 2d. Harrowing 3 2e. Cultipacking 3 3.0 Drill Seeding 3 3a. Equipment 3 3b. Methods of Use 4 4.0 Broadcast Seeding 5 5.0 Hydroseeding 6 6.0 Seed Planting Rates and Species Selection for Individual Seed Mixtures 6 7.0 Seed Quality 7 8.0 Seed Storage 7 9.0 Seeding Dates for the Raton Basin 8 10.0 Seed Germination 8 11.0 Seeding Success 8 12.0 Seed Mixtures for the Raton Basin 8 13.0 Mulching and Erosion Control 9 14.0 Maintenance of Seeded Areas 9 APPENDIX B: EQUIPMENT PHOTOS 10 Photo 1: Three Point Spreader 10 Photo 2: Fertilizer Buggy Wagon 10 Photo 3: Tandem Disk 11 Photo 4: Rhome Offset Construction Disk 11 Photo 5: Chisel Plow — Brillion 8' 12 Photo 6: Chisel Plow — John Deere 12 Photo 7: Subsoiler — John Deere 13 Photo 8: Spike Tooth Harrow 13 EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 1 Photo 9: Flex -tine Tooth Harrow 14 Photo 10: Spring Tooth Harrow 14 Photo 11: Cultipacker — Brillion 15 Photo 12: Truax Brand Drill Seeder 15 Photo 13: Horizon Brand Drill Seeder 16 Photo 14: Close-up of Double Disk Furrow Openers and Depth Bands 16 Photo 15: Press Wheels 17 Photo 16: Drag Chains in Transport Position 17 Photo 17: Trashy Seed Box Picker Wheels 18 Photo 18: Small Grain Standard Seed Box/Seed Cups 18 Photo 19: Seed Drill Gear Assembly 19 Photo 20: Seed Tubes 19 Photo 21: Hand Broadcast Seeder 20 Photo 22: Hydroseeder — 3000 Gallon Tank 20 Photo 23: Hydroseeder with Gun Operator 21 Photo 24: Seed Tag 21 EnCana Oil & Gas (USA), Inc. Revegetation Manual Introduction The objective of a revegetation program is to establish a diverse self sustaining vegetative cover that provides for erosion control and a productive land use. There is not a single best method to revegetation practices. This is why revegetation is considered "an Art and a Science". As many revegetation practitioners have said in the past it is better to be lucky than good. Meaning that the most critical ingredient needed to complete the cycle of revegetation is adequate and timely rainfall. Achieving successful revegetation of a disturbed area is even more complicated than a successful crop from dry land farming. Farming practices are normally completed on land that has prime soil for plant growth and consist of cereal grain crops that are easier to grow than native grasses. This manual is for the layman who needs to understand revegetation as part of their job duties with EnCana Oil & Gas (USA), Inc., but does not necessarily have the college degree or hands on experience to complete this type of work. This manual will present steps and options that will help increase the chances of successful revegetation. There are sections EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 2 that outline methods and materials needed to accomplish revegetation on differing site conditions. 1.0 Fertilization Fertilization of areas to be revegetated is often times a consideration. Soil test of the areas to be seeded are the best way to determine if fertilizer is needed. The major nutrients needed by native vegetation for growth is Nitrogen, Phosphorus, and Potassium. Nitrogen is for top growth of plants, Phosphorus is for root growth, and Potassium is for the overall health and vigor of plants. All fertilizer will list the nutrients in the order of Nitrogen, Phosphorus, and Potassium or N -P -K. For example a product listed as 18-46-0 will contain 18 % Nitrogen, 46% Phosphorus, and 0% Potassium. Nitrogen may not be at desirable levels in the soil at the time of seeding. However, research has shown that adding nitrogen at the time of seeding can often times increase the growth and cover of weed species at the expense of the desirable seeded species. Also, nitrogen can not be metabolized by native grasses until they are approximately one year old. For these reasons, most experienced revegetation specialists will not recommend the use of nitrogen at the time of seeding. Instead, they will tend to place nitrogen fixing legumes in the seed mixture. These legumes will pull nitrogen from the atmosphere and provide it later to other plants such as grasses. Phosphorus most likely will be the limiting nutrient in the soil. It is advisable to add phosphorus prior to soil tillage and work it into the soil to a depth of 6 to 8 inches. Most native soils in Colorado contain optimum levels of potassium. Therefore, potassium should very seldom if ever be needed in the Colorado Fields. Fertilizer is typically applied using a Three Point Hitch Tractor Mounted Spreader or Fertilizer Buggy Wagon Implement (See photo #'s 1 and 2: Three Point Spreader and Fertilizer Buggy Wagon). Both of these styles of spreaders are considered broadcast spreaders. Their width of application is typically between 10 and 30 feet. The amount of fertilizer applied per acre is controlled by a slide gate opening on the bottom of the spreader. 2.0 Soil Preparation Soil Preparation is a critical first step to revegetation. The objective is to have the surface 8 inches of soil loose enough to allow for root growth and firm enough on the surface for good seed to soil contact. The soil surface should also be relatively free of rocks, debris, and dirt clods greater than 3 inches in diameter. Too much debris, rock, and clods will prohibit proper seed placement. There are several types of implements that can be pulled behind farm tractors or small dozers to till the soil. These consist of disk, chisel plows, subsoilers, and harrows. The working widths commercially available for soil preparation implements typically vary 6 feet to over 20 feet. The working width of implements used by contractors is typically based on site access and size. Also, smaller contractors may have a limited number and size of tillage implements in their equipment fleet. 2a. Disking Disks are normally used where there is significant surface compaction and the soil needs to be tilled to loosen and large soil clods need to be broken down. Disks also are used where there is a concern of bringing more rock up to the soil surface as will occur with chisels, EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 2 rippers, and subsoilers. Disks should not be used alone where extreme subsoil compaction exist. There are offset disks and tandem disks available on the market. Tandem disks turn the soil twice and offset disks move the soil in opposing directions and help level the surface (See photo #'s 3 and 4: Tandem Disk and Rhome Offset Construction Disk). On very rough sites a Rhome brand construction type disk is recommended because of the weight of the disk and its ability to withstand rough conditions (See photo #4: Rhome Offset Construction Disk). A heavy construction disk normally needs to be pulled behind a mid-size dozer or large 4WD tractor because of its weight and soil penetration ability. 2b. Chisel Plowing A chisel plow cuts through the soil and helps to eliminate soil compaction to a depth of approximately 8 inches (See photo #'s 5 and 6: Chisel Plow). Chisel plowing to a shallower depth can help cut off and kill weeds. Some rock and clod material can be brought to the soil surface during this operation. If a significant amount of clods are brought up to the soil surface then a cultipacker (See Section 2e.) should be utilized to break clods back down prior to seeding. 2c. Subsoiling Subsoiling is used to break up compacted soil layers 6 to 24 inches in depth (See photo #7: Subsoiler). Subsoiling helps to improve water infiltration and aerates subsoil layers to encourage root penetration. Subsoiling can bring up significant large clods in zones with heavy clays and compacted zones. Cultipacking (See Section 2e.) will need to follow subsoiling when large volumes of clods greater than 3 inches are brought to the soil surface. 2d. Harrowing Harrows lightly scratch the ground to loosen a shallow layer of soil (4 inches or shallower). The three styles of harrows consist of a spike tooth harrow (See photo #8), flex -tine tooth harrow (See photo #9), and spring tooth harrow (See photo #10). Harrows should only be used on loose friable soils that do not require deep tillage. Harrows can be used to remove undesirable vegetation such as weeds that will interfere with seeding operations. Harrows will break up surface crust and generally break up clods of topsoil material, but not hard and massive subsoil material. Harrows are excellent for preparing a seedbed for small seeds such as forbs and some shrub seeds. 2e. Cultipacking Cultipackers consist of front rollers that are an open mesh, a middle set of rippers, and a back set of rollers with knurled edges (See photo #11: Cultipacker). The front set of rollers crushes clods, the rippers bring additional clod material to the soil surface, and the rear roller crushes remaining clods and firms the soil surface. 3.0 Drill Seeding 3a. Equipment Drill seeders are implements that are towed behind an agricultural seeder or small crawler dozer (See photo #'s 12 and 13: Truax and Horizon Brand Drills). Drill seeding is considered the optimum means of planting grasses, forbs, and most shrub seed. Rangeland type drill seeders used for planting native vegetation should have several critical features or components. This includes three seed boxes, double disk furrow openers equipped with depth bands, press wheels or drag chains (See photo #'s 14, 15, and 16: Close-up of Double Disk Furrow Openers and Depth Bands, Press Wheels, and Drag Chains in Transport Position). EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 3 The drill seeder should be equipped with three different seed boxes: A legume box is needed for small seed such as wildflowers, alfalfa, sweet clover, etc., a trashy seed box with aggressive picker wheels for handling trashy seed such as bluestems and gramas (See photo #17: Trashy Seed Box Picker Wheels), and a standard seed box used for flowable seeds such as wheat grasses and small grains (See photo #18: Small Grain Standard Seed Box/Seed Cups). Most native grass drill seeders come in 8 to 10 foot planting widths. The seed drill is activated by a series of gears and chains that are attached to one of the drill wheels on the drill (See photo #19: Seed Drill Gear Assembly). When the drive wheel is activated it turns the gears which turn the shafts that run through the seed boxes. The seed gravity feeds into seed cups that are attached to the shaft (See photo #18: Small Grain Standard Seed Box/Seed Cups). The trashy seed box has an extra shaft that runs above the seed cup shaft and has an aggressive picker spiral agitator wheel which forces the seed down to the seed cup so it does not simply float in the seed box (See photo #17: Trashy Seed Box Picker Wheels). The seed from all seed boxes falls through a hole in the seed box where a flexible rubber tube is connected between the bottom of the seed box and the double disk furrow openers (See photo #20: Seed Tubes). The double disk furrow openers, as the name implies, opens a small trench in the soil that the seed falls into. As the drill moves forward the seed is covered with soil and pressed into the ground by the press wheels or drag chains (See photo #1s 15 and 16: Press Wheels and Drag Chains in Transport Position). It is very important that the seed is planted to the right depth and the seed is pressed into the soil firmly to press out air and allow the seed to absorb moisture as it becomes available to help germinate the seed. The double disk is attached to a lift arm assembly that allows it to roll and float over minor obstacles in the ground such as small rocks tree branches, and dirt clods. The drill should be lifted up by using the hydraulic cylinder when large rocks and debris are encountered in the drills path. While rangeland type drill seeders are built to handle tough conditions they can be high maintenance and require a supply of extra parts in the field when breakdowns occur. 3b. Methods of Use Drill seeders should be calibrated for use on a small area before all seeding is completed. Most manufacturers of drill seeding equipment can provide general guidelines as to the amount of seed output by seed box for flowable seeds versus trashy seeds. Calibration will help ensure that the proper amount of Pure Live Seed (PLS) is planted. PLS of any given vegetation species is determined by a registered seed testing laboratory. Individual seeds from individual species are normally placed in a growth chamber to determine the percentage of seeds that will germinate, For example, if 100 seeds are placed in a growth chamber and forced to germinate and only 90 germinate, the germination percentage is considered 90%. Purity is the measure of viable seed and separates out inert material, weed seed (not more than 1% according to federal regulations) and other crop seed. Therefore, the total viable seed is the percent by count that will germinate. The following example provides an illustration of a method of calculating an amount of seed to be planted which takes into account the variation of seed germination and purity of the seed source: Example of a Pure Live Seed (PLS) Calculation: A recommended seed mixture requires that 5 lbs. (PLS) of intermediate wheatgrass be planted: EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 4 Intermediate wheatgrass germination = 80% Intermediate wheatgrass purity = 90% 80% X 90% (PLS) = 0.72 5 lbs (PLS) to be planted 0.72 (PLS factor) = Approximately 7 lbs of bagged seed should be included in the mixture so that 5 lbs of PLS will be planted. Thus, a seed species PLS factor is based on germination X purity. In order to plant one PLS pound of a species you may end up planting 1.6 to 2.0 times more seed which is considered the bulk seed amount. The operator should first decide whether to have the seed mixture divided by trashy vs. flowable species or to combine the species and utilize both seed boxes to achieve proper seed output. It is best to consult with your seed dealer to determine just how trashy or fluffy the seed will be. There are several different opinions in the industry as to how to calibrate a native grass seed drill. The most elaborate method of calibration involves jacking up the drill and spinning the drive wheel the number of revolutions that represent an acre. Seed is caught from one of the seed tubes and weighed after spinning the gauge wheel and the seed weight for one tube is converted into the fraction of an acre that the tube represents. Most drill seeders contain either a slide bar with number settings or gear ratios with numbers to increase or decrease the seed output. These adjustments should be made if more than a 10 % variance of less seed than required occurs. Also, adjustments should be made for too much seed being put down which can be a costly mistake as well as planting too much seed for what the soil and environment will support. The simplest way to calibrate a seed drill is to place two acres worth of seed in the seed box and drill seed 1/2 acre. Fill the seed box back up to the height it existed with two acres worth of material. Next determine if you had to fill more than a 1/2 acre of material or less than, or you were right on with the calibration. Be aware that if you had to place less seed back in the box, than the volume you started with, you are not seeding enough. Calibration of a seed drill can change overnight if seed is left in the drill. Seed may settle in the seed box causing a slight amount of packing and humidity can change the way seed flows from the drill. It is best to finish out the seed in the seed box by the end of the day and start fresh the next day. Remember to check the calibration of the drill at least every 10 acres or each time you refill the drill. Always keep the drill boxes full enough that the seed feeds properly. Remember when seeding on side slopes that seed can slide to the down hill side of the seed box leaving little or no seed to be planted on the high side of the drill. Most drills come equipped with divider boxes to keep seed from sliding all the way to the low end of the drill. If the seed drill does not have divider boxes think of ways to place sheet metal or even card board in the drill to divide it into at least three different compartments. All drill seeding should be completed parallel to slopes or on the slope contour. Drill seeding up and down a slope can result in accelerating erosion after rainfall since the indentations from the drill rows help to concentrate flow and accelerate soil movement down hill. Most native grass species and forbs germinate best if seeded to a depth of 1/4 to 1/2 inch. Most depth bands on drills are set at 1/2 inch so the seed can not be planted any deeper. 4.0 Broadcast Seeding EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 5 Broadcast seeding is typically done where steep slopes prohibit safe operation of a farm tractor or the soil surface is covered with large rock that cannot be economically removed. Hand seeding may be needed in small, tight access areas where machinery cannot effectively operate. Broadcast seeding can be performed either with a hand seeder (See photo #21: Hand Broadcast Seeder) or tractor mounted spreader (See photo #1: Three Point Spreader). Broadcast spreaders typically spread an even swath of seed onto the soil surface. Depending on the roughness of the ground, the seed can end up at various depths in the soil. Broadcast seeding by hand or machine alone will not typically provide good results unless the seed is covered with soil. Broadcast seeding with a tractor should be followed by using a flex harrow to cover the seed with soil. Hand broadcast seeding should be followed by hand raking with a hard tine rake. In both cases the seed should not be raked deeper than 1/2 inch into the ground. 5.0 Hydroseeding Hydroseeding is completed with an actual hydroseeder machine. Most people in the industry use the term hydroseeder/hydromulcher interchangeably since they do both operations (See photo #22: Hydroseeder — 3000 Gallon Tank). A hydroseeder/hydromulcher machine consists of a water tank equipped with a motor that operates a hydraulic agitation system. The top of the machine contains a turret or gun where the seed is discharged (See photo #23: Hydroseeder with Gun Operator). The operator will mix the seed and a small amount of hydromulch in the tanker. The green dyed hydromulch will help the operator see the sprayed area during the seeding operation. The objective of using the hydraulic pressure of the machine is to use enough force from the engine RPM's to shoot or push the seed into the ground. If the seed is not adequately covered with soil, hand raking of the area or slope harrowing should be employed. 6.0 Seed Planting Rates and Species Selection for Individual Seed Mixtures Establishing seed mixtures and planting rates for different native grass, forbs, and shrub seeds is normally done by a revegetation specialist, soil scientist, plant ecologist, or agronomist. These professionals have several years of experience in knowing how many pounds of each type of seed are needed to increase the chances of revegetation success. Any expert in the revegetation industry knows that there are no absolutes in designing a seed mixture. Designing a seed mixture combines both an "Art and a Science". The consultant takes into account what vegetation species are currently growing by vegetation zone on the site. A native vegetation zone or community is controlled by several environmental factors including elevation, degree of slope, aspect of slope (East, west, north, or south facing), soil type (for example sandy or clayey), and the amount of precipitation that the area receives each year. Vegetation communities will typically have at least two grass species to as many as eight species. Shrub and forbs species will also typically be present. There should be at least three grass species in a revegetation seed mixture. Having a number of species in the mixture will promote diversity in the final vegetative cover and will reduce the risk of revegetation failure if one or more of the species does not adapt to site conditions. EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 6 Typically a consultant will base the poundage of each species on several factors. Some species are hard to establish and may require higher poundage of seed to have a chance to establish. Some species may be easy to establish and are seeded at a higher rate to ensure some initial vegetation cover after seeding. Some vegetation species are very aggressive and should represent a small percentage of the seed mixture or they will dominate the site. Each vegetation species has a different number of seeds per pound. For example, Western Wheat Grass has approximately 110,000 seeds per pound while Blue Grama has 825,000 seeds per pound. There are different opinions with scientist as to how much seed to plant on an acre or square foot basis. Typically, the number of seeds planted per square foot is a consideration. Chenoweth & Associates believes that 30 to 75 seeds per square foot should be planted on any site. Others believe that 144 seeds per square foot should be planted on any site, especially steeper windblown slopes. The higher number of seeds per square foot could be based on the risk of loosing seed to water erosion on steep hill sides or wind erosion in high wind prone areas. Higher seeding rates could also be based on very good topsoil replacement that will allow a site to support more vegetation. The general role of thumb for hydroseeding and broadcast seeding is to double the drill seed rate of seed. This rule was established since broadcast and hydroseeding does not typically provide for optimum seed placement and planting depth as compared to drill seeding. A seed mixture at a minimum will consist of native grasses and forbs. As previously mentioned at least three grass species should be in any revegetation seed mixture. The operator (such as EnCana), landowner (either private landowner or federal agencies such as the Forest Service or BLM), and Revegetation Specialist typically consult with one another to determine what the seed mixture should contain. These individuals or organization will determine if the seed mixture should contain only grasses or whether shrub and forbs seed should be added to the seed mixture as well. Typically cost of seed is a driving factor on deciding if these species are added to a seed mixture. 7.0 Seed Quality Seed purchased from a reputable seed dealer should contain a seed tag that provides the germination and purity of each species in the bag. The seed tag should also indicate the Lot number of the seed (See photo #24: Seed Tag). The lot number is to document where and when the seed was harvested. The seed supplier should supply seed that has been tested within one year of the purchase date. 8.0 Seed Storage Seed should be properly stored until it is used. Seed should be kept in a cool dark environment. The temperature in the storage area should never exceed 85°F for enclosed containers and 90°F for good ventilated storage. Seed is not typically impacted by freezing temperatures and in fact some seeds benefit from cold and heat scarification in order to germinate. Seed which becomes wet for any period of time exceeding 48 hours should not be used. If seed is stored over winter or for any extended period of time should be retested. Some seed species will decrease in germination percentage faster than others. Additional seed of some species may have to be purchased and reblended into the original seed mixture to bring the mixture back up to the proper PLS rate desired. EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 7 9.0 Seeding Dates for Colorado Oil & Gas Fields Desirable seeding dates are typically tied to periods when precipitation will closely follow the actual seed planting. Moisture in the Colorado oil & gas fields typically comes during the summer monsoon period which occurs in July and winter rain or snow which is highest in January, February and March. Seeding needs to be completed when the soil is not frozen or wet. Therefore, consultants feel that optimum seeding dates are early in the spring until May 1, mid-July until September 1, and after the first heavy frost until permanent ground freeze. These dates do not always coincide with construction schedules and the urgency to seed after earth work is completed to help control erosion. There are times that seeding a cover crop during a poor seeding period may be beneficial. There are several sterile hybrid seeds on the market today that germinate easily as long as there is some degree of soil moisture available. They are considered sterile since they will not reseed themselves. These hybrids are called treticale. They are typically a cross between winter wheat and a wheatgrass. 10.0 Seed Germination Depending on the vegetation species, germination can occur as soon as 10 days after seeding. Germination is dependent on adequate soil moisture and soil temperature. Normally grass seed needs at least 54°F surface soil temperature to germinate. These temperatures should exist from late April until late August in the Colorado oil & gas fields depending on elevation and soil shading. Germination of all species can often times take several days or weeks depending on the number of species in the seed mixture. Again, this assumes there is adequate soil moisture in addition to proper soil temperatures for seed germination. At the time of peak germination flush as many as 10 to 20 seedlings per square foot may be present. Approximately 75% of the seedlings die off shortly after germination as the plants reach equilibrium of what the soils moisture and nutrient levels will support. If hot dry periods follow germination, some or all of the grasses and forbs may die. A further discussion of this situation is provided in the following section. 11.0 Seeding Success After germination occurs, new seedlings are very dependent on continued available soil moisture to survive. Some grass species are more susceptible to desiccation and die back than others. Thus, if adequate and timely precipitation does not occur during the first growing season failure of the revegetation may occur. This is why it is very important to use the proper materials and procedures identified throughout this report. There are at least two university research units that agree on determining revegetation success after the first growing season. Typically, 3 to 4 live healthy seedlings per square foot after the first growing season will yield long term revegetation success. These seedlings will ultimately yield approximately 40% to 60% canopy cover after the plants mature. 12.0 Seed Mixtures for the Colorado Oil & Gas Fields Seed mixtures will have to be prepared for use in the Colorado oil & gas fields of EnCana Oil & Gas (USA), Inc. well pads, road cut and fill slopes, pipelines and borrow pits. These seed mixtures will be site specific to the ecosystems present. See Appendix A — Seed Mixture Charts with geographic photos for the seven zones of the Colorado oil & gas fields. EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 8 13.0 Mulching and Erosion Control Conserving soil moisture and controlling surface erosion are very important during seedling establishment. Lack of proper erosion control can result in seed being washed away before it germinates. Mulch materials can help conserve soil moisture and reduce erosion. Mulch materials also provide other beneficial functions. They include increasing moisture infiltration from rain and snow, cooling the soil surface, and providing valuable soil organic matter to increase soil structure. Several different types of mulch materials can be used for revegetation purposes. The most common ones used are hay/straw mulch, hydromulch, Flexible Growth Medium and Bonded Fiber Matrix. There are also several types of roll out erosion control blankets that are available to be used in place of mulches on steep slope areas, drainage areas, and stream channels. Erosion control is now required by federal and state laws on most disturbed construction sites and falls under what is called Storm Water Management Permitting. A separate report was prepared for EnCana Oil & Gas (USA), Inc. dealing with education on Storm Water Management Planning and Permitting. An extensive list of mulching and erosion control products is discussed in this report. 14.0 Maintenance of Seeded Areas Maintenance of seeded areas includes weed control, erosion control, and touch up seeding. Most newly seeded sites require these maintenance operations during the first growing season to help insure successful revegetation. In general weed control should be employed anytime weed cover exceeds 20% canopy cover. Site specifics will vary; sometimes 20% weed canopy cover may be desirable. Mechanical weed control must be used immediately after seeding is completed and most likely until the second growing season. Mechanical weed control consists of mowing or hand pulling weeds. Herbicide applications will kill new seedlings and seed in the ground. Herbicides can only be used after the vegetation becomes established at mature height. Reseeding or touch up seeding should occur after adequate time for germination and when bare spots greater than 10 square feet exist. A more extensive discussion of maintenance of seeded areas and weed control can be found in Oil & Gas Field Specific Revegetation Plans. APPENDIX A: SEED MIXTURE CHARTS WITH GEOGRAPHIC PHOTOS APPENDIX A: SEED MIXTURE CHARTS WITH GEOGRAPHIC PHOTOS Seed Mixture # 1 = to be developed per field area Seed Mixture # 2 = to be developed per field area Seed Mixture # 3 = to be developed per field area Seed Mixture # 4 = to be developed per field area Seed Mixture # 5 = to be developed per field area Seed Mixture # 6 = to be developed per field area Seed Mixture # 7 = to be developed per field area EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 9 APPENDIX B: EQUIPMENT PHOTOS Photo 1: Three Point Spreader Photo 2: Fertilizer Buggy Wagon EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 10 Photo 3: Tandem Disk Photo 4: Rhome Offset Construction Disk EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 11 Photo 5: Chisel Plow — Brillion 8' Photo 6: Chisel Plow — John Deere EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 12 Photo 7: Subsoiler — John Deere Photo 8: Spike Tooth Harrow EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 13 Photo 9: Flex -tine Tooth Harrow Photo 10: Spring Tooth Harrow EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 14 Photo 11: Cultipacker — Brillion Photo 12: Truax Brand Drill Seeder EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 15 Photo 13: Horizon Brand Drill Seeder Photo 14: Close-up of Double Disk Furrow Openers and Depth Bands EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 16 Photo 15: Press Wheels Photo 16: Drag Chains in Transport Position EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 17 Photo 17: Trashy Seed Box Picker Wheels Photo 18: Small Grain Standard Seed Box/Seed Cups EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 18 Photo 19: Seed Drill Gear Assembly Photo 20: Seed Tubes EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 19 Photo 21: Hand Broadcast Seeder Photo 22: Hydroseeder — 3000 Gallon Tank tit WESTER% 0` STATES '0021 :'',on i�.. EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 20 Photo 23: Hydroseeder with Gun Operator Photo 24: Seed Tag Kind: EnCana Table 1-3 Shrobland Grasses Pad 1-27 Int 21994AR Mixture;Variety: Thick$pike Wheatgras5e OritanA Ellmobunch Wheatgrass, Socar Slender Wheatgrao*, SAO Lui Canby Dioegraus, Oanbar Prairie Junegraus! Pure', Gr' Origin 30.65 87 WA 30.54 05 WA 28.14 92 WA 5.54 85 CAN 0.9a 87 WA Crop: 0.S7'. 'pert.: 3.34' Weed's: 0.32% Not Wgt: 25.6.4 TE$T DATE:2-07 NOXIOUS 'ArEEDS: NOME FOUND EMARKS: ito'cky Mt. Environmental Concern .51/ ---dov-evrr-1—a-EPe- broa-dra- a e, ac es rill rate Seal -1333 Hwy fir) 1.,)nmorit, "011I5I:J EnCana Oil & Gas (USA), Inc Chenoweth & Associates Environmental Consultants 21 Appendix C Existing Soil and Vegetation Data li F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc Updated February 2008 Figure 1. Mamm Creek Soil Types Mamm Creek Unit Soils MAP SYMBOL, SOIL NAME 12, Bucklon-Inchau loams 16, Cimarron loam 17, Cochetopa loam 24, Dollard -Rock outcrop, shale, complex 28, Heldt clay loam 29, Heldt clay loam 3, Arvada loam 30, Heldt clay loam 31, Heldt clay loam 32, Holderness Variant clay loam 33, Ildefonso stony loam 34, Ildefonso stony loam 39, Jerry loam 4, Arvada loam 40, Kim loam 41, Kim loam 42, Lamphier loam 44, Morval loam 45, Morval-Tridell complex 46, Nihill channery loam 5, Ascalon fine sandy loam 50, Olney loam 51, Olney loam 54, Potts loam 55, Potts loam 56, Potts loam 58, Potts-Ildefonso complex 6, Ascalon fine sandy loam 65, Torrifluvents 66, Torriorthents-Camborthids-Rock outcrop complex 67, Torriorthents--Rock outcrop complex 68, Vale silt loam 69, Vale silt loam 7, Ascalon -Pena complex 70, Vale silt loam 71, Villa Grove -Zoltay loams 9, Badland •RA1 I • •143.144 1-24 1- �6R11 018 • F28 • K28NW • H21 4i 121421 K22NW •J22W •B27 D27NW • •K27NW •M27NW 027NW A33NWC34NW G33NW • • K33NW H27NW •B34NW •H34N W 34NW P33BW N33 SP33• • K� 33NWM34NW �K4B •B9W •C9W E9• F9 K8W • N29 No Soil Data Available M3 :M3A N9B •19W .N9W •B16W •C28 J16W • F10 • D151/41i5 • C15B 13+13 H23NW •J23NW • P238 P23 C26N W • A19N 0 H24NW K24M•J24 K19CNEBNE KRONE • C3ONE MCEF G25NW •B3ONE • H26NW •F25 • 126NW J25 J26NW •KA ••J26NWB P2do..6B P26 C35 PABX • •B35W H1035 H356 L35 K35NW 135 • H3 6N W • •K3A36 H367 6 •p@p35 N36 LB1:6NW J2W 12iWW CSR2-15•RR2-w • N16 •N1 A10B • A10 CSR11-6 8118WD126D12 RUMBA� • E 3- 1 $ W • •N25 B36X•36 •CCS N3ONE •P36 :1W HMWT •P1 • HMC:C7E C29NE B29NE • •A29NE •K29NE 30NE : 29 B31 D3`2D32 • D32WF3•RBWF •328 32 f�32W 3jK32 L J32 • •M32 N32 • +P32 • •J6 •16 •L5 •J5^ UNNS-9 • K31 J31 N31 • •B33N E D34N E • E33NE •` F33 G333NE L34 • P6 N5AN5 • M4E FED5-1e 87 KRK7-1 DS COUEY8-3 • • • wCOUEY8-1 F12 KRK7-7H7 • J11�11W SJ12•FFERK�� J• KRK7-9 •CHRISTNJ8ER8-6 11p8 110 ••• P11 • • KRIA-�B •COU9'411 X108 PARK11•4 012 •PKiK7-1 �O7WO�P7E• •N8E •4W814W D13WD13 • A113:A13 �840: __ • •E G13W •F1S •LI5W 115a115W H15 •G22 N22W • A22W • G14W • 113 J18 •J14•J1341° • P13B • •N18 P14N13WjN13 • P13 62, • M23WN23W K27 • 0127W F26W L15SW • • aF24 W S H23W • P27W P26W N26W • C2SW D2 � M24W •B25 L25W 1 H2SW • K2SW I2SW • •M2S W P11SW K19E.F19 G19 719E • • • K4E P33N433 •M34NE L3E • • P4E • • N4E C9E • • •L9 017E M MR17-1 • • •C17AE E16 1 • • H17E • • X18 L17E MMR17-9 ••K17E• •H1 :E20E •019E 29E • 630E • •J25W •C36W •G1SW P306 • •C31E •H31 •K31 E 031E • •H6 J6SE •• •N7 •COUEY17-12A • ii/1MRT45 MMRT45-20P •G32E HSSE • • FOE •J9E •B16E •C21 •K28E K16SE • 1 M15 N3E • •FLOE E22E • E27E • DOSE • M1OSE • •P34NE 115SE A15 • 102 •M1E 4101E •H23 M24E D26 • •B26E •K26E C2• •G11SE •N12E •B25E B1SE • •P1SE .4 Reference: Soil Survey Staff, Natural Resources, Conservation Service, United States Department of Agriculture. Web Soil Survey. Available online at http://websoilsurvey.nrcs.usda.gov/accessed [02/01/2008] APPENDIX C Soils Table - Mamm Creek Unit SWMP Page 1 of 6 Map Unit Number - Soil Name Surface Runoff (slow/ medium/ rapid) Erosion Potential (slight/ moderate/ severe) Soil Description Soil Depth - USDA Texture(s) m Unified Classification Permeability (inch/hour) Available Water Capacity (inch/inch) Organic Matter (%) R3 -Arvada loam, 1 to 6% slope medium moderate Deep, well drained, sloping soil on fans and high terraces. 0-3 Loam CL -ML 0.60-2.00 0.16-0.18 0.5-1 3-17 Clay, Silty clay loam CL, CH 0.06-0.20 0.07-0.09 17-60 Clay loam, Silty clay loam CL 0.06-0.20 0.09-0.11 R4 -Arvada loam, 6 to 20% slope moderate/rapid severe Deep, well drained, sloping soil on fans and high terraces. 0-3 Loam CL -ML 0.60-2.00 0.16-0.18 0.5-1 3-17 Clay, Silty clay loam CL, CH 0.06-0.20 0.07-0.09 17-60 Clay loam, Silty clay loam CL 0.06-0.20 0.09-0.11 R5 -Ascalon fine sandy loam, 1 to 6% slope medium moderate Deep, well drained, nearly level to gently sloping soil on mesas, alluvial fans, and terraces. 0-5 Fine sandy loam SM 0.60-6.00 0.11-0.16 1-3 5-30 Sandy clay loam SC, CL 0.60-2.00 0.13-0.15 30-60 Sandy clay loam SC, CL 0.60-6.00 0.11-0.15 R6 -Ascalon fine sandy loam 6 to 12% slope medium moderate Deep, well drained, moderately sloping to rolling soil on mesas, terraces, sides of valleys and alluvial fans. 0-5 Fine sandy loam SM 0.60-6.00 0.11-0.16 1-3 5-30 Sandy clay loam SC, CL 0.60-2.00 0.13-0.15 30-60 Sandy clay loam SC, CL 0.60-6.00 0.11-0.15 R7 -Ascalon -Pena complex, 6 to 25% slope medium moderate Moderately sloping to hilly soils are on sides of valleys an alluvial fans. 0-5 Fine sandy loam - Ascalon SM 0.60-6.00 0.11-0.16 1-3 5-30 Sandy clay loam - Ascalon 5C, CL 0.60-2.00 0.13-0.15 30-60 Sandy clay loam - Ascalon SC, CL 0.60-6.00 0.11-0.15 0-12 Stony Loam - Pena CL -ML 0.60-2.00 0.12-0.15 1-3 12-60 Very stony loam - Pena 5C 0.60-2.00 0.03-0.08 R9-Badland rapid severe Steep and very steep, nearly barren land dissected by many intermittent drainage channels. NA Not Available Not Available Not Available Not Available Not Available R12-Buc to 50 50% % slope sl looms, 255 to medium severe Moderately sloping to very steep soils on ridges and mountainsides. 0-4 Loam CL, CL -ML, ML 0.06-2.00 0.16-0.20 2-5 4-25 Clay loam, Loam, Gravelly loam, Gravelly clay loam CL, GM -GC, GM, GC 0.06-2.00 0.11-0.18 25-60 Clay loam, Silty clay loam N/A 0.00-0.00 0.00-0.00 R16 -Cimarron loam, 2 to 12% slope medium moderate Deep, well drained, nearly level to undulating soil in narrow mountain valleys and drainage ways. 0-4 Loam ML 0.60-2.00 0.16-0.18 2-4 4-60 Clay, silty clay loam, silty clay CH, ML 0.06-2.00 0.14-0.16 R17- Cochetopa loam, 9 to 50% sloe P slow severe Deep, well drained, rolling to steep soil is on mountainsides and alluvial fans. 0-21 Loam ML 0.60-2.00 0.16-0.18 3-6 21-60 Clay, stony clay, Stony clay loam CL, CH 0.06-2.00 0.11-0.14 R21 -Cushman -Lamar stony loams, 15 to 65% slope Not available. Not available. Hilly to very steep soils are on mountainsides and mesa banks. 0-4 Stony loam GM -GC 0.60-2.00 0.08-0.11 0.5-1 4-16 Stony loam SM -SC 0.60-2.00 0.08-0.11 16 Unweathered bedrock N/A N/A N/A R24-Dolland-Rock outcrop, shale, complex, 25 to 65% slope rapid very severe 0-5 Clay CL, CH 0.06-0.20 0.17-0.19 1-2 Complex consists of moderately steep to steep Dollard soil and shale outcrop on hills and mountainsides. 5-25 Silty clay, Silty clay loam, Clay CH,CL 0.06-0.20 0.13-0.18 25 Weathered bedrock N/A N/A N/A R27 -1-l0 aquept0 nearly level Not Available Not Available Broadly defined unit consists of deep, somewhat poorly drained to poorlydrained, near) level and y gently sloping, salt -affected soils in narrow foothill valleys, on fans, and on low terraces. 0-8 Clay Loam CH- CL Not available. Not available. Not Available 8-24 Loam ML 24-60 Gravelly cobbly sand GM, SM R28-Heldt clay loam, 1 to 3 % sloe P Not available Not available Deep, well drained, nearly level soil on alluvial fans and sides of voile valleys. 0-8 Clay loam CH- CL 0.06-0.20 0.12-0.17 i 2 8-60 Silty clay, Clay, Clay loam CH- CL 0.06-0.20 0.12-0.17 R29 -Held[ clay loam, 3 to 6% slope P medium moderate Deep, well drained, gently sloping soil on alluvial fans and sides of valleys. Y 0-8 Clay loam CH- CL 0.06-0.20 0.12-0.17 1-2 8-60 Silty clay, Clay, Clay loam CH- CL 0.06-0.20 0.12-0.17 R30-Heldt clay loam, 6 to 12% sloe P medium moderate Deep, well drained, moderately sloping to rolling soil on alluvial fans 0-8 Clay loam CH- CL 0.06-0.20 0.12-0.17 1-2 and sides of valleys. Y 8-60 Silty clay, Clay, Clay loam CH- CL 0.06-0.20 0.12-0.17 R31 -Held[ clay loam, 12 to 25% slope P medium moderate Deep, well drained, moderately steep to hilly soil on alluvial fans and sides of valla Ys. 0-8 Clay loam CH- CL 0.06-0.20 0.12-0.17 i 2 8-60 Silty clay, Clay, Clay loam CH- CL 0.06-0.20 0.12-0.17 R32-Holderness variant clay loam, 6 to 25% slope Not available. Not available. Deep, well drained, moderately sloping to hilly soil on alluvial fans and sides of valleys. 0-11 Clay loam CL -ML, CL 0.2-0.6 0.15-0.19 2-4 11-30 Clay CL -CH 0.06-0.20 0.15-0.19 30-60 Clay loam CL 0.2-0.6 0.15-0.19 R33-I1defonso stony loam, 6 to 25 % slope pe moderate moderate Moderately -sloping to hilly, deep, well -drained stony loam formed from reworked alluvium derived from basalt. Found on mesas, benches, and the sides of valleys. 0-8 Stony loam SM, GM 2.00-6.00 0.08-0.10 1-2 8-60 Very stony loam, very gravelly sandy loam. SM, GM 2.00-6.00 0.06-0.08 0.5-1 R34-I1defonso stony loam, 2510 45 % slope pe moderate severe Hilly, deep, well -drained stony loam formed from reworked alluvium derived from basalt. Found on mesa breaks, alluvial fans and the sides of valleys. 0-8 Stony loam SM, GM 2.00-6.00 0.08-0.10 1-2 8-60 Very stony loam, very gravelly sandy loam. SM, GM 2.00-6.00 0.06-0.08 0.5-1 R35-Ildefonso-Lazear complex, 6 to 65 % slope medium/rapid moderate/severe Moderately sloping to very steep soils on hillsides and mesa breaks. 0-6 Stony loam, Gravelly loam SM, GM, ML 0.60-6.00 0.08-0.16 0.5-1 6 16 Very stony loam, Very gravelly sandy loam, Gravelly loam, Cobbly loam SMGMML , , 0.60-6.00 0.06-0.16 16-60 Very stony loam, Very gravelly sandy loam, Unweathered bedrock SM, GM 0.00-0.00 0.00-0.00 F4Projects\014-2797\Documents \Operational Does \SWMP \Appendix C -Mamm Creek Soils Table 021208.x95 Updated February 2008 APPENDIX C Soils Table - Mamm Creek Unit SWMP Page 2 of 6 Map Unit Number - Soil Name Characteristic Plant Communities Suitability For: Small Commercial Buildings Local Roads & Streets Roadfill Topsoil Pond Reservoir Areas Embankments, Dikes, & Levees Drainage Irrigation Terraces and Diversions Grassed Waterways R3 -Arvada loam, 1 to 6 % slope Western wheatgrass, Alkali sacaton, Inland saltgrass, Winterfat, Bottlebrush Squirreltail, Gardner saltbmsh, Greasewood Severe: shrink -swell. Severe: shrink -swell, low strength. Poor: shrink -swell, low strength. Poor: too clayey,Peres excess sodium. Favorable Excess sodium slowl excess y' sdium, slope. Slo e, eres slowl p p y' excess sodium Peres slowly. Peres slowly, excess y' sodium. R4 -Arvada loam, 6 to 20% slope Big sagebrush, Greasewood, Galleta, Shadscale, Bottlebrush Squirreltail, Western wheatgrass Severe: slope, shrink- swell. Severe: shrink -swell, low strength. Poor: shrink -swell, low strength. Poor: too clayey, excess sodium. Slope Excess sodium Peros slowly, excess sodium, slope. Slope, percs slowly, excess sodium. Slope, pens slowly. Slope, percs slowly, excess sodium. R5 -Ascalon fine sandy loam, 1 to 6% slope Needleandthread, Western wheatgrass, Bluebunch wheatgrass, Big sagebrush, Utah serviceberry Moderate: low strength Moderate: frost action, low strength. Poor: low strength. Fair: too clayey. Seepage, slope. Favorable. Slope. Slope. Slope. Slope. R6 -Ascalon fine sandy loam 6 to 12% slope Needleandthread, Western wheatgrass, Bluebunch wheatgrass, Big sagebrush, Utah serviceberry Severe: slope. Moderate: slope, frost action, low strength. Poor: low strength. Fair: slope, too clayey. Seepage, slope. Favorable. Slope. Slope. Slope. Slope. R7 -Ascalon -Pena complex 6 to 25% slope Needleandthread, Western wheatgrass, Bluebunch wheatgrass, Big sagebrush, Utah serviceberry- Ascalon Severe: slope. Moderate: slope, frost action, low strength. Poor: low strength. Fair: slope, too clayey. Seepage, slope. Favorable. Slope. Slope. Slope. Slope. True mountain mahogany, Big sagebrush, Utah serviceberty, Bluebunch wheatgrass, Western wheatgrass, Indian ricegrass, Bottlebrush Squirreltail -Pena Severe: slope, large stones. Severe: slope, large stones. Poor: large stones. Peer: slope, large stones. Slope, large stones. Large stones. Slope, large stones. Slope, large stones droughty. Slope, large stones. Slope, large stones droughty. R9-Badland Not Available Not Available Not Available Not Available Not Available Not Available Not Available Not Available Not Available Not Available Not Available R72-Buckton-Inchau 25 to 50% slope Gambel oak, Elk sedge, Mountain brome, Utah serviceber ry'Western wheatgrass, Slender wheatgrass, snowberry Severe: depth to rock, slope. Severe: depth to rock, slope, low strength. Poorthin layer, slope, area reclaim. Poor: slope, area thin layer, small stones. Depth to rock, slope, seepage.Common Thin Slope, depth to rock. Rootingdepth, slope. Slope, depth to rock. Slope, rootingdepth.th.looms, R16 -Cimarron loam, 2 to 12% slope Idaho fescue, Bearded wheatgrass, Western wheatgrass, Mountain brome, Big sagebrush, Muttongrass, Slender wheatgrass, Needlegrass, Nodding bromegrass Severe: shrink -swell, low strength. Severe: shrink -swell, low strength. Poor: shrink -swell, low strength. Poor: too clayey. Slope. Hard to Pack Slope, pens slowly. Peres slowly, slope. Slope, pares slowly. Slope, parts slowly. R17- Cochelopa loam, 9 to 50% slope Gambel oak, Mountain brome, Utah serviceberry, Elk sedge, Bearded wheatgrass, Columbia needlegrass, Mountain snowberry Severe: shrink -swell, slope, low strength. Severe: shrink -swell, slope, low strength. Poor: shrink -swell, slope, low strength. Poor: slope, small stones. Slope. Hard to Pack Peres slowly, slope. Slope, pens slowly. Peres slowly, slope. Peres slowly, slope. R21-Cushman-Lazear stony looms, 15 to 65% slope Not available. Severe: slop depthp to rock. Severe: depth to rock, slope. layer, Poor: thin er, area y reclaim. Poor: slope, small stones. Slope, depth of rock. y g Thin layer, lar a stones. Slope, depth to rock. Slope, rooting depth, large stones, droughty. Slope, de depth to rock, large stones, Slope, dep th to rock, large stones, R24-Dolland-Rock outcrop, shale, complex, 25 to 65 % slope Western wheatgrass, Muttongrass, Bigsagebrush, Utah g g g serviceberry, Arizona fescue, True mountain mahogany Severe: slope, pe, shrink- swell, low strength. Severe: slope, shrink- swell, low strength. Poor thin layer, slope, low strength. Poor: slope, too clayey. Slope, depth of rock. Thin layer, hard to pack. Depth to rock, slope, percs slowly. Slope, pens slowly, rooting depth. Depth to rock, pens slowly, slope. Slope, pens slowly, rooting depth. R27-Halequepts, needy level Not Available Not available. Not available. Not available. Not available. Not available. Not available. Not available. Not available. Not available. Not available. R28-Heldt clay loam, 1 to 3% slope Western wheatgrass, Big sagebrush, Green needlegrass, Squirreltail, Wintertat, Prairie junegrass, Low rabbitbmsh, Sandberg bluegrass Severe: shrink -swell, low strength. Severe: shrink -swell, low strength. Poor: shrink -swell, low strength. Poor: too clayey. Slope Hard to Pack Percs slowly, slope. Slope, percs slowly. Percs slowly. Percs slowly. R29-Heldt clay loam, 3 to 6% slope Western wheatgrass, Big sagebrush, Green needlegrass, Squirreltail, Wintertat, Prairie junegrass, Low rabbitbrush, Sandberg bluegrass Severe: shrink -swell, low strength. Severe: shrink -swell, low strength. Poor: shrink -swell, low strength. Poor: too clayey. Slope Hard to Pack Peres slowly, slope. Slope, percs slowly. Peres slowly. Peres slowly. R30-Heldt clay loam, 6 to 12% slope Western wheatgrass, Big sagebrush, Green needlegrass, Squirreltail, Wintertat, Prairie junegrass, Low rabbitbmsh, Sandberg bluegrass Severe: slope, shrink- swell, low strength. Severe: shrink -swell, low strength. Poor: shrink -swell, low strength. P°or: too clayey. Slope Hard to Pack Peres slowly, slope. Slope, percs slowly. Peres slowly, slope. Slope, percs slowly. R31-Heldt clay loam, 12 to 25% slope Western wheatgrass, Big sagebrush, Green needlegrass, Squirreltail, Winterfat, Prairie junegrass, Low rabbitbrush, Sandberg bluegrass Severe: slope, shrink- swell, low strength. Severe: slope, shrink- swell, low strength. Poor: shrink -swell, low strength. Poor: slope, too clayey. Slope Hard to Pack Percs slowly, slope. Slope, percs slowly. Slope, percs slowly. Slope, percs slowly. R32-Holderness variant clay loam, 6 to 25% slope Westem wheatgrass, Letterman needlegrass. Muttongrass, Slender wheatgrass, Prairie junegrass, Big sagebrush, Utah serviceberry Severe: slope, shrink- swell, low strength. Severe: slope, shrink- swell, low strength. Poor: low strength, shrink -swell. Poor: slope. Slope Hard to Pack Slope, percs slowly.Sloe,percs P slowly.Sloe, percs slow) P P Y Slope, pe, Peres slowly. R33-1ldefonso stony loam, 6 to 25% slope N/A Severe: slope, large stones. Severe: slope, large stones. Poor: slope, large stones. Poor: slope, large stones. Seepage, slope. Large stones. Slope, large stones. Slope, large stones, droughty. Large stones, slope. Slope, large stones, droughty. R34-Ildefonso stony loam, 25 to 45% slope N/A Severe: slope, large stones. Severe: slope, large stones. Poor: slope, large stones. Poor: slope, large stones. Seepage, slope. Large stones. Slope, large stones. Slope, large stones, droughty. Large atones, slope. Slope, large stones, droughty. R35-Ildefonso-Lazear complex, 6 to 65% slope Junegrass, Serviceberry, bitterbrush, wheatgrass, sagebrush. Severe: slope, large stones, depth to rock. Severe: slope, large stones, depth to rock. Poor: slopethin , layer, area reclaim. Poor: slope, large stones, small stones, area reclaim. Seepage, slope, depth to rock. Large stones, thin layer. Slope, large stones, depth to rock. Slope, large stones, droughty, rootlng depth. Large stones, slope, depth to rock. Slope, large stones, droughty, rooting depth. F:\Projects\014-2797\Documents\Operational Does \SWMP \Appendix C -Mamm Creek Soils Table 021208.xds Updated February 2008 APPENDIX C Soils Table - Mamm Creek Unit SWMP Page 3 of 6 Map Unit Number - Soil Name Surface Runoff (slow/ medium/ rapid) Erosion Potential (slight/ moderate/ severe) Soil Description Soil Depth USDA Texture(s) Unified Classification Permeability (inch/hour) Available Water Capacity (inch/inch) Organic Matter (%) J R39 -Jerry loam, 12 to 50% slope sos moderate _ Deep, well drained, strongly sloping to steep soil is on mountainsides. 0-3 Loam ML 0.60-2.00 0.16-0.18 3-5 3-40 Gravelly clay loam, cobbly clay loam, cobbly clay GC, CL, CH 0.06-0.20 0.13-0.15 40-60 Gravelly loam, cobbly clay GC, CL, CL -ML, GM -GC 0.60-2.00 0.13-0.15 R40 -Kim loam, 3 to 6% slope slow slight Deep, well drained, gently sloping soil on alluvial fans and benches. 0-60 Loam ML 0.60-2.00 0.15-0.18 0.5-1 R41 -Kim loam, 6 to 12% slope slow slight Deep, well drained, moderately sloping to rolling soil on alluvial fans and benches. 0-60 Loam ML 0.60-2.00 0.15-0.18 0.5-1 R42-Lamphier loam, 15 to 50% slope slow slight Deep, well drained, steep soil on fans and mountainsides. 0-60 Loam ML 0.60-2.00 0.18-0.21 2-4 R44-Morval loam, 3 to 12% slope slow slight Deep, well drained, gently sloping to rolling soil on mesas and sides of valleys. 0-5 Loam CL 0.60-2.00 0.18-0.21 1-2 5-17 Silty clay loam, clay loam CL 0.60-2.00 0.14-0.21 17-60 Stony clay loam, stony loam CL, SC 0.60-2.00 0.08-0.10 R45-Morval-Tridell complex, 6 to 25% slope medium moderate Moderately sloping to hilly soils are on alluvial fans and sides of mesas. 0-5 Loam CL 0.60-2.00 0.18-0.21 1-2 5-17 Silty clay loam, clay loam CL 0.60-2.00 0.14-0.21 17-60 Stony clay loam, stony loam CL, SC 0.60-2.00 0.08-0.10 R46-Nihill channeryDeep, loam, 1 to 6% slope slow severe well drained, gently sloping soil is on alluvial fans and side of valleys derived from Green River shale and sandstone Y 0-11 Channery loam GM, GM -GC, SM, ML 0.60-2.00 0.12-0.16 0 1 11- 60 Very channery loam, very channery sandy loam. GM, GM -GC 2.00-6.00 0.06-0.09 R50 -Olney loam, 3 to 6% slope slow severe Deep, well drained, gently sloping soil is on alluvial fans and side of valleys Y 0-12 Loam CL -ML, ML 0.60-2.00 0.15-0.18 1 2 12-33 Sandy clay loam SC, SM -SC 0.60-2.00 0.14-0.16 33-43 Gravelly sandy clay loam, gravelly sandy loam SC, SM -SC, GC, GM -GC 0.60-2.00 0.10-0.15 43-60 Very gravelly sandy loam, very gravelly sandy clay loam GM, GM -GC, GC 0.60-2.00 0.07-0.10 R51 -Olney loam, 6 to 12 % sloe P slow severe Deep, well drained, moderately sloping to rolling soil on alluvial fans 0-12 Loam CL -ML, ML 0.60-2.00 0.15-0.18 i 2 12-33 Sandy clay loam SC, SM -SC 0.60-2.00 0.14-0.16 and sides of valla Ys 33-43 Gravelly sandy clay loam, gravelly sandy loam SC, SM -SQ, GC, GM -GC 0.60-2.00 0.10-0.15 43-60 Very gravelly sandy loam, very gravelly sandy clay loam GM, GM -GC, GC 0.60-2.00 0.07-0.10 R54 -Potts loam, 1 to 3% slope slow slight Deep, well drained soil on mesas, benches, and sides of valleys. 0-4 Loam ML 0.60-2.00 0.16-0.18 1-2 4-28 Clay loam CL 0.60-2.00 0.19-0.21 28-60 Loam ML 0.60-2.00 0.16-0.18 R55 -Potts loam, 3 to 6 % slope slow moderate Moderately -sloping, deep, well -drained loam and clay loam formed from in alluvium derived from sandstone, shale, and basalt. Found on mesas, benches, and the sides of valleys. Y 0-4 Loam ML 0.60-2.00 0.16-0.18 1-2 4-28 Clay loam CL 0.60-2.00 0.19-0.21 28-60 Loam ML 0.60-2.00 0.16-0.18 R56 -Potts 5loam, 6 to 12%slope 12 % pe moderate severe Gently -sloping to rolling, deep, well -drained loam and clay loam formed from in alluvium derived from sandstone, shale. and basalt. Found on mesas, benches, and the sides of valleys. 0-4 Loam ML 0.60-2.00 0.16-0.18 1-2 4-28 Clay loam CL 0.60-2.00 0.19-0.21 28-60 Loam ML 0.60-2.00 0.16-0.18 R57-Potts-Ildefonso complex, 3 to 12% slope slow moderate Gently -sloping to rolling, deep, well -drained loam and clay loam formed from in alluvium derived from sandstone, shale, and basalt. Found on mesas and the sides of valleys. 0-4 Loam ML 0.60-2.00 0.16-0.18 1-2 4-28 Clay loam CL 0.60-2.00 0.19-0.21 0.5-1 28-60 Loam ML 0.60-2.00 0.16-0.18 0-0.5 R58-Potts-Ildefonso complex, 12 to 25% slope moderate moderate Strongly -sloping to hilly, deep, well -drained loam andclay loam formed from 5 alluvium derived from sandstone, shale, and basalt. Found on mesas and the sides of valleys. 0-4 Loam ML 0.60-2.00 0.16-0.18 1-2 4-28 Clay loam CL 0.60-2.00 0.19-0.21 0.5-1 28-60 Loam ML 0.60-2.00 0.16-0.18 0-0.5 R59-Potts-Ildefonso complex, 25 to 45% slope moderate severe Hilly to very steep, deep, well -drained loam and clay loam formed from in alluvium derived from sandstone, shale, and basalt. Found on alluvial fans and the sides of valleys. 0-4 Loam ML 0.60-2.00 0.16-0.18 1-2 4-28 Clay loam CL 0.60-2.00 0.19-0.21 0.5-1 28-60 Loam ML 0.60-2.00 0.16-0.18 0-0.5 665-Torrifluvents, 0 to 6% slope Not available. low Broadly defined unit consisting of deep, well drained to somewhat poorly drained, nearly level soils on flood plains adjacent to the Colorado River and its major tributaries. Not available. The surface layer ranges from loamy sand and fine sandy loam to silty loam and clay loam. The underlying layers are generally sandy loam or loam stratified with sand, gravel, and cobbles. Not available. Not available. Not available. Not available. R66-Torriorthents-Exposed Camhorthids-Rock outcrop complex, 15 to 70% slope very rapid very severe sandstone and shale bedrock, loose stones, and shallow to deep stony looms and clay found on toe slopes and concave open areas on foothills and mountainsides. 0-4 Variable, Unweathered bedrock CL -ML, ML, SC -SM, SM 0.00-6.00 0.00-0.18 0.5-1 4-30 Clay loam, Fine sandy loam, Loam, Unweathered bedrock CL, CL -ML, SC -SM, SM 0.00-2.00 0.00-0.18 0-0.5 30-34 Unweathered bedrock N/A 0.00-0.20 0.00-0.00 0 R67-Torriorthents- Rock outcrop complex, 15 to 70% slope very rapid very severe Exposed sandstone and shale bedrock, loose stones, and shallow to deep stony loams and clay found on toe slopes and concave open areas on foothills and mountainsides. 0-4 Variable, Unweathered bedrock CL -ML, ML, SC -SM, SM 0.00-6.00 0.00-0.18 0.5-1 4-30 Clay loam, Fine sandy loam, Loam, Unweathered bedrock CL, CL -ML, SC -SM, SM 0.00-2.00 0.00-0.18 0-0.5 30-34 Unweathered bedrock N/A 0.00-0.20 0.00-0.00 0 R68 -Vale silt loam, 3 to 6% slope medium moderate Deep, well drained, gently sloping soil on mesas, terraces, and alluvial fans. 0-11 Silt loam CL, CL -ML 0.60-2.00 0.19-0.22 2-4 11-26 Silty clay loam, clay loam, silt loam CL 0.60-2.00 0.17-0.22 26-60 Loam, silty clay loam, silt loam CL, CL -ML 0.60-2.00 0.13-0.20 R69 -Vale silt loam, 6 to 12% slope Not available. Not available. Deep, well drained, moderately sloping to rolling soil on mesas, benches, and alluvial fans. 0-11 Silt loam CL, CL -ML 0.60-2.00 0.19-0.22 2-4 11-26 Silty clay loam, clay loam, silt loam CL 0.60-2.00 0.17-0.22 26-60 Loam, silty day loam, silt loam CL, CL -ML 0.60-2.00 0.13-0.20 F:\Projects\014-2797\Documents\Operational Does \SWMP \Appendix C -Mamm Creek Soils Table 021208.x45 Updated February 2008 APPENDIX C Soils Table - Mamm Creek Unit SWMP Page 4 of 6 Map Unit Number - Soil Name Characteristic Plant Communities Suitability For: Small Commercial Buildin s Local Roads & Streets Roadfill Topsoil Pond Reservoir Areas Embankments, Dikes, & Levees Drainage Irrigation Terraces and Diversions Grassed Waterways R39 -Jerry loam, 12 to 50% slope Gambel oak, Sedge, Big sagebrush, Utah serviceberry, Nodding bromegrass, Big bluegrass, Western wheatgrass, Slender wheatgrass, Common snowberry Severe: shrink -swell, slope. Severe: shrink -swell, slope, low strength. Poor: shrink -swell, slope, low strength. Poor: slope, too clayey, large stones. Slope Hard to Pack Slope, per.slowly. Slope, peres slowly. Slope, peres slowly. Slope, peres slowly. R40 -Kim loam, 3 to 6 % slope Indian ricegrass, Bluebunch wheatgrass, Prairie junegrass, Muttongrass, Westem wheatgrass, Big sagebrush, Needleandthread, Low rabbitbrush Moderate: shrink- swell, slope. Moderate: shrink - swell, low strength. Fair: low strength. Good. Slope, seepage. Piping. Slope. Slope. Favorable. Favorable. R41 -Kim loam, 6 to 12% slope Indian ricegrass, Bluebunch wheatgrass, Prairie junegrass, Muttongrass, Westem wheatgrass, Big sagebrush, Needleandthread, Low rabbitbrush Severe: slope. Moderate: slope, shrink -swell, low strength. Fair: low strength. Fair: slope. Slope, seepage. Piping. Slope. Slope. Slope. Slope. R42-Lamphier loam, 15 to 50% slope Not available Severe: sloe. p Severe: sloe. p Poor: sloe. p Poor: sloe. p pPiping. Sloe, seepage. Pi in Sloe. p Sloe. p Sloe. p Slope. pe. R44-Morval loam, 3 to 12% slope Western wheatgrass, Needleandthread, Big sagebrush, Bluebunch wheatgrass, Utah serviceberry Moderate: slope, shrink -swell. Moderate: low strength, shrink swell, slope. Fair: low strength, shrink -swell, frost action.. Good. Seepage, slope. Favorable. Slope. Erodes easily, slope. Erodes easily. Erodes easily. R45-Morval-Tridell complex, 6 to 25% slope Western wheatgrass, Needleandthread, Big sagebrush, Bluebunch wheatgrass, Utah serviceberry Severe: slope, large stones. Moderate: low strength, shrink swell, slope. Severe: slope, large stones. Fair: low strength, shrink -swell, frost action. Poor: large stones. Fair: slope. Poor: slope, large stones. Seepage, slope. Large stones. Slope, large stones. Slope, large stones, droughty. Large stones, slope. Slope, large stones, droughty. R46-Nihill channery loam, 1 to 6% slope Western wheatgrass, Bluebunch wheatgrass, Big sagebrush, Needleandthread grass, Indian ricegrass, Low rabbitbrush Slight Slight Good Poor: small stones, area reclaim. Seepage. Seepage. Slope. Slope, droughty. Favorable. Droughty. R50-01ney loam, 3 to 6% slope Western wheatgrass, Bluebunch wheatgrass, Big sagebrush, Needleandthread grass, Indian ricegrass, Rabbitbrush Slight Slight Fair: low strength. Fair: small stones. Slope, seepage. Favorable. Slope. Slope. Slope. Slope. R51 -Olney loam, 6 to 12% slope Western wheatgrass, Bluebunch wheatgrass, Big sagebrush, Needleandthread grass, Indian ricegrass, Rabbitbrush Severe: slope. Severe: slope. Fair: low strength. Fair: small stones, slope.Slope, seepage. Favorable. Slope. Slope. Slope. Slope. R54 -Potts loam, 1 to 3% slope Western wheatgrass, Needleandthread, Bluebunch wheatgrass, Big sagebrush, Indian ricegrass, Low rabbitbrush, Squirreltail Slight Slight Fair: low strength. Fair: small stones. Seepage. Piping. Slope. Slope, erodes easily. Erodes easily. Erodes easily. R55 -Potts loam, 3 to 6% slope Western wheatgrass, Needleandthread, Bluebunch wheatgrass, Big sagebrush, Indian ricegrass, Low rabbitbrush, Squirreltail Moderate: slope. Slight Fair: low strength. Fair: small stones. Seepage. Piping. Slope. Slope, erodes easily. Erodes easily. Erodes easily. R56 -Potts loam, 6 to 12% slope Western wheatgrass, Needleandthread, Bluebunch wheatgrass, Big sagebrush, Indian ricegrass, Low rabbitbrush, Squirreltail Severe: slope. Moderate: slope. Fair: low strength. Fair: slope, small stones. Seepage. Piping. Slope. Slope, erodes easily. Slope, erodes easily. Slope, erodes easily. R57-Potts-Ildefonso complex 3 to 12% slope Western wheatgrass, Needleandthread, Bluebunch wheatgrass, Big sagebrush, Indian ricegrass, Low rabbitbrush, Squirteltail Moderate/Severe: slope, large stones. stones. large o, stones. Fair/Poor: low strength, large stones. Fair/Poor: small stones, large stones. Seepage, slope. Piping, large stones. Slope, large stones. Slope, erodes easily, large stones, droughty, Erodes easily, large stones, slope. Erodes easily, slope, large stones, droughty. R58-Potts-Ildefonso complex, 12 to 25 % slope Western wheatgrass, Needleandthread, Bluebunch wheatgrass, Big sagebrush, Indian ricegrass, Low rabbitbrush, Squirreltail Severe: slope, large stones. Severe: slope, large stones. Fair/Poor: slope, low strength, large stones. Poor: slope, large stones. Seepage, slope. Piping, large stones. Slope, large stones. Slope, erodes easily, large stones, droughty. Slope, erodes easily, large stones. Slope, erodes easily, large stones, droughty. R59-Potts-Ildefonso complex, 25 to 45% slope Western wheatgrass, Needleandthread, Bluebunch wheatgrass, Big sagebrush, Indian ricegrass, Low rabbitbrush, Squirreltail Severe: slope, large stones. Severe: slope, large stones. Poor: slope, large stones. Poor: slope, large stones. Seepage, slope. Piping, large stones. Slope, large stones, Slope, erodes easily, large stones, droughty. Slope, erodes easily, large stones. Slope, erodes easily, large stones, droughty. R65-Torrifluvents, 0 to 6% slope Cottonwood, Willow, Tamarisk, Water -tolerant grasses, sedges, and rushes. Not available. Not available. Not available. Not available. Not available. Not available. Not available. Not available. Not available. Not available. R66-Torriorthents- Cambodhids-Rock outcrop complex, 15 to 70% slope Not available. Not rated Not rated Not available. Not available. Not available. Not available. Not available. Not available. Not available. Not available. R67-Torriorthents- Rock outcrop complex, 15 to 70% slope Not available. Not rated Not rated Not available. Not available. Not available. Not available. Not available. Not available. Not available. Not available. R68 -Vale silt loam, 3 to 6% slope Westem wheatgrass, Prairie sandreed, Needleandthread, Blue grams, Green needlegrass, Rabbitbrush, Utah Serviceberry Moderate: slope. Moderate: low strength. Poor: low strength. Good. Seepage. Piping. Favorable. Favorable. Erodes easily. Erodes easily. R69 -Vale silt loam, 6 to 12% slope Western wheatgrass, Prairie sandreed, Needleandthread, Blue grams, Green needlegrass, Rabbitbrush, Utah Serviceberry Severe: slope. Moderate: slope, low strength. Poor: low strength. Fair: slope. Slope, seepage. Piping. Slope. Slope. Erodes easily, slope. Slope, erodes easily. F:\Projects\014-2797\Documents\Operational Does \SWMP \Appendix C -Mamm Creek Soils Table 021208.xds Updated February 2008 APPENDIX C Soils Table - Mamm Creek Unit SWMP Page 5 of 6 Map Unit Number - Soil Name Surface Runoff (slow/ medium/ rapid) Erosion Potential (slight/ moderate/ severe) Soil Description Soil Depth USDA Texture(s) Unified Classification Permeability (inch/hour) Available Water Capacity (inch/inch) Organic Matter (%) R70 -Vale silt loam, 12 to 25% slope Not available. Not available. Deep, well drained, strongly sloping to hilly soil on mesas, mesa sides, and alluvial fans. 0-11 sot loam CL, CL -ML 0.60-2.00 0.19-0.22 2-4 11-26 Silty clay loam, clay loam., silt loam CL 0.60-2.00 0.17-0.22 26-60 Loam, silty clay loam, silt loam CL, CL -ML 0.60-2.00 0.13-0.20 R71 -Villa Grove-Zoltay loams, 15 to 30 % slope slow/medium slight/moderate Moderately steep to hilly soils on mountainsides and alluvial fans. 0-4 Loam CL 0.20-2.00 0.16-0.19 2-4 4-17 Clay loam, Sandy clay loam, Gravelly clay, Cobbly clay, Cobbly clay loam CL, SC, GC 0.60-6.00 0.10-0.19 17-60 Sandy loam, Loam, Gravelly clay, Cobbly clay, Cobbly clay loam SM -SC, CL -ML, CL, GC,SC 0.06-2.00 0.13-0.16 R72-Wann sandy loam, 1 to 3% slope slow moderate Deep, somewhat poorly drained, nearly level to gently sloping, low- lying soil on terraces and bottom land in valleys. 0-17 Sandy loam SM, SM -SC 2.00-6.00 0.16-0.18 3 6 17-60 Sandy loam, Fine sandy loam, Coarse sandy loam SM, SM -SC 2.00-6.00 0.15-0.17 `The R preceding the soil number represents the Soil Survey of Rifle Area, Colorado. F:\Projects\014-2797\Documents\Operational Does \SWMP \Appendix C -Mamm Creek Soils Table 021208.xds Updated February 2008 APPENDIX C Soils Table - Mamm Creek Unit SWMP Page 6 of 6 Map Unit Number - Soil Name Characteristic Plant Communities Suitability For: Small Commercial Buildings Local Roads &Pond Streets Roadfill Topsoil Reservoir Areas Embankments, Dikes, & Levees Drainage Irrigation Terraces and Diversions Grassed Waterways R70 -Vale silt loam, 12 to 25% slope Western wheatgrass, Prairie sandreed, Needleandthread, Blue grama, Green needlegrass, Rabbitbrush, Utah Serviceberry Severe: slope. Severe: slope. Fair: low strength, slope.Poor: slope. Slope. seepage. F',pl-:g. Slope. Slope. Slope, erodes easily. Slope, erodes easily. R71 -Villa Grove-Zoltay loams, 15 to 30% slope Gambel oak, Utah serviceberry, Western wheatgrass, Elk sedge, Mountain brome, Mountain snowberry Severe: slope, shrink- swell. Severe: slope, low swell. strength, shrink- Poor: low strength, shrink -swell. Poor: slope, small stones. Slope, seepage. Favorable. Slope, excess salt, percs slowly. Slope, excess salt, pens slowly. Favorable, slope, pens slowly. Excess salt, slope, pens slowly. R72-Wann sandy loam, 1 to 3% slope Alkali sacaton, Saltgrass, Baltic rush, Low rabbitbrush, Skunkbush shumac, Sedge Severe: floods. Severe: floods, frost action. Fair: low strength, wetness. Good. Seepage. Seepage. Floods, frost action. Floods. Favorable. Favorable. 'The R preceding the soil number represents the Soil Survey of Rifle Area, Colorado. F:\Projects\014-2797\Documents\Operational Does \SWMP \Appendix C -Mamm Creek Soils Table 021208.xds Updated February 2008 Appendix D Master SWMP Permit Area Map *tgil*‘b* F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc Updated February 2008 RIVER s« BM 5360 Pref Ant34ne Rifle Cern 1 Pits e SJ>9 istif ►fir IMF B 23B , �cF23� 5950 G25NW H26NW F25NW 7' 25NW ,N25NW M27NW 027NW P26BX oq EAST MAMM CREEK COMPRE 029NE J( A33NW B33NE / J D 4NE K33NW G32C 32 G32B Well E33NE .5985 '5972 As Wall .3 H36X P33B11 aCO p33 N34NW :N34NW N36NWB itNo Access K41)W M3 M3A Flatiron WATER TREATMENT PACILITY 114E o I C OlE No Access ravel FIIE 6322 1113 1 COMPRESSOR ST 11 /ON' „6408 Log Mesa Cony,. No Access DI3W CI7AE\ K13242 JI3W LI7E M23W _ 1 'o N23W D 519. Aaif>aka ri "rt / Nzaw 6988 6559 o BISE ro ce. iftir i �os i Pi x 7618 eint1 � o l6 � .irr-14.7Aw s ,...t .. � 7Mt�\ lam. cc:. � r � •�.,` ' ►t l / " `ire PISE 7399 EFINITE 16 TONAL 8400 920o Legend = EnCana Oil & Gas (USA) Inc. 10343 Mamm Creek Unit SWMP Boundary COR 034840 T6S-T8S, R92W-R94W, 6th P.M. 11eled Server, 9 (435) 781-2501 180 North Vernal Ave. Vernal, Utah 84078 SCALE 1" = 2,000' DRAWN BY: mw Existing Road Proposed Access Gas Pipeline SWMP Boundary Line Appendix E Stormwater Manual of Best Managem F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc Updated February 2008 Prepared for: EnCana Oil & Gas (USA) Inc. Parachute, CO 81635 Stormwater Manual of Best Management Practices (BMPs) June 2008 Prepared for: EnCana Oil & Gas (USA) Inc. Parachute, CO 81635 Stormwater Manual of Best Management Practices (BMPs) June 2008 Contents 1.0 Introduction 1 2.0 Planning 2 3.0 Types of Best Management Practices 3 4.0 Principles and practices of erosion control 4 5.0 Erosion control concepts 5 6.0 Selection and implementation of controls 6 7.0 Inspection and maintenance 7 8.0 References 8 Figures Site Isometrics SI -1 Site Isometric — Flat and Gently Sloping Terrain SI -2 Site Isometric — Steep Terrain Site Plans SP -0 Site Plan — Preconstruction SP -1 Site Plan — Flat and Gently Sloping Terrain SP -2 Site Plan — Steep Terrain Details D-1 Access Road Intersection — Well Pad below Road D-2 Access Road Intersection — Well Pad above Road D-3 Well Pad D-4 Road Parallel to Gathering Line and Stream D-5 404 Stream Crossing D-6 Gathering Line Crossing Stream (During Construction Condition) Best Management Practices (BMPs) Erosion Control BMPs: Erosion Control Blanket (ECB) Hydraulic Mulching (HM) Land Grading (LG) — Roads Low Water Crossing (LWC) Mulching (M) Retaining Wall (RW) Revegetation (RV) Riprap (R) Soil Stabilizers (SS) Stockpiling (SP) — Topsoil and Subsoil Surface Roughening (SR) Terracing (T) Turf Reinforcement Mat (TRM) Vegetated Buffer (VB) Wattles (W) M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM i June 2008 Final for revised pages06-09-08.doc Contents (continued) Drainage Control BMPs: Berm (B) Culvert (C) Culvert Inlet Protection (CIP) Culvert Outlet Protection (COP) Diversion (D) Drainage Dip (DD) Level Spreader (LS) Roadside Ditches (RSD) and Turnouts (TO) Run -On Diversion (ROD) Slope Drain (SD) Trench Breaker (TB) Water Bar (WB) Sediment Control BMPs: Check Dam (CD) Detention Pond (DP) Filter Berm (FB) Sediment Reservoir (SedR) Sediment Trap (ST) Silt Fence (SF) Slash (SL) Stabilized Construction Entrance (SCE) Straw Bale Barrier (SBB) Wattles (W) — BMP is provided with erosion controls Non-Stormwater BMPs: Dewatering (DW) Dust Control (DC) Material Delivery and Storage (MDS) Scheduling (S) Spill Prevention and Control (SPC) Vehicle and Equipment Maintenance (VEM) Waste Management (WM) M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM II June 2008 Final for revised pages06-09-08.doc 1.0 Introduction The primary purpose of this Stormwater Manual of Best Management Practices (BMPs) is to provide EnCana personnel, contractors, and subcontractors with information on the proper selection, design, installation, and maintenance of BMPs to manage oil and gas (O&G) related stormwater and to meet federal and state Stormwater Management Plan (SWMP) implementation requirements. The BMPs found in this manual are operating practices that may be used to control erosion, drainage, and sedimentation associated with stormwater runoff from areas disturbed by clearing, grading, and excavating activities related to site preparation and construction of oil and gas production facilities. Although the BMPs in this manual were derived from both common industry practices and from practical field experience, they may not be applicable for certain sites and field conditions. Personnel responsible for stormwater management, whether it is design, construction, maintenance, or environmental compliance, should have a thorough knowledge of the applicable erosion and sediment control measures and the related specifications. The main objectives of this manual are to: 1. Serve as an easy-to-use guide for selecting, designing, constructing, and maintaining BMPs. 2. Function as a reference for construction plans and specifications. 3. Ultimately lead to the avoidance of any net increase in off-site erosion and sedimentation of waters of the U.S. In the preparation of this document, emphasis was placed on the selection and practical application of BMPs, given a variety of basic physical circumstances. The series of figures within this document are provided as a tool to quickly evaluate which BMPs may be useful at a given construction site, whether new or existing. This document anticipates that the user will be prudent and exercise good judgment in evaluating site conditions and deciding which BMP or combination of BMPs is to be used at a specific site. If the BMPs selected are not effective to prevent discharges of potentially undesirable quantities of sediment to a regulated water body, different or additional BMPs should be employed. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM 1 June 2008 Final 06-09-08.doc 2.0 Planning Planning for the inclusion of appropriate BMPs should occur early in the site development process, and can be divided into five separate steps: 1. Site Assessment — Collect the information from the site regarding topography, soils, drainage, vegetation, and other predominant features. Also make note of any existing erosion that is present. Analyze the information to anticipate erosion and sedimentation problems. 2. Avoidance and Minimization — Avoiding or minimizing disturbances on construction sites are the best protection measures against erosion and sedimentation problems. Inclusion of these measures will also decrease the amount of BMPs required during construction. 3. Construction Scheduling and Phasing — Develop a construction schedule and phasing plan that minimizes the amount of area exposed thus minimizing erosion and impacts to the area from development. 4. SWMP — Develop and implement a SWMP that specifies effective BMPs, taking into consideration the information generated from the site assessment and the construction schedule and phasing. 5. Inspections and Maintenance — Inspection and maintenance of BMPs are required by the SWMP. Evaluate the BMPs that will be implemented and allocate the necessary resources to provide for timely and thorough inspections and maintenance. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM 2 June 2008 Final 06-09-08.doc 3.0 Types of Best Management Practices Erosion Control — any source control practice that protects the soil surface and/or strengthens the subsurface in order to prevent soil particles from being detached by rain or wind, thus controlling raindrop, sheet, and/or rill erosion. Drainage Control — any practice that reduces or eliminates gully, channel, and stream erosion by minimizing, diverting, or conveying runoff through engineered systems. Sediment Control — any practice that traps the soil particles after they have been detached and moved by wind or water. Sediment control measures are usually passive systems that rely on filtering or settling the particles out of the water or wind that is transporting them prior to leaving the site boundary. Non-Stormwater Control — any general site and materials management measure that indirectly aids in minimization of erosion and pollution of water. Types of pollution sources include, but are not limited to, litter, oil and grease, hazardous material spills, and sediment. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM 3 June 2008 Final 06-09-08.doc 4.0 Principles and practices of erosion control Types of erosion Splash Energy from the raindrop dislodges soil particles and initiates the erosion process. Sheet Uniform removal of saturated soil particles. Rill Gully Long, narrow incisions in the soil caused by increased runoff velocities. Deep, wide incisions caused by concentrated flow. Streambank Bank sloughing, toe cutting in a natural drainage pattern. Factors affecting erosion Soil type The primary soil property that affects erosiveness is the cohesiveness of the soil. While there are other factors, this is the most dominant factor when considering temporary erosion controls. The generalized soil triangle shows the break between soils that can be considered cohesive or noncohesive soils. This rule of thumb has to be applied with good professional judgment. 4xr IL sr1J Vegetation Vegetation is the primary permanent erosion control for un -stabilized exposed surfaces. Anytime the existing vegetation is removed, there is immediate potential for wind and water erosion. Therefore, any un -vegetated surface should be treated with an appropriate BMP to prevent surface erosion. The appropriate BMP depends on the other factors affecting erosion. Climate The key climatic factors affecting erosion are rainfall intensity, duration, and return frequency, which in turn determine soil particle detachment and transport in runoff. Other climatic properties, such as temperature and growing season, have more to do with reestablishing permanent erosion controls. Topography The slope and length of slope have a direct influence on the transport of dislodged sediment and soil particles down slope. Even very erosive soils on flat slopes will not produce large amounts of sediment because there is not sufficient potential gravitational force to accelerate the surface runoff to velocities that will suspend and transport sediments. As slopes become steeper, the velocity of flow of surface runoff increases with a subsequent increase in sediment loads. That is why velocity management is a critical part of any erosion control practice. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM 4 June 2008 Final 06-09-08.doc 5.0 Erosion control concepts Surface protection Protecting the soil surface will help minimize the amount of soil that is detached and transported as sediment. Minimization of concentrated flows Concentrated flows generate more energy and velocity than sheet flows. Greater depths and velocity generate more erosion and suspension of eroded materials. If concentrated flows develop, BMPs, such as check dams, can be used to reduce the velocity. Where concentrated flows are directed to uniform surfaces, level spreaders can be used to reestablish sheet flows. Velocity reduction Velocity reduction is a key component of BMP strategies. Control measures such as rock check dams, wattles, etc., are placed perpendicular to the direction of flow, whether sheet flow or concentrated flow, to slow the velocity of the water. The BMP type must be selected based on the anticipated depth, velocity, and frequency of flows over the surface or in the channel. Sediment capture Effective sediment control measures are designed and implemented to slow the runoff velocity and retain the sediment -laden water to allow soil particles to fall from suspension and settle out of the runoff. This will facilitate transport reduction and thereby the quantities of sediment that leave the site. Runoff management Runoff management tools are designed to utilize proper grading, diversions, barriers, or interceptor ditches to minimize concentrated flows and divert runoff away from denuded slopes or other critical areas. This can be done by minimizing slope steepness and length through the use of terraces, interceptor berms or ditches or diversion ditches. The concept is to divert clean runoff before it becomes sediment laden. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM 5 June 2008 Final 06-09-08.doc 6.0 Selection and implementation of controls Implementation of BMPs will be successful if used appropriately, taking into account a number of factors. The following are guidelines recommended in determining the appropriate BMPs for the site: 1. Determine the limits of clearing and grubbing. If the entire site will not undergo excavation and grading, the boundaries of cut -and -fill operations should be defined. Buffer strips of natural vegetation may be utilized as a control measure. 2. Define the layout of buildings and roads. This will have been decided previously as part of the general development plan. If building layout is not final, the road areas stabilized with pavement and the drainage features related to roads should be defined as they relate to the plan. 3. Determine permanent drainage features. The location of permanent channels, storm sewers, roadside swales, and stormwater quality controls such as ponds, wetlands, grassed -lined swales, buffer strips, and areas of porous pavement, if known, should be defined. 4. Determine extent of temporary channel diversions. If permanent channel improvements are a part of the plan, the route, sizing, and lining needed for temporary channel diversions should be determined. Location and type of temporary channel crossings can be assessed. 5. Determine the boundaries of watersheds. The size of drainage basins will determine the types of sediment controls to be used. Areas located off site that contribute overland flow runoff must be assessed. Measures to limit the size of upland overland flow areas, such as run-on diversions, may be initially considered at this stage. 6. Select erosion controls. All areas exposed will require a control measure be defined dependent on the duration of exposure. These can be selected based on the schedule of construction. 7. Select sediment controls. Areas greater than 5 acres will require the installation of sediment basins. Consideration can be given to dividing large drainage basins into sub -areas, each served by a sediment basin. 8. Determine staging areas. The schedule of construction will determine what areas must be disturbed at various stages throughout the development plan. The opportunity for staging cut -and -fill operations to minimize the period of exposure of soils can be assessed. The sequence for installing sediment controls and erosion controls can also be determined at this time. 9. Identify locations of topsoil and other stockpiles. 10. Identify location of construction roads, access points, and material storage areas. Once BMPs have been selected, each control should be incorporated into a site-specific plan drawing as a requirement of the SWMP. Each of the following BMPs includes design criteria (to properly locate and size each control) and construction specifications (to properly install the control with the appropriate materials and methods), if applicable. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM 6 June 2008 Final 06-09-08.doc 7.0 Inspection and maintenance All BMPs must be properly inspected and maintained throughout the life of the entire operation according to the "Maintenance Considerations" section in each of the following BMPs. In general, the maintenance program should provide for inspection of BMPs on a regular basis in accordance with the SWMP. Inspection of BMPs should also occur as soon as possible after major rainfall events, particularly at sensitive areas in proximity to a perennial drainage. The inspection should include repair or replacement of the BMPs, where needed, to ensure effective and efficient operation. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM 7 June 2008 Final 06-09-08.doc 8.0 References Arizona Department of Transportation (ADOT), Erosion and Pollution Control Manual. February, 2005. <http://www.azdot.gov/ADOT_and/Storm_Water/Erosion_Pol lution_Control_Manual.asp> California Stormwater Quality Association, Stormwater Best Management Practice (BMP) Handbook — Construction. January, 2003. <http://www.cabmphandbooks.com/Construction.asp> City of Knoxville, Stormwater Engineering, Knoxville BMP Manual - Best Management Practices. July 2003. <http://www.ci.knoxville.tn.us/engineering> Colorado Department of Transportation (CDOT), Erosion Control and Stormwater Quality Guide. 2002. <http://www.dot.state.co.us/environmental/envWaterQual/wgms4.asp> Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> Federal Energy Regulatory Commission (FERC), Upland Erosion Control, Revegetation, and Maintenance Plan. January 2003. Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best Management Practices Field Guide. United States Department of Agriculture (USDA), Forest Service, US Agency of International Development (USAID), 2005. <http://www.blm.gov/bmp/field%20guide.htm> Maine Department of Conservation, Best Management Practices for Forestry: Protecting Maine's Water Quality. Maine Forest Service, Forest Policy and Management Division. Augusta, Maine. 2004. <http://www.state.me.us/doc/mfs/pubs/pdf/bmpmanual/bmpmanual.pdf> New York State Department of Environmental Conservation, New York Guidelines for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997. <http://www.dec.state.ny.us/website/dow/toolbox/escstandards> South Dakota Department of Transportation — Water Quality Enhancement Program, Construction Field Manual — Construction Site Management and Erosion and Sediment Control. South Dakota. United States Army Corps of Engineers (USACE), Engineering and Design - Handbook for the Preparation of Storm Water Pollution Prevention Plans for Construction Activities. February 1997. <http://www.usace.army.mil/inet/usace-docs/eng-pamphlets/ep1110-1-16/> United States Department of Agriculture (USDA), Natural Resources Conservation Service (NRCS), Field Office Technical Guide. 2002. <www.nrcs.usda.gov/technical/efotg> United States Department of the Interior and United States Department of Agriculture. Surface Operating Standards and Guidelines for Oil and Gas Exploration and Development "Gold Book." BLM/WO/ST-06/021+3071. Bureau of Land Management (BLM). Denver, Colorado. Fourth Edition, 2006. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM 8 June 2008 Final 06-09-08.doc SURFACE WATER FLOW CUT SLOPE EROSION CONTROL SEDIMENT CONTROL (i.e. SEDIMENT TRAP (ST)) (TYP.) EROSION CONTROL (i.e. WATTLE (W)) (TYP.) :DETENTION POND (DP) FILL SLOPE EROSION CONTROL WATTLE (W)(TYP.) SURFACE WATER FLOW \ \ \ SEDIMENT RESERVOIR (SEDR) GATHERING LINE TOPSOIL STOCKPILE (SP) �- - ______ 17. - SEDIMENT CONTROL (i.e. CHECK DAM (CD)) CULVERT (C) GATHERING LINE • SEDIMENT RESERVOIR (SEDR) SEDIMENT CONTROL::`5 .c i.e. SEDIMENT TRAP (ST)) (TYP.) h'• EROSION CONTROL -' i.e. WATTLE (W)) (TYP.) ENSRIAECOM NOT TO SCALE LEGEND CUT SLOPE FILL SLOPE ROADSIDE DITCH (RSD) DIVERSION (D) OR (ROD) BERM (B) TOPSOIL STOCKPILE (TS) EROSION CONTROL BLANKET (ECB) WATTLE (W) • RIPRAP (R) VEGETATED BUFFER (VB) CHECK DAM (CD) SEDIMENT TRAP (ST) GROUND SURFACE CONTOUR (BEFORE CONSTRUCTION) FLOW Storm Water Manual of Best Management Practices Encana, Parachute, Colorado DATE: 05/30/08 DRWN: E.S.S./GOL SEDIMENT CONTROL CHECK DAM (CD) FILTER BERM (FB) SEDIMENT TRAP (ST) SILT FENCE (SF) WATTLE (W) OPTIONS EROSION CONTROL OPTIONS EROSION CONTROL BLANKET (ECB) HYDRAULIC MULCHING (HM) MULCHING (M) RETAINING WALL (RW) REVEGETATION (RV) RIPRAP (R) SURFACE ROUGHENING (SR) TERRACING (T) WATTLE (W) SITE ISOMETRIC FLAT AND GENTLY SLOPING TERRAIN FIGURE SI -1 WilEncono BMP Monuol ENC—BMPM_S/-2.OWG Lo out: f7GURE 51-2 User. eschneider Plotted: Jun 09, 2008 — 2:•02'm Xrefs TOPSOIL STOCKPILE (SP) SEDIMENT CONTROL '.'(i.e. WATTLES (W)) (TYP.) \� SEDIMENT CONTROL (i.e. SEDIMENT TRAP (ST)) (TYP.) SEDIMENT CONTROL CHECK DAM (CD) FILTER BERM (FB) SEDIMENT TRAP (ST) SILT FENCE (SF) WATTLE (W) OPTIONS EROSION CONTROL OPTIONS EROSION CONTROL BLANKET (ECB) HYDRAULIC MULCHING (HM) MULCHING (M) RETAINING WALL (RW) REVEGETATION (RV) RIPRAP (R) SURFACE ROUGHENING (SR) TERRACING (T) WATTLE (W) Storm Water Manual of Best Management Practices Encana, Parachute, Colorado SEDIMENT CONTROL (i.e. SEDIMENT TRAP (ST)) (TYP.) ----------------------------- --------------------------- -SURFACE q WATER FLOW File: M:l Encono l BMP ManuaIl dwgs l ENC-BMPM_SP-O. DWG Layout: FIGURE SP-0 User: eschneider Plotted: dun 09 2008 - 2:02pm Xref s: GROUND SURFACE CONTOUR (BEFORE CONSTRUCTION) DIVERSION (D) OR (ROD) VEGETATED BUFFER (VB) SEDIMENT CONTROL �. (i.e. SEDIMENT TRAP (ST)) (TYP.) EROSION CONTROL (i.e. WATTLE (W))(TYP.) SEDIMENT CONTROL OPTIONS EROSION CONTROL OPTIONS CHECK DAM (CD) EROSION CONTROL BLANKET FILTER BERM (FB) (ECB) SEDIMENT TRAP (ST) HYDRAULIC MULCHING (HM) SILT FENCE (SF) MULCHING (M) WATTLE ON) RETAINING WALL (RW) REVEGETATION (RV) RIPRAP (R) SURFACE ROUGHENING (SR) TERRACING (T) WATTLE (W) Storm Water Manual of Best Management Practices Encana, Parachute, Colorado File: M.• Encano BMP Manuall dwgs l ENC-BMPM_ SP -1 and Ds.DWG Layout.: FIGURE SP -1 SURFACE WATER FLOW D-1 STABILIZED CONSTRUCTION ENTRANCE (SCE) ROAD —* CROWN l ---- _ GROUND SURFACE CONTOUR (BEFORE CONSTRUCTION) ------------------ SEDIMENT CONTROL (i.e. CHECK DAM (CD)) (TYP.) SURFACE /L WATER FLOW rD-2 --__ RUN ON DIVERSION (ROD) ---------------------------------- CUT SLOPE EROSION CONTROL D-3 4 DIVERSION (D) — BERM (B) _ FRACING - PIT WELL HEADS SURFACE WATER FLOW DETENTION - POND (DP) ROADSIDE DITCH (RSD) CROWN 4 FILL SLOPE ��P •'EROSION CONTROL SEDIMENT RESERVOIR (SEDR):::: `,/ ... .''.•.'.'. • TOPSOIL STOCKPILE (SP) ____TURNOUT (TO) GATHERING LINE RUN ON DIVERSION (ROD) . EROSION CONTROL ON WATTLE (W) (TYP) •:: • 'GATHERING LINE VEGETATED BUFFER OR SEDIMENT CONTROL (i.e. WATTLE(W)) ... . EROSION CONTROL (i.e. EROSION CONTROL . . BLANKET (ECB)) ENSR AECOM SEDIMENT CONTROL (i.e. SEDIMENT TRAP (ST))(TYP.) EROSION CONTROL (i.e. WATTLE (W))(TYP.) BERM -- SEDIMENT RESERVOIR (SEDR) TOPSOILSTOCKPILE•. . (SP) SLASH (SL) :' WATTLE (W) (TYP.) NOT TO SCALE BMW LEGEND CUT SLOPE FILL SLOPE ROADSIDE DITCH (RSD) DIVERSION (D) OR (ROD) BERM (B) TOPSOIL STOCKPILE (TS) EROSION CONTROL BLANKET (ECB) WATTLE (W) • RIPRAP (R) VEGETATED BUFFER (VB) CHECK DAM (CD) SEDIMENT TRAP (ST) GROUND SURFACE CONTOUR (BEFORE CONSTRUCTION) FLOW Storm Water Manual of Best Management Practices Encana, Parachute, Colorado DATE: 06/06/08 DRWN: E.S.S./GOL SEDIMENT CONTROL CHECK DAM (CD) FILTER BERM (FB) SEDIMENT TRAP (ST) SILT FENCE (SF) WATTLE (W) OPTIONS EROSION CONTROL OPTIONS EROSION CONTROL BLANKET (ECB) HYDRAULIC MULCHING (HM) MULCHING (M) RETAINING WALL (RW) REVEGETATION (RV) RIPRAP (R) SURFACE ROUGHENING (SR) TERRACING (T) WATTLE (W) SITE PLAN FLAT AND GENTLY SLOPING TERRAIN FIGURE SP -1 T W_ I. DIVERSION (D) — BERM (B) _ FRACING - PIT WELL HEADS SURFACE WATER FLOW DETENTION - POND (DP) ROADSIDE DITCH (RSD) CROWN 4 FILL SLOPE ��P •'EROSION CONTROL SEDIMENT RESERVOIR (SEDR):::: `,/ ... .''.•.'.'. • TOPSOIL STOCKPILE (SP) ____TURNOUT (TO) GATHERING LINE RUN ON DIVERSION (ROD) . EROSION CONTROL ON WATTLE (W) (TYP) •:: • 'GATHERING LINE VEGETATED BUFFER OR SEDIMENT CONTROL (i.e. WATTLE(W)) ... . EROSION CONTROL (i.e. EROSION CONTROL . . BLANKET (ECB)) ENSR AECOM SEDIMENT CONTROL (i.e. SEDIMENT TRAP (ST))(TYP.) EROSION CONTROL (i.e. WATTLE (W))(TYP.) BERM -- SEDIMENT RESERVOIR (SEDR) TOPSOILSTOCKPILE•. . (SP) SLASH (SL) :' WATTLE (W) (TYP.) NOT TO SCALE BMW LEGEND CUT SLOPE FILL SLOPE ROADSIDE DITCH (RSD) DIVERSION (D) OR (ROD) BERM (B) TOPSOIL STOCKPILE (TS) EROSION CONTROL BLANKET (ECB) WATTLE (W) • RIPRAP (R) VEGETATED BUFFER (VB) CHECK DAM (CD) SEDIMENT TRAP (ST) GROUND SURFACE CONTOUR (BEFORE CONSTRUCTION) FLOW Storm Water Manual of Best Management Practices Encana, Parachute, Colorado DATE: 06/06/08 DRWN: E.S.S./GOL SEDIMENT CONTROL CHECK DAM (CD) FILTER BERM (FB) SEDIMENT TRAP (ST) SILT FENCE (SF) WATTLE (W) OPTIONS EROSION CONTROL OPTIONS EROSION CONTROL BLANKET (ECB) HYDRAULIC MULCHING (HM) MULCHING (M) RETAINING WALL (RW) REVEGETATION (RV) RIPRAP (R) SURFACE ROUGHENING (SR) TERRACING (T) WATTLE (W) SITE PLAN FLAT AND GENTLY SLOPING TERRAIN FIGURE SP -1 File: M.• Encana l BMP Manual) dwgs l ENC-BMP41 SP-2.DWG Layout.: FIGURE SP -2 User: eschneider Plotted: dun 09, 2008 - 1.56pm Xref's: RUN ON DIVERSION (ROD) =11111 111- 1=111-111-= I1 111 1Ii=ll l= lll--I 11E111E11 5111E111E111.1E111E11 .. EROSION CONTROL =111=l1l=1l lal IIIc. 4 . (i.e. TERRACING (T)) 111 1 1 1 11 1 1 1-1 1- 1 _ 1 I11I111111111111111lle l-1l1-II11111111I "... 1 =1 I I-1 I I-1 1-111=1 -I 11111I I 1-1 11 1=II1=1l1-111-I11 :II l=ll 11 11=111=1 WELL PAD EROSION CONTROL I -III -1I 1=111=1 BERM (B) (i.e. TERRACING (T)) 1 I 1 1 I HI I 1-1 11=11I- s*; A!.....,. l I 111-I I I-111 1 l .-1 l BERM (B) li 111-11111_111-I . E 111-1111 1=111- -= - I -11111111=111 - •- -www" 11=111=1=1=1 El11 11-11 11 Elk -111=111E11 111=111= 11=11G =1 I 111 •=111=111E111 111 111 1 1= 1 11=111 =1111 11 1 111 111 FRACING PIT ;11 1111 11-111 111-1 -1III-III -1I 111-111 111 11 1 1 1 :1I 1' 1 DIVERSION (D) ll1I1111 111 -TOPSOIL 1=111911=11 1 I '1II= 1 1 ,11, 1 )11 11 111= . -111 III 111 111 111-111 1 DIVERSION (D) 1 111_111_111_111_11-040•04:•••••••••1 III -III I_ 1=111 111-111 111 111-111 1 1111111111 111111 1111 111111 111111111111111_ = STOCKPILE 1 1 1 1 1 1-1 W 1 1 I I-111 1 1 1-1 11 1= 11 =111-I I�. WATTLE (W) �111� 111-111-111=111=EE1 11=111=1 I 11111=11=111=1 I -=1 '- 1 111 1 1 1=1 1111 1111 1=_11= 1-II1 _ 1111II 1 111=11 1 l_ll=l1 1111 111 1 =r1==l l 1 =II- 11 \TO 11-1 11 11 I11 I_ 11=1 11 llll 1 I l l 11 I II 1111 1 1 I1 -II 11 111 11 1 IN. 1111 11 Il l 1 1=11=1=11=1 11:::44‘. 11111ll 111II H-1=1- =1W. ROADSIDE DITCH (RSD) 4?.r. -wall11-1=11=11= 11111 — 1111 L111 (SP) EROSION CONTROL WHEN CLOSE PROXIMITY SCREAM 1= 1 1 1 1 1111111 � ili-111 1 11=Ir 111-11 III_ I� �v =111 P� 1 1 = STREAM III III III 111 111 111 111=11 III III III III I I Il i'" III=11 — II III III III 111 I'' A -11 1 III -I I-111=111=' IIII-1111 -1 I I-1 1-111=11 _ _� i .- -I III 1II -I-II-m=1 1 1 1 IFA IMF RUN ON DIVERSION (ROD) SEDIMENT CONTROL (i.e. SEDIMENT TRAP (ST)) (TYP.) ih 1/ - EROSION CONTROL ■■■■�■■■■�■�■�■■■■■■■■■■■■All •• M.P`=N■■■■■Gi'N•■ CUT SLOPE •■:••■o•■N • (i.e. WATTLE (W)) (TYP.) :N:.0===NNNCN Emacs_ EROSION CONTROL . ■....�MMME...MM....:...... ■ ro '=.......... nerci?lib DIVERSION (D) AM: ------■_ ..■NNN... ..;mom ..N■C■, IIN/E/Jr human �� Cm.■'... \iNULL •iid•\ - .N.i■N_rcNrnNi CENiNlmmmmmm DRILLING - PIT -BERM B -- -- -- -'iEcEI ■:Ing. ROADSIDE ._- _ ce" . NEI iii�i ED DITCH (RSD) -- -� ■,� _-` a_��i'e_iill ._- •: -, °�N oriri■iNl BERM (B) - hili%sl NNi11■■ -- w.�.. eeea■c.ilsoma1 it /MINIM/ -- NEIN= MINEMIN - MA NI ■woNNNI,N -:w.N'c.F =imooN%- ENI ( WELL HEADS ,� riV - „�, r.� o ---- - —-r _ — — , DETENTION 1�• POND (DP) Sr r WATTLE (W) (TYP.) ROADSIDE '•••.,, - .: `.' :','a �. - TOPSOIL STOCKPILE (SP) DITCH (RSD) �. ~` SEDIMENT ��.--�e...•, _ ,...:r� r_s IP--' 1 - wn_w:� x K� k- RESERVOIR ' . ov mwa9 •vioow.0s (SEDR) ,.- .,ra ,mc,.A�� \ .asap. � .�G a. ' - ,....„.....„.-4,...,--11-1---r ---- o s mmmmmmmmm ..• VEGETATED BUFFER (VB) :, SEDIMENT CONTROL ------------ p., viii: _ _ _ _ _ _ _ _ _ _ ..`-wer�E FILL SLOPE _ (Le. SEDIMENT TRAP (ST)) (TYP.) I I -- - EROSION CONTROL -AA G� , VEGETATED BUFFER (VB) STREAM EROSION CONTROL WHEN IN PROXIMITY TO STREAM EROSION CONTROL (i.e. RIPRAP (R)) LEGEND 11 i CUT SLOPE _ RIPRAP (R) '.,ry, '' FILL SLOPE VEGETATED SEDIMENT CONTROL OPTIONS EROSION CONTROL OPTIONS .•••.-.• - BUFFER (VB) CHECK DAM (CD) EROSION CONTROL BLANKET FILTER BERM (FB) (ECB) I 1 ROADSIDE DITCH (RSD) SEDIMENT TRAP (ST) HYDRAULIC MULCHING (HM) lb CHECK DAM (CD) SILT FENCE (SF) MULCHING (M) IEW— 1 DIVERSION (D) OR (ROD) SEDIMENT TRAP (ST) BERM %"*=`' WATTLE (W) RETAINING WALL (RW) REVEGETATION (RV) RIPRAP (R) (B) - GROUND SURFACE SURFACE ROUGHENING (SR) TERRACING (T) TOPSOIL STOCKPILE (TS) ------- ----' CONTOUR (BEFORE WATTLE (W) CONSTRUCTION) EROSION CONTROL BLANKET (ECB) I FLOW WATTLE (W) ENSR NOT TO SCALE AECOM Storm Water Manual of Best Management Practices Encana, Parachute, Colorado SITE PLAN STEEP TERRAIN DATE. 06/06/08 DRAM: E.S.S./GOL FIGURE SP -2 File: M.• Encona l BMP Manuol i dwgs l ENC-BMPM SP -1 and Ds. DWG Layout: FIGURE 9-1 User: eschneider Plotted: Jun 09, 2008 - 1.58pm Xref "s.• I PI 1 1 1 1 1 SEDIMENT CONTOL (i.e. CHECK DAM (CD)) (TYP.) ,1,111 STABILIZED CONSTRUCTION ENTRANCE (SCE) SLASH AND/OR EROSION CONTROL SEDIMENT CONTROL (i.e. WATTLE(W)) (TYP.) ur_ Ii File: M.• Encona l BMP Manuol i dwgs l ENC-BMPM SP -1 and Ds. DWG Layout: FIGURE 9-2 User: eschneider Plotted: Jun 09, 2008 - 1.58pm Xref's: SEDIMENT CONTROL (i.e. CHECK DAM (CD)) EROSION CONTROL (i.e. EROSION CONTROL BLANKET (ECB)) SEDIMENT CONTROL (i.e. SEDIMENT TRAP (ST) & CHECK DAM (CD)) (SD) IF DISCHARGESLOPEDRAIN IS ON STEEP SLOPES EROSION CONTROL IN FILL SLOPES NEAR CULVERTS SEDIMENT CONTROL OPTIONS CHECK DAM (CD) FILTER BERM (FB) SEDIMENT TRAP (ST) SILT FENCE (SF) WATTLE (W) EROSION CONTROL OPTIONS EROSION CONTROL BLANKET (ECB) HYDRAULIC MULCHING (HM) MULCHING (M) RETAINING WALL (RW) REVEGETATION (RV) RIPRAP (R) SURFACE ROUGHENING (SR) TERRACING (T) WATTLE (W) Storm Water Manual of Best Management Practices Encana, Parachute, Colorado ACCESS ROAD INTERSECTION WELL PAD ABOVE ROAD DIVERSION (D) BERM (B) RUN ONI =1I ----_ _ _ DIVERSION (ROD) CUT..�,� I' LI BERM (B) � WELL PAD DETENTION POND (DP) EROSION CONTROL — (i.e. TERRACING (T)) EROSION CONTROL 1 lI I III 1 II= 11 11 III 4 _____ 11 (i.e. TERRACING (T)) II 111 111111II 1 I I' III I � . I I III III I III 1I=1I 1 III 1 � 7 -----_____ __FILL 11 1111=1111 111=III I I1=III III—III EII 111= _____ -1 q � �� III -11 i 1= 1111 I S I—II I III=III III=III III, —W-7-071!1111 i I I-111 DIVERSION (D) le —IIIIII III -III III IIII III III HI' --' , FRAC OR DRILL PIT TOPSOIL STOCKPILE (SP) WATTLE (W) WIDE BERM (B) BERM (B) rWITHIN ROADWAY ROAD WELL PAD CCESS pAD AI 1I 111 111 II Ii= —11 11 1=1 1=1 III 1=1 III—i II I III 1=1 III — I 1=1 1=1 1=1 _ III ,III III I I I � 1111=111=1111 1111 MIL ,1 11111111111 1111111 I I� 11- 1 - I i 1 1=1 7-=11,171,1,172,1,1:11111:111111:1111111"- /� -_ ill—III III III= DIVERSION (D) WITH CH CHECK DAMS CD ✓ I 1111 I ( ) 1111 11 SEDIMENT RUN ON EROSION CONTROL CONTROL DIVERSION (ROD) (i.e. WATTLE (W)) (TYP.) (i.e. SEDIMENT TRAP (ST)) (TYP.) . •'iMi�MMMMMMMMMMMMMM • • �I� M MMMMMaw•'. =sm. . •.'..11 M.iMMMMMMMMMMMMMM CUT SLOPE �• .lMMMMMMMMMMMMMMMMMM. DIVERSION (D) I' 4MMMMMMMMMMMMMMMMMM EROSION CONTROL .M MMMMMMMMMMMMMMMMMMM ,. • ••.•.•• ROADSIDE ,•, DITCH (RSD)'.'.'•"AnFLOW • lir A• NEW AM�i :IF BERM (B) FRACING _ PIT DRILLING r PIT \ . \, ''•SURFACE WATER C is M WELL HEADS i t • I R A 1. INSLOPE — / • 40 '\— SURFACE : WATER FLOW DETENTION POND (DP) .. ' .•.• BERM B .• ...: SEDIMENT3.8- `° RESERVOIR • ••••.,• ` ` :.SURFACE (SEDR) 03 WATER ' FILL SLOPE , ..dRB FLOW EROSION CONTROL' . TOPSOIL STOCKPILE •d�b (SP WATTLE (W)'• ) ,•' • '•'• •• SEDIMENT CONTROL • • .'• VEGETATED BUFFER ' i.e. WATTLE W =�1 (' ( )) ..•. s.. •'. `.'.'.'` , ,......:. a .• • .:.:. ...- .'...'.•..'. _. w.„ :,'.'.'. .'.'. 1 (VB) SLASH AND/OR - y4. n�ie�:;oma _' aww CONTROL OPTIONS EROSION CONTROL OPTIONS EROSION CONTROL = ••... '.' ,' •' et• w =SEDIMENT CHECK DAM (CD) EROSION CONTROL BLANKET FILTER BERM (FB) (ECB) SEDIMENT TRAP HYDRAULIC MULCHING •. o. GATHERING LINE i• .rki r' a _ _ ,, i ,,,,.. (ST) (HM) SILT FENCE (SF) MULCHING (M) WATTLE (W) RETAINING WALL (RW) NOT TO SCALE REVEGETATION (RV) RIPRAP (R) SURFACE ROUGHENING (SR) TERRACING (T) WATTLE (W) ENSR 1 AECOM Storm Water Manual of Best Management Practices Encana, Parachute, Colorado WELL PAD DATE: 06/06/08 DRWN: E.S.S./GOL FIGURE D-3 SLASH AND/OR EROSION CONTROL WINDROW ROADSIDE DITCH (RSD) EROSION CONTROL (i.e. RIPRAP (R)) _ INSLOPE -.116:60 1-111—1 ifil II III III III III -BACKFILL II— I II II II ICUILVERTI(G)I IIV II II= II I I I I I I I I I IIII 1=1 ��11 STREAM =l 1 1 111 111-11 1 1 1 1—III 1 11 1III IIIIII III 11 11 I_I I 11 111 1 1111 ;111 -III III=III-1 1 1 1 1 III III III I I I GATHERING LINE 1— iii—iii—ii 11 I—III I —III1 I III=IIII II I II IIII= III= I 1 I I—III I 111 111 111 111 _ —11 —1 H=1 i11=-111=111=111= III=111=_L== _ ___ _ ==111= _ __ =III=III=IIIIIIIII=III=III=III III I I I=I 11 I I I ,1 1111111 EROSION CONTROL (i.e. RIPRAP (R)) VEGETATED BUFFER (VB) CUT SLOPE SEDIMENT CONTROL _(i.e. SEDIMENT TRAP (ST)) EROSION CONTROL (i.e. EROSION BLANKET (ECB) AND REVEGETATION (RV)) LSURFACE I WATER FLOW <SLASH AND OR EROSION CONTROL INSLOPE EROSION CONTROL (i.e. RIPRAP (R)) CULVERT (C) I I :ice tiuffi-_" CULVERT PROTECTION (CP) .4111. ROAD SLOPE .•.' VEGETATED .BUFFER (VB) SLOPE DRAIN (SD) IF .'. . . DISCHARGE IS ON • STEEP SLOPES .EROSION CONTROL.•.•.• • ON STEEP SLOPES EROSION CONTROL (i.e. RIPRAP (R)) NOT TO SCALE ENSR AECOM SEDIMENT CONTROL OPTIONS CHECK DAM (CD) FILTER BERM (FB) SEDIMENT TRAP (ST) SILT FENCE (SF) WATTLE (W) EROSION CONTROL OPTIONS EROSION CONTROL BLANKET (ECB) HYDRAULIC MULCHING (HM) MULCHING (M) RETAINING WALL (RW) REVEGETATION (RV) RIPRAP (R) SURFACE ROUGHENING (SR) TERRACING (T) WATTLE (W) Storm Water Manual of Best Management Practices Encana, Parachute, Colorado DATE 06/06/08 DRWN E.S.S.\GOL ROAD PARALLEL TO GATHERING LINE AND STREAM 1 FIGURE D-4 File: M d Encana l BMP Manual) dwgs l ENC-BMPM_SP-1 and Ds.DWG Layout:: FIGURE D-5 User: eschneider Plotted:: Jun 09, 2008 - 2.01pm Xref's: EROSION CONTROL (i.e. RIPRAP (R)) ROAD 1 1 FILL - EROSION CONTROL ON STEEP SLOPES CONTROL 1-1,11 IliIII II1 II -%\(i EROSION — — • 1I _III I I I I I I I I III III III III III III III III — ��•� II 11 1-1I ll -ll — III III III III III III ERT (C) 11 III—III III III III—III III III 1. CULV 111 III—III =I 111=III III III 1 11 111111111111111 � 1 . l111=111 11111111111111111111 1 1 (i.e. RIPRAP (R)) SECTION VIEW ROAD —i PROFILE VIEW 40' MIN. SLIGHT MOUND OVER CULVERT CULVERT (C) 4-- ROAD EROSION CONTROL (i.e. RIPRAP(R)) SEDIMENT CONTOL (i.e. CHECK DAM (CD) OR SEDIMENT TRAP (ST)) ABOV FLOOD PLAIN SURFACE WATER FLOW ROADSIDE DITCH (RSD) i; my_ RENiii_ .- INSLOPE m D 1 EROSION CONTROL (i.e. EROSION CONTROL BLANKET (ECB) AND WATTLES (W)) VEGETATED BUFFER (VB) i i ROAD lV, 8%, —R 1UR1.4OVS Nim EROSION CONTROL (i.e. RIPRAP (R)) CULVERT (C) SURFACE WATER FLOW ROADSIDE DITCH (RSD) •\ ROAO 8%) _FtUCs�OPt SLOPE DRAIN (SD) IF•. DISCHARGE IS ON STEEP SLOPES, L'A;N'0 7.•. . VEGETATED BUFFER (VB) ; . NOT TO SCALE ENSR AECOM r INSLOPE EROSION CONTROL •,-,•. -,(i.e. RIPRAP (R)) •� EROSION CONTROL . • ON STEEP SLOPES SEDIMENT CONTROL OPTIONS CHECK DAM (CD) FILTER BERM (FB) SEDIMENT TRAP (ST) SILT FENCE (SF) WATTLE (W) EROSION CONTROL OPTIONS EROSION CONTROL BLANKET (ECB) HYDRAULIC MULCHING (HM) MULCHING (M) RETAINING WALL (RW) REVEGETATION (RV) RIPRAP (R) SURFACE ROUGHENING (SR) TERRACING (T) WATTLE (W) Storm Water Manual of Best Management Practices Encana, Parachute, Colorado DATE: 06/06/08 DRWN: E.S.S./GOL 404 STREAM CROSSING FIGURE D-5 STREAM SEDIMENT CONTROL FLUME (i.e. WATTLE (W)) VEGETATION BUFFER SEDIMENT CONTROL (i.e. WATTLE (W)) '• TRENCH BREAKER (TB) (LE. SAND BAGS) GATHER NG LINE RIGHT-OF-WAY r0� GATHERING LINE III Ell NIII E. I■1 I I BillIII TRENCH TRENCH BREAKER (TB) (i.e. SAND BAGS) (TYP.) i--1 I ]i vrv 1 TEMPORARY _ BRIDGE MOVABLE SEDIMENT CONTROL (i.e. WATTLE W/ HANDLES) VEGETATION BUFFER MOVABLE SEDIMENT CONTROL (i.e. WATTLE W/ HANDLES) / SEDIMENT CONTROL OPTIONS EROSION CONTROL OPTIONS NOTE: AFTER TRENCH IS BACK-FILLED, REVEGETATE ENTIRE RIGHT-OF-WAY AND COVER WITH SLASH AND/OR OTHER EROSION CONTROL.. CHECK DAM (CD) EROSION CONTROL BLANKET FILTER BERM (FB) (ECB) SEDIMENT TRAP (ST) HYDRAULIC MULCHING (HM) SILT FENCE (SF) MULCHING (M) WATTLE (W) RETAINING WALL (RW) REVEGETATION (RV) RIPRAP (R) SURFACE ROUGHENING (SR) TERRACING (T) WATTLE (W) I ENSR NOT TO SCALE 1 AECOM Storm Water Manual of Best Management Practices EncanParachute, Colorado GATHERING LINE (DURING CONSTRUCTIONCROSSING CONDITION) DATE: 06/06/08 DRWN E.S.S./GOL FIGURE D-6 Erosion Control BMPs Erosion Control Blanket (ECB) Hydraulic Mulching (HM) Land Grading (LG) — Roads Low Water Crossing (LWC) Mulching (M) Retaining Wall (RW) Revegetation (RV) Riprap (R) Soil Stabilizers (SS) Stockpiling (SP) — Topsoil and Subsoil Surface Roughening (SR) Terracing (T) Turf Reinforcement Mat (TRM) Vegetated Buffer (VB) Wattles (W) M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc June 2008 Erosion Control Blanket (ECB) Description Erosion control blankets are porous fabrics and are manufactured by weaving or bonding fibers made from organic or synthetic materials. Erosion control blankets are installed on steep slopes, over berms, or in channels to prevent erosion until final vegetation is established. However, blankets can also be used as separators or to aid in plant growth by holding seeds, fertilizers, and topsoil in place. Applicability Erosion control blankets may be used in the following applications: • To control erosion on steep slopes and to promote the establishment of vegetation. • To stabilize channels against erosion from concentrated flows. • To protect berms and diversions prior to the establishment of vegetation. • To protect exposed soils immediately and temporarily, such as when active piles of soil are left overnight. • As a separator between riprap and soil to prevent soil from being eroded from beneath the riprap and to maintain the riprap's base. • May be used on slopes as steep as 1:1. Limitations • Blankets used on slopes should be biodegradable, or photodegradable, non-toxic to vegetation or germination of seed, and non-toxic or injurious to humans. • Should not be used on slopes where vegetation is already established. • Some blankets might promote increased runoff and might blow away if not firmly anchored. • If the fabric is not properly selected, designed, or installed, the effectiveness may be reduced drastically. Manufacturer's specifications should be followed. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc ECB -1 June 2008 Design criteria There are many types of erosion control blankets available. Therefore, the selected fabric should match its purpose. Effective netting and matting require firm, continuous contact between the materials and the soil. If there is no contact, the material will not hold the soil, and erosion will occur underneath the material. Fabric should be purchased at an appropriate with to cover the whole width of the channel, if possible. Table ECB -1 indicates some recommended criteria for the selection of erosion control blankets. Construction specifications 1. Smooth soil prior to installation and apply seed prior to fabric installation for stabilization of construction sites. 2. Select the appropriate fabric type. North American Green products are listed in Table ECB -1. However, other products may also be used. Site specifics shall dictate blanket selection and use. 3. Select the appropriate seed mix according to the specification in Revegetation (RV). 4. Installation of the blankets shall be in accordance with the manufacturer's recommendations and according to Figure ECB -1. For blankets being placed in channels, the fabric should be rolled out parallel to the channel if the width is sufficient to cover the entire width of the channel. The fabric needs to be in continuous contact with exposed soil. 5. Pins or staples shall be made of wire 0.162 inch or larger in diameter. "U" shaped staples shall have legs 8" long, and a 1" crown. "T" shaped pins shall have a minimum length of 8". The bar of the "T" shall be at least 4" long. Triangular survey stakes can also be used. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Inspections should determine if cracks, tears, or breaches have formed in the fabric. If the effectiveness of the BMP has been reduced, the fabric should be repaired or replaced immediately. Re -anchor loosened matting and replace missing matting and staples as required. It is necessary to maintain contact between the ground and the blanket at all times. Trapped sediment should be removed after each storm event. References Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best Management Practices Field Guide. United States Department of Agriculture (USDA), Forest Service, US Agency of International Development (USAID), 2005. <http://www.blm.gov/bmp/field%20guide.htm> North American Green, 2004. <http://www.nagreen.com> M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc ECB -2 June 2008 Table ECB -1 Suggested Blanket Types Description (North American Green Product #) Longevity Applications Max. Flow Velocity (feet/sec.) Single Net Straw Blanket (S75) 12 months 4:1 - 3:1 Slopes Low Flow Channels 5 Rapid Degrading Net (DS75) 45 - 60 Days Double Net Straw Blanket (S150) 12 months 3:1 - 2:1 Slopes Moderate Flow Channels 6 Rapid Degrading Nets (DS150) 45 - 60 Days Double Net Blanket 70% Straw/30% Coconut (SC150) 24 months 2:1 - 1:1 Slopes Medium Flow Channels 8 Double Net Blanket 100% Coconut (C125) 36 months 1:1 & Greater Slopes High Flow Channels 10 Double Net Blanket Polypropylene Fiber (P300) 1:1 Slopes Extended Flow Areas High Flow Channels 9 (unveg.) 16 (veg.) Organic Net (S75BN) 12 months 4:1 - 3:1 Slopes Low Flow Channels 5 Organic Net (S150BN) 12 months 3:1 - 2:1 Slopes Moderate Flow Channels 6 Organic Net (SC150BN) 18 months 2:1 - 1:1 Slopes Medium Flow Channels 8 Organic Net (C125BN) 24 months 1:1 &Greater Slopes High Flow Channels 10 M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc ECB -3 June 2008 Figure ECB -1 Erosion Control Blanket Installation 13ury upsluptn rmd of bL]nkel in trench 6- deep by 6- .ick+ 9lanr[axC Use a b' rrr`. overlay whemwtr %mu maths of blarlel are applied side by arida. 8laple pallet Mini ntrn 3 pet sduare yard. Flaw fabric anchored 11 trench Use a 8' overlap wFletearer ohne NA 3 et Wankel*VS end anoi* b >,*. pari fabnc anchcxeid in trench Cher.* skits should be [rase every 18'. Insert a Fuld Or the blanket arta a trench 6" wile by 6' deep and lanilpfirmly Lay the blanket smoothly ash the surface or the sod. Do not stretch the bletlkeL end do nr.g allow wrinkles. Instal slap40 20' On Cerner in Irerdi. 15' 1.1 at 4- irpoasi<sks. purchase tfankel with a3 Width that its ureic entaugh to reach all the way:m=44 the Channel, Plaut Nankai parellrl td the direcGar, flow. Gro rant join strops in lie ceased' dick Lisa chock slots as rO141mnd. NOT TO SCALE L fabr anehorod in trench ,...-.. .. ilii llr�ii 1�1�1=1Fi�l�r, �IWal�al�nlzirylt�.l aillill�l`al�ll M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc ECB -4 Baanrel fatarrr, anchored in trench Placr~ Market parallrl Fir., Ikr dteciion all Flow and anchor securely. 'firing blanket to a Igan-1 arra br.4nm inrrninatrog the Installahor -Y_ June 2008 Hydraulic Mulching (HM) Description Hydraulic mulching (hydro -mulching) is a temporary erosion control practice in which materials such as grass, hay, wood chips, wood fibers, straw, or gravel are hydraulically applied to exposed or recently planted soil surfaces. Hydraulic mulching stabilizes soils by minimizing rainfall impact and reducing stormwater runoff velocity. When used in combination with seeding or planting, hydraulic mulching can aid plant growth by holding seeds, fertilizers, and topsoil in place, preventing birds from eating seeds, retaining moisture, and insulating plant roots against extreme temperatures. Hydraulic application of mulch (as well as seed) can be done quickly and efficiently with the correct equipment and ingredients. Applicability Hydraulic mulching is often used in steep areas where regular mulching is difficult because of environmental constraints. Hydraulic mulches can be used on seeded and planted areas where slopes are as steep as 1:1. Limitations • Hydro -mulching might delay seed germination because the cover changes soil surface temperatures. • The mulch itself is subject to erosion and may be washed away in a large storm. • Maintenance is necessary to ensure that hydro -mulch provides effective erosion control. • Hydraulic application of mulch must be done when no rainfall is expected, preferably within a 24-hour time period. Design criteria No formal design is required. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc HM -1 June 2008 Construction specifications 1. Site preparation: a. Prior to mulching, install the necessary temporary or permanent erosion control practices and drainage systems within or adjacent to the area to be mulched. b. Slope, grade, and smooth the site to fit needs of selected mulch products. c. Remove all undesirable stones and other debris to meet the needs of the anticipated land use and maintenance required. 2. Hydraulic mulching: a. For steep slopes an Erosion Control Mulch (ECM) consisting of a hydraulic matrix such as a Bonded Fiber Matrix (BFM) or Flexible Growth Medium (FGM) may be used. A BFM refers to a continuous layer of elongated wood fiber strands that are held together by a water-resistant bonding agent to form a water -absorbing crust. b. The ECM shall be a hydraulically -applied, flexible erosion control blanket composed of long strand, thermally refined wood fibers, crimped, interlocking fibers, and performance enhancing additives. The ECM shall require no curing time period and upon application shall form an intimate bond with the soil surface to create a continuous, porous, absorbent and erosion resistant blanket that allows for rapid germination and accelerated plant growth. c. The ECM shall conform to the property values in Table HM -1 when uniformly applied at a rate of 3500 pounds per acre (3900 kilograms/hectare) under laboratory conditions. Composition shall be as follows: Thermally Processed Wood Fibers: 74.5% ± 2.5% Crosslinked Hydro -Colloid Tackifier: 10% ± 1% Crimped, Interlocking Fibers: 5% ± 1% Moisture Content: 10.5% ± 1.5% 3. Installation: a. Strictly comply with manufacturer's installation instructions and recommendations. Use approved hydro -spraying machines with fan -type nozzle (50 -degree tip) whenever possible to achieve best soil coverage. Apply ECM from opposing directions to soil surface to assure 95% soil surface coverage. Slope interruption devices or water diversion techniques are recommended when slope lengths exceed 100 ft (30m). b. Step One: Apply seed, fertilizer and other soil amendments with tackifier and a small amount of ECM for visual metering (see Revegetation (RV) for application rates). c. Step Two: Mix 50 Ib of ECM per 125 gallons (23 kg/475 liters) of water; confirm loading rates with equipment manufacturer (different manufacturers rates may vary slightly). d. Install materials at the typical application rates in Table HM -2. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Areas should be identified where mulch has loosened or been removed. Such areas should be reseeded (if necessary) and the mulch cover replaced. If washout, breakage, or erosion occurs, surfaces should be repaired, reseeded, and re -mulched. Inspections should be continued until vegetation is firmly established. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc HM -2 June 2008 References California Stormwater Quality Association, Stormwater Best Management Practice (BMP) Handbook — Construction. January, 2003. <http://www.cabmphandbooks.com/Construction.asp> Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> Table HM -1 Property Values for Erosion Control Mulch Property Test Method' English SI Physical Mass Per Unit Area ASTM D-6566 11.5 oz/yd2 390 g/m2 Thickness ASTM D-6525 0.19 in 4.8 mm % Ground Cover ASTM D-6567 99% 99% Flexural Rigidity (wet) ASTM D-6575 0.138 oz -in 10,000 mg -cm Color (fugitive dye) Observed Green Green Endurance Functional Longevity Observed Up to 18 months Up to 18 months Performance Cover Factor3 (6 in/hr event) ECTC Test Method #2 0.0066 0.0066 % Effectiveness3 ECTC Test Method #2 99.34% 99.34% Shear Stress ECTC Test Method #3 1 Ib/ft2 48 Pa Vegetation Establishment ECTC Test Method #4 800% 800% 1. ASTM and ECTC (Erosion Control Technology Council) test methods developed for Rolled Erosion Control Products. 2. Cover Factor is calculated as soil loss ratio of treated surface versus an untreated control surface. 3. % Effectiveness = 1 minus Cover Factor multiplied by 100%. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc HM -3 June 2008 Table HM -2 Typical Mulch Application Rates Slope Gradient/Condition English SI <3H to 1V 3000 Ib/ac 3400 kg/ha >3H to 1V and <2H to 1V 3500 Ib/ac 3900 kg/ha >2H to 1V and <1H to 1V 4000 Ib/ac 4500 kg/ha >1H to 1V 4500 Ib/ac 5100 kg/ha Below ECB or TRM 1500 Ib/ac 1700 kg/ha As infill for TRM 3500 Ib/ac 3900 kg/ha Slope Gradient/Condition Performance Specification <3H — 70-80% soil coverage, minimum 0.16 inch depth <3H to 1V — 90-100% soil coverage, <2" rocks uncovered, minimum 0.19 inch depth >3H to 1V and <2H to 1V 95-100% soil coverage, <6" rocks uncovered, minimum 0.22 inch depth >2H to 1V and <1H to 1V 100% soil coverage, <12" boulders uncovered, minimum 0.22 inch depth >1H to 1V All exposed surfaces including rock outcrops shall be covered at a minimum of 0.24 inch depth Below ECB or TRM 1500-2500 Ib/ac slope dependent, minimum 0.08 inch depth As infill for ECB 1500-3500 Ib/ac, minimum 0.19 inch depth As infill for TRM Perpendicular application with 100% infill, minimum 0.19 inch depth M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc HM -4 June 2008 Land Grading (LG) — Roads Description Land grading of roads involves reshaping the ground surface to planned grades as determined by an engineering survey, evaluation, and layout. This BMP shall include the following: • Proper road cut and fill techniques to ensure road remains stable over time. • Road crowning or sloping to properly route runoff off the roadway. • Surfacing the road with gravel to avoid mud, rutting, and large quantities of sediment that will wash away during storms. Applicability • This BMP is applicable to the construction and maintenance of any road, but particularly those located on steep topography or easily erodible soils. • Road gravel is applicable to all roads with "soft" sections, steep grades, highly erosive soils, or where all-weather access is needed. Road gravel may be used as "fill" material in ruts or as a full structural section over the entire road. Limitations • Improper cut and fill slopes that disrupt natural stormwater patterns might lead to poor drainage, high runoff velocities, and increased peak flows during storm events. • Rutting and washboarding may develop if surface gravel is not designed properly or if road is not sloped. • Flat-blading to maintain the roadway must be done properly to avoid changes in gravel thickness, road slope, and road grade. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc LG -1 June 2008 Design criteria Grading plan A grading plan should be prepared that establishes the extent to which the road will be graded, how drainage patterns will be directed, and how runoff velocities will affect receiving waters. The grading plan also includes information regarding when earthwork will start and stop, establishes the degree and length of finished slopes, and dictates where and how excess material will be disposed of (or where borrow materials will be obtained if needed). Practices must be developed for erosion control, slope stabilization, and safe disposal of runoff water and drainage, such as ditches and culverts, grade stabilization structures, retaining walls, and surface drains. Berms, roadside ditches, and other stormwater practices that require excavation and filling also should be incorporated into the grading plan. Slope failures Landslides and failed road cuts and fills can be a major source of sediment, they can close the road or require major repairs, and they can greatly increase road maintenance costs. Slope failures, or landslides, typically occur where a slope is over -steep, where fill material is not compacted, or where cuts in natural soils encounter groundwater or zones of weak material. Good road location can often avoid landslide areas and reduce slope failures. When failures do occur, the slide area should be stabilized by removing the slide material, flattening the slope, adding drainage, or using structures, as discussed below. Designs are typically site specific and may require input from geotechnical engineers and engineering geologists. Failures that occur typically impact road operations and can be costly to repair. Failures near streams and channel crossings have an added risk of impact to water quality. Road slope See Figure LG -1. All roads should be designed with one of the following three slope types: • Outsloped roads minimize the concentration of water and minimize road width by avoiding the need for an inside ditch, but may require roadway surface and fill slope stabilization. Outsloped roads with clay rich, slippery road surface materials often require surface stabilization with gravel or limited use during rainy periods to assure traffic safety. On road grades over 10 to 12 percent and on steep hill slope areas, outsloped roads are difficult to drain and can feel unsafe. • Insloped roads are the best method to control surface water. However, insloped roads also concentrate water and require a system of ditches and turnouts or cross -draining culverts. • Crowned roads are appropriate for higher standard, two lane roads on gentle grades. They may or may not require roadside ditches, turnouts, and/or cross -drains. It is difficult to create and maintain a crown on a narrow road, so generally insloped or outsloped road drainage is more effective. Construction specifications Cut and fill slopes 1. All applicable perimeter erosion and sediment control practices and measures (berms, diversions, silt fence, vegetated buffer, or wattles) shall be constructed prior to any road grading activities, and maintained in accordance with this BMP and the Stormwater Management Plan (SWMP). Perimeter controls should remain in place until all graded or disturbed areas, including slopes, are adequately stabilized. 2. All areas to be disturbed (both cut and fill) shall be cleared, grubbed, and stripped of topsoil to remove trees, vegetation, roots, or other objectionable material. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc LG -2 June 2008 3. Fill material shall be free of brush, logs, stumps, roots, or other objectionable materials that would interfere with, or prevent, construction of satisfactory fills. This material can be set aside and later used at the toe of fill slopes as filter berms. Frozen material shall not be placed in the fill nor shall the fill material be placed on a frozen foundation. 4. Table LG -1 presents a range of commonly used cut and fill slope ratios appropriate for the soil and rock types described. Figures LG -2 and LG -3 present typical cut slope and fill slope design options for varying slope and site conditions. Vertical cut slopes should not be used unless the cut is in rock or very well cemented soil. Ideally, both cut and fill slopes should be constructed with a 2:1 or flatter slope to promote growth of vegetation, but cut slopes in dense, sterile soils or rocky material are often difficult to vegetate. 5. All fills shall be compacted as required to reduce erosion, slippage, settlement, subsidence, or other related problems. 6. Topsoil required for the establishment of vegetation shall be stockpiled in the amount necessary to complete finished grading of all exposed areas. Areas that are to be topsoiled shall be scarified to a minimum depth of 4 inches prior to placement of topsoil. 7. Terraces or contour trenches (see Terracing (T)) shall be provided whenever the vertical interval (height) of any 2:1 cut or fill slope exceeds 20 feet; for 3:1 slope it shall be increased to 30 feet and for 4:1 to 40 feet. 8. All graded cut and fill areas shall be stabilized, either structurally or vegetatively, immediately following finished grading. Some common slope stabilization options appropriate for roads include hydroseeding, hydromulching, erosion control blankets, riprap, and retaining walls. Road slope 1. See Figure LG -1. Compact soil or road base material to direct runoff. 2. If crowning a road, runoff is directed to both sides of the road requiring two roadside ditches, unless runoff will drain directly to well stabilized areas. 3. If using an inslope design, runoff is directed toward the hillside and requires a roadside ditch with periodic turnouts or cross drain culvert installation. 4. If using an outslope design, ensure a moderate road slope with dense vegetative cover. Surface gravel 1. Gradation of gravel should be according to Figure LG -4. This figure shows the typical gradation ranges of aggregates used in road construction, how the materials, ranging from coarse to fine, best perform for a road, and the approximate limitations to the desirable gradation ranges. Ideally, aggregate surfacing material is (1) hard, durable, and crushed or screened to a minus 2 -inch size; (2) well graded to achieve maximum density; (3) contains 5-15% clayey binder to prevent raveling; and (4) has a Plasticity Index of 2 to 10. 2. Gravel should be placed to a thickness of at least twice the diameter of the largest stone with a minimum thickness of 4 inches. Over very weak soils gravel thickness can be reduced with the use of geotextile or geogrid subgrade reinforcement. Also, geotextile layers are useful over soft soils to separate the gravel from the soil, keep it uncontaminated, and extend the useful life of the gravel. 3. Compact the aggregate during construction and maintenance to achieve a dense, smooth road surface and thus reduce the amount of water that can soak into the road. 4. "Spot" stabilize local wet areas and soft areas with 4 to 6 inches of coarse rocky material. Add more rock as needed. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc LG -3 June 2008 5. Blend coarse aggregate and fine clay -rich soil (when available) to produce a desirable composite roadway material that is coarse yet well -graded with 5-15% fines for binder. Maintenance considerations The frequency of inspections should be in accordance with the SWMP. Inspect cut and fill slopes for rills or other indications of erosion. Maintain all crowns, outslopes, inslopes, and surface gravel. The road surface and shoulders should be periodically smoothed and reshaped with a grader blade (flat- blading). This should be done when the gravel is moist. Maintain the proper road slope and grade while flat- blading. Also be sure to avoid plugging roadside ditches or altering adjacent drainage structures, as this may cause them to not function properly. Flat-blading may also cause road gravel to be pushed off the main roadway and onto the shoulders. To avoid this, blade toward the center of the road. References Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best Management Practices Field Guide. United States Department of Agriculture (USDA), Forest Service, US Agency of International Development (USAID), 2005. <http://www.blm.gov/bmp/field%20guide.htm> New York State Department of Environmental Conservation, New York Guidelines for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997. <http://wvvw.dec.state.ny.us/website/dow/toolbox/escstandards> United States Department of the Interior and United States Department of Agriculture. Surface Operating Standards and Guidelines for Oil and Gas Exploration and Development "Gold Book." BLM/WO/ST- 06/021+3071. Bureau of Land Management (BLM). Denver, Colorado. Fourth Edition, 2006. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc LG -4 June 2008 Table LG -1 Stable Slope Ratios for Various Conditions Soil/Rock Condition Slope Ratio (Hor:Vert) Most rock '/4:1 to '/2:1 Very well cemented soils 1/4:1 to 1/2:1 Most in-place soils 3/4:1 to 1:1 Very fractured rock 1:1 to 1 1/2: 1 Loose coarse granular soils 1 1/2: 1 Heavy clay soils 2:1 to 3:1 Soft clay rich zones or wet seepage areas 2:1 to 3:1 Fills of most soils 1 1/2:1 to 2:1 Fills of hard, angular rock 1 1/3 :1 Low cuts and fills (<10 ft high) 2:1 or flatter (for revegetation) M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc LG -5 June 2008 FILTER BERM :JR OTHER SEDIMENT CONTROL ,,_ Figure LG -1 Typical Road Surface Drainage Options Crown Section Outslope Section 2 lyp. 1I— 5-5% Irtslope with Ditch Section 1p --- —.—'�► NOT TO SCALE a_ Balanced Cut and Eli Use a Balanced Cul and SII Section for Moral cOnSlinidinn on Hill slopes Roadside Bich itypp.b Road y� k FIll ROADSIDE DITCI-1 Figure LG -2 Cut Slope Design Options b. Full nen Ji Ground Surface Col Typical Cut slopes in Most Soils 1:1 lo 1:1 Finer Berm dr -00W S+irngnl Comm! 0-60% Ground Slopes c. Through Cul Road — Ground Surface Low Cut Can his Steepcx Rater 0 Ground Slopes M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc .4 k Iligh Cul Typical Sleeper Mere Statile LG -6 1 'Fp. 11 Typical Cut dopes II Meat's aL 1 to 1.1 Ty{sieal cath Cel Slovras • p_1 to ;!9 Road Use Full Bench Guts When 1Fre Ground elopes Exceed PUG% 50%+ Ground Slopes NOT TO SCALE June 2008 a. Tryis!col FNI Note. Side-c1lill material arty slqrsas. eisey from strzwriE b. Bianchd Slope Fill with L35013( Piecemeal On ground where slcoes exceed .10-4.V14, iecirininel bid-,r...A I 11) elde0 ele enough ice esatimilliOa and cenviettion equipment c. Reinforced FIN Figure LG -3 Fill Slope Design Options Roadside Mb ltygg Rood FiIIr Bann or Other Sediment Conlrol (tm ) •Scarify end rernoso organic material Cr:Met:1.50.W 0-40% Ground Slopes Ground SU rface Road 10,80% Grtimicl Slopes Fill mold:mini i layrs- Lien It or 5 to 12 In. Mick Gorioaa: to spwilisid clarisityn ihml rcM oac-ri leyer 'Ground Surface Heinlorced fits ore used on sleep gm:urethan SIM ;Remain* lu relairmr.9 Structures. The 1:1 (oversleep) face usually riNuipes slablicatium. d. Through Fill NOT TO Sit -.A1 F Lang Road slime 2:1 M:\Encana\BMP Manual \BMP Manual - Round 2\SWMM Final 06-09-08.doc Shari Slope 3:1 -Ground Surface 4-413% GrOurs121101101 LG -7 June 2008 a.x 143 Figure LG -4 Gradation and Performance of Roadway Surfacing Materials 4tQu In Inch.. S1EYE ,Ah1ILY5I5 MYibW kI.S- 1'ly AME 5IZ[ 111 1101U.11AtT119RL NOTE: Gradation Rsngcc Shown Are Approximate. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc LG -8 June 2008 Mill_ NIS .A _ i0 iiiirdis iori. MI '111 %iiLiIi' Milli Milli ir.,, l 'f. i�i I� Jy i � ,1„ .. ij� rIJ � 1 __I !ii j, 1„:% IRM Mill .I ,cott,,,,,t,„ iii '4..4. -+i Ilk tt -lri1111 1111 II i_s ie AME 5IZ[ 111 1101U.11AtT119RL NOTE: Gradation Rsngcc Shown Are Approximate. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc LG -8 June 2008 Low Water Crossing (LWC) Description A low water crossing is a temporary structure erected to provide a safe and stable way for construction vehicle traffic to cross waterways. The primary purpose of such a structure is to provide streambank stabilization, reduce the risk of damaging the streambed or channel, and reduce the risk of sediment loading from construction traffic. A low water crossing may be a bridge, a culvert, or a ford surfaced with gravel, rip rap, or concrete. Applicability Low water crossings may be used for the following applications: • Wherever heavy construction equipment must be moved from one side of a stream channel to the other, or where lighter construction vehicles will cross the stream a number of times during the construction period. • Bridges are ideal to pass the year-round flows associated with perennial drainages. • Vented fords can be used to pass drainages with low flows and keep vehicles out of the water, avoiding water quality degradation. • Fords can be designed as a broadcrested weir in order to pass larger flow. • Fords can be "forgiving" and accommodate uncertainties in the design flow and thus are ideal for ephemeral and intermittent drainages with unknown or variable flow characteristics. Limitations • Low-water crossings that are not surfaced should not be used in wet conditions. • Installation may require dewatering or temporary diversion of the stream. • Bridges can be a safety hazard if not properly designed and constructed. Bridges might also prove to be more costly in terms of repair costs and lost construction time if they are washed out or collapse. • The construction and removal of culverts are usually very disturbing to the surrounding area and erosion and downstream movement of soils is often great. • The approaches to fords often have high erosion potential. In addition, excavation of the streambed and approach to lay riprap or other stabilization material causes major stream disturbance. Mud and other debris are transported directly into the stream unless the crossing is used only during periods of low flow. • Ford -type structures may imply some periodic or occasional traffic delays during periods of high flow. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc LWC-1 June 2008 Design Criteria Site location Locate the crossing where there will be the least disturbance to the soils of the existing waterway banks. When possible, locate the crossing at a point receiving minimal surface runoff. Elimination of fish migration barriers Bridges pose the least potential for creating barriers to aquatic migration. The construction of any specific crossing method shall not cause a significant water level difference between the upstream and downstream water surface elevations. Crossing alignment Where possible, the low water crossing shall be at right angles to the stream. Road approaches The centerline of both roadway approaches shall coincide with the crossing alignment centerline for a minimum distance of 50 feet from each bank of the waterway being crossed. If physical or right-of-way restraints preclude the 50 feet minimum, a shorter distance may be provided. All fill materials associated with the roadway approach shall be limited to a maximum height of 2 feet above the existing flood plain elevation. Bridges Over -stream bridges are generally the preferred low water crossing structure. The expected load and frequency of the stream crossing, however, will govern the selection of a bridge as the correct choice for a temporary stream crossing. Bridges usually cause minimal disturbance to a stream's banks and cause the least obstruction to stream flow and fish migration. They should be constructed only under the supervision and approval of a qualified engineer. Culverts Temporary culverts are used where a) streams are perennial or intermittent, b) the channel is too wide for normal bridge construction, or c) anticipated loading may prove unsafe for single span bridges. Culverts are normally preferred over a ford type of crossing, since disturbance to the waterway is only during construction and removal of the culvert. Fords Fords are appropriate in steep areas subject to flash flooding, where normal flow is shallow or intermittent across a wide channel. Fords should be used for crossing seasonally dry streambeds (ephemeral or intermittent drainages) or streams with low flows during most periods of road use. Use fords in place of culverts when there is a high possibility of plugging by debris or vegetation. Use improved (vented) fords with pipes or concrete box culverts to pass low water flows and keep vehicles out of the water. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc LWC-2 June 2008 Construction specifications Bridges See Figure LWC-1. 1. Clearing and excavation of the stream shores and bed should be kept to a minimum. 2. A temporary bridge structure shall be constructed at or above bank elevation to prevent the entrapment of floating materials and debris. 3. Abutments should be parallel to the stream and on stable banks. 4. If the crossing is to extend across a channel wider than 8 feet (as measured from top of bank to top of bank), the bridge should be designed with one in -water support for each 8 feet of stream width. No footing, pier, or bridge support will be permitted within the channel for waterways less than 8 feet wide. 5. Stringers shall either be logs, saw timber, pre -stressed concrete beams, metal beams, or other approved materials. 6. Decking shall be of sufficient strength to support the anticipated load. All decking members shall be placed perpendicular to the stringers, butted tightly, and securely fastened to the stringers. Decking materials must be butted tightly to prevent any soil material tracked onto the bridge from falling into the waterway below. 7. Run planking (optional) shall be securely fastened to the length of the span. One run plank shall be provided for each track of the equipment wheels. Although run planks are optional, they may be necessary to properly distribute loads. 8. Curbs or fenders may be installed along the outer sides of the deck. Curbs or fenders are an option, which will provide additional safety. 9. Bridges shall be securely anchored at only one end using steel cable or chain. Anchoring at only one end will prevent channel obstruction in the event that floodwaters float the bridge. Acceptable anchors are large trees, large boulders, or driven steel anchors. Anchoring shall be sufficient to prevent the bridge from floating downstream and possibly causing an obstruction to the flow. 10. All areas disturbed during installation shall be stabilized in accordance with Revegetation (RV). Culverts See Culvert (C). Fords See Figure LWC-2. 1. Locate fords where stream banks are low and where the channel is well confined. 2. Clearing and excavation of the stream shores and bed should be kept to a minimum. 3. Excavate streambed as necessary and place an 18 -inch thick layer of 4 -inch to 8 -inch riprap. Cover this layer of riprap with a 6 inch thick layer of 2 inch to 4 inch crushed aggregate. The total thickness of riprap/aggregate should be a minimum of 24 inches thick. This type of simple low water crossing is ideal for ephemeral drainages. 4. For all approach roads the cut banks shall be no steeper than 5:1. The road approach shall be a minimum distance of 50 feet from each bank. Spoil material from the banks shall be stored out of the floodplain and stabilized. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc LWC-3 June 2008 5. Use an adequately long aggregate surface to protect the "wetted perimeter" of the natural flow channel. Add protection above the expected level of the high flow. Allow for some freeboard, typically a minimum of 12 inches in elevation, between the top of the reinforced driving surface and the expected high water level. 6. The downstream edge of a ford is a particularly critical location for scour and may need energy dissipaters or riprap protection. 7. Use well-placed, sturdy depth markers at fords to advise traffic of dangerous water depths. 8. All areas disturbed during ford installation shall be stabilized in accordance with Revegetation (RV). Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Bridges Inspection shall ensure that the bridge, streambed, and streambanks are maintained and not damaged. If any structural damage is reported, construction traffic should stop use of the structure until appropriate repairs are made. Evidence of streambank erosion should be repaired immediately. Any trapped sediment or debris shall be removed and disposed of outside of the floodplain and stabilized. Culverts Inspection shall ensure that the culverts, streambed, and streambanks are not damaged, and that sediment is not entering the stream or blocking fish passage or migration. Evidence of structural or streambank erosion should be repaired immediately. Any trapped sediment or debris shall be removed and disposal of outside of the floodplain and stabilized. Fords Inspections shall ensure that stabilization material (aggregate) remains in place. If the material has moved downstream during periods of peak flow, the lost material should be replaced immediately. Removal All low water crossings shall be removed when the structure is no longer needed. References Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/storamater/menuofbmps/con_site.cfm> Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best Management Practices Field Guide. United States Department of Agriculture (USDA), Forest Service, US Agency of International Development (USAID), 2005. <http://www.blm.gov/bmp/field%20guide.htm> New York State Department of Environmental Conservation, New York Guidelines for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997. <http://www.dec.state.ny.us/website/dow/toolbox/escstandards> United States Department of the Interior, Bureau of Land Management (BLM), United States Department of Agriculture (USDA), Forest Service, Surface Operating Standards for Oil and Gas Exploration and Development "Gold Book". Fourth Edition, 2005. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc LWC-4 June 2008 Sdririgers NOT TO SCALE Thri 24" Figure LWC-1 Bridge Installation A1nj1iriin1 'IIM StatAlze4 B nk5 RD' min. Road afphyach 1?robrboald 1r min. Abubnerile Docking Curbs Figure LWC-2 Ford Installation Traxr: F, . N.es o1 s troarn bod W min RgAd P{penaach maxi -num 4Kp S.N.(1 WO water llesael Ahreaniach F - Y Crashed kggrogaie (2' -4 dia.) NOT TO SCALE Amirmaile e+,.) M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc LWC-5 June 2008 Mulching (M) Description Mulching is a temporary erosion control practice in which materials such as grass, hay, wood chips, wood fibers, straw, or gravel are placed on exposed or recently planted soil surfaces. Mulching stabilizes soils by minimizing rainfall impact and reducing stormwater runoff velocity. When used in combination with seeding or planting, mulching can aid plant growth by holding seeds, fertilizers, and topsoil in place, preventing birds from eating seeds, retaining moisture, and insulating plant roots against extreme temperatures. Mulch mattings are materials such as jute or other wood fibers that are formed into sheets and are more stable than loose mulch. Jute and other wood fibers, plastic, paper, or cotton can be used individually or combined into mats to hold mulch to the ground. Netting can be used to stabilize soils while plants are growing, although netting does not retain moisture or insulate against extreme temperatures. Mulch binders consist of asphalt or synthetic materials that are sometimes used instead of netting to bind loose mulches. Hydraulic mulching is a temporary erosion control practice in which materials such as grass, hay, wood chips, wood fibers, straw, or gravel are hydraulically applied to exposed or recently planted soil surfaces. See Hydraulic Mulching (HM) for details. Applicability Mulching is often used in areas where temporary seeding cannot be used because of environmental constraints. On steep slopes and critical areas such as waterways, mulch matting is used with netting or anchoring to hold it in place. Mulches can be used on seeded and planted areas where slopes are steeper than 2:1 or where sensitive seedlings require insulation from extreme temperatures or moisture retention. Mulch is most effective when used on an area less than 2 acres in size and can last for 1 to 2 years. Limitations • Mulching, matting, and netting might delay seed germination because the cover changes soil surface temperatures. • The mulches themselves are subject to erosion and may be washed away in a large storm. • Maintenance is necessary to ensure that mulches provide effective erosion control. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc M-1 June 2008 Design criteria No formal design is required. Construction specifications 1. Site preparation: a. Prior to mulching, install the necessary temporary or permanent erosion control practices and drainage systems within or adjacent to the area to be mulched. b. Slope, grade, and smooth the site to fit needs of selected mulch products. c. Remove all undesirable stones and other debris to meet the needs of the anticipated land use and maintenance required. 2. Mulching & anchoring for relatively flat slopes: a. Select the appropriate mulch and application rate that will best meet the need and availability of material. When possible, organic mulches should be used for erosion control and plant material establishment. See Table M-1 for suggested materials and application rates. Other materials include hydraulic mulch products with 100 -percent post -consumer paper content and yard trimming composts. All materials should be free of weed and seed. b. Apply mulch immediately after soil amendments and planting is accomplished or simultaneously if hydroseeding is used. See Table M-1 for installation guidelines. c. Mulch before seeding if construction of restoration activity is interrupted for extended periods, such as when seeding cannot be completed due to seeding period restrictions. If mulching before seeding, increase mulch rate. Of application on all slopes within 100 feet of waterbodies and wetlands. d. Use a mulch crimper to apply and anchor mulch. Crimper should have approximately 6 inch cleats with perpendicular, dull, disc blades. If a crimper is unavailable the Contractor shall apply mulch and anchor it to the soil using one of the methods described in Table M-2. The mulch should be anchored the same day as mulch application. Materials that are heavy enough to stay in place (for example, bark or wood chips on flat slopes) do not need anchoring. Mulches may or may not require a binder, netting, or tacking. Mulch binders should be applied at rates recommended by the manufacturer. Effective use of netting and matting material requires firm, continuous contact between the materials and the soil. 3. Hydraulic mulching for steeper slopes: See Hydraulic Mulching (HM). Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Areas should be identified where mulch has loosened or been removed. Such areas should be reseeded (if necessary) and the mulch cover replaced. If washout, breakage, or erosion occurs, surfaces should be repaired, reseeded, and re -mulched, and new netting should be installed. Inspections should be continued until vegetation is firmly established. Removal Anchor netting and any other artificial mulch material should be removed when protection is no longer needed and disposed of in a landfill. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc M-2 June 2008 References Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. New York State Department of Environmental Conservation, New York Guidelines for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997. <http://www.dec.state.ny.us/website/dow/toolbox/escstandards> United States Department of Agriculture (USDA), Natural Resources Conservation Service (NRCS), Field Office Technical Guide. 2002. <www.nrcs.usda.gov/technical/efotg> Table M-1 Typical Mulching Materials and Application Rates Material Rate per Acre Requirements Notes Organic Mulches Straw 1 - 2 tons Dry, unchopped, unweathered; certified weed free. Spread by hand or machine; must be tacked or tied down. Wood fiber or wood cellulose 1/2- 1 ton Use with hydroseeder; may be used to tack straw. Do not use in hot, dry weather. Wood chips 5 - 6 tons Air dry. Add fertilizer N, 12 Ib/ton. Apply with blower, chip handler, or by hand. Not for fine turf areas. Bark 35 yd3 Air dry, shredded, or hammermilled, or chips Apply with mulch blower, chip handler, or by hand. Do not use asphalt tack. Nets and Mats Jute net Cover area Heavy, uniform; woven of single jute yarn. Used with organic mulch. Withstands water flow. Excelsior (wood fiber) mat Cover area M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc M-3 June 2008 Table M-2 Mulch Anchoring Guide Anchoring Method or Material Kind of Mulch to be Anchored How to Apply 1. Mulch netting Hay or straw Staple the light -weight paper, jute, wood fiber, or plastic nettings to soil surface according to manufacturer's recommendations. Should be biodegradable. Most products are not suitable for foot traffic. 2. Wood cellulose fiber Hay or straw Apply hydroseeder immediately after mulching. Use 500 lbs. Wood fiber per acre. Some products contain an adhesive material, possibly advantageous. 3. Mulch anchoring tool/Crimper Hay or straw Apply mulch and pull a mulch anchoring tool (blunt, straight discs) over mulch as near to the contour as possible. Mulch material should be "tucked" into soil surface about 3". 4. Chemical Hay or straw Apply Terra Tack AR 120 lbs./ac. In 480 gal. of water (#156/ac.) or Aerospray 70 (60 gal/ac.) according to manufacturer's instructions. Avoid application during rain. A 24-hour curing period and a soil temperature higher than 45 deg. Fahrenheit are required. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc M-4 June 2008 Retaining Wall (RW) Rock Retaining Wall Timber Retaining Wall Gabion Retaining Wall Description Retaining walls are structures that are used to stabilize and hold soil in place, gain space on roadways or well pads, or to keep soil contained within a site boundary. This BMP will cover retaining walls constructed with rock, boulders, or gabions. Gabions are rectangular, rock -filled wire baskets that are pervious, semi -flexible building blocks which can be used to armor the bed and/or banks of channels or to divert flow away from eroding channel sections. Several different retaining wall types are: 1. Rigid gravity and semi -gravity walls. These walls may be constructed of concrete or stone masonry. The rigid gravity and semi -gravity walls develop their capacity from their dead weights and structural resistance, and are generally used for permanent applications. 2. Non -gravity cantilevered walls. These walls develop lateral resistance through the embedment of vertical wall elements and support retained soil with wall facing elements. Vertical wall elements are normally extended deep in the ground to provide lateral and vertical support. The vertical wall elements can be piles, drilled shafts, steel sheet piles, etc. Wall faces can be reinforced concrete, metal, or timber. Cantilevered walls are generally limited to a maximum height of about 15 feet. 3. Anchored walls. These walls typically consist of the same elements as the non -gravity cantilevered walls but derive additional lateral resistance from one or more tiers of anchors. The anchored walls are typically used in the cut situation, in which the construction proceeds from the top to the base of the wall. Applicability Retaining walls should be used when sites have very steep slopes or loose, highly erodible soils that cause other methods, such as vegetative stabilization or regrading, to be ineffective. The preconstruction drainage pattern should be maintained to the extent possible. Retaining walls may be used for the following applications: M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc RW -1 June 2008 • Near the toe of a cut or fill slope to mechanically stabilize steep slopes and so that a flatter slope can be constructed to prevent or minimize slope erosion or failure. Particularly useful along access road cut slopes. • Along a stream bank or drainage channel, to keep a toe of a slope from encroaching into a stream and thus prevent potential undercutting of the toe by flowing water. • As headwalls at culvert inlets and outlets to prevent scour and undercutting. Limitations • Some retaining walls are a structural element that must be professionally designed. • To be effective, retaining walls must be designed to handle expected loads. Non -engineered walls should not be used where traffic is expected near the top of the wall. • Retaining walls must be properly installed and maintained to avoid failure. • Some types of retaining walls must be placed on a good foundation, such as bedrock or firm, in- place soil. • Some walls have height restrictions and backfill may be required to meet specific material property requirements. • Materials costs and professional design requirements may make use of gabions impractical. • When used in channels with high sediment loads, the galvanizing wire on gabion cages quickly wears off, causing rusting and the premature failure of the cages. Design criteria Most retaining walls require a site-specific design. Wall heights, requirements for drainage, and suitable materials must be determined through on-site investigation. An engineered retaining structure is a designed structure that is supported by plans and specifications signed and sealed by a Professional Engineer. Non - engineered retaining structures may be designed by an engineer; however, if the design is not supported by the seal and signature, the retaining structure is not considered engineered. Gabions Gabions should be designed and installed in accordance with manufacturer's standards and specifications and must be able to handle expected storm and flood conditions. At a minimum, they should be constructed of a hexagonal triple twist mesh of heavily galvanized steel wire (galvanized wire may also receive a polyvinyl chloride coating). The maximum linear dimension of the mesh opening shall not exceed 4 1/2 inches and the area of the mesh opening shall not exceed 10 square inches. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc RW -2 June 2008 Design velocity The design water velocity for channels utilizing gabions should not exceed those listed as follows: Gabion Thickness (feet) Maximum Velocity (feet per second) 0.5 6 0.75 11 1.0 14 Construction specifications Rock retaining wall guidelines See Figure RW -1. 1. Excavate a footing trench at the location of the proposed wall. 2. Place the largest rocks in the footing trench with their longitudinal axis normal to the wall face. Arrange subsequent rock layers so that each rock above the foundation course has a firm seating on the underlying rocks. 3. The batter of the wall face shall be between'/2H:1V and vertical, depending upon the height of the wall, the height of the slope, the width of the right-of-way, or other limitations on space. 4. Place fill material behind the rock wall. Slope above the wall should be maintained at 2H:1V or flatter. Backfill the footing trench with excavated material. If a roadway is located at the toe of the wall, pave the roadway up to the base of the rock wall and provide roadway curb for water transport. If a roadway is not located at the toe of the retaining wall, slope the backfilled material away from the wall. 5. Revegetate the stabilized slope with a method applicable to the particular site. Gabion retaining wall guidelines See Figure RW -2. Gabions shall be fabricated in such a manner that the sides, ends, and lid can be assembled at the construction site into a rectangular basket of the specified sizes. Gabions shall be of single unit construction and shall be installed according manufacturer's recommendations. General specifications are listed below. 1. Clear and grade the area of trees, brush, vegetation, and unsuitable soils. Compact subgrade firmly to prevent slumping or undercutting. 2. Install a filter fabric or granular filter according to the Riprap (R) BMP to maintain separation of rock material with the underlying soil, if required. 3. Place empty gabion baskets. Each row, tier, or layer of baskets should be reasonably straight and should conform to the specified line and grade (see Figure RW -2 for details). The empty gabion baskets should be fastened to the adjacent baskets along the top and vertical edges. Each layer should be fastened to the underlying layer along the front, back and ends. Fastening should be performed in the same manner as provided for assembling the gabion units. 4. Unless otherwise indicated on the plans, the vertical joints between basket units of adjacent tiers or layers, along the length of the structure, should be staggered by at least one cell. 5. Before filling each gabion with rock, all kinks and folds in the wire mesh should be removed and all baskets should be properly aligned. A standard fence stretcher, chain fall or steel rod may be used to stretch the wire baskets and hold alignment. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc RW -3 June 2008 6. The gabion cells should be carefully filled with 4 to 8 -inch rock placed by hand/machine in such a manner that the alignment of the structure will be maintained and so as to avoid bulges and to minimize voids. Rock should be sound, durable, and well graded. All exposed rock surface should have a reasonably smooth and neat appearance. No sharp rock edges should project through the wire mesh. 7. The gabion cells in any row or layer should be filled in stages so that local deformations may be avoided. 8. At no time should any cell be filled to a depth exceeding 12 inches more than any adjacent cell. 9. The layer of rock should completely fill the gabion basket so that the lid will bear on the rock when it is secured. The lid should be joined to the sides, ends, and diaphragms in the same manner as specified for joining the vertical edges. The gabion basket lid should be secured so that no more than 1 -inch gap remains at any connection. 10. Gabion rows or layers not completed at the end of each shift should have the last gabion filled with rock tied internally as an end gabion. 11. The area behind the gabion structure should be backfilled with granular material. Geotextile, if required, should be spread uniformly over the back of the gabion structure. Joining edges of the geotextile should be overlapped a minimum of 12 inches and should be anchored in position with approved anchoring devices. The Contractor should place the backfill material in a manner that will not tear, puncture, or shift the geotextile. All other retaining walls should be constructed as designed by a Professional Engineer. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Check for structural failure, erosion, damage, instability, or other signs of deterioration. In stream bank installations and culvert inlets and outlets also inspect for signs of undercutting. Check wire of gabion cages for rusting and wear. Repair or replace any damaged areas immediately to restore designed effectiveness and to prevent damage or erosion of the slope or stream bank. References City of Knoxville, Stormwater Engineering, Knoxville BMP Manual - Best Management Practices. July 2003. <http://www.ci.knoxville.tn.us/engineering> Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best Management Practices Field Guide. United States Department of Agriculture (USDA), Forest Service, US Agency of International Development (USAID), 2005. <http://www.blm.gov/bmp/field%20guide.htm> New York State Department of Environmental Conservation, New York Guidelines for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997. <http://www.dec.state.ny.us/website/dow/toolbox/escstandards> M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc RW -4 June 2008 Figure RW -1 Construction of Rock Retaining Structures V ruin. t,1 Wfidih = 0.7 Haigh! Flai Baddll Isrri aIh facet, 13 Note: L eakfat condilims are frac silly sand to sand end gravel bacl'.iill. For firlaS erclay nal still$,,(larthpr1> rrrq 41 11112 wall 12111 inr,.rea1A ad111 the wall Laaem w.rllh have 10 Increase for each hao]hl f: arA ill ye IN = 110 pef, - Same aparnsl cn'Brturnlnp for SWIa with a n'anilnurn hearing. capac ty of 2 Tamale -Far SAL or 810p 11 bareklille„ either s, nal or Slapped f8[R+Inlay tr6uaad. NOT TO SCALE Figure RW -2 Gabion Design =a al Ti 1 {fae®wilh slops) No. 01 H I3 No. o1 levels gabions tPer width) 3'-' 1 2 5'-6' 4-3' 1 3 g'- 9' S'-' 2 -0 5'-f 2 5 15'1' $'-2 2; 18'-P 4F-fr 3 M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc M RW -5 2Cr - — B 3 a s 5 15 HOT TO SCALE No. nP H B No. of levels gabions I,Par wider) 1 3-3r 3'-3' 1 I 5-8' 4'-11' 1 g 3 f1- 9" 5'-6' 2 4 13'-1' 5 15-0' 9'-g' 3 b 1^9'-7' 11'-5' 32 June 2008 Revegetation (RV) Description Revegetation involves planting seed to establish a vegetative cover on disturbed areas. Revegetation reduces erosion and sedimentation by stabilizing disturbed areas in a manner that is economical, adaptable to site conditions, and allows selection of the most appropriate plant materials. Revegetation also: • Absorbs the impact of raindrops • Reduces the velocity of runoff • Reduces runoff volumes by increasing water percolation into the soil • Binds soil with roots • Protects soil from wind • Improves wildlife habitat • Enhances natural beauty Applicability Revegetation is most effective on slopes no steeper than 2:1 and may be used in areas where exposed soil surfaces are not to be regraded for periods longer than 30 days. Such areas include denuded areas, soil stockpiles, berms, temporary road banks, etc. Limitations The effectiveness of revegetation can be limited due to the following: • High erosion potential during establishment. • The need for stable soil temperature and soil moisture content during germination and early growth. • The need to reseed areas that fail to establish. Proper seedbed preparation and the use of quality seed are important in this practice. Failure to carefully follow sound agronomic recommendations will often result in an inadequate stand of vegetation that provides little or no erosion control. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc RV -1 June 2008 Seeding does not immediately stabilize soils. Prior to seeding, install necessary erosion and sediment control practices such as diversions, straw bales, and basins until vegetation is established. Design criteria Successful plant establishment can be maximized with proper planning; consideration of soil characteristics; selection of plant materials that are suitable for the site; adequate seedbed preparation, liming, and fertilization; timely planting; and regular maintenance. A Revegetation Manual, which indicates the methods and materials needed to accomplish revegetation on differing site conditions, is provided as Appendix B to the Stormwater Management Plan (SWMP). Coordination and scheduling 1. Coordinate installation of seeding materials during normal planting seasons for each type of seed material required. 2. Seeding in areas that are non -irrigated or not provided with sprinkling or watering systems shall be restricted according to the following schedule: a. Below 6000' elevation: Spring seeding shall occur between spring thaw and July 1st. Fall seeding shall occur from September 1st until consistent ground freeze. b. 6000' to 7000' elevation: Spring seeding shall occur between spring thaw and July 1st. Fall seeding shall occur from August 15th until consistent ground freeze. c. 7000' to 8000' elevation: Spring seeding shall occur between spring thaw and July 15th. Fall seeding shall occur from August 1st until consistent ground freeze. d. Above 8000' elevation: Seeding shall occur from spring thaw until consistent ground freeze. e. Spring thaw shall be defined as the earliest date in a calendar year in which seed can be buried 1/2 inch into the topsoil thru normal drill seeding methods. f. Consistent ground freeze shall be defined as that time during fall months in which the topsoil, due to freeze conditions, prevents burying seed 1/2 inch thru normal drill seeding operations. Seed, soil amendments, and fertilizer 1. Seed mixes will vary depending on landowner requirements and the site elevation. 2. Soil amendments: a. AV Superphosphate 18-46-0: Commercial, phosphate mixture, soluble; minimum of 20 percent available phosphoric acid. Arkansas Valley Seed, 400 Moffat CR 220, Craig, CO 81625 Willard McLaughlin - District Sales Manager Mobile: 970-629-0263. Fax: 970-234-8023 Email: wmmclaughlin@seedsolutions.com b. Other soil amendments may also be used. 3. Fertilizers: a. Sustane 8-2-4: Slow release granular fertilizer. Sustane — Natural Fertilizer of America, Inc. 310 Holiday Avenue P.O. Box 19 Cannon Falls, MN 55009 Phone: 1-800-352-9245 Fax: 507-263-3029 www.sustane.com b. Other fertilizers may also be used. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc RV -2 June 2008 Mulches See Mulching (M) and Hydraulic Mulching (HM) for mulch materials to be used for flat and steep slopes, respectively. Erosion control materials 1. Flexible Growth Medium: Flexterra FGM. Strictly comply with manufacturer's installation instructions and recommendations. Use approved hydro -spraying machines with fan -type nozzle (50 -degree tip). Apply FGM from opposing directions to soil surface. Nilex, 15171 E. Fremont Drive, Centennial, CO 80112 Phone: 1-800-537-4241 Fax: 303-766-1110 www.nilex.com 2. Non -asphaltic Tackifier: Organic derivative vegetative gum tackifier recommended by fiber -mulch manufacturer for slurry application, nontoxic and free of plant growth- or germination -inhibitors. 3. Other erosion control materials may also be used. Construction specifications See Table RV -1 for typical seeding guidelines. See Table RV -2 for typical seeding guidelines when using an Erosion Control Blanket (ECB) or a Turf Reinforcement Mat (TRM). Seeding 1. Do not use wet seed or seed that is moldy or otherwise damaged in transit or storage. 2. Seed shall be uniformly sown by drill, by hydro -seeding (without mulch admixture), or by broadcasting. Drill and Hydro -seeding rates shall be the amount specified. Broadcast seeding rates shall be one and a half times the amount specified. Broadcast seeding shall be raked or chain dragged into the soil to a depth of approximately one-quarter inch (1/4") to one-half inch (1/2"). 3. The seeding shall be done in one application crossing the area at right angles to one another to guarantee even coverage. 4. Protect seeded areas against erosion by uniformly spreading mulch after completion of seeding operations in accordance with Mulching (M) and Hydraulic Mulching (HM). Cleanup and protection 1. During stormwater management & reclamation activities, keep pavements clean and work areas in an orderly condition. 2. Protect well pad, access road, private property, and federal lands from damage due to stormwater management & reclamation operations, operations by other contractors and trades, and trespassers. Maintain protection during installation and maintenance periods. Treat, repair, or replace damaged well pad, access road, private property, and federal lands work as directed. Maintenance considerations The frequency of inspections should be in accordance with the SWMP. Vegetation is considered established when a density of at least 70 percent of pre -disturbance levels has been reached. Seeded areas should be inspected for failure and any necessary repairs and re-seedings should be made within the same season, if possible. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc RV -3 June 2008 References EnCana Oil & Gas (USA), Inc, Revegetation Manual. Chenoweth & Associates Environmental Consultants. 2007. Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> High Mesa Water Park Seeding Specifications. April 2006. Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best Management Practices Field Guide. United States Department of Agriculture (USDA), Forest Service, US Agency of International Development (USAID), 2005. <http://www.blm.gov/bmp/field%20guide.htm> United States Army Corps of Engineers (USACE), Engineering and Design - Handbook for the Preparation of Storm Water Pollution Prevention Plans for Construction Activities. February 1997. http://www.usace.army.mil/inet/usace-docs/eng-pamphlets/ep1110-1-16/ Table RV -1 Typical Seeding Guidelines All slopes accessible to drill seeder and straw crimper Material Description Quantity Seed Mix Drill Seeding (twice in perpendicular directions) 20 lbs./acre SUSTANE 8-2-4 Sustane 8-2-4 (Nylex dlamanna@nilex.com) 1000 lbs./acre Soluble Humates Soluble Humates (Nylex dlamanna@nilex.com) 1100 lbs./acre Certified Weed Free Straw Weed Free Crimped Straw 2000 lbs./acre All slopes accessible to drill seeder Material Description Quantity Seed Mix Drill Seeding (installed in perpendicular directions) 20 lbs./acre SUSTANE 8-2-4 Sustane 8-2-4 (Nylex dlamanna@nilex.com) 1000 lbs./acre Soluble Humates Soluble Humates (Nylex dlamanna@nilex.com) 1100 lbs./acre Four wheeler broadcast seeding & tine harrowin Material Description Quantity Seed Mix Broadcast Seeded & Tine Harrowed 40 lbs./acre SUSTANE 8-2-4 Sustane 8-2-4 (Nylex dlamanna@nilex.com) 1000 lbs./acre Soluble Humates Soluble Humates (Nylex dlamanna@nilex.com) 1100 lbs./acre Chest broadcast seeding & hand rakin Material Description Quantity Seed Mix Broadcast Seeded & Hand Raked 40 lbs./acre SUSTANE 8-2-4 Sustane 8-2-4 (Nylex dlamanna@nilex.com) 1000 lbs./acre Soluble Humates Soluble Humates (Nylex dlamanna@nilex.com) 1100 lbs./acre M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc RV -4 June 2008 Table RV -2 Typical Seeding Guidelines if using Erosion Control Blankets (ECB) or Turf Reinforcement Mats (TRM) SLOPES 1:1 and/or Greater and Medium to High Concentrated Flows Material Description Quantity Seed Mix Seed Hydraulically Applied 50 lbs./acre Guar Tackifier Guar Tackifier (Nylex dlamanna@nilex.com) 75 lbs./acre SUSTANE 8-2-4 Sustane 8-2-4 (Nylex dlamanna@nilex.com) 1100 lbs./acre Soluble Humates Soluble Humates (Nylex dlamanna@nilex.com) 1100 lbs./acre ECB or TRM Per Table ECB -1 or TRM-1 per spec. SLOPES 2:1 to 1:1 and Medium Concentrated Flows Material Description Quantity Seed Mix Seed Hydraulically Applied 45 lbs./acre Guar Tackifier Guar Tackifier (Nylex dlamanna@nilex.com) 75 lbs./acre SUSTANE 8-2-4 Sustane 8-2-4 (Nylex dlamanna@nilex.com) 1100 lbs./acre Soluble Humates Soluble Humates (Nylex dlamanna@nilex.com) 11001bs./acre ECB or TRM Per Table ECB -1 or TRM-1 per spec. SLOPES 2:1 to 3:1 and Medium Concentrated Flows Material Description Quantity Seed Mix Broadcast Seeding 45 lbs./acre SUSTANE 8-2-4 Sustane 8-2-4 (Nylex dlamanna@nilex.com) 1100 lbs./acre Soluble Humates Soluble Humates (Nylex dlamanna@nilex.com) 1100 lbs./acre ECB or TRM Per Table ECB -1 or TRM-1 per spec. SLOPES 3:1 or less and Low Concentrated Flows Material Description Quantity Seed Mix Seed Hydraulically Applied 40 lbs./acre Guar Tackifier Guar Tackifier (Nylex dlamanna@nilex.com) 40 lbs./acre SUSTANE 8-2-4 Sustane 8-2-4 (Nylex dlamanna@nilex.com) 1100 lbs./acre Soluble Humates Soluble Humates (Nylex dlamanna@nilex.com) 1100 lbs./acre ECB or TRM Per Table ECB -1 or TRM-1 per spec. SLOPES 3:1 or Tess and Low Concentrated Flows Material Description Quantity Seed Mix Broadcast Seeding 40 lbs./acre SUSTANE 8-2-4 Sustane 8-2-4 (Nylex dlamanna@nilex.com) 1100 lbs./acre Soluble Humates Soluble Humates (Nylex dlamanna@nilex.com) 1100 lbs./acre ECB or TRM Per Table ECB -1 or TRM-1 per spec. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc RV -5 June 2008 Riprap (R) Description Riprap is a permanent, erosion -resistant layer made of stones or boulders. It is intended to stabilize areas subject to erosion and protect against scour of the soil caused by concentrated, high velocity flows. Applicability Riprap can be used for areas subject to erosion or weathering, particularly where conditions prohibit the establishment of revegetation or where flow velocities exceed 5 ft/sec. Riprap may be used in the following applications: • Cut -and -fill slopes • Channel side slopes and/or bottoms • Inlets and outlets to sediment traps • Roadside ditches Limitations Riprap is limited by steepness of slope, because slopes greater than 1.5:1 have potential riprap loss due to erosion and sliding. When working within flowing streams, measures should be taken to prevent excessive turbidity and erosion during construction. Bypassing base flows or temporarily blocking base flows are two possible methods. Design criteria Gradation A well -graded mixture of rock sizes should be used instead of one uniform size (with the exception of dry stacking boulders). 50% by weight should be larger than the specified design size. The diameter of the largest stone size in such a mixture should be 1.5 times the d50 size with smaller sizes graded down to 1 inch. When dry stacking up a slope, boulders may be uniform in size or may get gradually smaller as the boulders are placed up the slope. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc R-1 June 2008 Quality Riprap must be durable so that freeze/thaw cycles do not decompose it in a short time. They should be angular and not subject to breaking down when exposed to water or weathering. The specific gravity should be at least 2.5. Size The sizes of stones used for riprap protection are determined by purpose and specific site conditions: 1. Slope Stabilization. Riprap stone for slope stabilization not subject to flowing water should be sized for the proposed grade. The gradient of the slope to be stabilized should be less than the natural angle of repose of the stone selected. Angles of repose of riprap stones may be estimated from Figure R-1. Riprap used for surface stabilization of slopes does not add significant resistance to sliding or slope failure and should not be considered a retaining wall. Slopes approaching 1.5:1 may require special stability analysis. The inherent stability of the soil must be satisfactory before riprap is used for surface stabilization. 2. Stream bank Protection. If the shear stress is estimated, riprap stone for stream bank protection can be selected from the gradations in Table R-1, below. The shear stress can be estimated from the depth of flow and the channel slope (see note for Table R-1). The riprap should extend 2 feet below the channel bottom and be keyed into the bank both at the upstream end and downstream end of the proposed work or reach. Filter material Filter material is sometimes used between riprap and the underlying soil surface to prevent soil from moving through the riprap. Filter cloth material or a layer of sand and/or gravel is usually used for the filter. The design of a sand/gravel filter blanket is based on the ratio of particle size in the overlying filer material to that of the base material in accordance with the criteria below. Multiple layers (each a minimum of 6 inches thick) may be designed to affect a proper filter if necessary. A sand/gravel filter blanket should have the following relationship for a stable design: d15 filter d85 base <_ 5 d15 filter 5 < d50 base <_ 40 d50 filter d50 base <_ 40 The design of a synthetic filter fabric, which may be used with or in place of gravel filters, is based upon the following particle size relationships: 1. Filter fabric covering a base containing 50% or less by weight of fine particles (#200 sieve size): a. d85 base (mm) EOS*filter fabric (mm) > 1 b. total open area of filter fabric should not exceed 36 % M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc R-2 June 2008 2. Filter fabric covering other soils: a. EOS is no larger than 0.21 mm (#70 sieve size) b. total open area of filter fabric should not exceed 10% *EOS - Equivalent opening size compared to a U.S. standard sieve size No filter fabric should have less than 4% open area or an EOS less than U.S. Standard Sieve #100 (0.15 mm). The permeability of the fabric must be greater than that of the soil. The fabric may be made of woven or non- woven monofilament yarns and should meet the following minimum requirements: Thickness 20-60 mils Grab strength 90-120 lbs Conform to ASTM D-1682 or ASTM D-177 Construction specifications See Figure R-2 for riprap slope stabilization and stream bank protection. See Figure R-3 for dry stacking boulders. See Sediment Trap (ST) for a detail of a riprap lined channel leading into a sediment trap. 1. Subgrade Preparation. Prepare the subgrade for riprap to the required lines and grades shown on the plans. Compact any fill required in the subgrade to a density approximating that of the undisturbed material or overfill depressions with riprap. Remove brush, trees, stumps, and other objectionable material. Cut the subgrade sufficiently deep so that the finished grade of the riprap will be at the elevation of the surrounding area. Channels should be excavated sufficiently to allow placement of the riprap in a manner such that the finished inside dimensions and grade of the riprap meet design specifications. 2. Sand/gravel filter blanket. If using a granular filter, spread filter stone in a uniform layer to the specified depth. Where more than one layer of filter material is used, spread the layers with minimal mixing. 3. Synthetic filter fabric. If using a filter fabric, place the cloth directly on the prepared foundation. Where large stones are to be placed, a 4 -1 -inch layer of fine sand or gravel is recommended to protect the filter cloth. Filter fabric is not recommended as a filter on slopes steeper than 2 horizontal to 1 vertical. 4. Stone placement. Place riprap so that it forms dense, well -graded mass of stone with a minimum of voids. The desired distribution of stones throughout the mass may be obtained by selective loading at the quarry and controlled dumping during final placement. Place riprap to its full thickness in one operation. Do not place riprap by dumping through chutes or other methods that cause segregation of stone sizes. If a filter is used, be careful not to dislodge the underlying base filter or damage the filter cloth when placing the stones. If damage occurs, remove the riprap and repair filter. 5. The toe of the riprap should be keyed into a stable foundation at its base as shown in Figure R-2 if required for slope stabilization and stream bank protection. The finished slope should be free of pockets of small stone or clusters of large stones. Hand placing may be necessary to achieve proper distribution of stone sizes to produce a relatively smooth, uniform surface. The finished grade of the riprap should blend with the surrounding area. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan (SWMP). If riprap has been damaged or dislodged, repairs should be made to prevent a progressive failure. If repairs are needed repeatedly at one location, the site should be evaluated to determine if the original design conditions M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc R-3 June 2008 1:1 Slope (H:V) — 1.5 : 1 have changed. Channel obstructions such as trees and sediment bars can change flow patterns and cause erosive forces that may damage riprap. Control of weed and brush growth may be needed in some locations. Removal Riprap is generally not removed. References Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> New York State Department of Environmental Conservation, New York Guidelines for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997. <http://www.dec.state.ny.us/website/dow/toolbox/escstandards> Table R-1 Riprap Gradations Unit shear stress (Ib/ft2) D50 dmax Minimum blanket thickness (inches) 0.67 2 4 6 2 6 9 14 3 9 14 20 4 12 18 27 5 15 22 32 6 18 27 32 7.8 21 32 38 8 24 36 43 Unit shear stress calculated as T=y*d*s where: T = shear stress in Ib/ft2 y = unit weight of water, 62.4 Ib/ft2 d = flow depth in ft s = channel gradient in ft/ft 45 40' Angle of Repose 35a 30 Figure R-1 Angles of Repose of Riprap Stones Clashed Rik Angular Rock; Rounded Stones M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc 4" 1-1 10- Z0„ 40" R-4 June 2008 Figure R-2 Typical Riprap Slope Protection Detail 5 (min.) NOT TO SCALE MOTTO SCALE {irao41I hllni urilIi iul iI Figure R-3 Typical Boulder Drystack Detail She Re Beuklera M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc R-5 Z T110. June 2008 Soil Stabilizers (SS) Description Soil stabilizers (also known as soil binders) consist of stabilizing emulsions that are applied directly to the surface of disturbed soil to temporarily reduce soil erosion. Soil binders are categorized as: • Short-lived plant -based materials • Long-lived plant -based materials • Polymeric emulsion blends (acrylic polymers) • Cementitious-based binders Applicability Soil binders are used on bare soil areas where vegetation may not be desired (such as near compressor stations) in order to reduce soil loss. Soil binders are also suitable for use on stockpiles. Limitations • Soil binders are a temporary measure. • Product must be reapplied 6-12 months after initial application. • Soil binders may not be compatible with certain soils. • Runoff can penetrate a treated area at the top of a slope, undercut the treated soil, and cause spot failures by discharging at a point further down the slope. • Performance depends on temperature, humidity, and traffic across treated areas. Design criteria No formal design is required. Construction specifications 1. Soil binder must be non-toxic to plant and animal life. Some examples include Guar, Starch, Pitch & Rosin Emulsion, Liquid Polymers of Methacrylates & Acrylates, and Gypsum. However, many others are available and may be used. Select a soil binder that is appropriate for the region, use and soil type. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SS -1 June 2008 2. Soil binder is typically mixed in a water truck or hydroseeder and applied in a liquid state. Use emulsion formulas for applications with water trucks. 3. Apply soil binder over a roughened soil surface on slopes not greater than 1 H:1 V. Do not apply immediately before or during a rain event or where standing water is present. 4. Soil binder can be applied in combination with organic fertilizers and humates, if desired. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan (SWMP). Inspect for rill erosion and reapply soil binder if necessary, usually every 6 to 12 months or when the surface has been disturbed. References Colorado Department of Transportation (CDOT), Erosion Control and Stormwater Quality Guide. 2002. http://www.dot.state.co.us/environmental/envWaterQual/wqms4.asp California Stormwater Quality Association, Stormwater Best Management Practice (BMP) Handbook — Construction. January, 2003. <http://www.cabmphandbooks.com/Construction.asp> M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SS -2 June 2008 Stockpiling (SP) — Topsoil and Subsoil Description Stockpiling during construction of well pads involves the removal and stockpiling of all surface soil materials (topsoil) from the entire cut and fill area for later reuse during interim and final reclamation. Topsoil provides a planting and growth medium that is more desirable than deeper subsoils for use during reclamation and revegetation activities. If there is an excess of cut material, however, subsoil may als7o be stockpiled. Stockpiling during construction of roads involves the removal and temporary stockpiling of all surface soil materials (topsoil) from the entire cut and fill area for reuse along cut and fill slopes and roadside ditches. This helps to reduce the loss of forage, habitat, and sediment, decreases maintenance costs, and helps maintain the scenic quality. If there is an excess of cut material, subsoil may also be stockpiled. Applicability Stockpiling applies for the construction of all well pads, roads, pipelines, and any other construction activity where soil is disturbed and later revegetated. Limitations • Stockpiling increases the overall area of disturbance at a site. • Stockpiles often require revegetation and also require other erosion and sediment controls during the establishment of vegetation such as silt fences or diversions. Design criteria No formal design is required. Construction specifications Location 1. Locate the stockpile so that it meets specifications and does not interfere with work on the site. 2. Stockpiles should be located and protected so that wind and water erosion are minimized and reclamation potential is maximized. 3. Stockpiles located down slope of a well pad will serve as tertiary spill containment and a reservoir during storm events. See Figure SP -1. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SP -1 June 2008 4. Stockpiles located upslope of a well pad will serve as a berm to divert surface runoff around the site and to a stabilized outlet. See Figure SP -2. 5. During the installation of pipelines, soil will be stockpiled according to Figure SP -3. Stripping and excavation 1. All perimeter stormwater controls shall be in place prior to stripping topsoil or excavating subsoil. 2. Stripping shall be confined to the immediate construction areas. 3. The depth of topsoil to be stripped and stockpiled should be determined during an on-site inspection prior to the start of any excavation activity, but is commonly 4 to 6 -inches. Stockpiling 1. Soil shall be stockpiled in such a manner that natural drainage is not obstructed and no off-site sediment damage shall result. 2. Keep topsoil segregated and stored separately from subsoil materials to avoid mixing during construction, storage, and interim reclamation. Never place subsoil materials on top of topsoil material. 3. Side slopes of the stockpile shall not exceed 2:1. 4. Stockpiles should be tracked according to Surface Roughening (SR) and stabilized to prevent erosion and off-site sedimentation. Perimeter controls shall be placed around the stockpile immediately. This may involve a diversion to route sediment laden runoff to a stabilized outlet, a silt fence to capture sediments, or any other applicable stormwater perimeter control. Revegetation of the stockpile, according to Revegetation (RV), can help reduce erosion as well as maintain its biological viability. Topsoiling during reclamation Part of the reclamation process involves salvaging and reusing all available topsoil to spread over disturbed areas prior to revegetation. Reclamation measures should begin as soon as possible after the disturbance and continue until successful reclamation is achieved. 1. Well pads — interim reclamation — Minimize the footprint of disturbance by reclaiming all portions of the well site not needed for production operations. Respread topsoil over areas not needed for operations prior to revegetation. 2. Well pads — final reclamation — Where the topography is flat and it is, therefore, unnecessary to recontour the well location at the time of final reclamation, the operator should set aside sufficient topsoil for final reclamation of the small, unreclaimed area around the wellhead. On sloped ground, during final reclamation, the topsoil and interim vegetation must be restripped from portions of the site that are not at the original contour, the well pad recontoured, and the topsoil respread over the entire disturbed site to ensure successful revegetation. 3. Roads — interim reclamation — Reclaim portions of the road not needed for vehicle travel wherever possible by covering cut slopes, fill slopes, and borrow ditches with topsoil salvaged during road construction prior to revegetation. 4. Pipelines — final reclamation — Reclaim disturbed area on completion of pipeline installation. The stripped topsoil shall be respread over the entire ROW to ensure successful revegetation. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SP -2 June 2008 Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan (SWMP). Inspect for rills and other evidence of stockpile erosion. Also inspect perimeter stormwater controls in accordance with the appropriate BMP. Removal Stockpiles may be removed when the site is ready for interim or final reclamation. References United States Army Corps of Engineers (USACE), Engineering and Design - Handbook for the Preparation of Storm Water Pollution Prevention Plans for Construction Activities. February 1997. <http://www.usace.army.mil/inet/usace-docs/eng-pamphlets/ep1110-1-16/> United States Department of the Interior and United States Department of Agriculture. Surface Operating Standards and Guidelines for Oil and Gas Exploration and Development "Gold Book." BLM/WO/ST- 06/021+3071. Bureau of Land Management (BLM). Denver, Colorado. Fourth Edition, 2006. Figure SP -1 Topsoil Stockpile — Located Below Well Pad Berri Pa f €rrac "q NOT TO SCALE M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SP -3 T;'Pa 1I Pile Tracking V'egelater1 Butter Diversion June 2008 Veyelated &uffnr NOT TO SCALE Figure SP -2 Topsoil Stockpile — Located above Well Pad Tui File -r9::kng R 0.W Boundary Figure SP -3 Topsoil Stockpile for Pipeline Installation I Lip orl storage (Store topsoil cn taap3l) Trench Spol - ri - NOT TO SCALE Spgi Sltlr rj Additional loprroII storage R.0 W Boundary Thr Piper* M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc Warti tag Skis SP -4 June 2008 Surface Roughening (SR) Corrugating Minibenching Tracking Description Surface (soil) roughening is a temporary erosion control practice often used in conjunction with grading. Soil roughening involves increasing the relief of a bare soil surface using construction equipment. Slopes that are not fine graded and that are left in a roughened condition can reduce erosion. Soil roughening reduces runoff velocity, increases infiltration, reduces erosion, traps sediment, and prepares the soil for seeding and planting by giving seed an opportunity to take hold and grow. The following types of soil roughening are discussed in this BMP: • Corrugating • Tracking • Minibenching Applicability Soil roughening is most effective for areas of 1 acre or less, and works well for the following applications: • Any slope, but particularly fill slopes greater than 3:1 • Areas with highly erodible soils • Soils that are frequently disturbed • Prior to application of permanent or temporary seeding M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SR -1 June 2008 Limitations • Soil roughening is not appropriate for rocky slopes. • Soil compaction might occur when roughening with tracked machinery. • Soil roughening is of limited effectiveness in anything more than a gentle or shallow depth rain. • If roughening is washed away in a heavy storm, the surface will have to be re -roughened and new seed laid. Design criteria No formal design required. However, the selection of the appropriate method (corrugating or tracking) depends on the type of slope. Steepness, mowing requirements, and/or a cut or fill slope operation are all factors considered in choosing a roughening method. Construction specifications To slow erosion, roughening should be done as soon as possible after grading activities have ceased (temporarily or permanently) in an area. All cut and fill slopes should be roughened wherever possible. Do not blade or scrape the final fill slope face. Excessive compacting of the soil surface should be avoided during roughening, and areas should be seeded as quickly as possible after roughening is complete. Corrugating Corrugating (Figure SR -1) uses machinery to create a series of ridges and depressions that run across the slope on the contour. Groove using any appropriate implement that can be safely operated on the slope, such as disks, tillers, spring harrows, or the teeth of a front-end loader bucket. Do not make the grooves less than 3 inches deep or more than 15 inches apart. Tracking Tracking is the most common method of soil roughening and is sometimes used as a method to hold down mulch. However, tracking is generally not as effective as corrugating. Tracking should be used primarily in sandy soils to avoid undue compaction of the soil surface. Operate tracked machinery up and down the slope to leave horizontal depressions in the soil (Figure SR -2). Do not back -blade during the final grading operation. Minibenching Benches shall be constructed on an even contour line. Benches shall be constructed approximately 2 feet deep and according to Figure SR -3. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Roughening might need to be repeated after storm events. Inspections of roughened slopes will indicate where additional erosion and sediment control measures are needed. If rills appear, they should be filled, graded again, and reseeded as soon as possible. Proper dust control methods should be used. References Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SR -2 June 2008 Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. New York State Department of Environmental Conservation, New York Guidelines for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997. <http://www.dec.state.ny.us/website/dow/toolbox/escstandards> CUT FURROWS ALONG THE CONTOUR. IRREGULARITIES IN THE Salt suiRFACE CATCH 'RAINWATER AtN) RETAIN LMAC, FERTILIZER ADD SEED NOT 10 SCALE 3' 11: Figure SR -1 Corrugating 15- rr.g., Figure SR -2 Tracking RL h4 444 d. Li 3* 3 M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc >-4 ! 3 3. ! ! 3 t 3 3 3 3 SR -3 June 2008 Figure SR -3 Minibenching GUT BENCHES ALONG THE CONTOUR. NOT TO SCALE M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SR -4 June 2008 Terracing (T) Description Terraces (also called benches or contour trenches) are properly spaced along a cut or fill slope and made of either earthen embankments, ridge and channel systems, or are cut directly into a rock face of a cut slope. Terraces are often constructed with an adequate grade to promote drainage to a stabilized outlet. Terraces reduce damage from erosion by collecting and redistributing surface runoff to stable outlets at slower speeds and by decreasing the distance of overland runoff flow. They also surpass smooth slopes in holding moisture and help to minimize sediment loading of surface runoff. When terraces are constructed into steep bedrock faces they help to stabilize the slope by catching loose rocks and other material which may fall from above. Applicability Terraces are most effective for areas less than 10 acres in size and, are suitable for the following applications: • Areas with an existing or expected water erosion problem and no vegetation. • Cut or fill slopes greater than 5 feet in height, which are not part of a trench or excavation. • Graded areas with smooth hard surfaces or any cleared area prior to seeding. • Where the length of slopes need to be shortened by terracing. • On steep rock walls, particularly those greater than 60 feet in height. Limitations • Terraces are not appropriate for use on sandy or shallow soils. • If too much water permeates the soil in a terrace system, sloughing could occur, and cut and fill costs could increase substantially. Design criteria The design of terraces should be determined by a civil engineer based upon actual site conditions. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc T-1 June 2008 Construction specifications In the absence of a specific design, terraces may be constructed according to Figure T-1 for cut slopes and Figure T-2 for fill slopes. 1. Construct diversion ditches at the top of the slope (if necessary for large upslope drainage areas) to prevent or reduce surface water from running down the slope face. 2. The upper terrace should begin immediately below the top of the fill slope. Continue constructing terraces down to the toe of the slope. Terraces shall be a minimum of 6 feet wide. However, a minimum width of 8 feet is ideal so that a crimper has access for mulching. 3. Terraces must drain to a stabilized outlet, such as a stabilized waterway, vegetated area, or other suitable outlet. Slope drains (Slope Drain (SD)) may be needed to convey surface runoff from the terraces or benches to the toe of the slope without causing erosion. Analysis of the local site conditions should determine the needed outlets. 4. Remove the loose material that collects at the end of terraces or benches and blend the ends of each terrace or bench into the natural ground surface. 5. Stabilize or revegetate the slope with methods applicable to the particular site. For terraces constructed into high rock walls of cut slopes, the vertical spacing may be anywhere from 10 to 100 feet and the width anywhere from 6 to 100 feet, as determined by a civil engineer. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Maintain terrace ridge height and outlet elevations. Remove sediment that has accumulated in the terrace to maintain capacity and a positive channel grade. If excessive seepage or surface runoff is a problem, control the seepage/runoff with appropriate drainage facilities. Take prompt action as needed to ensure proper drainage and slope stability. Repair rills and reseed damaged areas as they develop. Substantial maintenance of the newly planted or seeded vegetation may be required. References City of Knoxville, Stormwater Engineering, Knoxville BMP Manual - Best Management Practices. July 2003. http://www.ci.knoxville.tn.us/engineering Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> United States Department of Agriculture (USDA), Natural Resources Conservation Service (NRCS), Field Office Technical Guide. 2002. <www.nrcs.usda.gov/technical/efotg> M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc T-2 June 2008 Diversion Figure T-1 Terracing — Cut Slopes elerrrial sicee line 2:1 1 11:V) Err Utter Ditch to catch loose material Diverakwn Slum MaXIFiluM SirVirKeighl 2:1 2t7 31 30 4V NOT1Q$CAJ.E Pad aerie Maximum sliarxr Nnight bee title 1 Terraces shall slope between 2% am] rwtcl slab-He:Rd 04Jile1 2. RD..... length slung 18114:148 4/i211 not ex.r.A.84.1 BOO foo. Figure T-2 Terracing — Fill Slopes Normal %lope. km 2:1 [H:fla1 SlOpe Ivlakurnyn Slope 1-l9,I 2'1 ZO' 3:1 4:1 40' NOT TO $GALE 5:1 Of lanai MEMITILIM UteflIoi slupe. 1-4e3ighC Wow malarial See kale M:\Encana\BMP Manual \BMP Manual - Round 2 \SWMM Final 06-09-08.doc Verayleled Buffer Divi 1. Terraces shall slope henoveen 2% an4 3% to a stabezed 2. Flow length along a larracethII NA exceed WO feet. T-3 June 2008 Turf Reinforcement Mat (TRM) Description A turf reinforcement mat (TRM) is a rolled permanent erosion control product composed of UV -stabilized, non- degradable, synthetic materials (which may include an organic, biodegradable fiber component) processed into a three-dimensional matrix. TRMs are typically installed in ditches, swales, channels, and slopes where design discharges exert velocities and shear stresses that exceed the limits of mature, natural vegetation to prevent erosion. Applicability TRMs may be used in the following applications: • To control erosion on steep slopes and to promote the establishment of vegetation. • To stabilize channels against erosion from concentrated flows. • Used in transition areas before and after hard armor (i.e., riprap, concrete, asphalt etc.) to provide for stable and non-erosive transition. • May be used on slopes steeper than 1:1. Limitations • In an unvegetated state, velocities should not exceed 14 ft/sec maximum or the limitations provided by the manufacturer. • In a vegetated state, velocities should not exceed 25 ft/sec maximum or the limitations provided by the manufacturer. • Maximum slope is dictated by the soil stability and above referenced limited velocity and shear stress limitations. • Soils must be conducive to the establishment of vegetation. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc TRM-1 June 2008 Design criteria No formal design is required. Construction specifications 1. All vegetation, roots, rocks, and other objectionable material shall be removed and disposed of so as not to create loss of soil contact by the TRM when installed. 2. Select the appropriate TRM. North American Green Products are listed in Table TRM-1. However, other products, such as Green Armor (www.greenarmorsystem.com) may also be used. Site specifics shall dictate TRM use. 3. Select the appropriate seed mix according to Revegetation (RV). Apply seed prior to fabric installation for stabilization of construction sites. 4. Installation of the blankets shall be in accordance with the manufacturer's recommendations and according to Figure TRM-1. For blankets being placed in channels, the fabric should be rolled out parallel to the channel if the width is sufficient to cover the entire width of the channel. The fabric needs to be in continuous contact with exposed soil. 5. Pins or staples shall be made of wire 0.162 -inch or larger in diameter. "U" shaped staples shall have legs 8" long, and a 1" crown. "T" shaped pins shall have a minimum length of 8". The bar of the "T" shall be at least 4" long. Triangular survey stakes can also be used. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Inspections should determine if cracks, tears, or breaches have formed in the fabric. If the effectiveness of the BMP has been reduced, the fabric should be repaired or replaced immediately. Re -anchor loosened matting and replace missing matting and staples as required. It is necessary to maintain contact between the ground and the blanket at all times. Trapped sediment should be removed after each storm event. References Colorado Department of Transportation (CDOT), Erosion Control and Stormwater Quality Guide. 2002. http://www.dot.state.co.us/environmental/envWaterQual/wgms4.asp Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best Management Practices Field Guide. United States Department of Agriculture (USDA), Forest Service, US Agency of International Development (USAID), 2005. <http://www.blm.gov/bmp/field%20guide.htm> North American Green, 2004. http://www.nagreen.com M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc TRM-2 June 2008 Table TRM-1 Suggested Blanket Types Description (North American Green Product #) Longevity Applications Max. Flow Velocity (feet/sec.) Three UV Stable Nets Top Net 5 Ib. Black Corrugated Center Net 24 Ib. Black Bottom Net 5 Ib. Black 70% Straw / 30% Coconut Matrix Material (SC250) 24 month grow- in period 1:1 & Greater Slopes Medium to High Flow Channels 9.5 (unveg.) 15 (veg.) Three UV Stable Nets Top Net 8 Ib. Black Corrugated Center Net 24 Ib. Black Bottom Net 8 Ib. Black 100% Coconut Fiber Matrix Material (C350) 36 month grow- in period 1:1 & Greater Slopes High Flow Channels 10.5 (unveg.) 20 (veg.) Three UV Stable Nets Top Net 24 Ib. Black Corrugated Center Net 24 Ib. Black Bottom Net 24 Ib. Black 100% Polypropylene Fiber Matrix Material (P550) 36 month grow- in period or when sparse vegetation stand is expected 1:1 & Greater Slopes Extreme High Flow Channels 12.5 (unveg.) 25 (veg.) M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc TRM-3 June 2008 Roo Figure TRM-1 Turf Reinforcement Mat Installation Duire qimIciw.- rg•ti blar144:1. iii If01V11 i 10C17., by d" Here eta Mot sectored en trench Me 8 6° owerlap where One nal erblanke.1 ends and waffler bowls ra! a 4trwtaverety wherever tvg3 2 weans of Waitel are applied soda by side. Sitaplie p31.18dt rolinirmirl 3 par square y..1rd. Flaw &onkel fabric anchored in trench dnt't &Mold be Made every 11V. Insert a Mid rif Itin Wankel t: 4 ; Ante a lx,enchlr witiy 6' deep and tarnp firrnly Lny tho biariNoi smoothly Cf the surface ar the sell. 00 not strata) Lhe blankaL do f allow wrinkles. Install Staple 20' 811 center in trench. 1 M. IF Nssoe ()lactase blantel with a %Alt that is wrEln enrJugh to reach all !he way OEM= the channel, Plage' hLni1 nelled * the drecixerl flow Do Not jowl stem In the ceetef or *WI Ul thatk Slab. as reqt...ed ENankeL fabric anchored in trench 1318nkul fii anchored in trench PIRM blanket parallel to !he *rectal cri kw and anarrcr securely. thing blanket La a laieol mrI 1141WrirninatIFISI lhl installalmx Nor TO SCALE M:\Encana\BMP Manual \BMP Manual - Round 2 \ SWMM Final 06-09-08.doc TRM-4 June 2008 Vegetated Buffer (VB) Description Vegetated buffers (also known as vegetated filter strips) are areas of either natural or established vegetation that are maintained to protect the water quality of neighboring areas. Buffers reduce the velocity of stormwater runoff, provide an area for the runoff to permeate the soil, contribute to groundwater recharge, and act as filters to catch sediment. The reduction in velocity also helps to prevent soil erosion. The use of existing natural vegetation is preferred over newly established vegetation for the following reasons: • Can process higher quantities of stormwater runoff than newly seeded areas. • Does not require time to establish. • Has a higher filtering capacity than newly planted vegetation because aboveground and root structures are typically denser. • Reduces stormwater runoff by intercepting rainfall, promoting infiltration, and lowering the water table through transpiration. • Provides a fully developed habitat for wildlife. Applicability Vegetated buffers can be used in any area that is able to support vegetation but they are most effective and beneficial on floodplains, near wetlands, along streambanks, and as stabilized outlets to runoff controls such as diversions, water bars, or culverts. Buffers are also effective in separating land use areas that are not compatible and in protecting wetlands or water bodies by displacing activities that might be potential sources of non -point source pollution. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc VB -1 June 2008 Limitations • Vegetated buffers require plant growth before they can be effective, and land on which to plant the vegetation must be available. • Although vegetated buffers help to protect water quality, they usually do not effectively counteract concentrated stormwater flows to neighboring or downstream wetlands. Design criteria No formal design is required. Construction specifications 1. Buffer widths should be determined after careful consideration of slope, vegetation, soils, depth to impermeable layers, runoff sediment characteristics, type and quantity of stormwater pollutants, and annual rainfall. Buffer widths should increase as slope increases. 2. Zones of vegetation (native vegetation in particular), including grasses, deciduous and evergreen shrubs, and understory and overstory trees, should be intermixed. 3. Fertilizing seeded or planted ground may enhance growth (and improve its effectiveness as a buffer). 4. When using naturally vegetated areas, vegetation should be marked for preservation before clearing activities begin. Barriers may be used to prevent the approach of equipment within protected areas. 5. Direct sediment -laden water onto the naturally vegetated or stabilized planted ground. 6. Do not place any equipment, construction debris, or extra soil in the buffer area. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Keeping vegetation healthy in a recently established buffer requires routine maintenance, which (depending on species, soil types, and climatic conditions) may include weed control, fertilizing, liming, and irrigating. Once established or if using a naturally vegetated area, buffers do not require much maintenance beyond repairing or replacing damaged vegetation. Inspections should focus on encroachment, gully erosion, density of vegetation, evidence of concentrated flows through the areas, and any damage from foot or vehicular traffic. If there is more than 6 inches of sediment in one place, it should be removed. Removal During final site cleanup, any barriers placed around preserved natural areas should be removed. References Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc VB -2 June 2008 Wattles (W) Description A wattle (also called a fiber roll) consists of straw, flax, or other similar materials bound into a tight tubular roll. Excelsior log (aspen fiber) is the preferred wattle. When wattles are placed at the toe and on the face of slopes, they intercept runoff, reduce its flow velocity, release the runoff as sheet flow, and provide removal of sediment from the runoff. By interrupting the length of a slope, fiber rolls can also reduce erosion. Applicability Wattles may be suitable: • As slope breakers along the toe, top, face, and at grade breaks of exposed and erodible slopes to shorten slope length, reduce runoff velocity, and spread runoff as sheet flow • At the end of a downward slope where it transitions to a steeper slope • Along the perimeter of a project • At the overflow locations of sediment traps • As check dams in unlined ditches • Around temporary stockpiles Limitations • Wattles are not effective unless trenched. • Wattles placed directly at the toe of slopes greater than 5:1 (H:V) should be a minimum of 20 -in. diameter or installations achieving the same protection (i.e. stacked smaller diameter wattles, etc.). • Difficult to move once saturated. • If not properly staked and trenched in, wattles could be transported by high flows. • Wattles have a very limited sediment capture zone. • Wattles should not be used on slopes subject to creep, slumping, or landslide. • Wattles should not be used where periodic road or surface maintenance activities are expected. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc W-1 June 2008 Design criteria No formal design is required. Construction specifications Wattles should be either prefabricated rolls or rolled tubes of erosion control blanket. (If using an erosion control blanket, roll the length of erosion control blanket into a tube of minimum 8 in. diameter and bind roll at each end and every 4 ft along length of roll with jute -type twine.) See Figure W-1 for wattles used to control erosion along slopes. 1. Locate wattles on level contours spaced as follows: a. Slope inclination of 4:1 (H:V) or flatter: Fiber rolls should be placed ata maximum interval of 20 ft. b. Slope inclination between 4:1 and 2:1 (H:V): Fiber Rolls should be placed at a maximum interval of 15 ft. (a closer spacing is more effective). c. Slope inclination 2:1 (H:V) or greater: Fiber Rolls should be placed at a maximum interval of 10 ft. (a closer spacing is more effective). 2. Turn the ends of the wattles up slope to prevent runoff from going around the roll. 3. Stake wattles into a 2 to 4 in. deep trench with a width equal to the diameter of the wattle. Drive stakes at the end of each wattle and spaced 4 ft maximum on center. If wattles are part of a layered BMP system (3 or more) and a vegetated buffer (VB) is used, the wattles may be staked without trenching. Staking must insure continuous contact with the ground. 4. If more than one wattle is placed in a row, the rolls should be overlapped, not abutted. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Repair or replace split, torn, unraveling, or slumping rolls. If the wattle is used as a sediment capture device, or as an erosion control device to maintain sheet flows, sediment that accumulates must be periodically removed in order to maintain wattle effectiveness. Sediment should be removed when sediment accumulation reaches one-half the designated sediment storage depth, usually one-half the distance between the top of the wattle and the adjacent ground surface. Removal Wattles are typically left in place. If wattles are removed, collect and dispose of sediment accumulation, and fill and compact holes, trenches, depressions or any other ground disturbance to blend with adjacent ground. References California Stormwater Quality Association, Stormwater Best Management Practice (BMP) Handbook — Construction. January, 2003. <http://www.cabmphandbooks.com/Construction.asp> M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc W-2 June 2008 Figure W-1 Wattle Installation Irlall wattle neer sings wham it Iruha?liuwa• i rrlu slesp9' slope Verncsl w,smng mo-asurutl ulcng mc, 'ace 1 the siva cense betreisq 1Cr grid 23:2 NOT TO SCALE M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc W-3 Nule Install walna a lba lare140a4Pdr. Exiand and of wattlsugsiopgb amid flow arwrrd acrd. June 2008 Drainage Control BMPs Berm (B) Culvert (C) Culvert Inlet Protection (CIP) Culvert Outlet Protection (COP) Diversion (D) Drainage Dip (DD) Level Spreader (LS) Roadside Ditches (RSD) and Turnouts (TO) Run -On Diversion (ROD) Slope Drain (SD) Trench Breaker (TB) Water Bar (WB) M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc June 2008 Berm (B) Description A berm is a ridge of compacted soil located at the top or base of a sloping disturbed area to contain or divert surface runoff. Berms may be constructed from either excavated topsoil or subsoil. The purpose of a berm is to control runoff velocity, divert on-site surface runoff to a sediment trapping device, and/or divert clean water away from disturbed areas. Applicability Berms are usually appropriate for drainage basins smaller than 5 acres, but with modifications they can be capable of servicing areas as large as 10 acres. With regular maintenance, earthen berms have a useful life span of approximately 18 months. Berms are applicable for the following applications: • At the perimeter of a well pad (particularly the outer edge) to ensure that runoff remains on the pad and is diverted to a well pad detention pond, if available. See Detention Pond (DP). • Along the outside shoulder of an insloped road to ensure that runoff from the roadway drains inward and to protect the fill slope from continual disturbances during road blading and maintaining. See Land Grading (LG) — Roads. • Upslope of cut or fill slopes to divert flows away from disturbed areas. • Downslope of cut or fill slopes to divert on-site runoff to a stabilized outlet or sediment trapping device, although diversions are more commonly used for this application. See Diversion (D). • As temporary slope breakers to reduce runoff velocity and divert water off the construction right-of- way. Limitations • Berms may erode if not properly compacted and stabilized with vegetation or an erosion control blanket. Berms which are adjacent to concentrated flows will require erosion blanketing according to Erosion Control Blanket (ECB). • If a berm crosses a vehicle roadway or entrance, its effectiveness can be reduced. Wherever possible, berms should be designed to avoid crossing vehicle pathways. Design criteria No formal design is required. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc B-1 June 2008 Construction specifications 1. Prior to berm construction, remove all trees, brush, stumps, and other objects in the path of the berm and till the base of the berm before laying the fill. Fill may consist of topsoil or subsoil excavated during the construction of nearby roads or well pads. If fill material is excavated adjacent to berm, follow the specification for Diversion (D). 2. Construct the berm according to Figure B-1 for the appropriate drainage area. For points where vehicles will cross the berm, the side slope should be no steeper than 3:1 and the mound may be constructed of gravel rather than soil. This will prolong the life of the berm and increase effectiveness at the point of vehicle crossing. For well pad perimeter installation the pad side of the berm should be sloped at 1.5:1 to help prevent vehicles from backing over the edge of the pad. 3. To remain effective, berms should be compacted with tracked equipment, if possible. 4. All berms shall have positive drainage to a stabilized outlet so that runoff does not collect in ponds on the upslope side of the berm, but instead flows along the berm until it reaches a stabilized outlet. Field location should be adjusted as needed. Stabilized outlet may be a well -vegetated area, a well pad detention pond, or a sediment control such as a silt fence or a sediment trap where sediment can settle out of the runoff before being discharged to surface waters. 5. If the expected life span of the berm is greater than 15 days, it is strongly recommended that the berm be stabilized with vegetation or an erosion control blanket immediately after construction. Stabilization is required where concentrated flows are expected. See Table B-1 for recommended stabilization methods for berms on various slopes. 6. Berms should be constructed and fully stabilized prior to commencement of major upslope land disturbance. This will maximize the effectiveness of the structure as a stormwater control device. 7. If using berms as temporary slope breakers to reduce runoff velocity, space the berms according to the following table: Slope (%) Spacing (feet) 5 —15 300 >15 — 30 200 >30 100 Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Berms should be inspected for evidence of erosion or deterioration to ensure continued effectiveness. Berms should also be maintained at the original height. Any decrease in height due to settling or erosion, which impacts the effectiveness of the BMP, should be repaired immediately. Removal Berms should remain in place and in good condition until all upslope disturbed areas are permanently stabilized. There is no need to formally remove the berm on completion of stabilization until interim or final reclamation. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc B-2 June 2008 References Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> New York State Department of Environmental Conservation, New York Guidelines for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997. http://www.dec.state.ny.us/website/dow/toolbox/escstandards Table B-1 Temporary Berm Stabilization Type of Treatment Channel Grade' A (<5 Ac.) B (5-10 Ac) 1 0.5-3.0% Seed & Straw Mulch Seed & Straw Mulch 2 3.0-5.0% Seed & Straw Mulch Seed and cover with erosion control blanket, or lined with 2 -inch stone 3 5.0-8.0% Seed and cover with erosion control blanket, or line with 2 -inch stone Line with 4 to 8 -inch stone or rock2 4 r 8.0-20.0% Line with 4 to 8 -inch or stone or rock2 Engineering Design Notes: 1 In highly erodible soils, as defined by the local approving agency, refer to the next higher slope grade for type of stabilization. 2 Site rock if available, shall be broken into the required size. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc B-3 June 2008 Figure B-1 Berm Installation TYPE A - GENERAL SITE PERIPAETER INSTALLATION 5iP as 1,x°5 rnk� Sled112a1nm F require.1 (Fos takee) On stoop slopes oxratalc La pravult requraad 1lrlta width at now alcplh N(11 TO tiCN_ Slap* I'?a ton. -* NOT TO SCALE B Max 2 7 1 O A NrRn, Shale^_ I.4 rm 13 5`k ID .4`•'.. I><I slalnlic*c ILt:L 2 Mala. Cut cr FIA Slope 1 Natural gratirKIsurlacxi BERM A BERME icy acs 111 ace A - F1ERti WEIGHT 1@ r= 36 an 6. -BERM WIDTH 24 J. 36m C-FLCAA"WIDTH AB in 60 St -FWLQWIMPH can Is in TYPE B - WELL PAD PERIMETER INSTALLATION Ma°a 1.5 Stabilization as 'squired (sae table). War Slope Nam 0 V t4 11O% IO dataaeliraaa perxl 2�. 2#• 2 Max, Well Pbd Cur or Fdl FnII {Tolril or SLSaI I TYPE O - ROADSIDE INSTALLATION PJOT TO SCALE M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc B-4 June 2008 Culvert (C) Description Culverts are typically concrete, steel, aluminum, or plastic pipe used to move ditch water under the road or to direct stream flow under the road or construction area. Applicability Culverts are ideal on road grades less than 15%. For grades over 15%, it is difficult to slow down the water or remove it from the road surface rapidly. On such steep grades, it is best to use frequently spaced relief culverts and drainage crossing culverts with armored ditches. Culverts may be used in the following applications: • As drainage crossing culverts in streams and gullies to allow normal drainage to flow under the traveled way. • As ditch relief culverts to periodically relieve the inside ditch line flow by piping water to the opposite side of the road where the flow can be dispersed away from the roadway. Culverts placed in natural drainages may be utilized for ditch relief. Limitations • If undersized, culverts are susceptible to plugging and require cleaning. • Culverts will not filter sediment. • Culverts are easily crushed if not properly designed. Design criteria Capacity All culverts should be designed for a minimum 25 -year -frequency storm with an allowable head that does not overlap the roadway. However, the minimum acceptable size culvert diameter to prevent failure from debris blockage is 18 inches for intermittent stream crossings and 36 inches for perennial stream crossings. Pipe M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc C-1 June 2008 size can be determined using general design criteria, such as in Table C-1, but is ideally based upon site- specific hydrologic analysis. Depth The depth of culvert burial must be sufficient to ensure protection of the culvert barrel for the design life of the culvert. This requires anticipating the amount of material that may be lost due to road use and erosion. Headwalls Use headwalls on culvert pipes as often as possible (see Retaining Wall (RW)). The advantages of headwalls include: preventing large pipes from floating out of the ground when they plug; reducing the length of the pipe; increasing pipe capacity; helping to funnel debris through the pipe; retaining the backfill material; and reducing the chances of culvert failure if it is overtopped. Construction specifications Drainage crossing culverts 1. Make road crossings of natural drainages perpendicular to the drainage to minimize pipe length and area of disturbance (Figure C-1). 2. Use single large pipes versus multiple smaller diameter pipes to minimize plugging potential in most channels (unless roadway elevation is critical). In very broad channels, multiple pipes are desirable to maintain the natural flow spread across the channel. All culverts should be concrete, corrugated metal pipe (CMP) made of steel or aluminum, or properly bedded and backfilled corrugated plastic pipe. 3. Align culverts in the bottom and middle of the natural channel flowline so that installation causes no change in the stream channel alignment or stream bottom elevation. Culverts should not cause damming or pooling or increase stream velocities significantly. 4. Extend the outlet of the culvert at least 1 foot beyond the toe of the slope to prevent erosion of the fill material. Alternatively, use retaining walls (headwalls) to hold back the fill slope. 5. It may be necessary to install riprap, erosion control blanketing, a combination of the riprap and blanketing, or other energy dissipater device at the outlet end of the culvert to reduce soil erosion or to trap sediment (see Culvert Outlet Protection (COP)). 6. It may be desirable to construct pulloffs/turnouts for vehicles on one or both sides of narrow culvert crossings. This will help avoid culvert crushing as well as disturbance to roadside ditches and berms. Ditch relief culverts 1. See Figure C-2 for installation details. 2. Ditch relief culverts can provide better flow when skewed 0 to 30 degrees perpendicular to the road. 3. The culvert gradient should be at least 2% greater than the approach ditch gradient. This improves the flow hydraulics and reduces siltation and debris from plugging the culvert inlet. 4. Discharge culvert at natural ground level where possible (see Figure C 3 Type A), on firm, non-erosive soil or in rocky or brushy areas. If discharged on the fill slopes, armor outlets with riprap or slash (see Figure C-3 — Type B), or use down -drain structures (see Figure C-3 — Type C and Slope Drain (SD)). 5. Extend the inlet of the culvert at least 1 foot beyond the flowline of the roadside ditch. Extend the outlet of the culvert at least 1 foot beyond the toe of slopes to prevent erosion of the fill material. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc C-2 June 2008 6. It may be necessary to install riprap or other energy dissipater devices at the outlet end of the culvert to prevent soil erosion or to trap sediment (see Culvert Outlet Protection (COP)). 7. Spacing of culverts is dependent on the road gradient, soil types, and runoff characteristics according to the following table: Soil type Road grade 2-4% 5-8% 9-12% Highly corrosive granitic or sandy 240' 180' 140' Intermediate erosive clay or load 310' 260' 200' Low erosive shale or gravel 400' 325' 250' 8. It may be desirable to construct pulloffs/turnouts for vehicles on one or both sides of narrow culvert crossings. This will help avoid culvert crushing as well as disturbance to roadside ditches and berms. Backfill and compaction 1. See Figure C-4. 2. Firmly compact well -graded fill material (soil or road base) around culverts, particularly around the bottom half, using placement in layers to achieve a uniform density. Use slightly plastic sandy gravel with fines. Avoid the use of fine sand and silt rich soils for bedding material because of their susceptibility to piping. Pay particular attention to culvert bedding and compaction around the haunches of the pipe. Do not allow the compaction to move or raise the pipe. In large fills, allow for settlement. 3. Cover the top of metal and plastic culvert pipes with fill to a depth of at least 1 foot to prevent pipe crushing by heavy trucks. Use a minimum cover of 2 feet of fill over concrete pipe. For maximum allowable fill height, follow the manufacturer's recommendations. 4. Mound fill over the top of culvert pipes so that the road is slightly raised at culvert locations to help prevent erosion and water from ponding over culvert crossings. This practice, as well as placing large boulders around the culvert outlets, will also help to prevent culverts from crushing. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. If any damage to culvert or inlet/outlet protection is noted or if there is any evidence of scour, repairs should be made immediately. Any debris that may be blocking the culvert inlet or outlet should be removed. References Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best Management Practices Field Guide. United States Department of Agriculture (USDA), Forest Service, US Agency of International Development (USAID), 2005. <http://www.blm.gov/bmp/field%20guide.htm> M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc C-3 June 2008 United States Department of the Interior and United States Department of Agriculture. Surface Operating Standards and Guidelines for Oil and Gas Exploration and Development "Gold Book". BLM/WO/ST- 06/021+3071. Bureau of Land Management (BLM). Denver, Colorado. Fourth Edition, 2006. Table C-1 Culvert Sizing Drainage Area (acres) Size of Drainage Structure (diameter and area) Steep Slopes (Light Vegetation) C=0.7 Gentle Slopes (Heavy Vegetation) C=0.2 Round Pipe (in) Area (sq. ft) Round Pipe (in) Area (sq. ft) 0 —10 30" 4.9 18" 1.8 10 - 20 42" 9.6 24" 3.1 20 - 35 48" 12.6 30" 4.9 35 - 75 72" 28.3 42" 9.6 75 - 125 84" 38.5 48" 12.6 125 - 200 96" 50.3 60" 19.6 Notes: If pipe size is not available, use the next larger pipe size for the given drainage area. For intermediate terrain, interpolate between pipe sizes. Pipe size is based upon the Rational Formula and Culvert Capacity curves. Assumes a rainfall intensity of 3 to 4 in/hr. Values of "C" are the Runoff Coefficients for the terrain. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc C-4 June 2008 Figure C-1 Drainage Crossing Culvert Alignment & Overflow Dip Noe. Make road crossing perper sr Is) inn drainage -in neairnizn pipe Iorgrh and area or elts[urterre. NOT TO SCALE Turnout when) crossings are nsrrrrr, Fill Figure C-2 Ditch Relief Culvert Installation t^day[ prnlodion ar .ir ixli, ! Spac!ng 110-11:Ce bnMwncn culvaerrs L9u[le1 protBcarxii antis Amp Roadsde ditch ExIonn cllvr}n al IRas1 9` kiR'graand the 1loelrne of Pie roadelde diM1r Intel pro[ac6on as nestled Extend cul,rnn 1" Beyond toed slope NOT TO SCALE M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc Fill gape Place const paps al natural ground Israel ar romp aurae( the till raaterial C-5 June 2008 Figure C-3 Culvert Installation Options TYPE A Natural ground surtax Roar/hod -- Inskpw 3-5% Comparted Fill Culvert Cog Alain Culvert TYPE CuIverl NOT TJ SCALE SIlght mound aver cul•eurl Roadbed Base and slrieewall Ffr rnlle.rral shutud bre: rpmpaclrr.. Cnrnpact the fill a minium of each culvert diampler on each sem of trio wlverl. NOT TO SCALE M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc Rrladbad Insrcpe 3-5.% TYPE B r Culvert Cadet proteCon with rock rfprap aaarrd Inslcpa 3-5% Compacted Fill Add riprap or (idler ape protedion QartIm1 pro!daon wrlh roc* rrpraQ .canpaaled Fla Anchor the elope drain pie to the lilt slope walIi stakie3, rah1e anchor bkeiir.s, errs. Cutlet protection with rock riprap Figure C-4 Culvert Backfill and Compaction d0' C-6 At tease 1 1t. or cover for CN1P rr Ma third cr diaeniet er Fur large culvarls Use 2 ttcover for concerto pipe. CU! ail Tamp backfill malarial at regualarmtervals tIrlt Of G -r Level ail natural slreambed Gra•.e1(sr Mil culvert. bed Elea rMk larger than 3.) June 2008 Culvert Inlet Protection (CIP) Description Culvert protection is required at both the inlet to the culvert (upstream side) and the outlet to the culvert (downstream side). Culvert inlet protection may involve placing boulders, riprap, gabions, rock retaining walls, slash, and/or any other protection at the inlets of pipes. Riprap, or other energy -dissipating devices, will reduce the velocity of stormwater flows and thereby prevent erosion and help protect the inlet structure. Applicability Riprap inlet protection should be used where velocities and energies at the inlets of culverts are sufficient to erode around the inlet structure. Riprap may also be used to help channel the stormwater to the inlet of the culvert. Design criteria Riprap, gabions, or rock retaining walls at culvert inlets shall be designed according to their appropriate BMPs. Construction specifications Figure CIP-1 shows typical culvert inlet protection. However, site specifics shall dictate actual design. 1. Riprap, gabions, or rock retaining walls at culvert inlets shall be constructed according to their appropriate BMPs. 2. After installation of a culvert, examine the stream channel for the amount of debris, logs, and brushy vegetation present. In channels with large amounts of debris, consider using oversized pipes. 3. Boulders should be drystacked around the culvert inlet and up the slope to the edge of the road. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Inspect for debris at the entrance to culverts and within culverts. Inspect riprap at culvert inlets for damaged or dislodged stones. Any needed repairs that reduce the effectiveness of the BMP should be made immediately. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc CIP-1 June 2008 References Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best Management Practices Field Guide. United States Department of Agriculture (USDA), Forest Service, US Agency of International Development (USAID), 2005. <http://www.blm.gov/bmp/field%20guide.htm> New York State Department of Environmental Conservation, New York Guidelines for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997. <http://www.dec.state.ny.us/website/dow/toolbox/escstandards> Figure CIP-1 Typical Inlet Protection / F Acrid ruNsirl I _ _ rrr 1` tliaraidirec# sPape S" 4.116100. "S dirnLWp Trap R°ad Ja diltri NOT TO SCALE M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc Rpxap CRJ °T Erosion control IA:inknl iEO ) CIP-2 f June 2008 Culvert Outlet Protection (COP) Description Culvert protection is required at both the inlet to the culvert (upstream side) and the outlet to the culvert (downstream side). Culvert outlet protection involves placing structurally lined aprons or other appropriate energy -dissipating devices, such as large boulders or plunge pools, at the outlets of pipes to reduce the velocity of stormwater flows and thereby prevent scouring at stormwater outlets, protect the outlet structure, and minimize potential for erosion downstream. Applicability Culvert outlet protection should be used where discharge velocities and energies at the outlets of culverts or channels are sufficient to erode the next downstream reach. Limitations Rock aprons at culvert outlets should not be placed on slopes steeper than 10 percent. Runoff from pipe outlets at the top of cuts/fills or on slopes steeper than 10 percent should be routed via slope drains or riprap chutes to a rock apron at the toe of the slope. Otherwise flows will re -concentrate and gain velocities as the flow leaves the apron. Design criteria Gabions or rock retaining walls at culvert outlets shall be designed according to their appropriate BMPs. No formal design is required for plunge pools at outlets. Riprap aprons at culvert outlets shall be designed as follows: Tailwater depth. The depth of tailwater immediately below the pipe outlet must be determined for the design capacity of the pipe. If the tailwater depth is less than half the diameter of the outlet pipe, and the receiving stream is wide enough to accept divergence of the flow, it shall be classified as a Minimum Tailwater Condition. If the tailwater depth is greater than half the pipe diameter and the receiving stream will continue to confine the flow, it shall be classified as a Maximum Tailwater Condition. Pipes which outlet onto flat areas with no defined channel may be assumed to have a Minimum Tailwater Condition. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc COP -1 June 2008 Riprap apron size & D50. The apron length (LA) and the D50 of the riprap shall be determined from Table COP -1 according to the design flow and whether there is a minimum or maximum tailwater condition. The apron width (W) shall then be determined as: W = d + 0.4 LA where d is the diameter of the culvert. If the pipe discharges directly into a well defined channel, the apron shall extend across the channel bottom and up the channel banks to an elevation 1 foot above the maximum tailwater depth or to the top of the bank, whichever is less. The upstream end of the apron, adjacent to the pipe, shall have a width two (2) times the diameter of the outlet pipe, or conform to pipe end section if used. Riprap materials. The outlet protection may be done using rock riprap or grouted riprap. Riprap shall be composed of a well -graded mixture of stone size so that 50 percent of the pieces, by weight, shall be larger than the D50 size determined from Table COP -1. A well -graded mixture, as used herein, is defined as a mixture composed primarily of larger stone sizes, but with a sufficient mixture of other sizes to fill the smaller voids between the stones. The diameter of the largest stone size in such a mixture shall be 1.5 times the D50 size. All grout for grouted riprap must be one part Portland cement for every 3 parts sand, mixed thoroughly with water. Filter. If a filter cloth or gravel is used, it should be designed according to Riprap (R). Apron thickness. The minimum thickness of the riprap layer shall be 1.5 times the maximum stone diameter for D50 of 15 inches or less; and 1.2 times the maximum stone size for D50 greater than 15 inches. Riprap stone quality. Stone for riprap shall consist of field stone or rough unhewn quarry stone. The stone shall be hard and angular and of a quality that will not disintegrate on exposure to water or weathering. The specific gravity of the individual stones shall be at least 2.5. Site rock or site boulders may be used provided it has a density of at least 150 pounds per cubic foot, and does not have any exposed steel or reinforcing bars. Construction specifications Gabions or rock retaining walls at culvert outlets shall be constructed according to their appropriate BMPs. Riprap aprons at culvert outlets shall be constructed according to Figure COP -1 and as follows: 1. Prepare the subgrade for the riprap to the required lines and grades. Any fill required in the subgrade shall be compacted to a density of approximately that of the surrounding undisturbed material. 2. If a pipe discharges into a well-defined channel, the channel's side slopes may not be steeper than 2:1. 3. Construct apron to the design length and width with no slope (Figure COP -1). The invert elevations must be equal at the receiving channel and the apron's downstream end. No overfall at the end of the apron is allowed. The elevation of the downstream end of the apron shall be equal to the elevation of the receiving channel or adjacent ground. The outlet protection apron shall be located so that there are no bends in the horizontal alignment. 4. Line the apron with riprap, grouted riprap, or concrete. Riprap should be the appropriate size and thickness as designed. See Riprap (R) for the placement of riprap. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc COP -2 June 2008 5. If a culvert outlets at the top of cuts/fills or on slopes steeper than 10 percent one of the following two options is suggested: a. Transition culvert to a slope drain according to Slope Drain (SD). The slope drain shall convey stormwater to the bottom of the slope where a riprap apron, as designed above, shall prevent erosion at the slope drain outlet. b. Line slope below culvert outlet with a riprap channel to convey stormwater to the bottom of the slope where a riprap apron, as designed above, shall prevent erosion at the bottom of the slope. The riprap channel shall be designed according to the table in the Riprap (R) BMP that is based on depth of flow and slope. The riprap channel shall dip into the slope so that all water is contained within the channel, flows to the riprap outlet apron at the base of the slope, and does not spill over the sides onto unprotected soil. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. The maintenance needs are usually very low for properly installed riprap aprons at culvert outlets. However, inspect for evidence of scour beneath riprap at outlet aprons or for dislodged stones. And needed repairs that reduce the effectiveness of the BMP should be made immediately. References Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best Management Practices Field Guide. United States Department of Agriculture (USDA), Forest Service, US Agency of International Development (USAID), 2005. <http://www.blm.gov/bmp/field%20guide.htm> New York State Department of Environmental Conservation, New York Guidelines for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997. <http://www.dec.state.ny.us/website/dow/toolbox/escstandards> M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc COP -3 June 2008 Table COP -1 Outlet Protection Design Riprap Aprons for Law TiaMater (downstream flow death < 0.5 x pipe diameter) Caved est 'fie E+1'.a fl mit,-3f�P J3!° C s to inierpolate kern I- '. ' tis Ft In as R 111 (s Ft In Cfs Ft In ' Ofs Ft 1 12'- 4 7 2 f 6 1C) 34 1311 5 12 16 7 14 17 '9 IS 15- 55 3 10 12 5 1 15 718 10l Imo, 111"' IC 9 3 c 15 14 , ", .-' 17 7 .3'1' 22 11 400 25 14 2r 15 11 4 1& 7 +. 22 10 45 13 23 1 _ _ 24` _ 1 I3 , 35 23.3.5 1 L Iii 30 16 -33 1'_I ► , , .".... 24 9 5 i' 14 % 31 1,1i 110 i ".- 3r{ i . 90 9.5 3 'B 1213, 38 20 14:3 Ota ', 24 36- _ .'L 100 13 11:, 10 I 1801 45 2.3 . 20 50 i 42"?' - 120 v 112 1.7...-; c1 . 17 :tel 45 20 52 2.6 120 .yr i' 170 2:7 14 z-,., 4�s 1':, :.270 23 37 Riprap downstream Aprons flow de for Haigh Tailwater l > 0.5 x pipe d"ian titer) CJ.e1 Demeter + LWf St ratue lA'Y*`-rrned, a stointer ApIaI.efr4''a 119Logii witue (I LA Gym 0 L. Cite O LA 135, 0 L,,, DA t L# Dm Cts Ft I'5 Fa 1n Cis Ft In as Ft 1n 9 In 12` 4 8 2 6 -. 18 2 6 9 28 4 E 12 M. 7 40 ' 8 1'5' 7 ' 10 21;11__2.5 _ . 15 34 5 21} 42 7-}' 1 10 18 - IC, g 2 15ri. 3 30 93, 1 1 1 21- L. 8 .;- 32 45 LiS 48 7 45 58 II : L.o } ) 14 .1- 2C 8 2 3.5 36 5 50 55, $.5 5 603 1 ? . 808C 15 27- 27 10 2 60 41 6 73 58 10 90' 7P 14 : v.::: 82 17 30• .:, 11 2 42 6 9) 54 11 120 f0 115 14.0. S0 1 :, -?. 1 2. - 100 f ) ' 7 140 a5 13 180 104 16 22U , 12) 2. 42- 2 t-- 120 r r E) : € 16375 -. 10 rte_ 516 14 29 0 120 19 • .. " 110 7 220 85 1 27i} 11 16 320 12l] 21} M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc COP -4 June 2008 Figure COP -1 Typical Outlet Protection A w = d$0.416 d — 1.5xa... pr 1 a CAR.,, 2 Graded aggregale 11Iter ur NW da111 Graders antsrowte tiller or lillat cloth La NOT TO SCALE M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc COP -5 June 2008 Diversion (D) Definition A diversion is a drainage way of parabolic or trapezoidal cross section with a supporting ridge on the lower side that is constructed across the slope. The purpose of a diversion is to prevent off-site storm runoff from entering a disturbed area, to prevent sediment laden storm runoff from leaving the construction site or disturbed area, to prevent flows from eroding slopes, and to direct sediment laden flows to a trapping device. Applicability Diversions may be designed for temporary or permanent use. The maximum drainage area for temporary, un -compacted diversions is 2 acres. For drainage areas larger than 2 acres but less than 10 acres, the diversion should be compacted. For undisturbed drainage areas larger than 10 acres, a permanent diversion may be designed to handle larger flows. Diversions may be used for the following applications: • Upslope of cut or fill slopes to convey or divert flows away from disturbed areas. See Run -On Diversion (ROD). • Down-slope of cut or fill slopes to divert on-site runoff to a stabilized outlet or sediment trapping device. • At the outer edge of a well pad to ensure that runoff remains on the pad and is diverted to a well pad detention pond, if available. See Detention Pond (DP). • Where runoff from higher areas has potential for causing erosion, or interfering with, or preventing the establishment of, vegetation on lower areas. • Where the length of slopes needs to be reduced so that soil loss will be kept to a minimum. • At the perimeter of a site or disturbed area. Limitations • The area around the diversion channel that is disturbed by its construction must be stabilized (with vegetation or other erosion control) so that it is not subject to similar erosion as the steep slope the channel is built to protect. • To alleviate erosion capability, diversions must be directed into a stabilized outlet or well -vegetated area or to sediment trapping devices, where erosion sediment can settle out of the runoff before being discharged to surface waters. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc D-1 June 2008 • Temporary diversions should be designed to avoid crossing vehicle pathways. • Diversions should be used with caution on soils subject to slippage. Design criteria For a temporary diversion (drainage area less than 10 acres), no formal design is necessary. For a run-on diversion see the Run -On Diversion (ROD) BMP. For other permanent diversions (drainage area larger than 10 acres) the following guidelines apply: Location Diversion location shall be determined by considering outlet conditions, topography, land use, soil type, length of slope, and the development layout. Capacity Peak rates of runoff values used in determining the capacity requirements shall be as outlined by TR -55, Urban Hydrology for Small Watersheds. The constructed diversion shall have capacity to carry, as a minimum, the peak discharge from a 10 -year frequency rainfall event with freeboard of not less than 0.3 feet. Cross section See Figure D-2 for details. The diversion channel shall be parabolic or trapezoidal in shape, if possible. The diversion shall be designed to have stable side slopes. The side slopes shall not be steeper than 2:1 and shall be flat enough to ensure ease of maintenance of the diversion and its protective vegetative cover. The ridge shall have a minimum width of 4 feet at the design water elevation; a minimum of 0.3 feet freeboard and a reasonable settlement factor (10%) shall be provided. Velocity and grade The permissible velocity for the specific soil type will determine the maximum grade. The maximum permissible velocity for sand and silt vegetated channels is 3 ft/sec, and 5 ft/sec for clay vegetated channels. Diversions are not usually applicable below high sediment producing areas unless structural measures, designed to prevent damaging accumulations of sediment in the channels, are installed with, or before, the diversions. Construction specifications General 1. All trees, brush, stumps, obstructions, and other objectionable material shall be removed and disposed of so as not to interfere with the proper functioning of the diversion. 2. All diversions shall have uninterrupted positive grade to an outlet. 3. Each diversion must have an adequate outlet where outflow will not cause damage. Diverted runoff from a disturbed area shall be conveyed to a sediment trapping device. Diverted runoff from an undisturbed area shall outlet to a sediment trapping device or into an undisturbed stabilized area at non-erosive velocities. Vegetated outlets shall be installed before diversion construction, if needed, to ensure establishment of vegetative cover in the outlet channel. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc D-2 June 2008 Temporary diversion (drainage area <10 acres) See Figure D-1. 1. The diversion shall be excavated or shaped to line, grade, and cross section as required to meet the specified criteria. The diversion does not need to be compacted if the contributing drainage area is less than 2 acres. 2. Stabilization with vegetation is not required as long as sediment traps or other sediment control devices are provided. Permanent diversion (drainage area >10 acres) See Figure D-2. 1. The diversion shall be excavated or shaped to line, grade, and cross section as required to meet the criteria specified herein, and be free of bank projections or other irregularities which will impede normal flow. 2. Parabolic and triangular-shaped, grass -lined channels should not have a top width of more than 30 feet. Trapezoidal, grass -lined channels may not have a bottom width of more than 15 feet unless there are multiple or divided waterways, they have a riprap center, or other methods of controlling the meandering of low flows are provided. 3. If grass -lined channels have a base flow, a stone center or subsurface drain or another method for managing the base flow must be provided. 4. Fills shall be compacted as needed to prevent unequal settlement that would cause damage in the complete diversion. 5. All earth removed and not needed in construction shall be spread or disposed of on the construction side of the diversion so that it will not interfere with the functioning of the diversion. 6. Immediately after the ridge and channel are constructed, they must be seeded or hydro -seeded and mulched according to Revegetation (RV) and Mulching (M) or Erosion Control Blanket (ECB) along with any disturbed areas that drain into the diversion. a. For design velocities less than 3.5 ft/sec, seeding and mulching may be used for establishment of the vegetation. It is recommended that, when conditions permit, temporary diversions or other means should be used to prevent water from entering the diversion during the establishment of the vegetation. b. For design velocities of more than 3.5 ft/sec, the diversion shall be stabilized with seeding protected by Jute or Excelsior matting, or with seeding and mulching until the vegetation is established. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Channels should be cleared of sediment, repairs made when necessary, and seeded areas reseeded if a vegetative cover is not established. Maintain diversion capacity, ridge height, and outlet elevations especially if high sediment yielding areas are in the drainage area above the diversion. Establish necessary cleanout requirements. Redistribute sediment as necessary to maintain the capacity of the diversion. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc D-3 June 2008 Removal Temporary and un -compacted diversions shall remain in place only until the disturbed areas are permanently stabilized. Permanent diversions shall remain in place until final reclamation. References Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> New York State Department of Environmental Conservation, New York Guidelines for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997. <http://www.dec.state.ny.us/website/dow/toolbox/escstandards> United States Department of Agriculture (USDA), Natural Resources Conservation Service (NRCS), Field Office Technical Guide. 2002. <www.nrcs.usda.gov/technical/efotg> 5mal'. pression In Capture R;irCA1 him nrrr r r..Y Jircfsinn NOT TO SCALE Figure D-1 Temporary Diversion Installation 24' mu 8' rain Figure D-2 Permanent Diversion Installation FLOW DaeIgn Top W Th — Max 1 llgsign Depth 2 Mu., 2 vtammia.10" — 15'max — fifir it SCA...E M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc Flory L Nr: 1) E1wy'ersion shall slopo bolwoon 9.5% and a% la a slablitea male!. 2}EIi'.aesn[>e'rsIP_tiledet ,e or 1,8104+ wall parrs Shan halo a vocgoralod butler beaver' Vie diovraiurr and the Fred. it pyba,b4ii. 48' min. — i r SeI einerrl .1 D-4 F41 ramal r min. Froebixard' Srabiliro with V'og,nlaloan aril Mulrh or Erosion C 1n1rnl eLa nkol 1 M. StnaiIl derferssion ba Ceplur Runoff from ammo/ Diversion 2 June 2008 Drainage Dip (DD) Description Drainage dips intercept and remove surface water from the road and shoulders before the combination of water volume and velocity begins to erode the surface materials. Drainage dips are constructed diagonally across and as part of the road surface, and will pass slow traffic while dispersing surface water. Applicability Drainage dips may be used in the following applications: • To move water off the road surface efficiently and economically • In place of a culvert, which is costly and susceptible to plugging or failure • On low volume, low to moderate speed roads (10-35 mph) with grades less than 12% Limitations • Size limited by the safe passage of trucks and equipment • May cause concentrated flows from sheet flows • Requires vegetative cover or other sediment filter/trap at discharge point Design criteria No formal design required. Construction specifications See Figure DD -1. 1. Construct rolling dips deep enough to provide adequate drainage, angled 0-25 degrees from perpendicular to the road, with a 3-5% outslope, and long enough (50 to 200 feet) to pass vehicles and equipment. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc DD -1 June 2008 2. In soft soils, armor the mound and dip with gravel or rock, as well as the outlet of the dip. 3. Spacing of drainage dips depends upon local conditions such as soil material, grade, and topography. See Table DD -1 for recommended maximum distances between drainage dips. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Inspections should pay close attention to discharge points. References Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best Management Practices Field Guide. United States Department of Agriculture (USDA), Forest Service, US Agency of International Development (USAID), 2005. <http://www.blm.gov/bmp/field%20guide.htm> Maine Department of Conservation, Best Management Practices for Forestry: Protecting Maine's Water Quality. Maine Forest Service, Forest Policy and Management Division. Augusta, Maine. 2004. <http://www.state.me.us/doc/mfs/pubs/pdf/bmp_manual/bmp_manual.pdf> United States Department of the Interior and United States Department of Agriculture. Surface Operating Standards and Guidelines for Oil and Gas Exploration and Development "Gold Book". BLM/WO/ST- 06/021+3071. Bureau of Land Management (BLM). Denver, Colorado. Fourth Edition, 2006. Table DD -1 Maximum Distance between Drainage Dips Road Grade, % Low to Non -Erosive Soils (1) Erosive Soils (2) 0 - 3 400' 200' 4 - 6 300' 160' 7 - 9 250' 130' 10 - 12 200' 110' 12+ 160' 100' (1) Low Erosion Soils = Coarse Rocky Soils, Gravel, and Some Clay (2) High Erosion Soils = Fine, Friable Soils, Silt, Fine Sands M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc DD -2 June 2008 Figure DD -1 Typical Drainage Dip 1 a kneel Grade [ 2% 10. 4% 14* 6% 16' 6% zr ry Mound NOT TO SCALE M:\Encana\BMP Manual \BMP Manual - Round 2 \SWMM Final 06-09-08.doc D D-3 June 2008 Level Spreader (LS) Description A level spreader is a device used to prevent erosion and to improve infiltration by spreading concentrated stormwater runoff evenly over the ground as shallow flow instead of through channels. It usually involves a depression in the soil surface that disperses flow onto a flatter area across a slight slope and then releases the flow onto level vegetated areas. This reduces flow speed and increases infiltration. Applicability A level spreader is most effective for a contributing area less than 5 acres in size and slopes no steeper than 2:1. Level spreaders may be used where: • Sediment -free storm runoff can be released in sheet flow down a stabilized slope without causing erosion. • A level lip can be constructed without filling. • The area below the level lip is uniform with a slope of 10% or less and the runoff will not re - concentrate after release. • No traffic will be allowed over the spreader. Limitations This practice applies only in those situations where the spreader can be constructed on undisturbed soil and the area below the level lip is uniform with a slope of 10% or less and is stabilized by natural vegetation. The runoff water should not be allowed to reconcentrate after release unless it occurs during interception by another measure (such as a detention basin) located below the level spreader. Design criteria Capacity The design capacity shall be determined by estimating the peak flow from the 10 -year storm. The drainage area shall be restricted to limit the maximum flows into the spreader to 30 cubic feet per second (cfs). M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc LS -1 June 2008 Construction specifications See Figure LS -1 for details. 1. A transition section will be constructed from the diversion channel to the spreader to smoothly blend the different dimension and grades. 2. The level lip will be constructed in undisturbed soil to a uniform height and zero grade over the length of the spreader. For design flows less than 5 cfs, a vegetated level lip may be constructed with an erosion -resistant material, such as jute or excelsior blankets, to inhibit erosion and allow vegetation to become established. The matting should be a minimum of 4 ft. wide extending 6 inches over the lip and buried 6 inches deep in a vertical trench on the lower edge. 3. For design flows higher than 5 cfs and permanent installations, a rigid level lip of non -erodible material, such as site rock and gravel, should be used. 4. The runoff will be discharged onto a stabilized and generally smooth vegetated slope not exceeding 10%. 5. Seed and mulch the disturbed area immediately after construction. 6. Heavy equipment and traffic should not be allowed on the level spreader, as they can cause compaction of soil and disturbance of the slope grade. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. The spreader should be regraded if ponding or erosion channels develop. Dense vegetation should be sustained and damaged areas reseeded when necessary. Removal Level spreaders may be left in place or removed upon final site reclamation. References City of Knoxville, Stormwater Engineering, Knoxville BMP Manual - Best Management Practices. July 2003. http://www.ci.knoxville.tn.us/engineering Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> New York State Department of Environmental Conservation, New York Guidelines for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997. <http://www.dec.state.ny.us/website/dow/toolbox/escstandards> United States Army Corps of Engineers (USACE), Engineering and Design - Handbook for the Preparation of Storm Water Pollution Prevention Plans for Construction Activities. February 1997. http://www.usace.army.mil/inet/usace-docs/eng-pamphlets/ep1110-1-16/ M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc LS -2 June 2008 TranSilann Fnr.tion See nate 2 Figure LS -1 Level Spreader Installation • 444 - k r y. i * L d k fa k -i A 44. ▪ * i i * * Level trig for SpreacPer See. r4:4e 1 Notes: V'egc4hlyd tip for level 51:4ra1or moult' not too €mslructed irom tie material. Oo rut ailow any IrarriG oulo ✓ egetaled lip. 2 The lavl 26, of appo.ach charnel stbull be a transeion • arid h9arear tideless than 1%. d # * * �* * * Vegetated Lip Transitmon miction See rate 2 41, ** 6'- anin, * i4 4 i1*el - f Connie aggregate gaboar zed wire -•; baskeLcrtiahfon: robars alreguLar inlervels lu anchor rigid lip ,' t * • 49 4 ▪ 4,4 • .F 4 * 4 * 4 * 4 J ▪ * 1 - k i t • 4 a •ti JULe .1 L or excelsior nlat so!piloil in plar..o nrxt anchored 6- into gourd 1{i' 10 30- !ENV! ! i 1r" rei▪ t *Y` i '1i4 * 6' min. 4 Sre wire Basket acuJ *. • 4 or cotillion 10 Qrut. m1 i * 4,6 ` web stakes 4 i i 4.4 4 4. I it Rigid Lip NOT TO SCALE M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc 2' 11iS i LS -3 G,eo1exfle illter Cc4ee31 June 2008 Roadside Ditches (RSD) and Turnouts (TO) Description Roadside ditches are channels constructed parallel to roads. The ditches convey concentrated runoff of surface water from roads and surrounding areas to a stabilized outlet. Turnouts (wing ditches) are extensions of roadside ditches. Turnouts effectively remove runoff water from the roadside ditch into well -stabilized areas before it reaches a waterway. Applicability • Roadside ditches should be used for all roads built on sloping topography and with either an insloped or a crowned design. • Ditch turnouts should be used as much as possible but their best use may be on slopes longer than 150 ft or greater than 5%, as conditions allow. • Turnouts are applicable where fairly flat naturally vegetated areas exist at intervals by the roadside. Limitations • If these structures are not installed correctly they may become a source of erosion. • Roadside ditches do not necessarily filter sediment from runoff. • Turnouts should be on gradual slopes only. • Turnouts require vegetative cover or other filter at the discharge point. • Turnouts only work well if small volumes of runoff drain into the turnout. Turnouts should only receive runoff from the road and ditch surface, not from large, uphill watersheds. Design criteria No formal design is required. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc RSD/TO-1 June 2008 Construction specifications Roadside ditches 1. Roadside ditches should be constructed with no projections of roots, stumps, rocks, or similar debris. 2. Excavate ditches along roadside to a width and depth that can handle expected flows according to Figure RSD -1. 3. All ditches shall have uninterrupted positive grade to an outlet. Slope ditch so that water velocities do not cause excessive erosion, but no less than 0.5%. If steep slopes and high velocities exist, use check dams to slow runoff and catch sediment. 4. To control erosion and collect sediment, construct aggregate check dams according to Figure CD -1 of Check Dam (CD). 5. All ditches shall convey runoff to a sediment trapping device such as a Sediment Trap (ST) or an undisturbed, well vegetated, and stabilized area at non-erosive velocity. 6. If necessary, stabilize ditches with Riprap (R) or erosion control blanketing. Turnouts 1. Use turnouts wherever possible and on undisturbed soil. 2. Slope turnout gradually down from bottom of roadside ditch. 3. Angle turnout at approximately 30 degrees to the roadside ditch. 4. Discharge turnout into well -vegetated area or install a secondary control such as a wattle, sediment trap, or silt fence. As a good Rule of Thumb, the vegetated outlet area should be a minimum of one-half the size of the total drainage area draining into it. If well -vegetated outlet areas are not available, use culverts or other controls to direct runoff to a stabilized area. 5. Space turnouts according to slope as indicated on Figure TO -1. 6. Turnouts only work well if small volumes of runoff drain into the turnout. Turnouts should only receive runoff from the road and ditch surface, not from large, uphill watersheds. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Road ditches and turnouts should be inspected for any signs of channelization, and repaired as necessary. Structures will fail if water exits in channelized flow. Also inspect for sediment buildup at the outlet and at aggregate check dams and remove if necessary. References Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best Management Practices Field Guide. United States Department of Agriculture (USDA), Forest Service, US Agency of International Development (USAID), 2005. <http://www.blm.gov/bmp/field%20guide.htm> United States Department of the Interior and United States Department of Agriculture. Surface Operating Standards and Guidelines for Oil and Gas Exploration and Development "Gold Book". BLM/WO/ST- 06/021+3071. Bureau of Land Management (BLM). Denver, Colorado. Fourth Edition, 2006. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc RSD/TO-2 June 2008 — Cur slope Figure RSD -1 Roadside Ditch Installation rpyp•1 Stooge Area NOT TO SCALE M7OT TO OGALE mantra meal -X.2 (iv Yedelmet: ft•'I 3-5 Raalrwy Stabdira with egg oga1n check, dams and 'iRinV c arosiun alun4eiing i1 nmsassseryr NAP 51%4i6e110.5%ID20%laelabiixEKIoupe4 Figure TO -1 Turnout Layout lt,P'J R0146010 Dirii D.5% min_ RaactWa NM 0.7%nitn. ■ea: eednrerlt lrapY M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc (ex: wit 1E•V ! Oa: wads) RSD/TO-3 Road Slope TLI1r t M e2?�4001 1t 1-5% 100 5. 5-10% 161111. }1(15h i5L June 2008 Run -On Diversion (ROD) Definition A run-on diversion is a drainage way of parabolic or trapezoidal cross section with a supporting ridge on the lower side that is constructed across the slope. The purpose of a run-on diversion is to prevent off-site storm runoff from entering a disturbed area and to direct the runoff to a sediment or erosion control device. Applicability A run-on diversion is typically a permanent control designed for a drainage area larger than 10 acres where high flow is expected. Run-on diversions are used upslope of cut or fill slopes to convey or divert flows away from disturbed areas. Limitations • The area around the diversion channel that is disturbed by its construction must be stabilized (with vegetation or other erosion control) so that it is not subject to erosion similar to that of the steep slope the diversion is built to protect. • To alleviate erosion capability, diversions must be directed into a stabilized outlet or well -vegetated area or to sediment trapping devices, where erosion sediment can settle out of the runoff before being discharged to surface waters. • Run-on diversions should be used with caution on soils subject to slippage. Design criteria Location Run-on diversions should be located above cut or fill slopes. Where possible (shallow slopes), a vegetated buffer strip should be left between the edge of the cut or fill slope and the diversion. Location shall also depend on outlet conditions, topography, land use, soil type, length of slope, and the development layout. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc ROD -1 June 2008 Capacity Peak rates of runoff values used in determining the capacity requirements shall be as outlined by TR -55, Urban Hydrology for Small Watersheds. The constructed diversion shall have capacity to carry, as a minimum, the peak discharge from a 10 -year frequency rainfall event with freeboard of not less than 0.3 feet. Cross section See Figure ROD -1 for details. The diversion channel shall be parabolic or trapezoidal in shape. The diversion shall be designed to have stable side slopes. The side slopes shall not be steeper than 2:1 and shall be flat enough to ensure ease of maintenance of the diversion and its protective vegetative cover. The ridge shall have a minimum width of 4 feet at the design water elevation; a minimum of 0.3 feet freeboard and a reasonable settlement factor (10%) shall be provided. Velocity and grade The permissible velocity for the specific soil type will determine the maximum grade. The maximum permissible velocity for sand and silt vegetated channels is 3 ft/sec, and 5 ft/sec for clay vegetated channels. Run-on diversions are not usually applicable below high sediment producing areas unless structural measures, designed to prevent damaging accumulations of sediment in the channels, are installed with, or before, the diversions. Construction specifications 1. All trees, brush, stumps, obstructions, and other objectionable material shall be removed and disposed of so as not to interfere with the proper functioning of the diversion 2. All diversions shall have uninterrupted positive grade to an outlet. 3. Each diversion must have an adequate outlet where outflow will not cause damage. Diverted runoff shall outlet to a sediment trapping device or into an undisturbed stabilized area at non- erosive velocities. Vegetated outlets shall be installed before diversion construction, if needed, to ensure establishment of vegetative cover in the outlet channel. 4. The diversion shall be excavated or shaped to line, grade, and cross section as required to meet the criteria specified herein, and be free of bank projections or other irregularities which will impede normal flow. 5. Parabolic and triangular-shaped, grass -lined channels should not have a top width of more than 30 feet. Trapezoidal, grass -lined channels may not have a bottom width of more than 15 feet unless there are multiple or divided waterways, they have a riprap center, or other methods of controlling the meandering of low flows are provided. 6. If grass -lined channels have a base flow, a stone center or subsurface drain or another method for managing the base flow must be provided. 7. Fills shall be compacted as needed to prevent unequal settlement that would cause damage in the complete diversion. 8. All earth removed and not needed in construction shall be spread or disposed of on the well pad side of the diversion so that it will not interfere with the functioning of the diversion. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc ROD -2 June 2008 9. Immediately after the ridge and channel are constructed, they must be seeded or hydroseeded, and mulched or covered with erosion blanketing according to Revegetation (RV), Mulching (M), and/or Erosion Control Blanket (ECB) along with any disturbed areas that drain into the diversion. a. For design velocities less than 3.5 ft/sec, seeding and mulching may be used for establishment of the vegetation. It is recommended that, when conditions permit, temporary diversions or other means should be used to prevent water from entering the diversion during the establishment of the vegetation. b. For design velocities or more than 3.5 ft/sec, the diversion shall be stabilized with seeding protected by Jute or Excelsior matting, or with seeding and mulching including temporary diversion of the water until the vegetation is established. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Channels should be cleared of sediment, repairs made when necessary, and seeded areas reseeded if a vegetative cover is not established. Maintain diversion capacity, ridge height, and outlet elevations especially if high sediment yielding areas are in the drainage area above the diversion. Establish necessary cleanout requirements. Redistribute sediment as necessary to maintain the capacity of the diversion. Removal Run-on diversions shall remain in place until final reclamation. References Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> New York State Department of Environmental Conservation, New York Guidelines for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997. <http://wvvw.dec.state.ny.us/website/dow/toolbox/escstandards> United States Department of Agriculture (USDA), Natural Resources Conservation Service (NRCS), Field Office Technical Guide. 2002. <www.nrcs.usda.gov/technical/efotg> FLOVYf Design Top Width Figure ROD -1 Run -On Diversion Installation Na,. 1 43' Rii r - 1v' Se'.Ilrsren1 Sh01511We wi1Mi' ow fmfl and iallloh or Erosion Contra elarlsal 15' mac. HOT TO $CJ&E M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc ROD -3 Small), rens0n10 Cupljru 'turiull rruiu 8urrn of D ycrsi:xi June 2008 Slope Drain (SD) Description A slope drain is a conduit extending the length of a disturbed slope and serving as a temporary outlet for a diversion. Slope drains convey runoff without causing erosion on or at the bottom of the slope. This practice is a temporary measure used during grading operations until permanent drainage structures are installed and until slopes are permanently stabilized. They are typically used for less than 2 years. Applicability Slope drains can be used on most disturbed slopes to eliminate gully erosion problems resulting from concentrated flows discharged at a diversion outlet. Recently graded slopes that do not have permanent drainage measures installed should have a slope drain and a temporary diversion installed. A slope drain used in conjunction with a diversion conveys stormwater flows and reduces erosion until permanent drainage structures are installed. Limitations The area drained by a temporary slope drain should not exceed 5 acres. Physical obstructions substantially reduce the effectiveness of the drain. Other concerns are failures from overtopping because of inadequate pipe inlet capacity, and reduced diversion channel capacity and ridge height. Design criteria No formal design is required. Construction specifications See Figure SD -1 for installation details. 1. The slope drain shall have a slope of 3 percent or steeper. 2. The top of the diversion berm over the inlet pipe, and those diversions carrying water to the pipe, shall be at least 6 inches higher at all points than the top of the inlet pipe. 3. A flared end section of corrugated metal shall be attached to the inlet end of the pipe with a watertight connection. The corrugated metal pipe should have watertight joints at the ends. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SD -1 June 2008 4. The drain should consist of heavy-duty material manufactured for the purpose and have grommets for anchoring at a spacing of 10 feet or less. The pipe is typically corrugated plastic or flexible tubing, although for flatter, shorter slopes, a polyethylene -lined channel is sometimes used. Where flexible tubing is used, it shall be the same diameter as the inlet pipe and shall be constructed of a durable material. 5. The soil around and under the pipe and end section shall be hand tamped in 4 in. lifts to the top of the diversion berm. 6. The slope drain shall outlet into a sediment trapping device when the drainage area is disturbed. A riprap apron shall be installed below the pipe outlet where water is being discharged into a stabilized area. 7. A riprap apron shall be used below the pipe outlet where clean water is being discharged into a stabilized area. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Inspections should determine if capacity or slope drain was exceeded or if blockages occurred. Repairs should be made promptly. Construction equipment and vehicular traffic must be rerouted around slope drains. Removal Remove slope drain on completion of construction and stabilization activities. References Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> New York State Department of Environmental Conservation, New York Guidelines for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997. <http://wvvw.dec.state.ny.us/website/dow/toolbox/escstandards> M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SD -2 June 2008 Anchnr 9r? fill SIS Provide outlet prolecU4n Flarud i rx1 SEt14rl Figure SD -1 Slope Drain Installation EarMorn Rem cx divnrwn {compacted) Corri ate l melel exle'r on caller Vika inn L_RJF Rigid or flexable ppEr M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc 10' Mel D SD -3 45P$II rgmpacgpd �I;bl4 P&1 slope Flared Efal seclir>'n Pr$inogn Prp Toting Area Diarrralar (in.) leges) D c0.5 12 <1.5 18 {2.5 21 c3.5 24 ‹5 a0 June 2008 Trench Breakers (TB) Description Trench breakers, also known as trench plugs, are used to slow the flow of subsurface water along a pipeline trench. Trench breakers may be constructed of materials such as sand bags or polyurethane foam. Applicability Trench breakers may be used in the following applications: • On steep slopes. • Above wetlands. • At waterbody crossings. • At road crossings. Design criteria No formal design is required. Construction specifications 1. Trench breakers should be installed both before and after the lowering -in of pipeline. 2. An engineer or similarly qualified professional shall determine the need for and spacing of trench breakers. Otherwise, spacing shall be according to the following table: Slope (%) Spacing (feet) 5 —15 300 15-30 200 >30 100 M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc TB -1 June 2008 3. At a minimum, install a trench breaker at the base of slopes greater than 5 percent where the base of the slope is less than 50 feet from a waterbody or wetland and where needed to avoid draining a waterbody or wetland. 4. Trench breakers should be installed to the top of the excavated trench line. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Repair any damaged areas. References Federal Energy Regulatory Commission (FERC), Upland Erosion Control, Revegetation, and Maintenance Plan. January 2003. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc TB -2 June 2008 Water Bar (WB) Description A water bar is an earthen ridge, or ridge and channel, constructed diagonally across a sloping road, trail, or disturbed area that is subject to erosion. Water bars are normally used for drainage and erosion protection of buried pipelines or closed, blocked, or infrequently used roads to limit the accumulation of erosive volumes of water by diverting surface runoff at pre -designed intervals. Applicability Water bars are applicable where runoff protection is needed to prevent erosion on sloping access right-of- ways or long, narrow sloping areas generally less than 100 feet in width. This is a practice that is often used on buried pipelines, limited -use roads, trails, and firebreaks. It is an excellent method of retiring roads and trails as well as abandoned roads where surface water runoff may cause erosion of exposed mineral soil. Limitations • Not for use on concentrated flows • May cause concentrated flows from sheet flow • Requires vegetative cover or other filter at discharge point Design criteria No formal design is required. Construction specifications See Figure WB -1. 1. Clear the base for the ridge before placing fill. 2. Install the water bar across the right-of-way according to Figure WB -1 as soon as the base is cleared and graded. The off -slope drainage should be 2 to 5 percent. 3. Use a trackhoe or bulldozer to compact the ridge to the design cross section. 4. Vehicle crossings shall be stabilized with gravel. Exposed areas shall be immediately seeded and mulched. 5. Extend the water bar inlet and outlet 1 foot or more beyond the edge of the right-of-way or disturbed area to keep the diverted water from re-entering the area. 6. Space the water bars according to Table WB -1. 7. Locate the outlet on an undisturbed area. Field spacing shall be adjusted to use the most stable outlet areas. Outlet protection will be provided when natural areas are not adequate. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc WB -1 June 2008 Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Inspect water bars for erosion damage and sediment. Check outlet areas and make repairs as needed to restore operation. Removal If water bars are used on a closed or blocked road, they should be removed prior to re -opening of the road. Water bars on infrequently used roads or other disturbed areas may remain in place as long as necessary. References Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best Management Practices Field Guide. United States Department of Agriculture (USDA), Forest Service, US Agency of International Development (USAID), 2005. <http://www.blm.gov/bmp/field%20guide.htm> Maine Department of Conservation, Best Management Practices for Forestry: Protecting Maine's Water Quality. Maine Forest Service, Forest Policy and Management Division. Augusta, Maine. 2004. <http://www.state.me.us/doc/mfs/pubs/pdf/bmp_manual/bmp_manual.pdf> New York State Department of Environmental Conservation, New York Guidelines for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997. <http://wwvv.dec.state.ny.us/website/dow/toolbox/escstandards> Table WB -1 Water Bar Spacing Road/Trail Grade (%) Low to Non -Erosive Soils (1) Erosive Soils (2) 0 - 5 245' 130' 6 — 10 200' 100' 11 - 15 150' 65' 16 - 20 115' 50' 21 - 30 100' 40' 31+ 50' 30' 'Low Erosion Soils = Coarse Rocky Soils, Gravel, and Some Clay 2High Erosion Soils = Fine, Friable Soils, Silt, Fine Sands M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc WB -2 June 2008 Figure WB -1 Water Bar Installation EDGE OF R.OW. OUTLET WO STABILIZED AREA (WELL VEGETATED) NOT TO SCALE M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc WB -3 EDGE OF R.O.W. Nola. Side 5Ic7pel shall be 4:1 where vehicles cross and wa r bar shall bestabtlrsEwith grarel. June 2008 Sediment Control BMPs Check Dam (CD) Detention Pond (DP) Filter Berm (FB) Sediment Reservoir (SedR) Sediment Trap (ST) Silt Fence (SF) Slash (SL) Stabilized Construction Entrance (SCE) Straw Bale Barrier (SBB) Wattles (W) (BMP is provided with erosion controls) M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc June 2008 Check Dam (CD) Description Check dams are small, temporary dams constructed across a diversion or roadside ditch. Check dams can be constructed using aggregate, rock, sandbags, gravel bags, earth with erosion control blanketing, straw bales, or wattles and are used to slow the velocity of concentrated flow in a channel and thus reduce erosion. As a secondary function, check dams can also be used to catch sediment from the channel itself or from the contributing drainage area as stormwater runoff flows through or over the structure. Applicability • Check dams are most often used in small, open channels with a contributing drainage area of less than 10 acres, and side slopes of 2:1 or less. Check dams may be used in the following applications: • In diversions or roadside ditches where it is not practical to line the channel or implement other flow control and sediment control practices. • In diversions or roadside ditches where temporary seeding has been recently implemented but has not had time to take root and fully develop. • As a series of check dams, spaced at appropriate intervals, used in one of the above two applications. Limitations • Check dams should not be used in live, continuously flowing streams unless approved by an appropriate regulatory agency. • Check dams may require frequent removal of accumulated sediments. Dams should therefore be located in areas accessible to maintenance vehicles. • Leaves have been shown to be a significant problem by clogging check dams in the fall. Therefore, they might necessitate increased inspection and maintenance. • Straw bale check dams decompose over time, and may be consumed by livestock. Design criteria No formal design is required. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc CD -1 June 2008 Construction specifications 1. Install aggregate check dams according to Figure CD -1. Other types of check dams shall have similar designs. 2. Check dams should be located in areas accessible to maintenance vehicles for the periodic removal of accumulated sediments. 3. Dams should be installed with careful placement of the construction material. Mere dumping of the dam material into a channel is not appropriate and will reduce overall effectiveness. 4. Check dams can be constructed from a number of different materials. When using rock, the material diameter should be 1 to 15 inches depending on the expected velocity and quantity of runoff within the channel. Aggregate check dams, ideal for application within roadside ditches, should use a material diameter between 3/4 to 1-1/2". Earth collected during excavation of diversions or roadside ditches may also be placed as check dams if covered with erosion control blanketing. Straw bales, wattles, or sand/gravel bags may also be used, but only if rock or aggregate is unavailable or not feasible for the location. 5. All check dams should have a maximum height of 3 feet with sufficient space up slope from the barrier to allow ponding, and to provide room for sediment storage. The center of the dam should be at least 6 inches lower than the edges. This design creates a weir effect that helps to channel flows away from the banks and prevent further erosion. 6. Additional stability can be achieved by implanting the dam material approximately 6 inches into the sides and bottom of the channel. 7. In order to be most effective, dams used in a series should be spaced such that the base of the upstream dam is at the same elevation as the top of the next downstream dam. 8. When installing more than one check dam in a channel, outlet erosion stabilization measures should be installed below the final dam in the series. Because this area is likely to be vulnerable to further erosion, riprap, erosion control blanket lining, or some other stabilization measure is highly recommended. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. During inspection, large debris, trash, and leaves should be removed. The center of a check dam should always be lower than its edges. If erosion or heavy flows cause the edges of a dam to fall to a height equal to or below the height of the center, and the effectiveness of the BMP is compromised, repairs should be made immediately. Accumulated sediment should be removed from the upstream side of a check dam when the sediment has reached a height of approximately one-half the original height of the dam (measured at the center). Close attention should be paid to the repair of damaged or rotting straw bales, end runs, and undercutting beneath bales. Replacement of bales should be accomplished promptly. Removal Removal of check dams is optional. Check dams within roadside ditches are usually used as temporary controls, where other check dams may be left in place to silt out. If removing a check dam, all accumulated sediment should be removed. Removal of a check dam should be completed only after the contributing drainage area has been completely stabilized. Permanent vegetation should replace areas from which gravel, stone, logs, or other material has been removed. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc CD -2 June 2008 References Colorado Department of Transportation (CDOT), Erosion Control and Stormwater Quality Guide. 2002. <http://www.dot.state.co.us/environmental/envWaterQual/wgms4.asp> Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. r,ker sway SECTION VIEW 6oklom a1 Swale Figure CD -1 Aggregate Check Dam Installation Trenah6' Ino641.Ye PROFILE VIEW Tap arsketa Flow Geo9ekt a (eaa8t' tot be coat ar check clam' @attain ar Seale E IrUP� Giro taxi ilm 1" TaF ar-4e Bal NAT of 5.4me NOT TO,SOALE M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc AgErnall3 L3 d. •1'r`� L — - CD -3 Lvpliancy.wChtlwilPr,r +.:.a-ri1) are equal *Minoan I~ali D June 2008 Detention Pond (DP) Description A detention pond shall be constructed on each well pad to collect and store all runoff from the surface of the pad. A culvert with a locking gate may be installed to allow dewatering to occur if the water tests clean and is acceptable for release from the pad. Applicability Detention ponds are applicable to all well pads. Limitations Well pads that have not been properly designed may collect runoff from areas other than the surface of the pad, which may be more volume than the detention pond is designed to handle. Design criteria Detention ponds shall be sized for a 25 -year frequency storm. In general, 4,000 cubic feet (150 cubic yards) of dry storage volume should be provided for each acre of pad surface area. Construction specifications Construct detention pond according to Figure DP -1. Location Detention ponds shall be located at an outside edge of the pad and as far as possible from the pad access road, utilities, and all infrastructures. Dewatering Dewatering may be achieved through a 6- to 12 -inch corrugated metal culvert. The culvert invert shall be located approximately 1 foot above the bottom of the pond to allow space for sedimentation. The culvert shall be sloped and routed through the berm at the perimeter of the well pad to discharge down the fill slope and directly into a pad perimeter diversion. A steel slide gate as manufactured by Waterman Industries, or similar, may be installed at the culvert inlet. The gate may use a positive one-quarter turn cam lock which will hold the gate in any position to enables easy regulation of flow. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Inspections shall verify that the pond has not been disturbed and that the original storage capacity has been maintained. If sedimentation has accumulated to within 2 inches of the culvert inlet, the sediment shall be removed while avoiding any unnecessary disturbance to the pond. Removal The detention pond and culvert shall be removed upon completion of well pad activities and final stabilization. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc DP -1 June 2008 Figure DP -1 Detention Pond Installation Shde {Madel C.8 by Wetemren f 1I1e* 9r WOW Par! Penrnahr &arm fr-12-Corrugated Mgtal {:zll,urrl Alyap twar Feu Perrlreler Cliyartion r,cyrr SCAC M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc 1' Wei Slrxage D P-2 JrlpPror. 150 Cr try sloraga poi' acre pr Oad aurieie area Slmpa 1% Inn. 1 r � Ply Slvraga 1 2 Max. June 2008 Filter Berm (FB) Description A filter berm is a temporary ridge made up of natural materials that already occur on the project site such. Brush filter berms use small tree branches, root mats, grass, leaves, stone, or other debris or material naturally available or left over from site clearing and grubbing (slash). Rock filter berms use site gravel, stone, or rock. Both types of filter berms are placed along a level contour to slow, filter, and divert flow and act as an efficient form of sediment control. In some configurations, filter berms are covered with a filter cloth to stabilize the structure and improve barrier efficiency. Applicability The drainage area for filter berms must be no greater than 2 acres. In addition, the drainage slope leading down to a filter berm must be no greater than 2:1 and no longer than 100 feet. The following are suitable applications: • 5 to 7 feet beyond the toe of slopes. • Along the site perimeter. • Along streams and channels, or adjacent to roadways. • Around temporary spoil areas or other small cleared areas. Limitations • Intended to be used only in gently sloping areas, and are not appropriate for high -velocity flow areas. • Brush filter berms have limited usefulness because they are constructed of materials that decompose. • A large amount of material is needed to construct a useful filter berm. Therefore, filter berms are only applicable to sites where there is enough brush material from clearing and grubbing or rock material to form a sufficiently sized berm. • May be difficult to remove after construction. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc FB -1 June 2008 Design criteria No formal design is required. Construction specifications Brush (slash) filter berms See Figure FB -1 for installation details. 1. Place material cleared from the site across the slope or swale. Material with a diameter larger than 6 inches should not be used. 2. Cut up brush if necessary and compact to avoid large voids within the barrier. 3. The barrier mound should be at least 3 feet high and 5 feet wide at its base. 4. It is recommended, but not required, that the mound be covered with a filter fabric barrier to hold the material in place and increase sediment barrier efficiency. If using a filter fabric cover, bury the edge in a trench 4 inches deep and 6 inches wide on the drainage side of the barrier. This is done to secure the fabric and create a barrier to sediment while allowing stormwater to pass through the water -permeable filter fabric. The fabric should be extended just over the peak of the brush mound and secured on the down-slope edge of the fabric by fastening it to twine or small - diameter rope that is staked securely. Rock filter berms See Figure FB -2 for installation details. 1. Place filter berm along a level contour. Use well -graded, angular site gravel or crushed rock of medium to large diameter with larger rocks on the bottom. 2. If desired, cover with geotextile fabric or wire screen (especially if concentrated flows are expected) to help keep berm in tack. Anchor fabric or wire by placing under the berm or use stakes. 3. Trenching is not required. 4. Berms should be spaced according to the steepness of the slope, with berms spaced closer together as the slope increases. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. If channels form through void spaces in the barrier, the barrier should be reconstructed to eliminate the channels. Ensure that sediment has not built up and that no damage has been done by vehicles. Regular inspection should indicate the frequency of sediment removal needed. Accumulated sediment should be removed from the uphill side of the barrier when sediment height reaches between 1/3 and 1/2 the height of the barrier. Sediment should be disposed of and the filter material and/or fabric should be replaced if necessary. It is important that repairs be performed at the first sign of deterioration to ensure that the berm is functioning properly. Removal Remove filter berms after uphill drainage areas are stabilized. Rock and brush may be left in place only if it does not cause any landscaping problems. Remove all manmade materials (wire, fabric, and/or stakes). M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc FB -2 June 2008 References Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. Exoawaloa SIsr irsnoh and inaeil fabric along bottom (staf! labile as needed!. NOT TO SCALE FIc Gde+9tixlile GN wife n ItrlgIDononalI Figure FB -1 Brush Filter Berm Installation 5'.a° barn Ilse sof slope Cern{iaoled brash%. free limen, roof mak grass. leaves. eic_ M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc FB -3 Slakes al 3' spacing (hP.) Rcpo, string, wire or (Mina {weave back and rain across Ixerril June 2008 beyond 1op or limp4 Llai C"tarc ar Cru hrxt Ronk NOT TO SCALE Figure FB -2 Rock Filter Berm Installation N66ir. Exliend end or b6mn upulope Il aaold riyor around ends. Wrap with geolextzm Apr wire mesh currrunlr lorl lloevs aro CUpoct®d M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc FB -4 Hole. Prate hemi eiony level vvukvr. June 2008 Sediment Reservoir (SedR) Description Sediment reservoirs are large ponding areas that allow sediment to settle out of runoff water. They are often installed at the base of well pads or down-slope of other large disturbed areas. Sediment reservoirs are formed by excavating below grade and/or by constructing an earthen embankment with a level spreader type of spillway to slow the release of runoff. Applicability Sediment reservoirs are applicable to any location where it is desired to capture runoff from a large drainage area (up to 10 acres). Sediment reservoirs are also used as tertiary spill containment to prevent any accidental discharges from leaving the site. Limitations • Regular maintenance is needed to remove sediment. Reservoirs should be located near roads or where accessible to remove sediment. • Water may remain in the reservoir for extended periods causing an ideal spot for mosquitoes and other insects to gather. Locate the reservoir in a sunny spot if possible. • Never construct a sediment reservoir on a live flowing stream or in wetlands. Design criteria Location Reservoirs should be located at points of discharge from disturbed areas. The location will be determined by the natural terrain, drainage pattern of the runoff, and the accessibility for maintenance. Sediment reservoirs should not be located in areas where their failure due to stormwater runoff excess can lead to further erosive damage of the landscape. Alternative diversion pathways should be designed to accommodate these potential overflows. Sediment reservoir locations should also allow for easy maintenance access for the periodic removal of accumulated sediment. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SedR-1 June 2008 Storage capacity A sediment reservoir should be designed to maximize surface area for infiltration and sediment settling. This will increase the effectiveness of the reservoir and decrease the likelihood of backup during and after periods of high runoff intensity. The approximate storage capacity of each trap should be 3,600 ft3 per acre of contributing drainage area. The volume of a natural sedimentation reservoir can be approximated by the following equation: Volume (ft3) = 0.4 x surface area (ft2) x maximum pool depth (ft) If the volume is more than 100 acre-feet the sediment reservoir should be constructed as designed by a Professional Engineer. Embankment If the embankment is more than 10 feet high (measured vertically from the ground surface to the crest of the spillway) the sediment reservoir should be constructed as designed by a Professional Engineer. Construction specifications 1. If possible, sediment reservoirs, along with other perimeter controls, shall be installed before any land disturbance takes place in the drainage area. 2. Reservoirs should be located above the floodplain, where possible. 3. Area under embankment shall be cleared, grubbed, and stripped of any vegetation and root mat. The pool area shall be cleared. 4. The fill material for the embankment shall be free of roots and other woody vegetation as well as over- sized stones, rocks, organic material or other objectionable material. The embankment shall be compacted by traversing with equipment while it is being constructed. Seeding of the embankment should be performed as soon as possible after construction of the sediment reservoir. Erosion control blanketing may also be used to cover the embankment in combination with seeding or during time periods when seeding is ineffective. 5. The spillway shall typically consist of a level spreader which may extend around as much as half of the reservoir berm. The level spreader may consist of compacted earth, which will be vegetated on completion of construction. However, if erosion is noted during inspections it may be necessary to install aggregate, erosion control blanketing, straw bales, or wattles along the length of the level spreader (see applicable BMP). Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. The primary maintenance consideration for sediment reservoirs is the removal of accumulated sediment from the basin to ensure the continued effectiveness of the reservoir. Sediments should be removed when the basin reaches approximately 50 percent sediment capacity. Inspectors should also ensure that the reservoir is draining properly and check the structure, specifically the level spreader, for damage from erosion. Removal After the contributing area has been properly stabilized, the reservoir may remain in place if the reservoir itself is also fully stabilized, or the reservoir may be removed and the newly disturbed area shall be stabilized. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SedR-2 June 2008 References Colorado Department of Transportation (CDOT), Erosion Control and Stormwater Quality Guide. 2002. <http://www.dot.state.co.us/environmental/envWaterQual/wgms4.asp> Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003 <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SedR-3 June 2008 Sediment Trap (ST) Description Sediment traps are small to medium sized ponding areas that allow sediment to settle out of runoff water. They are usually installed in a drainage way or other point of discharge from a disturbed area. Sediment traps are formed by excavating below grade and/or by constructing an earthen embankment with a lined spillway to slow the release of runoff. Applicability Sediment traps are generally temporary control measures used at the outlets of stormwater diversion structures, channels, slope drains, construction site entrance wash racks, or any other runoff conveyance that discharges waters containing erosion sediment and debris. Sediment traps should be used for drainage areas less than 5 acres. The effective life span of these temporary structures is usually limited to 24 months. Traps may be located in series to allow for backup control in case one trap fails. Limitations • Regular maintenance is needed to remove sediment. Traps should be located near roads or where accessible to remove sediment. • Although sediment traps allow for settling of eroded soils, because of their short detention periods for stormwater they typically do not remove fine particles such as silts and clays. • Water may remain in trap for extended periods causing an ideal spot for mosquitoes and other insects to gather. Locate the trap in a sunny spot if possible. • Never construct a sediment trap on a live flowing stream or in wetlands. Design criteria Location Traps should be located at points of discharge from disturbed areas. The location will be determined by the natural terrain, drainage pattern of the runoff, and the accessibility for maintenance. Sediment traps should not be located in areas where their failure due to stormwater runoff excess can lead to further erosive damage of the landscape. Alternative diversion pathways should be designed to accommodate these potential overflows. Sediment trap locations should also allow for easy maintenance access for the periodic removal of accumulated sediment. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc ST -1 June 2008 Storage capacity A sediment trap should be designed to maximize surface area for infiltration and sediment settling. This will increase the effectiveness of the trap and decrease the likelihood of backup during and after periods of high runoff intensity. The approximate storage capacity of each trap should be 3,600 ft3 per acre of contributing drainage area. Half of this volume may be in the form of wet storage (a permanent pool) and the other half may be in the form of dry storage. When possible, the wet storage volume should be contained within the excavated portion of the trap. The volume of a natural sedimentation trap can be approximated by the following equation: Volume (ft3) = 0.4 x surface area (ft2) x maximum pool depth (ft) Construction specifications See Figure ST -1 for installation details. 1. If possible, sediment traps, along with other perimeter controls, shall be installed before any land disturbance takes place in the drainage area. 2. Traps should be located above the floodplain, where possible. If there are space constraints, several small sediment traps may be constructed in series. 3. Area under embankment shall be cleared, grubbed, and stripped of any vegetation and root mat. The pool area shall be cleared. 4. The fill material for the embankment shall be free of roots and other woody vegetation as well as over- sized stones, rocks, organic material or other objectionable material. The embankment shall be compacted by traversing with equipment while it is being constructed. Seeding of the embankment should be performed as soon as possible after construction of the sediment trap. Erosion control blanketing may also be used to cover the embankment in combination with seeding or during time periods when seeding is ineffective. 5. The spillway may consist of a stone section in the embankment formed by a combination coarse aggregate/riprap to provide for filtering/detention capability. Riprap shall be 4- to 8 -inch rock, while the coarse aggregate shall be 1/2 to 3/4 inches. A geotextile may be placed at the stone -soil interface to act as a separator. 6. Another option for the spillway is to use straw bales or wattles at the overflow point in the trap and line the rest of the spillway with an erosion control blanket (see applicable BMP). Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. The primary maintenance consideration for temporary sediment traps is the removal of accumulated sediment from the basin to ensure the continued effectiveness of the sediment trap. Sediments should be removed when the basin reaches approximately 50 percent sediment capacity. Inspectors should also ensure that the trap is draining properly and check the structure for damage from erosion. The depth of the spillway should be checked and maintained at a minimum of 1.5 feet below the low point of the trap embankment. Removal The structure shall be removed and the area stabilized when the drainage area has been properly stabilized. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc ST -2 June 2008 References Colorado Department of Transportation (CDOT), Erosion Control and Stormwater Quality Guide. 2002. <http://www.dot.state.co.us/environmental/envWaterQual/wgms4.asp> Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc ST -3 June 2008 CuI&fl EffibanKrriein# CakPIRIC.I.Pratoray 01 ripiPp. largo b1 11flarKbor sm rianco (zoo Polak) A ) Figure ST -1 Sediment Trap Installation 'Cl3151:11113,lacslorage 0014arne <={ Fluff Wai1lF1 to at laaf.,k 16- wig.% grado Sal NAM {00.4.)0a1; Stake metalled10al !Baal 2- bE4Ow 9radel Straw barks or rdP iercvcrri variLrDI bLarAel NOT TO SCALE M:\Encana\BMP Manual \BMP Manual - Round 2 \SWMM Final 06-09-08.doc I _ I Small Hicrop Out or Ilk Erntardtrinenl Gee4exIlle C-taL ST -4 Rival" RI. at EriP24011 COrIV01 Blanicet (ECEIJ .463'r IrE.0011 Riprap or gravel (optional:. Max. posoded depth cSk June 2008 Silt Fence (SF) Description Silt fences are used as temporary perimeter controls around sites where there will be soil disturbance due to construction activities. They consist of a length of filter fabric stretched between anchoring posts spaced at regular intervals along the site perimeter. Applicability Silt fences are generally applicable to construction sites with relatively small drainage areas. They are appropriate in areas where runoff will be occurring as low-level shallow flow, not exceeding 0.5 cubic feet per second. The drainage area for silt fences generally should not exceed 0.25 acre per 100 -foot fence length. Slope length above the fence should not exceed 100 feet. Silt fence may be used as temporary slope breakers to reduce runoff velocity. Limitations • Silt fences should not be installed along areas where rocks or other hard surfaces will prevent uniform anchoring of fence posts and entrenching of the filter fabric. This will greatly reduce the effectiveness of silt fencing and can create runoff channels leading off site. • Silt fences are not suitable for areas where large amounts of concentrated runoff are likely. • Open areas where wind velocity is high may present a maintenance challenge, as high winds may accelerate deterioration of the filter fabric. • Silt fences should not be installed across streams, ditches, or waterways. • When the pores of the fence fabric become clogged with sediment, pools of water are likely to form on the uphill side of fence. Siting and design of the silt fence should account for this and care should be taken to avoid unnecessary diversion of stormwater from these pools that might cause further erosion damage. Design criteria The fence should be designed to withstand the runoff from a 10 -year peak storm event. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SF -1 June 2008 Construction specifications 1. Erect silt fence according to Figure SF -1. 2. If standard strength fabric is used in combination with wire mesh, the support posts should be spaced no more than 10 feet apart. If extra -strength fabric is used without wire mesh reinforcement, the support posts should be spaced no more than 6 feet apart. 3. Stakes used to anchor the filter fabric should be either wooden or metal. Wooden stakes should be at least 3 feet long and have a minimum diameter of 2 inches if a hardwood such as oak is used. Softer woods such as pine should be at least 4 inches in diameter. When using metal post in place of wooden stakes, they should have a minimum weight of 1.00 to 1.33 Ib/linear foot. If metal posts are used, attachment points are needed for fastening the filter fabric using wire ties. The height of the fence posts should be between 16 and 34 inches above the original ground surface. 4. Material for silt fences should be a pervious sheet of synthetic fabric such as polypropylene, nylon, polyester, or polyethylene yarn, chosen based on minimum synthetic fabric requirements, as shown in the following table: Physical Property Requirements Filtering Efficiency 75 — 85% (minimum): highly dependent on local conditions Tensile Strength at 20% (maximum) Elongation Standard Strength: 30 lbs/linear inch (minimum) Extra Strength: 50 lbs/linear inch (minimum) Ultraviolet Radiation 90% (minimum) Slurry Flow Rate 0.3 gal/ft2/min (minimum) 5. Use a continuous roll of fabric to eliminate unwanted gaps in the fence. If a continuous roll of fabric is not available, the fabric should overlap from both directions only at stakes or posts with a minimum overlap of 6 inches. 6. Extend silt fence across grade and upslope for a short distance. 7. Compact backfill at base of fabric. 8. A trench should be excavated to bury the bottom of the fabric fence at least 6 inches below the ground surface. This will help prevent gaps from forming near the ground surface that would render the fencing useless as a sediment barrier. 9. If using silt fence as temporary slope breakers to reduce runoff velocity, space according to the following table: Slope (%) Spacing (feet) 5 — 15 300 >15 — 30 200 >30 100 Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Inspect silt fences to ensure that they are intact and that there are no gaps at the fence -ground interface or tears along the length of the fence. If gaps or tears which impact the effectiveness of the BMP are found, they should be repaired or the fabric should be replaced immediately. Accumulated sediments should be removed from the fence base when the sediment reaches one-third to one-half the height of the fence. Sediment removal should occur more frequently if accumulated sediment is creating noticeable strain on the fabric and there is the possibility of the fence failing from a sudden storm event. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc S F-2 June 2008 Removal Remove silt fences and all accumulated sediment after uphill drainage areas are stabilized by vegetation or other means. References Colorado Department of Transportation (CDOT), Erosion Control and Stormwater Quality Guide. 2002. <http://www.dot.state.co.us/environmental/envWaterQual/wgms4.asp> Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. Keller, Gordon, and James Sherar, Low -Volume Roads Engineering, Best Management Practices Field Guide. United States Department of Agriculture (USDA), Forest Service, US Agency of International Development (USAID), 2005. <http://www.blm.gov/bmp/field%20guide.htm> Figure SF -1 Silt Fence Installation Pms1 Rk7 Now 1.4 \ 1G' Nola hikfc,or- -a ,1riwoveTm3-..I•. duck. NW* .41..751c Twrth Gfwr f71 N2nh 'r. SIM Sonsolablt i7eYymJ r rtre.v:.h NM Ma'had b p -A 3'»S a mry M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc S F-3 June 2008 Slash (SL) Description Slash is any natural debris or material left over from site clearing and grubbing. Slash may include small tree branches, root mats, grass, leaves, stone, etc... Placement of slash over disturbed areas can help control off-site transport of sediment by slowing the flow of runoff, which minimizes erosion, and trapping sediment until vegetation is established at the sediment source. Applicability Slash may be used for the following: • To create a filter berm or windrow. • As a blanket over any disturbed area, particularly pipeline corridors and areas of fill. • As outlet protection for culverts. Limitations • Material may need to be cut up or broken into smaller pieces. • Slash does not eliminate the need to revegetate. • Slash is not applicable for steep slopes. Design criteria No formal design is required. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SL -1 June 2008 Construction specifications 1. For slash filter berms, see the Filter Berm (FB) BMP. 2. Prior to spreading slash over a disturbed area, the area should be seeded in accordance with the Revegetation BMP. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Inspect for any excessive erosion and replace slash with an alternate BMP if necessary (such as erosion control blanket). Removal Removal of slash is not necessary. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SL -2 June 2008 Stabilized Construction Entrance (SCE) Description A stabilized construction entrance (tracking pad) is a pad of gravel over filter cloth where construction traffic leaves a site. The purpose of a stabilized entrance to a site is to minimize the amount of tracked mud and dust that leaves a site. As a vehicle drives over the gravel pad, mud and sediment are removed from the vehicle's wheels and off-site transport of soil is reduced. The gravel pad also reduces erosion and rutting on the soil beneath the stabilization structure. The filter fabric separates the gravel from the soil below, preventing the gravel from being ground into the soil. The fabric also reduces the amount of rutting caused by vehicle tires by spreading the vehicle's weight over a larger soil area than just the tire width. Applicability Typically, stabilized construction entrances are installed at locations where construction traffic leaves or enters an existing paved road. However, the applicability of site entrance stabilization should be extended to any roadway or entrance where vehicles will access or leave the site. Limitations • Although stabilizing a construction entrance is a good way to help reduce the amount of sediment leaving a site, some soil may still be deposited from vehicle tires onto paved surfaces. To further reduce the chance of these sediments polluting stormwater runoff, sweeping of the paved area adjacent to the stabilized site entrance is recommended. • Sediment traps or other secondary sediment controls are needed to capture that sediment that accumulates at the pad and may run off during storm events. Design criteria No formal design is required. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SCE -1 June 2008 Construction specifications See Figure SCE -1 for installation details. 1. Locate the pad approximately 60 feet back from the entrance at any county road. 2. If the pad is constructed on a crowned road, a roadside ditch with check dams or sediment traps shall be located on both sides of the road to collect runoff from the pad. If the road slopes to only one side of the road then only one roadside ditch with sediment controls will be needed. 3. Place woven or non -woven fabric filter cloth over the entire area prior to placing the stone. Piping of surface water under entrance shall be provided as required. 4. Place a matrix of 1" and 2" stone gravel, or reclaimed or recycled concrete equivalent, to a minimum thickness of six (6) inches, a minimum width of 12 feet and a minimum length of 50 feet. 5. All surface water flowing or diverted toward construction entrance shall be piped across the entrance. If piping is impractical, a mountable berm with 5:1 slopes will be permitted. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Stabilization of site entrances should be maintained until the remainder of the construction site has been fully stabilized. Stone and gravel might need to be periodically added to each stabilized construction site entrance to keep the entrance effective. Soil that is tracked off site should be swept up immediately for proper disposal. References Colorado Department of Transportation (CDOT), Erosion Control and Stormwater Quality Guide. 2002. <http://www.dot.state.co. us/environ mental/envWaterQual/wgms4.asp> Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. <http://cfpub.epa.gov/npdes/stormwater/menuofbmps/con_site.cfm> Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SCE -2 June 2008 Figure SCE -1 Stabilized Construction Entrance Installation MY inn. r -r grwerl 1 Fakir Ddlh r nrim. M7unlOW town ionlinnal) EF451011 sedirtnryi EDI -111'4i IT411:151J10 wal1143? Road Side Dila, with ThireC511 (d0WrIVC.P.D Bidel SO' mi. OD' ir , RiNt . *tetp..y.wo.A.A M:\Encana\BMP Manual \BMP Manual - Round 2 \ SWMM Final 06-09-08.doc Road Side Bitch NM Sediment Trap ufhal cc* aide SCE -3 Exisang Cm* 11!-Eusw9COunty Rowl r 1!L4 June 2008 Straw Bale Barrier (SBB) Description A straw bale barrier is a series of entrenched and staked straw bales placed on a level contour to intercept sheet flows. The barrier reduces runoff velocity and filters sediment laden runoff from small drainage areas of disturbed soil. The barrier may also be used to protect against erosion. Straw bale barriers have an estimated design life of three (3) months. Applicability Straw bale barriers may be used below disturbed areas subject to sheet and rill erosion where the length of slope above the straw bale barrier does not exceed the following limits: Constructed Slope Percent Slope Slope Length (ft) 2:1 50% 25' 3:1 33% 50' 4:1 25% 75' Straw bales may be used in the following applications: • Below the toe of erodible slopes or other small cleared areas • At the top of slopes to divert runoff away from disturbed slopes • As sediment traps at outlets to culverts, ditches, turnouts, etc. • Along the perimeter of a site • Around temporary stockpiles and spoil areas • Along streams and channels for both erosion and sediment control • As check dams across mildly sloped swales or construction roads M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SBB-1 June 2008 Limitations • For short-term use only • For use below small drainage areas less than 2 acres • Decomposes over time • May be consumed by livestock • Straw bales must be certified weed free to avoid invasive weeds that may develop and should not be used in areas where weeds are a concern. • Removal of anchor stakes will be necessary after stabilization is complete • Not recommended for concentrated flow, live streams, or swales where there is the possibility of a washout Design criteria No formal design is required. Construction specifications See Figure SBB-1 for installation details. 1. Bales shall be placed in a single row on a level contour with ends of adjacent bales tightly abutting one another. Bales shall be certified weed free. 2. Allow sufficient space up slope from the barrier to allow ponding, and to provide room for sediment storage. 3. All bales shall be either wire -bound or string -tied. Straw bales shall be installed so that bindings are oriented around the sides rather than along the tops and bottoms of the bales in order to prevent deterioration of the bindings. 4. A trench shall be excavated the width of a bale and the length of the proposed barrier to a minimum depth of 4 inches. Stake the bales with minimum 2" x 2" x 36" wood stakes or standard "T" or "U" steel posts (minimum weight of 1.33 pounds per linear foot). 5. After the bales are staked and chinked (gaps filled by wedging), the excavated soil shall be backfilled against the barrier. Backfill soil shall conform to the ground level on the downhill side and shall be built up to 4 inches against the uphill side of the barrier. 6. Each bale shall be securely anchored by at least two stakes driven through the bale. The first stake or steel post in each bale shall be driven toward the previously laid bale to force the bales together. Stakes or steel pickets shall be driven a minimum 12 inches deep into the ground to securely anchor the bales. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Close attention should be paid to the repair of damaged or rotting bales, end runs and undercutting beneath bales. Necessary repairs to barriers or replacement of bales should be accomplished promptly. Sediment deposits should be removed when the level of deposition reaches approximately one-half the height of the barrier. Removal Straw bale barriers may be removed when they have served their usefulness or may remain in place to decompose over time. Straw bales should not be removed, however, until the upslope areas have been M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SBB-2 June 2008 permanently stabilized. Any sediment deposits remaining in place after the straw bale barrier is no longer required should be dressed to conform to the existing grade, prepared and seeded. References Colorado Department of Transportation (CDOT), Erosion Control and Stormwater Quality Guide. 2002. <http://www.dot.state.co. us/environ mental/envWaterQual/wgms4.asp> Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. New York State Department of Environmental Conservation, New York Guidelines for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997. <http://wvvw.dec.state.ny.us/website/dow/toolbox/escstandards> Esalnx rnm1 M IIgIr.",r nbuVarg gin.* Stair* {irrslsged toed leas) 1 r be; grade) 4 - MOT TO SCALE t9Me Width M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc Figure SBB-1 Straw Bale Installation SBB-3 drk16'aot3' TSt use ar,otlm hlxlgno DX)mi HGI7 June 2008 Wattles (W) Wattles BMP is provided in Erosion Control section above. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc W-1 June 2008 Non-Stormwater BMPs Dewatering (DW) Dust Control (DC) Material Delivery and Storage (MDS) Scheduling (S) Spill Prevention and Control (SPC) Vehicle and Equipment Maintenance (VEM) Waste Management (WM) M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final for revised pages06-09-08.doc June 2008 Dewatering (DW) Description Dewatering involves the removal and discharge of excess water from construction sites. Excess water may be due to groundwater, accumulated precipitation after a storm event (stormwater), or water used during construction activities (i.e. for the testing of pipelines). Proper removal of excess water helps to prevent potential pollutants (such as sediment or toxic and petroleum products) from entering watercourses. Sediment control from dewatering operations is required on all projects where excess water containing sediment or other pollutants is planned to be discharged. A temporary settling or filtering device should be used to avoid pollutant discharges from dewatering operations. Applicability These practices are implemented where groundwater, accumulated precipitation (stormwater), or other water used during construction will be discharged from a site. Limitations • Site conditions will dictate design and use. • A settling device often allows only minimal settling time for sediment particles. • Multiple sediment control methods shall be used, if necessary, for better sediment removal when site conditions allow. • The controls discussed in this BMP address sediment only. If the presence of polluted water is identified, dewatering pollution controls should be implemented in accordance with regulatory requirements. Standards Groundwater dewatering 1. All dewatering operations must comply with the Stormwater Management Plan. Discharges to the ground of water from construction dewatering activities may be authorized, provided that: M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc DW -1 June 2008 a. The source is groundwater and/or groundwater combined with stormwater that does not contain pollutants in concentrations exceeding the State groundwater standards in Regulations 5 CCR 1002-41 and 42 b. The source is identified c. BMPs are utilized d. These discharges do not leave the site as surface runoff or to surface waters 2. Dewatered groundwater shall be pumped or diverted to a sediment control BMP prior to discharge to the ground. Stormwater Dewatering 1. The discharge of pumped stormwater (not including groundwater or other non-stormwater sources) from excavations, ponds, depressions, etc., to surface water, or to a municipal separate storm -sewer system is allowed as long as the dewatering activity and associated BMPs are implemented in accordance with this manual. 2. Stormwater that collects in open depressions or trenches during construction activities will be dewatered into an existing sediment control, such as a detention pond, a sediment trap, or simply into a well -vegetated area to percolate into the ground and catch suspended sediment. Pipeline Dewatering Once the hydrostatic testing of pipelines has been completed, dewatering of the pipeline will occur. 1. Insert a displacer, commonly referred to as a pig, in the pipeline. 2. Regulate the discharge rate and utilize energy dissipation devices and/or sediment controls as necessary to prevent erosion, streambed scour, suspension of sediments, or excessive stream flow. Specifications One of several types of dewatering structures may be constructed depending on site conditions and type of operation: 1. Water may be pumped or directed into existing stormwater sediment controls (such as sediment traps) capable of handling the volume and flow rate of dewatered water. 2. Water may be pumped or directed into a temporary settling device as described below. 3. Water may be land applied to approved non -wetland vegetation areas and allowed to soak into the soil. 4. Water may be hauled away from the project for disposal in accordance with applicable laws and regulations. If existing stormwater sediment controls are used to control water, the applicable sections of this BMP Manual shall be followed. If a settling device is utilized, the following design criteria shall be followed: M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc DW -2 June 2008 Straw Bale/Silt Fence Pit • It is recommended that the structure consist of an excavated basin surrounded by a perimeter control such as wattles, hay bales, or silt fence (see Figure DW -1). Install wattles, hay bales, or a silt fence as described in applicable sections of this BMP Manual. • The following formula should be used to determine the storage volume of the sediment tank: Pump discharge (gpm) x 16 = cubic feet of storage required • The excavated area should be a minimum of 3 feet below the base of the perimeter control. The excavated portion will serve for wet storage, and the remainder will provide dry storage. • When water reaches the outlet crest, pumping must stop until the water drains down to the elevation of the excavated area. • The remaining water may be removed only after a minimum of 6 hours of sediment settling time. This effluent should be pumped across an area with established vegetation or through a silt fence prior to entering a watercourse. • When the excavated area becomes filled to one-half of the excavated depth, accumulated sediment should be removed and properly disposed of. Sediment Filter Bag • A filter bag, constructed of non -woven geotextile material (to provide adequate filtering ability to capture the larger soil particles from the pumped water), will be clamped around the dewatering pump discharge hose so that all of the pumped water passes through the bag. • The filter bag should be used in combination with a straw bale/silt fence pit when located within 50 feet of a stream. When the distance to a stream is greater than 50 feet, the bag may be placed on well - vegetated area, or on an aggregate pad. The bag should never be placed on bare soil. • The capacity of the bag should be adequate to handle the dewatering pump discharge, and should be based on the bag manufacturer's recommendation. • When used in conjunction with a straw bale/silt fence pit, a filter bag may be operated until the water in the pit reaches the crest of the emergency overflow. • When placed on either a stone pad or well -vegetated area, the bag may be operated until such time the discharge from the bag reaches a stream. • When the bag has been completely filled with sediment it should be cut open, sediment regraded in place, and immediately stabilized with an erosion control. A settling device and/or sediment control may not be needed if the water is discharged to a well stabilized, on-site, vegetated area. The stabilized area should be capable of filtering sediment while at the same time withstanding the velocity of the discharged water without eroding. A minimum filtering length of 75 feet is recommended for the stabilized area. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. If using a settling device, sediments should be removed once they have accumulated to one-half of the excavated depth and properly disposed of. Sediment removal from dewatering devices shall be stabilized at the project site at pre -designated locations or shall be disposed of properly. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc DW -3 June 2008 References Arizona Department of Transportation (ADOT), Erosion and Pollution Control Manual. 2005. http://www.azdot.gov/ADOT_and/Storm_Water/Erosion_Pollution_Control_Manual.asp Colorado Department of Transportation (CDOT), Erosion Control and Stormwater Quality Guide. 2002. http://www.dot.state.co.us/environmental/envWaterQual/wgms4.asp Federal Energy Regulatory Commission (FERC), Upland Erosion Control, Revegetation, and Maintenance Plan. January 2003. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc DW -4 June 2008 Figure DW -1 Settling Device Installation Reprep 1 a 2 — ti"Thick aggregate base 8' Ag9naga4a burse NCir—C} S';rxLC INV 3'rdr1. &MIA I area moo• 44404114 M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc DW -5 June 2008 Dust Control (DC) Description Dust control involves practices (such as applying water or dust palliatives) to be implemented during construction operations to prevent dust and wind erosion from exposed soil surfaces. Applicability These practices are limited to exposed soil where wind erosion is expected. Limitations The effectiveness of this application can be limited by soil, temperature, and wind velocity. Standards and specifications Irrigation practices can be applied to a project site until the soil is moist and can be repeated as necessary. However, the soil shall not be oversaturated causing runoff to flow from the project site. The distribution system shall be equipped with a proper spray system to ensure even water distribution. When a distribution system is unavailable, at least one mobile unit shall be available at all times to apply water or a dust palliative to the project site. All non -potable tanks, pipes, and other conveyances shall be marked "non -potable water - do not drink." Seeding, mulching, soil binder, and grading techniques are also temporary methods to prevent dust and wind erosion. Refer to the applicable BMPs. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Inspect protected areas for adequate protection and signs of degradation. Perform spot-checks to ensure dust and wind erosion control techniques are properly implemented. References Colorado Department of Transportation (CDOT), Erosion Control and Stormwater Quality Guide. 2002. http://www.dot.state.co.us/environmental/envWaterQual/wgms4.asp M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc DC -1 June 2008 Material Delivery and Storage (MDS) Description These practices are to be implemented for proper handling, delivery, and storage of materials in order to prevent spills or leaks into the storm drains or watercourses. Applicability These practices are implemented at all construction sites where delivery and storage of materials may be detrimental to the environment. Materials of concern are not limited to soil, pesticides, herbicides, fertilizers, petroleum products, asphalt and concrete components, and hazardous chemicals such as acids, paints, solvents, adhesives, and curing compounds. Limitations Space limitation may preclude indoor storage. Storage sheds must meet building and fire code requirements. Standards and specifications Deliver and loading/unloading areas • Keep an accurate, up-to-date inventory of material delivered and stored on site. • Minimize hazardous material storage on site. • Employees trained in emergency spill clean-up procedures should be present when dangerous materials or liquid chemicals are unloaded. • Cover loading and unloading areas to reduce exposure of materials to rainfall. • Routinely check vehicles and equipment such as valves, pumps, flanges, and connections for leaks. • Direct off-site stormwater flows away by grading, berming, or curbing the area around the loading/unloading area. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc MDS -1 June 2008 Storage and material handling areas • Designate storage areas at the project site. • Locate the storage area away from the storm drain system and watercourses. • Provide curbs or dikes around the perimeter of material storage areas to prevent run-on from adjacent areas as well as runoff of stormwater from the material storage areas. • Prevent spills or leakage of liquid materials from contaminating soil (i.e., soaking into the ground) by placing storage areas on impervious surfaces. • Stockpile soil in accordance with the Stockpiling BMP for topsoil and subsoil. • Store materials indoors within existing structures or sheds when available. • Material safety data sheets (MSDS) shall be made available for all materials. • Training for proper material handing and storage techniques shall be required. • Provide sufficient separation between storage containers to allow cleanup and emergency response. • Chemically incompatible materials should not be stored together or in the same storage facility. • Label all materials properly and maintain current legible labels; also maintain a current inventory of all material delivered and stored. • Do not store hazardous chemicals, drums, or bagged materials directly on the ground. Place these items on a pallet and when possible, under cover in secondary containment. • Keep hazardous chemicals in their original containers and keep them well labeled. Spill Clean-up • Immediately contain and cleanup any spills according to the Spill Prevention and Control BMP as well as the Spill Prevention and Control Countermeasures (SPCC) Plan. • If significant residual materials remain on the ground after construction is complete, properly remove and dispose of any hazardous materials or contaminated soil. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Inspect equipment and vehicles for leaks. Maintain an ample supply of cleanup materials at all designated storage and handling areas where leaks and spills are likely to occur. Spot-check material storage and handling areas for compliance. Material storage areas shall be checked for accumulation of non -labeled materials and spills. Containment structures or other perimeter controls shall be inspected and repaired when signs of degradation are visible. References Arizona Department of Transportation (ADOT), Erosion and Pollution Control Manual. 2005. http://www.azdot.gov/ADOT and/Storm Water/Erosion_Pollution_Control_Manual.asp Colorado Department of Transportation (CDOT), Erosion Control and Stormwater Quality Guide. 2002. http://www.dot.state.co.us/environmental/envWaterQual/wgms4.asp M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc MDS -2 June 2008 Scheduling (S) Description Develop a schedule for every project that includes sequencing of construction activities in conjunction with the implementation of construction site BMPs in order to reduce the amount and duration of soil exposed by construction activities. The purpose is to minimize erosion of disturbed soils by wind, rain, runoff, and vehicle tracking by reducing the amount and duration of soil exposed to erosion and ensuring that BMPs are implemented in a timely manner as construction proceeds. Applicability • Construction activities shall be planned to minimize the amount of disturbed land exposed to erosive conditions. • Stabilization measures shall be installed and maintained as work progresses, not just at the completion of construction. Standards and specifications • Schedule the installation of temporary and permanent controls as specified in the Construction General Permit (CGP). • The schedule of construction activities and concurrent application of temporary and permanent BMPs is developed as part of the Stormwater Management Plan (SWMP). • Schedule clearing and grubbing activity to allow existing vegetation to remain in place as long as possible. • For larger projects, the contractor shall not expose more than 750,000 square feet in any location until temporary or permanent BMPs have been installed. • Schedule shall include dates for significant long-term operations or activities that may have planned non-stormwater discharges such as dewatering, sawcutting, grinding, drilling, boring, crushing, blasting, painting, hydro -demolition, mortar mixing, bridge cleaning, etc. • Schedule shall include dates for installation of permanent drainage systems and runoff diversion devices. These devices should be installed as early as possible in the construction process. • The schedule shall include non-stormwater BMPs, waste management, and materials pollution control BMPs. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc S-1 June 2008 • Stabilize non-active areas as specified in the CGP. • Monitor weather forecast and adjust construction schedule to allow for the implementation of soil stabilization and sediment controls on all disturbed areas prior to the onset of rain. Maintenance considerations The frequency of inspections should be in accordance with the SWMP. Verify that work is progressing in accordance with the schedule. The schedule must be updated when changes are warranted or when directed by the Engineer. References Arizona Department of Transportation (ADOT), Erosion and Pollution Control Manual. 2005. http://www.azdot.gov/ADOT and/Storm Water/Erosion_Pollution_Control_Manual.asp M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc S-2 June 2008 SpiII Prevention and Control (SPC) Description These practices are implemented to prevent and control spills to ensure that spills and leaks do not result in water quality impacts. Applicability This BMP applies to all construction activities. SpiII prevention and control measures shall be implemented any time chemicals or hazardous substances are used, stored, or handled. Limitations The measures described in this BMP are general. Appropriate practices for specific materials used, stored, or handled on a project site should be identified by site personnel. Standards and specifications The following general design guidelines can be implemented for spill prevention and control measures for various activities and areas: • Identify materials delivered, handled, stored, and used at a project site. • Identify project areas and activities potentially susceptible to spills. Areas and activities that are most vulnerable to spills include: transportation facilities, loading and unloading areas, fuel and chemical storage areas, process activities, dust or particulate generating processes, and waste disposal activities. • Develop spill response procedures. SpiII Prevention Control and Countermeasures (SPCC) Plan A SpiII Prevention Control and Countermeasures (SPCC) Plan has been developed and will be implemented for certain products that are stored at the site. The SPCC Plan identifies areas where spills can occur on site, specifies material handling procedures and storage requirements, and identifies spill cleanup procedures. The purpose of this plan is to establish standard operating procedures and the necessary employee training to minimize the likelihood of accidental releases of pollutants that can contaminate stormwater runoff. SpiII M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SPC -1 June 2008 prevention is prudent both environmentally and economically, since spills increase operating costs and lower productivity. Emergency spill cleanup plans should include the following information: • A description of the facility including the nature of the facility activity and general types and quantities of chemicals stored at the facility. • A site plan showing the location of storage areas for chemicals, location of storm drains, site drainage patterns, fire -fighting equipment and water source locations, and the location and description of any devices used to contain spills such as positive control valves. • Notification procedures to be implemented in the event of a spill, such as, posting phone numbers of key personnel and appropriate regulatory agencies. • Instructions regarding cleanup procedures. • Designating personnel with overall spill response cleanup responsibility. • A summary of the plan should be written and posted at appropriate points in the building (i.e., project trailer and areas with a high spill potential), and shall identify the spill cleanup coordinators, location of cleanup kits, and phone numbers of regulatory agencies to be contacted in the event of a spill. • Cleanup of spills should begin immediately. No emulsifier or dispersant should be used. In fueling areas, absorbent materials should be packaged in small bags for easy use, and small drums should be available for storage of absorbent and/or used absorbent. Absorbent materials shall not be washed into the floor drain or storm sewer. Cleanup response procedures Response guidelines have been identified below for contractors responding to spills that may potentially result in an illicit discharge. It is the contractor's responsibility to have all emergency phone numbers available at the construction site as well to notify the proper response agencies in a timely manner. It is also the contractor's responsibility to ensure timely and proper cleanup of any spill. Minor spills For non—hazardous materials such as gasoline, paint, or oil that may be spilled in small quantities which do not enter state waters or pose a potential to do so, the following measures shall be implemented: 1. Use absorbent materials to contain spills. Do not hose down spill area with water or bury the spill. 2. Recover spilled materials. 3. Clean the contaminated area of residuals and/or properly dispose of the absorbent material. Semi -significant spills For non -hazardous materials that qualify as a semi -significant spill or spills of any size which do not enter state waters or pose a potential to do so and can be controlled by the first responder along with the aid of other personnel, the following measures shall be implemented: 1. Notify the project foreman immediately. The foreman should notify the resident engineer. 2. Contain the spills to prevent spreading. 3. If the spills occur on paved or impermeable surfaces, clean-up using "dry" methods (adsorbent materials, cat litter, and/or rags). Contain the spill by encircling with absorbent materials and do not let the spill spread widely. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SPC -2 June 2008 4. If the spill occurs in a dirt area, immediately contain it by constructing an earthen dike. Dig up and properly dispose of contaminated material. 5. If the spills occur during rain, cover affected area if possible. Significant spills For non -hazardous materials that qualify as a significant spill or spills of any size that enter state waters or have the potential to do so, the following measures shall be implemented: 1. Contact the Colorado Department of Public Health and Environment (CDPHE) Environmental Emergency Spill Reporting Line (1-877-518-5608) within 24 hours of the spill event. A written notification to the CDPHE-Emergency Management Program (EMP) is necessary within 5 days. 2. Contact the Colorado State Patrol 24-hour hotline (1-303-239-4501) if the spill is on a state highway. 3. Notify the project foreman and maintenance personnel on patrol immediately and follow up with a written report. 4. If possible, cleanup the spill immediately. Use absorbent materials if the material is on an impermeable surface. Construct an earthen dike to contain a spill on dirt areas. If rainfall is present at the time of the spill, cover the spill with a tarp to prevent contaminating runoff. Hazardous spills For all spills involving hazardous materials, the following measures shall be implemented: 1. Contact the local emergency response team by dialing 911. 2. Contact the CDPHE-EMP 24 Environmental Emergency Spill Reporting Line (1-877-518-5608) within 24 hours of the spill event. A written notification to the CDPHE-EMP is necessary within 30 days. 3. Contact the Colorado State Patrol 24-hour hotline (1-303-239-4501) if the spill is on a state highway. 4. Report spills to project foreman and maintenance personnel on patrol and follow up with a written report. 5. Construction personnel shall not try to clean up the spill. 6. Cleanup spill immediately; a licensed contractor or HazMat team shall be used to properly clean up spills. Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. Inspect equipment and vehicles for leaks. Maintain an ample supply of cleanup materials at all designated maintenance areas where leaks and spill are likely to occur. Spot-check material storage and handling areas for compliance. Material storage and use areas shall be checked for accumulation of non -labeled materials and spills. Identify spills or leaks into to the storm drain at or near work areas. Containment structures or other perimeter controls shall be inspected and repaired when signs of degradation are visible. References Arizona Department of Transportation (ADOT), Erosion and Pollution Control Manual. 2005. http://www.azdot.gov/ADOT and/Storm Water/Erosion_Pollution_Control_Manual.asp Colorado Department of Transportation (CDOT), Erosion Control and Stormwater Quality Guide. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc SPC -3 June 2008 Waste Management (WM) Description Stormwater runoff from areas where construction wastes are stored or disposed can be polluted. Wastes leached or spilled from management areas may build up in soils or on other surfaces and be carried by stormwater runoff. The optimal approach to reduce the potential for stormwater contamination from wastes is to reduce the amount generated and, consequently, the amount stored on site. The following types of waste management are covered under this BMP: Concrete waste management: Practices to be used in order to minimize and prevent concrete waste associated with construction activities from entering storm drains and watercourses. Concrete waste may be generated where concrete trucks or concrete -coated equipment are washed on site, where slurries containing concrete are generated, or where mortar -mixing areas exist. Solid waste management: Practices to be used in order to minimize and prevent solid waste associated with construction activities from entering storm drains and watercourses. Solid waste can be classified as non- hazardous solid material including: concrete, rock, debris, soil, wood, vegetative material, plastic, fabrics, mortar, metal scraps, Styrofoam, and general litter such as but not limited to beverage containers and plastic wrappers. Sanitary and septic waste management: Practices to be used in order to minimize and prevent sanitary and septic waste associated with construction activities from entering storm drains and watercourses. Liquid waste management: Practices to be used in order to minimize and prevent liquid waste associated with construction activities from entering storm drains and watercourses. Hazardous waste management: Practices to be used in order to prevent hazardous waste associated with construction activities from entering storm drains and watercourses. Hazardous wastes may be discovered or generated (by lead paint removal operations) and are designated as hazardous by the Code of Federal Regulations or Colorado state laws. Contaminated waste management: Practices to be used in order to minimize and prevent pollutants from contaminated soils from leaching into watercourses or drainage systems. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc WM-1 June 2008 Applicability Facilities or designated construction work areas where each type of waste is discovered or generated. Limitations During the non -rainy season or in arid portions of the state, temporary stockpiling of non -hazardous solid waste may not require stringent drainage control measures. The engineer for the project shall determine if drainage control measures are warranted for a specific construction site where non -hazardous solid waste is being stockpiled. Liquid waste management does not apply to solid wastes, hazardous wastes, concrete slurries/wastes, dewatering operations, sanitary/septic wastes, or permitted allowable non-stormwater discharges. Disposal of some liquid wastes may be subject to regulations or requirements of other permits secured for the construction site. This BMP provides general hazardous waste management guidelines, but does not relieve the contractor from full responsibility of complying with federal, state, and local laws regarding storage, handling, transportation, and disposal of hazardous wastes. It is the contractor's full responsibility to identify all hazardous waste generated at the project site. The contractor is responsible for identifying pollutant -specific handling and disposal procedures for contaminated soils at the project site. Standards Concrete waste Waste generated from concrete activities shall not be allowed to flow into drainage ways, inlets, or receiving waters. Concrete waste shall be placed in a temporary concrete washout facility. • Concrete washout facilities will be comprised of an excavation with erosion bales and construction fences along the perimeter. The facility may be similar to the settling device used for dewatering (see Figure DW -1). The bottom of the excavation must be proven to be at least 5 vertical feet above groundwater or, alternatively, the excavation must be lined with either a clay or synthetic liner that is designed to control seepage. The facilities shall be maintained in good condition to contain all liquid and concrete waste generated by operations at a project site. • Proper signage such as "Concrete Washout" shall be placed near concrete washout facilities to inform construction personnel of the location of designated concrete washout facilities. • Temporary concrete washout facilities shall be located 50 horizontal feet from drainageways, inlets, and receiving waters unless otherwise approved by the engineer. • Adding solvents, flocculents, or acid to washwater is prohibited. • Whenever a concrete washout area is within 300 feet of the access to a road or highway, a stabilized construction entrance must be built as part of the washout, or at the entrance to the road or highway. • Hardened concrete waste shall be properly disposed of following solid waste management procedures. • Removal of temporary facilities, including the solid concrete waste and the material used to construct the facilities, shall be the responsibility of the contractor, who shall remove the waste from the project site and dispose of it properly following guidelines outlined in solid, liquid waste management and any applicable regulations. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc WM-2 June 2008 Solid waste • Litter shall be minimized at all construction sites and collected on a weekly basis into water -tight dumpsters. Trash receptacles shall be provided in various locations within the construction site boundaries. • Collected trash shall not be placed near drainage inlets or watercourses. • A trash hauling contractor shall be used to properly dispose of the collected waste in a timely manner. Dumpster washout at the construction site is not permissible. • Priority shall be given to remove waste and debris from drainage inlets, trash racks, and ditches in order to prevent clogging of the stormwater system. • Waste storage areas shall be pre -approved by the engineer. • Storage areas for solid waste shall be located at least 50 feet from drainageways and watercourses, and shall not be located in areas susceptible to frequent flooding. Sediment barriers such as berms, dikes, or other temporary diversion structures shall be used to prevent stormwater runoff from contacting stored solid waste at the project site. • Solid waste shall be segregated properly into various categories for recycling or disposal. Proper disposal is required for each waste category. The contractor shall make every attempt to recycle useful vegetation, packaging material, and surplus construction materials when practical. • Most construction materials can be recycled at recycling facilities. Septic and sanitary waste • Temporary sanitary facilities shall be located away from drainage ways, inlets, receiving waters, areas of high traffic, and areas susceptible to flooding or damage by construction equipment. • Temporary sanitary facilities shall be properly connected into a sanitary sewer system where permissible to prevent illicit discharges. Authorized sanitary sewer system connections shall comply with local health agency, county, and sanitary sewer district requirements. • Wastewater generated from sanitary facilities shall not be allowed to flow into drainageways, inlets, or receiving waters. • Only licensed sanitary/septic waste haulers shall be used to properly dispose of waste from temporary sanitary facilities. • In project areas susceptible to strong winds, temporary sanitary facilities shall be secured to prevent overturning. Liquid waste • The contractor shall oversee and enforce all liquid waste measures and will instruct all employees and subcontractors on the identification of hazardous and non -hazardous liquid waste, and non -hazardous handling, storage, and proper disposal. • The contractor shall hold regular safety meetings to ensure proper liquid waste measures are being adhered to and efforts are being made to minimize the amount of liquid waste produced. • The contractor shall ensure compliance with all liquid waste management procedures and practices. • Liquid wastes generated from operational procedures such as drilling residue and fluids shall not be allowed to flow into drainageways, inlets, or receiving waters. • All liquid wastes shall be contained in designated areas such as sediment basins, holding pits, or portable tanks. Designated containment areas shall be located away from drainageways, inlets, receiving waters, areas of high traffic, and areas susceptible to flooding. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc WM-3 June 2008 • Precautions shall be taken to ensure that proper spill prevention and control measures are being implemented to avoid accidental spills. • If a liquid waste is released or spilled, capture the liquid with proper cleanup methods. Do not allow the liquid waste to flow uncontrolled or into drainageways, inlets, and receiving waters. Use diverting methods such as temporary dikes to control the spill and direct it to containment areas for capture. • The contractor shall be responsible for adhering to all permit requirements, federal, state, and local regulations for properly disposing liquid waste. Hazardous waste The following are general guidelines provided for planning the management of hazardous wastes. • Hazardous waste storage, transportation, and disposal shall comply with 49 CFR 172, 173, 178, 179, and 261-263, and state regulations. • Special materials and equipment may be required to manage wastes that are corrosive, combustible, flammable, oxidizer, poison, toxic, or reactive. Clearly label all waste containers with the appropriate description of the wastes being contained. • Hazardous wastes shall be segregated, and incompatible or reactive wastes shall be disposed of properly in a manner to prevent fires and explosion. Always consult the health and safety officer, engineer, and/or project manager prior to mixing hazardous wastes for disposal. Hazardous waste shall be segregated properly into various categories such as liquids, semi -liquids, and solids. • Select the most appropriate disposal container to store the hazardous waste. Additionally, select a container that is compatible with the hazardous material being stored. For instance, use plastic or plastic -lined steel drums for storing corrosive materials. Corrosive materials will react with steel and cause the waste to be released from the drum. Always consult the engineer or project manager to ensure that the container and waste are compatible. • Waste containers shall be stored and managed in temporary containment facilities that shall meet the following requirements: A spill containment volume 1.5 times the volume of all containers Impervious to the materials contained for a minimum contact time of 72 hours — Free of accumulated rainwater or spills, with sufficient separation provided between stored containers to allow for spill cleanup Incompatible, ignitable, and reactive materials shall not be stored in the same temporary containment facility "Caution: Flammable Material" signs must be posted near containment areas to prevent fires or explosions • The following management guidelines are recommended for containment facilities: Keep containers closed at all times except when adding or removing waste from the container. Use a funnel or hose to transfer wastes to drums. You must open, handle, and store containers to prevent ruptures or leaks. Make sure to open drums with a spark -proof wrench. - If the container begins to leak or you notice dents or bulges, transfer the waste to another container. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc WM-4 June 2008 • Locate containment areas away from high -traffic areas, waterways, drainage inlets, sensitive habitats, and areas prone to flooding or ponding. • Waste residuals from equipment or brushes shall be cleaned in designated containment areas and shall not be allowed to seep into soils causing soil contamination or to discharge into watercourses or drainageways. • Secondary containment needs to be provided for all hazardous waste containers. In addition, containment berms shall be used in fueling and maintenance areas where the potential for spills is high. • Hazardous waste containment areas shall be pre -approved by the engineer and/or project manager. • It is the contractor's responsibility to ensure that all hazardous waste discovered or generated at a project site is disposed of properly by a licensed hazardous material disposal contractor/facility utilizing properly completed Uniform Waste Manifest forms. The contractor is responsible for not exceeding hazardous waste storage requirements mandated by the state or other localities. • Additional disposal guidelines for non -hazardous solid and liquid waste are included in Sections WM 2 and WM 4, respectively. Contaminated waste The following are general guidelines provided for planning the management of contaminated soils. • The contractor is responsible for reviewing relevant environmental reports, appropriate plans, and project special provisions for contaminated soils information. The contractor shall also take initiative to further inform the engineer of any potential or identified contaminated soils on the project site. • Contractor and employees are responsible for meeting safety training requirements mandated by 29 CFR 1910.120 prior to performing any construction work or excavation at projects sites where contaminated soils have been classified as hazardous materials. • The contractor is responsible for following all rules and regulations applicable to the excavation, handling, transport, and disposal of contaminated and hazardous materials. The applicable rules and regulations are not limited to the standards of Occupational Safety and Health Administration, U.S. Environmental Protection Agency, U.S. Department of Transportation (USDOT), Colorado Department of Public Health and Environment (CDPHE), and local agencies. • Contaminated soils should be placed in a lined and bermed area. • Surround the perimeter of the exclusion zone with a security fence for safety. • Collect impacted soil samples and complete a characterization analysis. • Collect non -reusable protective equipment used at the project site and dispose of it properly. Additionally, treat and/or dispose of wastewater from decontamination procedures. • Contaminated soil shall be transported to a licensed disposal facility on vehicles registered for that purpose. • When an underground storage tank is discovered at a construction site, coordinate with the regional environmental project manager for guidance on handling and disposal procedures. • Preventive measures, such as berms, freeze walls, cofferdams, and grout curtains, should be installed to prevent stormwater runoff or groundwater from mixing with hazardous materials or underground tank excavations. Water exposed to contaminated areas should be placed in water -tight holding tanks, tested, and properly disposed. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc WM-5 June 2008 Maintenance considerations The frequency of inspections should be in accordance with the Stormwater Management Plan. The contractor shall monitor concrete activities to ensure proper waste management techniques are being utilized. Maintenance of temporary concrete washout facilities shall include removing hardened concrete and proper disposal. It is recommended that facilities be cleaned out once they are 75 percent full, or new facilities shall be constructed to provide additional concrete waste storage. Check for and remove litter and debris from drainage grates and other drainage structures. Provide cover for dumpsters and waste containers to prevent entry of rainwater and loss of contents by high winds. Inspect perimeter controls, containment structures, berms, covers, and liners. Repair or replace as needed to function properly. The contractor shall be responsible for monitoring on-site contaminated storage and disposal procedures. References Arizona Department of Transportation (ADOT), Erosion and Pollution Control Manual. 2005. http://www.azdot.gov/ADOT and/Storm Water/Erosion_Pollution_Control_Manual.asp Colorado Department of Transportation (CDOT), Erosion Control and Stormwater Quality Guide. 2002. http://www.dot.state.co.us/environmental/envWaterQual/wgms4.asp M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc WM-6 June 2008 Vehicle and Equipment Management (VEM) VEHICLE -- WASH AREA 1=11 icRWA Description Procedures and practices used to minimize or eliminate the discharge of pollutants during the following operations: • Cleaning of vehicles and equipment prior to or during use on project site. • Fueling of vehicles. • Maintenance of vehicles and equipment. Applicability These procedures are applied on all construction sites where vehicle and equipment cleaning, fueling, and/or maintenance takes place. Limitations Only use on-site vehicle and equipment fueling when it is impractical to send vehicles and equipment off site to be refueled. Comply with local codes and ordinances regarding the disposal of fluids and consumables, and the on-site maintenance of equipment. Standards and specifications Vehicle and equipment cleaning • On-site vehicle and equipment washing is discouraged, but may be necessary to eliminate spread of invasive species to areas outside of project site. • Cleaning of vehicles and equipment with soap, solvents, or steam shall not occur on the project unless the Engineer has been notified in advance and the resulting wastes are fully contained and disposed of outside of the highway right-of-way in conformance with the Standard Specifications. Resulting wastes shall not be discharged or buried. • When equipment/vehicle washing/cleaning must occur on site and the operation cannot be located within a structure or building equipped with appropriate disposal facilities, the outside cleaning shall have the following characteristics and shall be arranged with the Erosion Control Coordinator: — A washout area shall be an excavated pit, which will later be backfilled or where the concrete wash can harden and be properly disposed of. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc VEM-1 June 2008 — Locate wash out areas close to the active construction site on the project. Locate wash out pits away from storm drains, open ditches, or receiving waters. — Use only when necessary. When cleaning vehicles/equipment with water use as little water as possible. Consider using high pressure sprayers, which require less water. Vehicle and equipment fueling • When fueling must occur on site, the contractor shall select and designate an area to be used, subject to approval by the Engineer. • Federal, state, and local requirements shall be observed for any stationary aboveground storage tanks. • Mobile fueling of construction equipment throughout the site shall be minimized. Whenever practical, equipment shall be transported to the designated fueling area. • Spill prevention, containment, and countermeasures shall be included in the Stormwater Management Plan (SWMP) if the volume of project site fuel in a single container exceeds 660 gallons, or if the total fuel storage volume at any one site exceeds 1,320 gallons. • Designated fueling areas shall be protected from stormwater runoff and shall be located at least 50 feet from downstream drainage facilities or watercourses. Fueling must be performed on level -grade areas. • Protect fueling areas with berms and/or dikes to prevent run-on, runoff and to contain spills. • Absorbent spill clean-up materials and spell kits shall be available in fueling areas and on fueling trucks and shall be disposed of properly after use. • Drip pans or absorbent pads shall be used during vehicle and equipment fueling, unless the fueling is performed over an impermeable surface in a dedicated fueling area. • Nozzles used in vehicle and equipment fueling shall be equipped with an automatic shut-off to control drips. Fueling operations shall not be left unattended. Fuel tanks shall not be "topped off." Vehicle and equipment maintenance • Plan for the proper recycling or disposal of used oils, hydraulic fluids, gear lubricants, batteries, and tires. • Use appropriate, leak -proof containers for fuels, oils, and lubricants to provide for proper disposal. • Use steam or high-pressure water instead of thinners and solvents to wash down equipment. Wash water and detergents can be disposed of in the sanitary sewer system after grit is removed, after checking with local authorities. • Use drip pans or absorbent pads under equipment during maintenance that involves fluids. • Equipment maintenance and wash-out areas should be located at least 50 feet away from drainages. • Provide spill containment areas around stored oil and chemical drums. • Provide a contained wash-out area to wash down heavy equipment. M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc VEM-2 June 2008 Maintenance considerations The frequency of inspections should be in accordance with the SWMP. Vehicles and equipment shall be inspected for leaky gaskets and damages hoses. Leaks shall be repaired immediately or problem vehicles or equipment shall be removed from the project site. Any damaged hoses shall be repaired or replaced as needed. Fueling areas and storage tanks shall be inspected. Immediately clean up spills and properly dispose of contaminated soil and cleanup materials. Inspect equipment maintenance areas and wash-out areas. Inspect fluid containers for leaks. Repair leaky fluid containers immediately. References Arizona Department of Transportation (ADOT), Erosion and Pollution Control Manual. 2005. http://www.azdot.gov/ADOT_and/Storm_Water/Erosion_Pollution_Control_Manual.asp Colorado Department of Transportation (CDOT), Erosion Control and Stormwater Quality Guide. 2002. http://www.dot.state.co.us/environmental/envWaterQual/wqms4.asp M:\Encana\BMP Manual\BMP Manual - Round 2\SWMM Final 06-09-08.doc VEM-3 June 2008 Appendix F Oil and Gas Construction Field Permit Certification NOTICE OF AMENDMENT OF PERMIT COVERAGE and/or Final Stabilization Certification F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc Updated February 2008 STATE OF COLORADO Oil and Gas Construction Field Permit Certification NOTICE OF AMENDMENT OF PERMIT COVERAGE Terminating coverage for a portion of a permitted area GENERAL PERMIT FOR STORMWATER DISCHARGES ASSOCIATED WITH CONSTRUCTION ACTIVITY This form is for construction activities associated with oil and gas construction only. The form is applicable to field permit certifications only, and is not applicable to construction activities for other sectors, such as residential, commercial, or transportation. Additional options for administration and amendments for construction permits, including for activities not associated with oil and gas, is available on the Division's permitting web page, coloradowaterpermits.com (follow the link to "Stormwater Permitting," and then "Construction Stormwater"). This form is to be used to amend an oil and gas field permit certification under Colorado's Stormwater Construction Permit, to terminate permit coverage when all of the following conditions have been met: 1. The permit certification to be amended is a field permit certification for construction associated with oil and gas construction. The field permit covers all construction activities disturbing over one acre, or that are part of a common plan of development exceeding one acre, within the applied -for field. 2. The area is a distinct and separate area where construction has been completed and is not part of a specific facility, such as a single well pad or road segment, where construction is ongoing. 3. The area must be Finally Stabilized. An area is Finally Stabilized when all ground surface disturbing activities at the site have been completed, and all disturbed areas have been either built on, paved or equivalently hard -armored, or a uniform vegetative cover has been established with an individual plant density of at least 70 percent of pre -disturbance levels. Upon acceptance of this notice by the Water Quality Control Division (the Division), the permit certification will be automatically amended to exclude the specific portion described in the notice. The current permittee will not receive a revised certification. The corrected information will be placed in the permit file. In order to receive notification of the Division's receipt of this information, it is up to the permittee to request verification of delivery from the carrier (i.e., by sending certified mail). If the Area Has Not Been Finally Stabilized: This form is only for terminating an area that has been finally stabilized. If the area has not been finally stabilized the permittee must either maintain permit coverage, or can reassign permit coverage to another entity that owns or has operational control over that area. The Division's Notice of Reassignment of Permit Coverage form should be used. The form is available at coloradowaterpermits.com Stormwater Management Plan (SWMP): The permittee must maintain a SWMP that accurately reflects the activities and BMPs for the areas for which they will have permit coverage. Therefore, the SWMP must be updated to reflect the changes described in this form. Appendix A of the General Permit Application and SWMP Guidance for Stormwater Discharges Associated with Construction Activity (available from the Division's web site at coloradowaterpermits.com) contains the requirements for the SWMP. Failure by the permittee to maintain a SWMP in accordance with this guidance is a violation of the permit. Additional guidance for multi owner/operator development is also available in the Stormwater Fact Sheet for Construction, available from the Division's web site. 12/08/OGcoverageamend Notice Due Dates: At least ten days prior to the requested effective date for permit coverage to end, the permittee shall submit this form to the Division. This form may be reproduced, and is also available from the Division's web site at coloradowaterpermits.com. Permit Fee: There are no new permit fees associated with amending the construction permit certification. Application Completeness: All items on the form must be completed accurately and in their entirety or the notice will be deemed incomplete, and processing of the form will not begin until all information is received. A map of the revised area must be included that clearly indicates the area with continued coverage under the permit certification, and the area excluded. (Do not include a copy of the SWMP.) One original copy of the completed form (no faxes or e-mails), signed by the current permittee, shall be submitted, only to: Colorado Department of Public Health and Environment Water Quality Control Division - Permits 4300 Cherry Creek Drive South Denver, Colorado 80246-1530 If you have questions on completing this application, you may contact the Division at cdphe.wqstorm@state.co.us or (303) 692-3517. SITE MAP INSTRUCTIONS Site Map: A Site Map must be provided. The map must clearly define the boundaries of the area to be excluded from permit coverage relative to that with continued coverage. The level of detail that must be provided will depend on the nature of the project, and must be adequate to determine during a field audit what construction activities are still covered under the issued certification. Two maps (a vicinity map and excluded site boundary map) may be necessary to provide sufficient detail to meet this requirement for large field areas. Maps must not exceed 8 Y2 x 17 inches. Do not submit grading plans or other blueprints as the site map. 12/08/OGcoverageamend Colorado Department of Public Health & Environment FOR AGENCY USE ONLY Water Quality Control Division WQCD-P-B2 REC 4300 Cherry Creek Drive South EFF Denver, Colorado 802464530 YEAR MONTH DAY Amendment notice for Oil and Gas Construction Field Permit Certification CONSTRUCTION STORMWATER DISCHARGE GENERAL PERMIT CERTIFICATION Please print or type. Form must be filled out completely. Certification Number: COR -03 1234 Permittee (Company) Name: Permittee Address: Phone No. Field Permit Certification Information (refer to your permit certification): Field Permit Site/Facility Name: County(s): Contact Person: Contact Person Phone No.: Contact Person Email: Information on Area to be Excluded from Permit Coverage: Site Map: Must include Site Map indicating the boundaries of the area to be excluded from permit coverage. Refer to the Site Map Instructions on page ii of this form. Maps must be folded to 8% x 11 inches. Map enclosed? Yes No Summary of work performed and description of final stabilization for the area shown in the attached map: I certify under penalty of law that by the date of my signature below, at the identified construction site area, all disturbed soils have been finally stabilized; all temporary erosion and sediment control measures have been removed; all construction and equipment maintenance wastes have been disposed of properly; and all elements of the Stormwater Management Plan have been completed. I understand that by submitting this notice of amendment, I am no longer authorized to discharge stormwater associated with construction activity by the general permit, for this specific area. I understand that discharging pollutants in stormwater associated with construction activities to the waters of the State of Colorado, where such discharges are not authorized by a CDPS permit, is unlawful under the Colorado Water Quality Control Act and the Clean Water Act. I certify under penalty of law that I have personally examined and am familiar with the information submitted herein, and based on my inquiry of those individuals immediately responsible for obtaining the information, I believe that the information is true, accurate and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment. (See 18 U.S.0 1001 and 33 U.S.C. 1319.) Signature of Permit Applicant (Legally Responsible Party) Date Signed Name (printed) Title 12/08/OGcoverageamend Encana SWMP — Final Stabilization Certification Date: Site ID: Type of Area: ❑ Well Pad ❑ Access Road to Well Pad ❑ Other Road ❑ Pipeline ❑ Other Facility "The above referenced site has reached final stabilization. All ground surface disturbing activities have been completed, including the removal of all temporary BMPs, and all disturbed areas have been either built on, or a uniform vegetative cover has been established with an individual plant density of at least 70 percent of pre -disturbance levels, or equivalent permanent, physical erosion reduction methods have been employed." Printed name Title Signature Date Appendix G Inspection and Maintenance Report Form F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc Updated February 2008 EnCana SWMP Inspection and Maintenance Report Form Area Inspected (Site ID): Title of Inspector: Name of Inspector: Date: Type of Area: Well Pad I- Access Road to Well Pad [ Other Road I- Pipeline I Other Facility: Phase of Construction: I Preconstruction onstruction P rifling f ompletions P Reoccupy I- :erm Reclamation I- inal Reclamation Type of Inspection: 7 Active (14 days since last inspection) I ompleted (1 month since last inspection) I Active (Within 24 hours of a rain/snowmelt event that causes surface erosion or 72 hours for temporarily idle sites) Winter Conditions Exist Site Specific Information Approximate area of site to be disturbed (acres): Receiving Water(s): Soil Type(s): Ecosystem/Vegetation Type(s): Other Site Specific Information: Vegetation Observations Site Revegetated: Yes I No P Current Vegetation: % Pre -disturbance Vegetation: % (estimate from undisturbed surrounding areas) Vegetation Growth uniform and at least 70% of pre -disturbance levels: Yes F Jo F Best Management Practice (BMP) Check List Erosion Control: In Use? Comments Drainage Control: In Use? Erosion Control Blanket P Berm Hydraulic Mulching I- Culvert Land Grading - Roads (slopes/gravel/etc) I- Culvert Inlet Protection Mulching P Culvert Outlet Protection Retaining Wall I Diversion Revegetation f Drainage Dip Riprap I Level Spreader Soil Stabilizers Roadside Ditches and Turnouts Stockpiling - Topsoil and Subsoil P Run On Diversion Surface Roughening I Slope Drain Terracing I Trench Breaker I Turf Reinforcement Mat Water Bar Vegetated Buffer I Wattles Sediment Control: In Use? Comments Sediment Control: In Use? Check Dam Slash f Detention Pond I Stabilized Construction Filter Berm 1 Straw Bale Barrier f Sediment Reservoir Riprap Sediment Trap 1 Wattles Silt Fence I- r Non-Stormwater Control: In Use? Comments Non-Stormwater Control: In Use? Dewatering Dust Control Location/Observation: Additional Comments: New BMPs installed , changes, dates performed, etc...) Site perimeter/discharge points inspected? Yes I- No I- N/A P All disturbed areas inspected? Yes I- No I- N/A I - Vehicles entrance(s)/exit(s) inspected? Yes I- No I- N/A I - Material storage areas inspected? Yes I No 1- N/A (- Acceptable waste management procedu res? Yes I- No I- N/A 1 - Acceptable Acceptable vehicle/equipment maintenance? Yes I- No I- N/A I Any sediment/pollutant discharged off-site? Yes fl No E N/A I^ If no change since above inspection (no changes to BMPs or SWMP) Date Signature Type of Inspection 14 day I Monthly Pptn. Event I- 14 day I Monthly I- Pptn. Event I- 14 day I Monthly 1 - Pptn. Event I- 14 day P Monthly I Pptn. Event f 14 day I- Monthly I- Pptn. Event Signature certifying that the site is in compliance (after all necessary repairs, maintenance, and changes have been made): Date Signature Appendix H Inactivation Form F:\Projects\014-2797\Documents\O pe rati on a l Docs\SWMP\1. Mamm_Creek_SWMP_20101210.doc Updated February 2008 Colorado Department of Public Health & Environment FOR AGENCY USE ONLY Water Quality Control Division WQCD-P-B2 REC 4300 Cherry Creek Drive South EFF Denver, Colorado 80246-1530 YEAR MONTH DAY INACTIVATION NOTICE FOR CONSTRUCTION STORMWATER DISCHARGE GENERAL PERMIT CERTIFICATION Please print or type. Form must be filled out completely. Certification Number: COR -03 Permittee (Company) Name: Permittee Address: Site/Facility Name: Taxpayer ID or EIN Phone No. ( Construction Site Address/Location: County: Contact Person: Summary of work performed and description of final site stabilization: I certify under penalty of law that by the date of my signature below, all disturbed soils at the identified construction site have been finally stabilized; all temporary erosion and sediment control measures have been removed; all construction and equipment maintenance wastes have been disposed of properly; and all elements of the Stormwater Management Plan have been completed. I understand that by submitting this notice of inactivation, I am no longer authorized to discharge stormwater associated with construction activity by the general permit. I understand that discharging pollutants in stormwater associated with construction activities to the waters of the State of Colorado, where such discharges are not authorized by a CDPS permit, is unlawful under the Colorado Water Quality Control Act and the Clean Water Act. I certify under penalty of law that I have personally examined and am familiar with the information submitted herein, and based on my inquiry of those individuals immediately responsible for obtaining the information, I believe that the information is true, accurate and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment. (See 18 U.S.0 1001 and 33 U.S.C. 1319.) Signature of Permit Applicant (Legally Responsible Party) Date Signed Name (printed) Title 9/97/cn/in Article 4-203.E.18 Reclamation Plan Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OA Project No. 014-2797 encana.____ Encana Oil and Gas (USA) Inc. Operator # 100185 K19NE Lavdown Yard Surface Reclamation Plan Location ID: 335338 NESE Section 19 T6S R92W Garfield County Site Description: The existing well pad is a 5.3 acre disturbance. The land surface is fee (Encana), with fee minerals (Encana). The dominant vegetation community in the lease area can be characterized as sagebrush shrublands. The average annual temperature for Rifle, CO is 47.75 F, with an average precipitation accumulation of 11.61 inches, with somewhat similar averages expected for this site. The existing surrounding land use is rangeland, and the site elevation is 5,500 feet. Soils Description: The USDA National Soils Cooperative website was used to identify boundaries of soils mapping units. The site resides within the Arvada loam mapping unit, which averages 6-20% slopes; the Potta loam unit, which averages 3-6% slopes; the Potts-Ildefonso complex, which averages 12-25% slopes; and the Torriothents-Rock outcrop complex, which is classified as steep. Pre -Disturbance Vegetation Composition: Ocular assessment for canopy cover on near -by undisturbed land is 35%. Known weed infestations: There are no known or identified Colorado List A or B weed infestations at this location Management of Waste Material: Before reclamation earthwork is initiated, qualified Environmental personnel will complete a site - assessment for the purpose of identifying soil impacts resulting from current and historic activities on the pad. The site -assessment includes collection of field notes and a photographic record of site conditions. Soil samples are collected from the footprint of removed production equipment, from any visibly stained soil, and wherever stormwater accumulations may concentrate contaminants. Collected soil samples are analyzed for compliance with Colorado Oil and Gas Conservation Commission (COGCC) Table 910-1 constituents of concern. If laboratory analysis identifies hydrocarbon contaminated soil, impacted material will be excavated using heavy equipment and transported to an offsite facility for disposal. All remediation and disposal activities will be directed by qualified Environmental personnel using field screening techniques, verified by laboratory analysis, and in compliance with COGCC 900 Series Rules. Removal of contaminated material will be reported to the landowner and the COGCC. Access Road: There are no existing well pads or public permitted access beyond this well. The access road associated with this pad is the entrance on the West side. It will be decommissioned and is included in the reclamation area. Pre-existing roads to the West and North will remain in place. Recontouring: Re -contouring will start with pulling the fill material back to the cut and blending with the natural slope of the area. Micro drainages will be re-established to allow natural flow. The surface cover and size distribution of exposed rock will not exceed pre -disturbance site conditions. Any gravel will be removed from the working surface prior to re -contouring. If the topsoil pile is present, it will be spread evenly across the reclaimed pad. If a topsoil stockpile is not present, we will use the soil at the bottom of the fill side of the location. On older pads, prior to topsoil storage practices, all topsoil was pushed to the bottom of the pad and covered with fill. We will make every effort to save and distribute any available topsoil found. Re-establish and stabilize drainage features: The goal for stormwater management on this location will be to stabilize soils on the reclaim and to prevent excessive erosion, such as slope or soil instability, subsidence and or slumping. All structural BMPs, such as culverts and ditches, will be removed during final reclamation. The site will be maintained to keep the location free of any trash or construction debris. Seedbed Preparation and Seeding: All seed beds will be prepared by contour ripping to 6-10" in depth. Contours will be shaped to natural repose of the reclaim surface. Seeding will take place within 24 hours of completion of the dirt work. Seed depth will be drilled to a minimum depth of 0.25" and a maximum of 0.50". Soil amendments that are recommended by the BAR will be applied. Encana will drill where possible or broadcast and drag on steeper slopes where drilling is not safe. Encana also would like to keep all available options open such as Hydro -seeding, seeded wattles and erosion blankets along with new technology to improve on the success of re -vegetation of the site. Establish desired self-perpetuating plant community: The anticipated seed mix for this location is listed below. The recommended application rate is 24 lbs/acre at drill rate. Double rate will be used for broadcast seeding. However, based upon the soil conditions determined by the BAR soil analysis, another seed mix may be better suited for the location if needed. Common Name Scientific Name Variety Pounds Pure Live Seed (PLS) per acre Grasses Slender Wheatgrass Elymus trachycaulus Revenue 3.49 Pubescent Wheatgrass Thinopyrum intermedium Luna 2.96 Western Wheatgrass Pascopyrum smithii Rosana 2.97 Sideoats Grama Bouteloua curtipendula El Reno 2.44 Thickspike wheatgrass Elymus lanceolatus Critana 1.91 Intermediate Wheatgrass Thinopyrum intermedium OAHE 1.90 Galleta Pleuraphis jamesii Viva 1.91 Russina Wildrye Bozoisky Psathyrostachys juncea VNS 1.10 Idaho Fescue Festuca idahoensis VNS 0.80 Perennial Ryegrass Lolium multiflorum VNS 0.86 Indian Ricegrass Achnatherum hymenoides Rimrock 0.56 Alkali Sacaton Sporobolus airoides VNS 0.33 Total PLS 21.23 Fencing: If needed, Encana will install BLM standard wildlife friendly fence installed at perimeter of reclaim disturbance, to reduce the potential for herbivory impacts to the germinating and establishing desired species. Manage Invasive Plants: Through the annual site visits, noxious and invasive weeds will be identified, inventoried and treated by licensed contracted herbicide applicators. Encana will monitor, control and reduce the spread of noxious and invasive weed species within Encana's disturbances as determine in the Colorado Noxious Weed Act and rules pertaining to the administration and enforcement of the Colorado Noxious Weed Act. Reclamation Monitoring and Reporting: State regulations and Encana's Best Management Practices require routine site visits and active management over construction activities, along with annual reclamation reporting requirements. At a minimum, the location will be visited every 14 days during active construction and monthly thereafter until the vegetation has reached 70% cover of pre -disturbance levels. Once final reclamation has been reached, vegetation establishment is 80% cover of pre -disturbance levels, and Encana has received the approved Final Abandonment Notice (FAN) from COGCC, any wildlife friendly fence present will then be removed. THIS PAGE LEFT BLANK FOR TWO-SIDED DUPLICATION. Colorado Oil and Gas Conservation Commission Home Page HOME Colorado Oil and Gas MI Conservation Commission gm PRINT PAGE HELP CONTACTS COMPLAINTS DATABASE FORMS GENERAL HEARINGS IMAGES KIDS' PAGE LIBRARY LOCAL GOV MAPS MISSION NEWS/MEDIA ORDERS PERMITS POLICIES RULES STAFF RPT A division of the Colorado De.artment of Natural Resources Trans.arenc Online Pro•ect TOP COGIS - Surety Detail COMPANY DETAIL REPORT for Surety ID: 2009-0011 ENCANA OIL & GAS (USA) INC - #100185 370 17TH ST STE 1700 DENVER , CO 80202-5632 USA SURETY DETAIL INFORMATION Surety ID: 2009-0011 Status: ACTIVE Operator Number: 100185 Bond Amount: $25,000.00 Instrument: INSURANCE Instrument Number: 105189968 Coverage: BLANKET Bond Type: SURFACE Limitation: 0 Deposit Number: PDPA Number: Received Date: 2/12/2009 Approved Date: 3/12/2009 Maturity Expire Date: FA Provider Number: 200097 FA Provider Name: TRAVELERS CASUALTY AND SURETY COMPANY OF AMERICA Deposit Date: Release Request Date: N/A Release Date: N/A http://cogcc.state.co.us/[1/13/2015 3:34:15 PM] Article 4-203.G Impact Analysis Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OA Project No. 014-2797 OLSSON ASSOCIATES Article 4 — Impact Analysis Encana Oil & Gas (USA) Inc. K19 Storage Facility (Laydown Yard) SECTION 4-203.G. IMPACT ANALYSIS 1. Adjacent Land Use The proposed site is located within the boundaries of an 88.5 acre property. The storage use would be limited to a 5.17 acre area. Natural gas development, agriculture, light industrial, and wasteland are the uses on the subject parcel and surrounding properties. Natural gas development is the predominate use in the immediate area. The closest residential use to the proposed laydown yard is approximately a half mile to the north. 2. Site Features The subject property is located in the Rural (R) zone district of Garfield County on Lot 3 of Section 19, Township 6 South, Range 92 West of the 6th PM. Access to the laydown yard is via Garfield County Road (CR) 315 (Mamm Creek Road) for approximately 4 miles from 1-70 exit 94 to CR 333 (Hunter Mesa Road) for approximately 2.8 miles to a private access road (see Access Road Map). The K19NE Laydown Yard location is approximately 0.5 miles east of CR 333 on this private access road. The elevation of the site is approximately 5,689 feet. All native vegetation has been removed from the project site and the area is currently being used as a COGCC permitted well pad. The proposed laydown yard exists in a disturbed vegetation community dominated by grasses. The site appears to have been dominated previously by sagebrush/greasewood shrublands. Scattered patches of grease wood and big sagebrush, rabbitbrush, fourwing saltbush, and shadscale still persist in some areas. The understory is not diverse and was dominated by downy brome with scattered patches of galleta grass and weedy annuals. Additional species occurred in lesser coverage and amounts. 3. Soil Characteristics Soils, consisting of the following units, are within the study area around the proposed laydown yard: Potts Loam, Map Symbol 55, is a moderately sloping soil found on mesas, benches, and the sides of valleys at elevations ranging from 5,000 feet to 7,000 feet amsl. The soil formed in alluvium derived from sandstone, shale, or basalt. Typically the surface layer is brown loam about four inches thick, the subsoil is reddish brown clay loam 760 Horizon Road, Suite 102 TEL 970.263.7800 Grand Junction, CO 81506 FAX 970.263.7456 www.olssonassociates.com Encana Oil & Gas (USA) Inc. K19 Storage Facility about 24 inches thick, and the substratum is pinkish white loam to a depth of 60 inches thick. Permeability is moderate, and the available water capacity is high. Surface runoff is slow and the erosion hazard is moderate. Community development and recreation are limited by low strength and the shrink -swell potential. Dwellings and roads can be designed to overcome these limitations. 4. Geology and Hazard This is a summary of the Natural and Geologic Hazard Assessment Report that is provided with this application. The K19NE Storage Yard is not expected to have any buried or aboveground utilities. Avalanche conditions are not expected to be a hazard in the area of the Site. Rockfall areas are not a geological hazard in the area of the Site, but may exist in areas along Mamm Creek and its tributary drainages. The Site is not in an area mapped as an alluvial fan hazard area. Slope is not a geologic hazard in the vicinity of the site, but is in areas to the north and west along West Mamm Creek and Mamm Creek drainages. The Potts Loam soils are listed as a high risk of corrosion to uncoated steel and a low risk of corrosion to concrete. These soil characteristics are not expected to pose a geologic hazard for the proposed development at the K19NE Storage Yard. The shrink -swell potential for the Potts Loam is low to moderate. Therefore, expansive soils are not a geologic hazard at the K19NE Storage Yard. Collapsible soils are not present in the vicinity of the proposed K19NE Storage Yard. No significant faults have been mapped or are known in the K19NE Storage Yard. The Site is located to the northwest of the Divide Creek anticline which was formed as a result of movement along a blind thrust fault associated with the uplift of the Colorado Rocky Mountains. The Site is not mapped as being within the 100 -year flood plain. Flash flooding is a hazard for lower elevations along the West Fork of Mamm Creek, Mamm Creek and its tributaries, and areas along the Colorado River located approximately two miles to the north and at elevations that are 100 feet to 200 feet lower than the Site elevation. Therefore, flooding is not expected to be a natural hazard affecting the Site. Uranium and Vanadium were mined to the northeast of the town of Rifle; and approximately ten miles north of the Site. There are no significant radioactive mineral deposits known in the immediate area of the Site. The presence of NORM may be an issue with exploration and production and could be an issue with used pipe scale or used equipment stored at the site. Radioactive materials are not expected to pose a significant hazard at the Site. Impact Analysis Page 2 Encana Oil & Gas (USA) Inc. K19 Storage Facility 5. Groundwater and Aquifer Recharge Areas No flood prone areas are mapped in the vicinity of the site. Areas along the West Fork of Mamm Creek are potentially prone to flash floods. An individual sewage disposal system (ISDS) is not being used at this site, so soils will not have to support waste disposal. The site was previously graded. Minor soil disturbance and construction activity may be required to accommodate the grading and drainage plan. All soil disturbances have been fully stabilized according to CDPHE and COGCC criteria. 6. Environmental Impacts a. Determination of long-term and short-term effects on flora and fauna Flora The continued use and redevelopment of the existing location would not adversely affect federally listed plant species. No additional vegetation removal is associated with the laydown yard. Vegetation communities and conditions will not be affected on a long- or short-term basis and would remain in their present condition. Fauna Federally Listed Threatened, Endangered, and Candidate Wildlife Species The continued use of the existing site as a laydown yard would not adversely affect federally listed wildlife species due to the lack of suitable habitat within or surrounding the project area. No federally designated critical habitat occurs within or near the site. Colorado State listed Threatened, Endangered or Sensitive wildlife species would not be impacted by the proposed laydown yard due to the lack of suitable habitat available for those species within or surrounding the proposed project area. Raptors, Birds of Conservation Concern, Migratory and Non -Migratory birds No additional vegetation removal would be associated with the proposed laydown yard; therefore no suitable raptor, BCC, or other migratory or non -migratory bird species nesting habitat would be impacted. Long- or short-term effects related to the project area would be minimal due to the area being previously disturbed from activities associated with the operation and maintenance of the existing oil and gas well pad, and a lack of suitable nesting habitat in proximity to the site. Loud noises and human activities at the site during the breeding and nesting season may have limited indirect impacts on habitat effectiveness around the pad site, possibly reducing the suitability or effectiveness for nesting activities in the native shrubland habitats; but as mentioned, a lack of suitable nesting habitat in proximity to the pad limits the amount of potential impacts. Foraging and other habitat use would likely continue within adjacent habitats, as available. American Elk and Deer The existing site is absent of any vegetation, and no additional direct impacts to elk or deer habitats would occur. Elk and deer may be indirectly impacted during the winter months by increased noise and human presence and increased traffic along the Impact Analysis Page 3 Encana Oil & Gas (USA) Inc. K19 Storage Facility access road, which may cause elk and deer to avoid this area during certain times of day or during times of more intense human activities. The winter months are a critical time of year for big game species, when deer and elk are more likely to be utilizing lower elevations, and disturbance can have a larger relative impact due to poor foraging opportunities and already stressed animals. Intensive use of the laydown yard during the winter months may force deer and elk away from the area, which could increase energy expenditures for the individuals impacted. During the summer and fall months, most deer and elk are at higher elevation habitats, and therefore use of the pad site outside of the winter would likely have no impact on deer or elk. The use of the laydown yard would not block or impede migration corridors for elk or mule deer. Long-term, reclamation of the site is recommended in order to improve winter range habitat effectiveness in the area. b. Determination of the effect on designated environmental resources, including critical Wildlife Habitat The K19NE Laydown Yard is not expected to affect any critical habitat for any wildlife species, as no federally designated critical habitat or species were identified within or near the site. According to the CPW GIS data, the project area occurs within Overall, Severe Winter Range, Winter Concentration Areas and Winter Range for elk and mule deer. No additional vegetation removal or new construction is associated with the site that would further decrease habitat. The site would not impede any natural migration or movement through the area, but use of the site during the winter months may temporarily cause animals to avoid habitats around the site. Given the limited size and temporary nature of activities associated with laydown yard use, these impacts would likely be short-term in nature, and no measureable impact to mule deer or elk herds would be expected from this project. Activities in the winter months would have a relatively larger potential effect given the condition of animals in the winter months, and reduced availability of forage and security habitats. As mentioned, some individual animals may be indirectly impacted by moving away from the site, but no significant impacts to herds, or long-term impacts to critical wildlife habitat would be expected. c. Impacts on wildlife and domestic animals through creation of hazardous attractions, alteration of existing native vegetation, blockade of migration routes, use patterns, or other disruptions The laydown yard would not create hazardous attractions to avian or mammalian wildlife species or domestic animals, alter additional native vegetation, block migration routes, or cause a change in habitat use. Wildlife species may be indirectly impacted by increased noise and human presence while equipment is being transferred and stored. Use of habitats by wildlife would still likely occur on or adjacent to the pad and storage yard site during the nighttime hours, and during times when there are no human activities at the laydown yard. The majority of the species occurring within the area have widespread habitats; therefore, most Impact Analysis Page 4 Encana Oil & Gas (USA) Inc. K19 Storage Facility wildlife species that may be indirectly affected would have other habitats in the greater area that are still available for foraging, reproduction, dispersal and shelter. The proposed project may impact individuals indirectly but would not likely impact populations. No impacts to domestic animals would be expected. d. Evaluation of any potential radiation hazard that may have been identified by the State or County Health Departments Radon is not expected to be a significant problem at the proposed Site, since the development will not include any occupied structures, personnel will not be onsite for extended periods, and the Site will not be developed with structures containing basements or substructures in which radon can accumulate. Colorado oil and gas operations are not known to have a significant problem with naturally occurring radioactive materials (NORM) or technologically enhanced naturally occurring radioactive materials (TENORM); however, there have been some instances where pipe scale has contained radium and associated radon gas. A NORM survey including site specific testing could be performed to further assess the radon potential at the Site to serve as a baseline assessment if used pipe or pipe scale is stored and is to be disposed offsite in the future. 7. Nuisance Adjacent land uses will not be adversely impacted by the generation of vapor, dust, smoke, glare or vibration generated by the storage use beyond the limits set forth by Garfield County, the COGCC, the CDPHE and other regulatory agencies. There will be no equipment stored on site that requires a CDPHE Air Quality Permit. Dust will be mitigated by use of water or other dust suppressants. A copy of Encana's Fugitive Dust Control Plan is included with this submittal. There will be no equipment associated with the laydown yard permanently installed on the site that could potentially create a noise nuisance. 8. Hours of Operation The K19 Laydown Yard will be accessible to Encana personnel 24 hours a day, year round. Materials will be picked -up and dropped -off on an as -needed basis. No personnel will be stationed at the facility on a regular basis. Impact Analysis Page 5 Encana Oil & Gas (USA) Inc. K19 Storage Facility This page left blank for two-sided printing. Impact Analysis Page 6 Article 4-203.G.3 NRCS Soils Report Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OA Project No. 014-2797 USDA United States aim Department of Agr culture \CS Natural Resources Conservation Service A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Rifle Area, Colorado, Parts of Garfield and Mesa Counties Encana K29NE Storage Yard November 6, 2014 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/portal/ nres/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (http:// offices.sc.egov.usda.gov/locator/app?agency=nres) or your NRCS State Soil Scientist (http://www.nres.usda.gov/wps/portal/nres/detail/soils/contactus/? cid=nres142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means 2 for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface 2 How Soil Surveys Are Made 5 Soil Map 7 Soil Map 8 Legend 9 Map Unit Legend 10 Map Unit Descriptions 10 Rifle Area, Colorado, Parts of Garfield and Mesa Counties 12 55—Potts loam, 3 to 6 percent slopes 12 Soil Information for All Uses 13 Soil Properties and Qualities 13 Soil Qualities and Features 13 Depth to Any Soil Restrictive Layer 13 Drainage Class 16 Frost Action 19 Hydrologic Soil Group 22 Representative Slope 26 Water Features 29 Depth to Water Table 29 Ponding Frequency Class 33 References 37 4 How Soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil -vegetation -landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil scientists classified and named the soils in the survey area, they compared the 5 Custom Soil Resource Report individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil - landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil -landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field -observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. 6 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 7 39° 30' 36" N 3 N 266930 Custom Soil Resource Report Soil Map 266950 266970 266990 267010 267030 267050 267070 267090 267110 267130 267150 267170 267190 39° 30' 36" N n M v 0 n _ n 0 10 4y '�,r 5 - .�• ���._ _ :c' ;' 6•• M 10- 39° 30' 30" N 266930 266950 266970 266990 267010 267030 267050 3 Map Scale: 1:1,260 if printed on A landscape (11" x 8.5") sheet. v Meters O ��NN\\\ 0 15 30 60 90 / \ 0 50 100 200 300Feet Map projection: Web Mercator Comer coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 8 267070 267090 267110 267130 A' } t� 4 4 1' "� r- ±w�'�r%t 4� ti 267150 267170 267190 — lD — N n 0 — P-1 n N n M M0 n — ip n a 39° 30' 30" N Custom Soil Resource Report MAP LEGEND Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons o Soil Map Unit Lines 0 Soil Map Unit Points Special Point Features • Blowout 01 Borrow Pit X Clay Spot Closed Depression Gravel Pit Gravelly Spot L Landfill Lava Flow Marsh or swamp Mine or Quarry • Miscellaneous Water O Perennial Water Rock Outcrop ▪ Saline Spot Sandy Spot .a Severely Eroded Spot 14. 0 Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation t++ Rails r ,.+ Interstate Highways US Routes Major Roads Local Roads Background III Aerial Photography MAP INFORMATION The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Rifle Area, Colorado, Parts of Garfield and Mesa Counties Survey Area Data: Version 8, Sep 22, 2014 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 7, 2011—Sep 3, 2011 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background gery displayed on these maps. Asa result, some minor shifting 9 of map unit boundaries may be evident. Custom Soil Resource Report Map Unit Legend Rifle Area, Colorado, Parts of Garfield and Mesa Counties (C0683) Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 55 Potts loam, 3 to 6 percent slopes 5.5 100.0% Totals for Area of Interest Map Unit Descriptions 5.5 100.0% The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. 10 Custom Soil Resource Report An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha -Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha - Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. 11 Custom Soil Resource Report Rifle Area, Colorado, Parts of Garfield and Mesa Counties 55—Potts loam, 3 to 6 percent slopes Map Unit Setting National map unit symbol: jnyr Elevation: 5,000 to 7,000 feet Farmland classification: Prime farmland if irrigated Map Unit Composition Potts and similar soils: 85 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Potts Setting Landform: Mesas, benches, valley sides Down-slope shape: Convex, linear Across -slope shape: Convex, linear Parent material: Alluvium derived from basalt and/or alluvium derived from sandstone and shale Typical profile H1 - 0 to 4 inches: loam H2 - 4 to 28 inches: clay loam H3 - 28 to 60 inches: loam Properties and qualities Slope: 3 to 6 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: High Capacity of the most limiting layer to transmit water (Ksat): Moderately high (0.20 to 0.60 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Salinity, maximum in profile: Nonsaline (0.0 to 2.0 mmhos/cm) Available water storage in profile: High (about 10.3 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 3c Hydrologic Soil Group: C Ecological site: Rolling loam (R048AY298C0) 12 Soil Information for All Uses Soil Properties and Qualities The Soil Properties and Qualities section includes various soil properties and qualities displayed as thematic maps with a summary table for the soil map units in the selected area of interest. A single value or rating for each map unit is generated by aggregating the interpretive ratings of individual map unit components. This aggregation process is defined for each property or quality. Soil Qualities and Features Soil qualities are behavior and performance attributes that are not directly measured, but are inferred from observations of dynamic conditions and from soil properties. Example soil qualities include natural drainage, and frost action. Soil features are attributes that are not directly part of the soil. Example soil features include slope and depth to restrictive layer. These features can greatly impact the use and management of the soil. Depth to Any Soil Restrictive Layer A "restrictive layer" is a nearly continuous layer that has one or more physical, chemical, or thermal properties that significantly impede the movement of water and air through the soil or that restrict roots or otherwise provide an unfavorable root environment. Examples are bedrock, cemented layers, dense layers, and frozen layers. This theme presents the depth to any type of restrictive layer that is described for each map unit. If more than one type of restrictive layer is described for an individual soil type, the depth to the shallowest one is presented. If no restrictive layer is described in a map unit, it is represented by the "> 200" depth class. This attribute is actually recorded as three separate values in the database. A low value and a high value indicate the range of this attribute for the soil component. A "representative" value indicates the expected value of this attribute for the component. For this soil property, only the representative value is used. 13 3 N 266930 266950 266970 266990 267010 Custom Soil Resource Report Map—Depth to Any Soil Restrictive Layer 267030 267050 267070 267090 267110 267130 267150 267170 267190 39° 30' 36" N 39° 30' 36" N LO: 0 M — n 39° 30'30" N 266930 rt. +A * saA 266950 266970 266990 267010 267030 267050 267070 267090 267110 267130 267150 267170 3 Map Scale: 1:1,260 if printed on A landscape (11" x 8.5") sheet. v Meters ��NN\\\ 0 15 30 60 90 / \ 0 50 100 200 300Feet Map projection: Web Mercator Comer coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 14 267190 —,o 39° 30' 30" N Custom Soil Resource Report MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) 0 Not rated or not available The soil surveys that comprise your AOI were mapped at 1:24,000. Water Features Soils Streams and Canals Soil Rating Polygons Transportation 0 0 - 25 r--1-+ Rails 25-50 Interstate Highways 50 - 100 US Routes 0 100 - 150 Major Roads 0 150 - 200 Local Roads > 200 Background 0 Not rated or not available ® Aerial Photography Soil Rating Lines ,. 0-25 • r 25-50 • 50-100 . + 100 - 150 r;,f 150 - 200 r+.r > 200 • a Not rated or not available Soil Rating Points ▪ 0-25 O 25-50 O 50 - 100 O 100 - 150 O 150 - 200 ▪ > 200 Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Rifle Area, Colorado, Parts of Garfield and Mesa Counties Survey Area Data: Version 8, Sep 22, 2014 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 7, 2011—Sep 3, 2011 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background gery displayed on these maps. Asa result, some minor shifting 15 of map unit boundaries may be evident. Custom Soil Resource Report Table—Depth to Any Soil Restrictive Layer Depth to Any Soil Restrictive Layer— Summary by Map Unit — Rifle Area, Colorado, Parts of Garfield and Mesa Counties (C0683) Map unit symbol Map unit name Rating (centimeters) Acres in AOI Percent of AOI 55 Potts loam, 3 to 6 percent slopes >200 5.5 100.0% Totals for Area of Interest Rating Options—Depth to Any Soil Restrictive Layer Units of Measure: centimeters Aggregation Method: Dominant Component Component Percent Cutoff. None Specified Tie-break Rule: Lower Interpret Nulls as Zero: No Drainage Class 5.5 "Drainage class (natural)" refers to the frequency and duration of wet periods under conditions similar to those under which the soil formed. Alterations of the water regime by human activities, either through drainage or irrigation, are not a consideration unless they have significantly changed the morphology of the soil. Seven classes of natural soil drainage are recognized -excessively drained, somewhat excessively drained, well drained, moderately well drained, somewhat poorly drained, poorly drained, and very poorly drained. These classes are defined in the "Soil Survey Manual." 16 100.0% 39° 30' 36" N 3 IV 266930 266950 266970 266990 267010 267030 Custom Soil Resource Report Map—Drainage Class 267050 267070 267090 267110 267130 267150 267170 267190 — 0 N N v 0 39° 3030" N a 1 i;' ; • :• yy 0 • 0 - N .( ,lF k 4 Y, - `3', „e #""� Ili 266930 266950 266970 266990 267010 267030 267050 267070 267090 267110 267130 267150 267170 Map Scale: 1:1,260 if printed on A landscape (11" x 8.5") sheet. o N 0 15 30 0 50 100 200 300 Map projection: Web Mercator Comer coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 60 Meters 90 Feet 17 267190 0 — i a 39° 30' 36" N 39° 30' 30" N Custom Soil Resource Report MAP LEGEND Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons Excessively drained Somewhat excessively drained Well drained Moderately well drained Somewhat poorly drained Poorly drained Very poorly drained Subaqueous Not rated or not available Soil Rating Lines r•/r Excessively drained r r Somewhat excessively drained O 0 Well drained r • Moderately well drained r • Somewhat poorly drained ✓ r Poorly drained ry Very poorly drained ,. Subaqueous ✓ r Not rated or not available Soil Rating Points ▪ Excessively drained O Somewhat excessively drained O Well drained o Moderately well drained 0 Somewhat poorly drained o Poorly drained ▪ Very poorly drained ▪ Subaqueous o Not rated or not available Water Features Streams and Canals Transportation t++ Rails r=tie Interstate Highways US Routes Major Roads Local Roads Background 1 Aerial Photography MAP INFORMATION The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Rifle Area, Colorado, Parts of Garfield and Mesa Counties Survey Area Data: Version 8, Sep 22, 2014 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 7, 2011—Sep 3, 2011 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background gery displayed on these maps. Asa result, some minor shifting 18 of map unit boundaries may be evident. Custom Soil Resource Report Table—Drainage Class Drainage Class— Summary by Map Unit — Rifle Area, Colorado, Parts of Garfield and Mesa Counties (C0683) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 55 Potts loam, 3 to 6 percent slopes Well drained 5.5 100.0% Totals for Area of Interest 5.5 100.0% Rating Options—Drainage Class Aggregation Method: Dominant Condition Component Percent Cutoff. None Specified Tie-break Rule: Higher Frost Action Potential for frost action is the likelihood of upward or lateral expansion of the soil caused by the formation of segregated ice lenses (frost heave) and the subsequent collapse of the soil and loss of strength on thawing. Frost action occurs when moisture moves into the freezing zone of the soil. Temperature, texture, density, saturated hydraulic conductivity (Ksat), content of organic matter, and depth to the water table are the most important factors considered in evaluating the potential for frost action. It is assumed that the soil is not insulated by vegetation or snow and is not artificially drained. Silty and highly structured, clayey soils that have a high water table in winter are the most susceptible to frost action. Well drained, very gravelly, or very sandy soils are the least susceptible. Frost heave and low soil strength during thawing cause damage to pavements and other rigid structures. 19 39° 30' 36" N Custom Soil Resource Report Map—Frost Action 266950 266970 266990 267010 267030 267050 267070 267090 267110 267130 267150 267170 267190 n r n O— 266930 266950 266970 266990 267010 267030 267050 267070 267090 267110 267130 267150 267170 267190 N Map Scale: 1:1,260 if printed on A landscape (11" x 8.5") sheet. v Meters O ��NN\\\ 0 15 30 60 90 / \ 0 50 100 200 300Feet Map projection: Web Mercator Comer coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 20 39° 30' 30" N Custom Soil Resource Report MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons 0 High 0 Moderate 0 Low 0 None 0 Not rated or not available Soil Rating Lines rV High ✓ r Moderate • r Low • r None ✓ + Not rated or not available Soil Rating Points ▪ High O Moderate O Low O None O Not rated or not available Water Features Streams and Canals Transportation t++ Rails .�C Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Rifle Area, Colorado, Parts of Garfield and Mesa Counties Survey Area Data: Version 8, Sep 22, 2014 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 7, 2011—Sep 3, 2011 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background gery displayed on these maps. Asa result, some minor shifting 21 of map unit boundaries may be evident. Custom Soil Resource Report Table—Frost Action Frost Action— Summary by Map Unit — Rifle Area, Colorado, Parts of Garfield and Mesa Counties (C0683) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 55 Potts loam, 3 to 6 percent slopes Low 5.5 100.0% Totals for Area of Interest 5.5 100.0% Rating Options—Frost Action Aggregation Method: Dominant Condition Component Percent Cutoff. None Specified Tie-break Rule: Higher Hydrologic Soil Group Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long - duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink -swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. 22 Custom Soil Resource Report If a soil is assigned to a dual hydrologic group (ND, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. 23 Custom Soil Resource Report Map—Hydrologic Soil Group 266950 266970 266990 267010 267030 267050 267070 267090 267110 267130 267150 267170 267190 I I 1 1 ! 39° 30' 36" N 266930 266950 266970 II 44- 266990 267010 267030 267050 267070 267090 267110267130 267150 267170 Map Scale: 1:1,260 if printed on A landscape (11" x 8.5") sheet. v Meters O ��NN\\\ 0 15 30 60 90 / \ 0 50 100 200 300Feet Map projection: Web Mercator Comer coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 24 oM — 267190 39° 30' 30" N Custom Soil Resource Report MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons 0 A 0 A/D 0 0 B/D 0 0 C/D 0 D 0 Not rated or not available Soil Rating Lines •s A A/D eke B , -t B/D s,r C eke C/D e ke D ✓ k Not rated or not available Soil Rating Points O A ® ND ■ B ■ B/D D c O C/D ■ D ® Not rated or not available Water Features Streams and Canals Transportation t++ Rails rkre Interstate Highways US Routes Major Roads Local Roads Background III Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Rifle Area, Colorado, Parts of Garfield and Mesa Counties Survey Area Data: Version 8, Sep 22, 2014 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 7, 2011—Sep 3, 2011 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background gery displayed on these maps. Asa result, some minor shifting 25 of map unit boundaries may be evident. Custom Soil Resource Report Table—Hydrologic Soil Group Hydrologic Soil Group— Summary by Map Unit — Rifle Area, Colorado, Parts of Garfield and Mesa Counties (C0683) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 55 Potts loam, 3 to 6 percent slopes C 5.5 100.0% Totals for Area of Interest 5.5 100.0% Rating Options—Hydrologic Soil Group Aggregation Method: Dominant Condition Component Percent Cutoff. None Specified Tie-break Rule: Higher Representative Slope Slope gradient is the difference in elevation between two points, expressed as a percentage of the distance between those points. The slope gradient is actually recorded as three separate values in the database. A low value and a high value indicate the range of this attribute for the soil component. A "representative" value indicates the expected value of this attribute for the component. For this soil property, only the representative value is used. 26 39° 30' 36" N M 39° 30'30" N 3 N 266930 266950 266970 266990 267010 267030 Custom Soil Resource Report Map—Representative Slope 267050 267070 267090 267110 267130 267150 267170 267190 39° 30' 36" N - M - — b rn 266930 f tip• 1 1 1 1 1 1 1 266950 266970 266990 267010 267030 267050 267070 267090 267110 267130 267150 267170 3 Map Scale: 1:1,260 if printed on A landscape (11" x 8.5") sheet. o N Meters 0 15 30 90 0 50 100 200 300Feet Map projection: Web Mercator Comer coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 60 27 — 0 n N n 0 — ip a 39° 30' 30" N 267190 Custom Soil Resource Report MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) 0 Not rated or not available The soil surveys that comprise your AOI were mapped at 1:24,000. Water Features Soils Streams and Canals Soil Rating Polygons Transportation 0 0 - 5 r--1-+ Rails 5-15 Interstate Highways 15 - 30 US Routes 0 30 - 45 Major Roads 0 45 - 60 Local Roads 60 - 100 Background 0 Not rated or not available ® Aerial Photography Soil Rating Lines rV 0-5 • r 5-15 • r 15-30 ✓ r 30 - 45 rays 45 - 60 rV 60 - 100 ✓ I Not rated or not available Soil Rating Points ▪ 0-5 O 5-15 O 15-30 O 30 - 45 O 45-60 ▪ 60-100 Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Rifle Area, Colorado, Parts of Garfield and Mesa Counties Survey Area Data: Version 8, Sep 22, 2014 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 7, 2011—Sep 3, 2011 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background gery displayed on these maps. Asa result, some minor shifting 28 of map unit boundaries may be evident. Custom Soil Resource Report Table—Representative Slope Representative Slope— Summary by Map Unit — Rifle Area, Colorado, Parts of Garfield and Mesa Counties (C0683) Map unit symbol Map unit name Rating (percent) Acres in AOI Percent of AOI 55 Potts loam, 3 to 6 percent slopes 5.0 5.5 100.0% Totals for Area of Interest 5.5 100.0% Rating Options—Representative Slope Units of Measure: percent Aggregation Method: Dominant Component Component Percent Cutoff. None Specified Tie-break Rule: Higher Interpret Nulls as Zero: No Water Features Water Features include ponding frequency, flooding frequency, and depth to water table. Depth to Water Table "Water table" refers to a saturated zone in the soil. It occurs during specified months. Estimates of the upper limit are based mainly on observations of the water table at selected sites and on evidence of a saturated zone, namely grayish colors (redoximorphic features) in the soil. A saturated zone that lasts for less than a month is not considered a water table. This attribute is actually recorded as three separate values in the database. A low value and a high value indicate the range of this attribute for the soil component. A "representative" value indicates the expected value of this attribute for the component. For this soil property, only the representative value is used. 29 3 N 266930 266950 266970 266990 267010 267030 Custom Soil Resource Report Map—Depth to Water Table 267050 267070 267090 267110 267130 267150 267170 267190 39° 30' 36" N 39° 30' 36" N aM LO: ":41. — N n 0 M — n 39° 30'30" N 266930 !.."let 1 1 1 1 1 1 1 266950 266970 266990 267010 267030 267050 267070 267090 267110 267130 267150 267170 3 Map Scale: 1:1,260 if printed on A landscape (11" x 8.5") sheet. v Meters O ��NN\\\ 0 15 30 60 90 / \ 0 50 100 200 300Feet Map projection: Web Mercator Comer coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 30 267190 — ,o 39° 30' 30" N Custom Soil Resource Report MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) 0 Not rated or not available The soil surveys that comprise your AOI were mapped at 1:24,000. Water Features Soils Streams and Canals Soil Rating Polygons Transportation 0 0 - 25 r--1-+ Rails 25-50 Interstate Highways 50 - 100 US Routes 0 100 - 150 Major Roads 0 150 - 200 Local Roads > 200 Background 0 Not rated or not available ® Aerial Photography Soil Rating Lines ,. 0-25 • r 25-50 • 50-100 . + 100 - 150 r;,f 150 - 200 r+.r > 200 • a Not rated or not available Soil Rating Points ▪ 0-25 O 25-50 O 50 - 100 O 100 - 150 O 150 - 200 ▪ > 200 Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Rifle Area, Colorado, Parts of Garfield and Mesa Counties Survey Area Data: Version 8, Sep 22, 2014 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 7, 2011—Sep 3, 2011 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background gery displayed on these maps. Asa result, some minor shifting 31 of map unit boundaries may be evident. Custom Soil Resource Report Table—Depth to Water Table Depth to Water Table— Summary by Map Unit — Rifle Area, Colorado, Parts of Garfield and Mesa Counties (CO683) Map unit symbol Map unit name Rating (centimeters) Acres in AOI Percent of AOI 55 Potts loam, 3 to 6 percent slopes >200 5.5 100.0% Totals for Area of Interest 5.5 100.0% 32 Custom Soil Resource Report Rating Options—Depth to Water Table Units of Measure: centimeters Aggregation Method: Dominant Component Component Percent Cutoff: Tie-break Rule: Lower Interpret Nulls as Zero: No Beginning Month: January Ending Month: December None Specified Ponding Frequency Class Ponding is standing water in a closed depression. The water is removed only by deep percolation, transpiration, or evaporation or by a combination of these processes. Ponding frequency classes are based on the number of times that ponding occurs over a given period. Frequency is expressed as none, rare, occasional, and frequent. "None" means that ponding is not probable. The chance of ponding is nearly 0 percent in any year. "Rare" means that ponding is unlikely but possible under unusual weather conditions. The chance of ponding is nearly 0 percent to 5 percent in any year. "Occasional" means that ponding occurs, on the average, once or less in 2 years. The chance of ponding is 5 to 50 percent in any year. "Frequent" means that ponding occurs, on the average, more than once in 2 years. The chance of ponding is more than 50 percent in any year. 33 39° 30' 36" N ko c 3 N 266930 Custom Soil Resource Report Map—Ponding Frequency Class 266950 266970 266990 267010 267030 267050 267070 267090 267110 267130 267150 267170 1 1 s 267190 39° 30' 36" N n M - — 0 n nr ` • — a rn 39° 30'30"N a _ e ▪ {r�fy7�,31"• 266930 266950 266970 266990 267010 267030 267050 267070 267090 267110 267130 267150 267170 3 Map Scale: 1:1,260 if printed on A landscape (11" x 8.5") sheet. v Meters O ��NN\\\ 0 15 30 60 90 / \ 0 50 100 200 300Feet Map projection: Web Mercator Comer coordinates: WGS84 Edge tics: UTM Zone 13N WGS84 34 267190 0 n N Mn 0 — ip a 39° 30' 30" N Custom Soil Resource Report MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons None Rare Occasional 0 Frequent 0 Not rated or not available Soil Rating Lines rV None • r Rare • r Occasional ,. Frequent ✓ + Not rated or not available Soil Rating Points ▪ None O Rare O Occasional ▪ Frequent O Not rated or not available Water Features Streams and Canals Transportation t++ Rails .�C Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Rifle Area, Colorado, Parts of Garfield and Mesa Counties Survey Area Data: Version 8, Sep 22, 2014 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 7, 2011—Sep 3, 2011 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background gery displayed on these maps. Asa result, some minor shifting 35 of map unit boundaries may be evident. Custom Soil Resource Report Table—Ponding Frequency Class Ponding Frequency Class— Summary by Map Unit — Rifle Area, Colorado, Parts of Garfield and Mesa Counties (C0683) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 55 Potts loam, 3 to 6 percent None slopes Totals for Area of Interest Rating Options—Ponding Frequency Class Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: More Frequent Beginning Month: January Ending Month: December 36 5.5 100.0% 5.5 100.0% References American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep -water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/soils/?cid=nres142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http://www.nres.usda.gov/wps/portal/ nres/detail/national/soils/?cid=nres142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http://www.nres.usda.gov/wps/ portal/nres/detail/national/soils/?cid=nres142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nres.usda.gov/wps/portal/nres/detail/soils/ home/?cid=nres142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nres.usda.gov/wps/portal/nres/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 37 Custom Soil Resource Report United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430 -VI. http://www.nrcs.usda.gov/wps/portal/ nres/detail/soils/scientists/?cid=nres142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nres. usda.gov/wps/portal/nres/detail/national/soils/? cid=nres142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2 052290.pdf 38 Article 4-203.G.4 Geologic and Soils Hazard Report Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OAProject No. 014-2797 NATURAL AND GEOLOGIC HAZARDS ASSESSMENT REPORT ENCANA OIL & GAS (USA) INC. K19NE STORAGE YARD NE 1/4 SW 1/4 (Lor 3) SECTION 19, T6S, R92W, 6TH P.M. GARFIELD COUNTY, COLORADO PREPARED FOR ENCANA OIL & GAS (USA) INC. 143 DIAMOND AVENUE PARACHUTE, COLORADO 81635 PREPARED BY OLSSON ASSOCIATES 4690 TABLE MOUNTAIN DRIVE, SUITE 200 GOLDEN, COLORADO 80403 FEBRUARY 2015 PROJECT NO. 014-2797 O\LOLSSON 0 ASSOCIATES Natural and Geologic Hazard Report Preface Garfield County, Colorado, finalized the Land Use and Development Code (LUDC) with an effective date of July 15, 2013, last amended December 16, 2013. According to Section 7-108 Use of Land Subject to Natural Hazards of the Garfield County LUDC "Land subject to identified Natural and Geologic Hazards, such as falling rock, landslides, snow slides, mud flows, radiation, flooding, or high water tables, shall not be developed unless it has been designed to eliminate or mitigate the potential effects of hazardous site conditions as designed by a qualified professional engineer and as approved by the County." The LUDC requires a Natural and Geologic Hazard Study be prepared by a qualified professional geologist and submitted with a development plan or plat. The LUDC defines a geologic hazard as "A geologic phenomenon that is so adverse to past, current, or foreseeable construction or land use as to constitute a significant hazard to public health and safety or to property. The LUDC defines a Hazard Area as "An area that contains oris directly affected by a geologic hazard, including but not limited to the following types of areas." 1f A. Avalanche Area. "A mass of snow or ice and other material that may become incorporated therein as such mass moves rapidly down a slope." B. Landslide Area. "An area with demonstrably active mass movement of rock and soil where there is a distinct surface rupture or zone of weakness that separates the landslide material from more stable underlying material." C. Mudflow Debris Area. "An area subject to rapid mud and debris movement or deposit occurring after mobilization by heavy rainfall or snowmelt runoff. Such areas are formed by successive episodes of deposition of mud and debris." D. Radioactive Area. "An area subject to various types of radiation emission from radioactive minerals that occur in natural or manmade deposits of rock, soil, or water." E. Potentially Unstable Soils. "An area of land identified as having soils that may cause damage to structures, such as buildings and roadways, as a result of over saturation or some other outside influence." According to the Garfield County LUDC Section 4-203 Description of Submittal Requirements, the professional qualifications for preparation and certification of certain documents required by this Code are as follows: "Geologist: Geology reports shall be prepared by either a member of the American Institute of Professional Geologists, a member of the Association of Engineering Geologists, or a qualified geotechnical engineer licensed in the State of Colorado." Geologic Hazard Report Encana K19NE Storage Yard Garfield County, Colorado i Olsson Associates Golden, Colorado February 2015 Currently, the State of Colorado does not require licensure or registration of geologists; however, Colorado Revised Statutes do require that geologic reports be prepared or authorized by a professional geologist, and the term "Professional Geologist" is defined in Colorado Statutes. The references for these Statutes are shown here: 34-1-201. Definitions. As used in this part 2, unless the context otherwise requires: (1) "Geologist" means a person engaged in the practice of geology. (2) "Geology" means the science which treats of the earth in general; the earth's processes and its history; investigation of the earth's crust and the rocks and other materials which compose it; and the applied science of utilizing knowledge of the earth's history, processes, constituent rocks, minerals, liquids, gases, and other materials for the use of mankind. (3) "Professional geologist" is a person who is a graduate of an institution of higher education which is accredited by a regional or national accrediting agency, with a minimum of thirty semester hours (forty-five quarter) hours of undergraduate or graduate work in a field of geology and whose post baccalaureate training has been in the field of geology with a specific record of an additional five years of geological experience to include no more than two years of graduate work. (4) 34-1-202. Reports containing geologic information. Any report required by law or by rule and regulation, and prepared as a result of or based on a geologic study or on geologic data, or which contains information relating to geology, as defined in Section 34-1-201 (2), and which is to be presented for any state agency, political subdivision of the state, or recognized state or local board or commission, shall be prepared or approved by a professional geologist as defined in Section 34-1-201(3). Geologic Hazard Report Encana K19NE Storage Yard Garfield County, Colorado ii Olsson Associates Golden, Colorado February 2015 Professional Geologist Certification By means of this certification, I attest that: - I am qualified to prepare a Natural and Geologic Hazard Study in accordance with the provisions of Section 7-207 of the Garfield County LUDC, and that I am a member of the American Institute of Professional Geologists per LUDC 4-203. - Although I have not visited the proposed Site, I am familiar with the geology and have performed field work in the area of the proposed Encana Oil & Gas (USA) Inc. Storage Yard located in the NE'/ SW'/, (Lot 3) Section 19 Township 6 South, Range 92 West, 6th Principal Meridian in Garfield County, Colorado. Although Colorado does not currently have a licensing board or registration program for professional geologists practicing in the state of Colorado, there are requirements within local and State statutes that require that geologic reports be prepared by a professional geologist. I attest that I meet the requirements of the Colorado Geological Survey's definition of a professional geologist having completed and met the educational requirements of the Colorado Geological Survey definition. I am a licensed Professional Geologist and Professional Geoscientist in other States, including Texas, Utah, and Wyoming which do have licensing programs for professional geologists. I have reviewed published geologic maps and reports applicable to this area and have considered the implications of these conditions in the context of the proposed development. This report has been prepared in accordance with good scientific principles and engineering practices including consideration of applicable industry standards, and with consideration of the requirements of the National Association of State Boards of Geology. The conclusions and recommendations contained in this report are based on information available and known to me at the time of this report. Good scientific principles and standard engineering practices were taken into consider -__a= ���� arriving at the conclusions and recommendations made in this repo „4k Reviewed 7J3O5 iia. �AIP�! SA Prepared by .44/ted— 40, /914x James W. Hix, PG Senior Geologist Date: 02/02/2015 Kevin J. Ta,'`` �; F� ; Cr_ Senior Geologis Date: 02/02/2015 Note: The PG's certification does not relieve the owner/operator of the facility of the duty to review this report or fully implementing the recommendations in accordance with all applicable Federal, State, and local requirements in order to achieve the desired goals or objectives. Geologic Hazard Report Encana K19NE Storage Yard Garfield County, Colorado Olsson Associates Golden, Colorado February 2015 TABLE OF CONTENTS Natural and Geologic Hazard Report Preface Professional Geologist Certification TABLE OF CONTENTS iv FIGURES iv 1.0 EXECUTIVE SUMMARY 1 2.0 GENERAL SITE LOCATION AND BACKGROUND 3 2.1 Project and Site Description 3 2.2 Structural Geology 3 2.3 Site Geology 4 2.4 Soil 4 2.5 Hydrologic Setting 4 2.6 Aquifers 5 2.7 Permitted Water Wells 5 3.0 NATURAL AND GEOLOGIC HAZARD ASSESSMENT 6 3.1 Utilities 6 3.2 Avalanche Hazard Area 6 3.3 Landslide Areas or Potential Landslide Hazard Areas 6 3.4 Rockfall Areas 7 3.5 Alluvial Fan Hazard Areas 7 3.6 Unstable or Potentially Unstable Slopes 7 3.7 Corrosive or Expansive Soils and Rock 7 3.8 Mudflow and Debris Fan Areas 7 3.9 Development Over Faults and Risk of Seismic Activity 7 3.10 Flood Prone Areas 8 3.11 Collapsible Soils 8 3.12 Mining Activity 8 3.13 Radioactivity 8 4.0 CONCLUSIONS AND RECOMMENDATIONS 10 5.0 REFERENCES 11 FIGURES List of Figures V-1 Vicinity Map T-1 Topographic Map G-1 Geology Map S-1 Soils Map F-1 Floodplain Map Geologic Hazard Report Encana K19NE Storage Yard Garfield County, Colorado iv Olsson Associates Golden, Colorado February 2015 1.0 EXECUTIVE SUMMARY Olsson Associates (Olsson) was contracted by Encana Oil & Gas (USA) Inc. (Encana) to assess natural and geologic hazards potentially present in the area of the proposed Storage Yard (Site) located in the Lot 3 of Section 19, Township 6 South, Range 92 West, of the 6th Principal Meridian, in Garfield County, Colorado. The Site location is shown on the V-1 Vicinity Map. The Site is at an elevation of about 5,689 feet above mean sea level (amsl) as shown on the attached T-1 Topographic Map. The purpose of this report is to identify geologic conditions that may pose hazards to a land development project in order that appropriate mitigation or avoidance techniques may be implemented as described in the Garfield County LUDC. According to the Garfield County LUDC, Section 7-207, the types of natural and geologic hazards identified pertain to the following: A. Utilities; B. Development in Avalanche Hazard Areas; C. Development in Landslide Hazard Areas; D. Development in Rock -fall Hazard Areas; E. Development in Alluvial Fan Hazard Areas; F. Slope Development; G. Development on Corrosive or Expansive Soils and Rock; H. Development in Mudflow Areas; and I. Development Over Faults. This report presents Olsson findings following an evaluation of these and other geologic hazards potentially affecting the Site and proposed development. The Encana site was found to be suitable for the proposed development with consideration of the following identified geologic hazards. • No utilities are planned for the proposed Site development. • The Site is not in an Avalanche Hazard Area. • The Site is located on a gently sloping parcel of land south of the Mamm Creek drainage and bound to the west by the West Mamm Creek drainage and to the east by unnamed tributary drainages to Mamm Creek. Slopes do not appear to be a hazard affecting the Site since it is in an area of gentle slopes. • The soil beneath the Site is mapped as the Potts Loam (Map Unit # 55). These soils are found on three percent to six percent slopes; however, soil in adjacent areas along Mamm Creek and the tributary drainages are mapped as Rock outcrop —Torriothents complex and are found on steep slopes ranging from 12 percent to 25 percent to the west, and steep slopes to the north. • The Site is not located in an area of rock -fall or landslide hazards. • According to the Colorado Oil and Gas Conservation Commission (COGCC) GIS online map, the bedrock geology has been mapped (scale of 1:500,000) in the vicinity of the Site as the Tertiary age Wasatch Formation including the Fort Union equivalent at its Geologic Hazard Report Encana K19NE Storage Yard Garfield County, Colorado 1 Olsson Associates Golden, Colorado February 2015 base and the Ohio Creek Formation. Quaternary gravels and alluviums of Pinedale and Bull Lake Age are shown to the south in Section 30, Township 6 South, Range 92 West. According to the Geologic Map of the Silt Quadrangle, Garfield County (1:24,000), the Site surficial geology consists of Quaternary age loess deposits overlying older terrace alluvium and bedrock consisting of the Eocene Shire Member of the Tertiary Wasatch Formation. • According to the Geologic Map of the Leadville Quadrangle, alluvial fan gravels are mapped on Grass Mesa to the west, but the site is not in an area mapped as having alluvial fan deposits; therefore, the site is not in an alluvial fan hazard area. • According to the Geologic Map of the Leadville 1° x 2° Quadrangle, Colorado (scale 1:250,000), and the Geologic Map of the Silt Quadrangle, there are no mapped faults in the area of the Site. The axis of the Rifle Syncline lies to the north of the Site subparallel to the Colorado River drainage. • The Eocene Shire Member bedrock dip angles in the vicinity of the Site have been measured and range from seven degrees to ten degrees to the west and northwest as plotted on the Geologic Map of the Silt Quadrangle. This compares to dip angles of nearly 90 degrees along the Grand Hogback north of the town of Rifle and areas where the bedrock strata is overturned. This is evidence of thrust faulting in the region. • The Silt topographic quadrangle map and the Geologic Map of the Silt Quadrangle do not show any mining operations in the immediate vicinity of the site. There are sand and gravel quarries located along the Colorado River drainage to the north. Natural gas wells and production facilities are present in the vicinity of the Site and surrounding areas. • The Site is not mapped within the FEMA 100-year flood plain. The Site is located at an elevation of approximately 5,689 feet approximately two miles south of the Colorado River which is at an elevation of approximately 5,368 feet above mean sea level (amsl). The bottom of the drainage to the west of the Site is at an elevation of approximately 5,581 feet amsl. These drainages and the Colorado River may experience flash floods, but the K19NE Site is located above the expected flood stage. There do not appear to be any significant natural or geologic hazards associated with the Site proposed for the Encana Site. This report should be read in its entirety, including but not limited to the conclusions and recommendations in Section 4.0. Geologic Hazard Report Encana K19NE Storage Yard Garfield County, Colorado 2 Olsson Associates Golden, Colorado February 2015 2.0 GENERAL SITE LOCATION AND BACKGROUND Encana contracted Olsson Associates (Olsson) to conduct a natural and geologic hazards assessment as part of the proposed development of the K19NE storage yard (Site). The proposed facility will be used to store surplus equipment and materials used in the drilling and production of natural gas wells in the area. The following sections provide information about the proposed development and the Site geologic setting. 2.1 Project and Site Description The proposed Site is located southeast of the town of Rifle, Colorado off of Garfield County Road 333 south of the Garfield County Municipal Airport. The Site is located in the Lot 3 of Section 19, T6S, R92W, 6th P.M. (39.50956° N -107.70974°W) and is located on parcel #2179- 193-00-128. The surface land parcel encompasses approximately 88.42 acres and is owned by Encana; however the storage yard occupies approximately 2.7 acres in the south central part of the parcel. 2.2 Structural Geology The Site is located in the southeastern part of the Piceance Basin. The Piceance Basin is an irregularly-shaped elongated basin formed by tectonic forces associated with the Laramide orogeny. These forces down warped the earth's crust and formed the Piceance Basin as a result of the uplift of the surrounding Colorado Rocky Mountains and the Colorado Plateau. The area geology is shown on the G-1 Geologic Map. The Piceance Basin is the major structural geologic feature in the region. It is bound to the east by the Grand Hogback monocline, the White River Uplift to the northeast, the Gunnison Uplift to the south, the Uncompahgre Uplift to the south and southwest, the Douglas Creek Arch to the west-northwest, and the axial basin uplift to the north. Sedimentary rocks in the southwestern Piceance Basin gently dip to the north-northeast except where this regional dip is interrupted by low -amplitude folds. Numerous small sub -parallel northwest trending folds have been identified within the basin. The Divide Creek and Wolf Creek anticlines are two gentle, north-northwest trending, natural gas producing intrabasin folds located near the eastern margin of the Piceance basin. (Grout and Verbeek, 1992). These anticlines are located south-southeast of the Site. The bedrock in the vicinity of the Site dips at angles between seven degrees and ten degrees to the west-northwest. A fault is a fracture in rock along which movement has occurred. Mountains are bound by faults and are a visible indication of a structural weakness in the earth's crust. The Colorado Rocky Mountains are bound by faults; however, these faults are not always visible at the ground surface either because the fault trace is `blind', meaning that the fault does not have surface expression since it does not cut across overlying sedimentary bedrock units, or that it has been buried and concealed by unconsolidated sediments deposited over the area where the faults are present. There are no mapped faults shown in the immediate area of the Site on the Geologic Map of the Leadville 1° x 2° Quadrangle, Garfield County, Colorado (Tweto, Moench, and Reed, 1978) or on the Geologic Map of the Silt Quadrangle, Garfield County, Colorado (Shroba and Scott, Geologic Hazard Report Encana K19NE Storage Yard Garfield County, Colorado 3 Olsson Associates Golden, Colorado February 2015 2001) (Scale 1:24,000). However, folds such as the intrabasinal Divide Creek anticline and Wolf Creek anticline, and the Grand Hogback monocline, which defines the eastern margin of the Piceance Basin, have been interpreted as the surface expression of thrust faulting in which a wedge of basement rock was moved west-southwest during the uplift of the Rocky Mountains during the Laramide orogeny. Movement along the thrust fault compressed the overlying sedimentary rock which formed these low amplitude folds and the Grand Hogback (Grout and Verbeek, 1992). 2.3 Site Geology The area geology is shown on the G-1 Geologic Map. According to the Geologic Map of the Silt Quadrangle ((Shroba and Scott, 2001), bedrock mapped in the area of the Site consists of the Eocene Shire Member of the Wasatch Formation which consists of variegated purple, lavender, red, gray, and brown claystone; some locally lenticular, fine- to coarse-grained sandstone and conglomerate, and thin limestone beds. The maximum exposed thickness of the Shire Member is approximately 1,600 feet, and reaches up to 3,900 feet thick in the Silt Quadrangle (Shroba and Scott, 2001). The Shire Member is the upper member of the Wasatch Formation and overlies the Molina Member and Atwell Gulch Member, which in turn lie above the Ohio Creek Formation. The Ohio Creek Formation marks the boundary between the Cretaceous and Tertiary sedimentary rocks in the Piceance Basin (Donnell, 1969). The bedrock at the site is mantled by Quaternary age terrace alluvium and loess deposits. Terrace deposits associated with Pinedale and Bull Lake age are mapped to the south in Section 30 and the SE 1/4 SE 1/4 Section 19, T6S, R92W. 2.4 Soil The Natural Resources Conservation Service (NRCS) S-1 Soils Map shows the area soil types. Soils, consisting of the following units, are within the study area around Site: Potts Loam, Map Symbol 55, is a moderately sloping soil found on mesas, benches, and the sides of valleys at elevations ranging from 5,000 feet to 7,000 feet amsl. The soil formed in alluvium derived from sandstone, shale, or basalt. Typically the surface layer is brown loam about four inches thick, the subsoil is reddish brown clay loam about 24 inches thick, and the substratum is pinkish white loam to a depth of 60 inches thick. Permeability is moderate, and the available water capacity is high. Surface runoff is slow and the erosion hazard is moderate. Community development and recreation are limited by low strength and the shrink -swell potential. Dwellings and roads can be designed to overcome these limitations. 2.5 Hydrologic Setting The Site is located at an elevation of approximately 5,689 feet, bound to the west by the West Fork of Mamm Creek and the main branch of Mamm Creek lies to the north. The surface water hydrology and shallow groundwater contained in the alluvium are controlled by Mamm Creek and its tributary drainages. Surface water flow is to the west — southwest toward the confluence Geologic Hazard Report Encana K19NE Storage Yard Garfield County, Colorado 4 Olsson Associates Golden, Colorado February 2015 with the main branch of Mamm Creek. Shallow groundwater is expected to follow topography and flow toward and parallel the flow of the West Fork of Mamm Creek to the north toward the confluence with Mamm Creek and its confluence with the Colorado River approximately two miles north of the Site. These surface water features are shown on the H-1 Hydrography Map. 2.6 Aquifers The Wasatch Formation consists predominantly of very fine-grained claystone and mudstone with lenses of very fine-grained to coarse-grained sandstone and conglomerate. The matrix of these rock types generally exhibits low porosity, relatively low hydraulic conductivity, or the ability to transmit groundwater. Therefore the Wasatch Formation is generally considered a confining unit. Some lenticular sandstones yield water wells in some areas south of the town of Rifle; however, the quantity and quality of this water is variable. The most productive wells are those completed in areas with secondary porosity or interconnected bedrock fractures. Alluvial aquifers consist of unconsolidated sediments deposited along the Colorado River, Mamm Creek, and major tributaries to these streams. The thickness of the unconsolidated sediments must provide for sufficient volume and stream valley size to be capable of yielding groundwater to domestic wells to be of significance for domestic or use for livestock. 2.7 Permitted Water Wells Three groundwater monitoring holes were permitted by Encana in 2007 in anticipation of constructing a centralized E&P waste management facility per COGCC Rule 908 on the property. The E&P waste management facility was never constructed, and it does not appear that the monitoring wells were ever drilled as the last correspondence with the Colorado Division of Water Resources was to request an extension. There are permitted water wells located in the NW 1/4 NW 1/4 Section 19, Township 6 South, Range 92 West. Well permit #190496 MH 26571 was drilled in November 1995, and recorded in May 1996 by the Division of Water Resources. The total depth of the well is listed at 203 feet. The driller's log indicates that from the surface to 56 feet below ground surface (bgs) consisted of large river gravels, from 56 feet to 130 feet bgs consisted of hard red sandstone, from 130 feet to 135 feet consisted of fractured gray shale, from 135 feet to 180 feet bgs consisted of hard red sandstone, and from 180 feet to 203 feet bgs consisted of gray shale. Groundwater was reportedly encountered at 130 feet to 135 feet bgs with a yield of approximately one gallon per minute (gpm). Water well permit 26571 MH is a monitoring hole permitted in 1995. The notification for this well was for a second monitoring/observation well drilled since the first hole was drilled to 333 feet in depth, was dry, and was plugged and abandoned per state rules (see 25935 MH) to the Division of Water Resources. A water well was drilled in the NW 1/4 NW 1/4 of Section 19 in April 1998, and was advanced to 400 feet bgs. Lithologies consisted of sandstone, shale, mudstone to the total depth. Groundwater was reportedly encountered at 285 feet to 292 feet bgs with a yield of gpm, and at 360 feet to 367 feet with a yield of 1 to 11/2 gpm. Geologic Hazard Report Encana K19NE Storage Yard Garfield County, Colorado 5 Olsson Associates Golden, Colorado February 2015 3.0 NATURAL AND GEOLOGIC HAZARD ASSESSMENT The following sections present the assessment of geologic hazards in the vicinity of the Site. The T-1 Topographic Map shows the location of the Site in relation to the affected parcel and local roads. 3.1 Utilities Trenches for water pipelines, natural gas pipelines, and electrical lines are not expected to be associated with the proposed development of the Site. The slopes and rocky soil may pose technical challenges to the installation of utilities; however, it is expected that these limitations can be overcome with proper design and installation if utilities are installed. Aboveground utility facilities located in Hazard Areas are to be protected by barriers or diversion techniques approved by a qualified professional engineer. The determination to locate utility facilities aboveground will be based upon the recommendation and requirements of the utility service provider and approved by the County. Aboveground utilities, such as transformers and electrical lines, are not expected to be affected by geologic or other natural hazards. 3.2 Avalanche Hazard Area Winters are cold in the mountainous areas of Garfield County, and valleys are colder than the lower parts of adjacent mountains due to cold air drainage. Average seasonal snowfall in Garfield County is 50 inches. The greatest snow depth at any one time during the period of record from 1951 to 1974 was 29 inches recorded at Rifle, Colorado approximately 5 miles to the northwest of the proposed Site. Avalanches are not expected to affect the proposed Site, since it is located at an elevation of approximately 5,689 feet amsl. Areas in eastern Garfield County are at higher elevations, receive more snow pack, and are, therefore, more prone to avalanches in certain years. Avalanches are the most dangerous geologic hazard in Colorado resulting in injuries, loss of life, and about $100,000 in direct property damage, and indirect economic losses in the millions of dollars annually. However, the avalanche prone areas include the Park Range and Flat Tops in northeastern Garfield County, Colorado, to the north of Glenwood Springs. Glenwood Springs, near the east edge of the area, averages about one degree cooler than Rifle and receives about five inches more precipitation per year (Harman and Murray, 1985). 3.3 Landslide Areas or Potential Landslide Hazard Areas The Shire Member has been identified in areas of steeper slopes on the Rifle Quadrangle to the west as being a potential landslide hazard, but these conditions are not present in the vicinity of the Site. According to Map 24 — Surface Geology map, Geologic Hazards Identification Study (Lincoln Devore, 1975-1976), there are landslide areas shown to the southwest of the town of Rifle, but not in areas to the southeast of Rifle or County Road 333 (Garfield County, Surface Geology, 2007). Geologic Hazard Report Encana K19NE Storage Yard Garfield County, Colorado 6 Olsson Associates Golden, Colorado February 2015 3.4 Rockfall Areas The Site is located in an area with moderate to gentle slopes ranging from three percent to six percent slopes. The underlying bedrock in the vicinity of the Site dips seven to ten degrees to the west-northwest. Rock fall is not a potential geologic hazard in the vicinity of the Site. Rockfall is a potential geologic hazard in areas along the West Mamm Creek and Mamm Creek drainages to the west and north of the Site. 3.5 Alluvial Fan Hazard Areas The Site is not located in an area that is mapped as being in an alluvial fan hazard area according to the Garfield County Surficial Geology, 2007. The Site is located on loess deposits and older alluvium mantling bedrock of the Wasatch Formation. There are alluvial fans to the west on Grass Mesa. 3.6 Unstable or Potentially Unstable Slopes According to the Garfield County Slope Hazard Study Areas 1, 2, & 3 Map 22, areas of moderate slope are depicted south of the Colorado River and Interstate 70 near the town of Rifle, Colorado, but have not been mapped as being areas of major slope hazard. The areas along County Road 333 are not mapped as a slope hazard area in the vicinity of the Site. Moderate slope hazard areas were identified along the West Mamm Creek and Mamm Creek drainages. 3.7 Corrosive or Expansive Soils and Rock According to the Soil Survey of the Rifle Area, the Potts Loam soils pose a high risk of corrosion to uncoated steel, but a low risk of corrosion to concrete. The Potts Loam soils have a low to moderate shrink -swell potential. These soil characteristics are not expected to pose a hazard to the proposed Site development as a storage yard. Some Tertiary and Cretaceous age sedimentary rocks with high clay content are capable of accepting water into their chemical structure and expanding many times their volume when dry. These sedimentary rocks and soils formed from these rock types, may expand or contract as they become wet and then dry out resulting in damage to structures built upon them. 3.8 Mudflow and Debris Fan Areas The Site is not located in an area of mapped mud flow and debris fan areas. Mudflows and debris flows have been mapped on the Rifle Quadrangle and Rulison Quadrangle further to the west of the Site. 3.9 Development Over Faults and Risk of Seismic Activity There are no major faults shown in the immediate area of the Site; however, the Site is located to the northwest of the Divide Creek anticline which trends to the northwest. The Divide Creek anticline and Wolf Creek anticline are the surface expression of compressional forces associated with movement along a blind thrust fault that occurred during the uplift of the Colorado Rocky Mountains. Geologic Hazard Report Encana K19NE Storage Yard Garfield County, Colorado 7 Olsson Associates Golden, Colorado February 2015 Today, Colorado is considered a region of minor earthquake activity; however, there is uncertainty due to the relatively short historic record. According to the USGS Colorado Earthquake History online, newspaper accounts were the primary source of earthquake data in Colorado prior to 1962. Few earthquakes have been reported in this part of Colorado. A very minor earthquake occurred in the northwestern part of Colorado on November 22, 1982 at 3:09 a.m. MST. The magnitude 2.9 (Richter scale) earthquake was located about 18 miles northeast of the town of Rifle and was felt at a fish hatchery in the area. The largest quake in the area occurred on April 22, 1984 and had a magnitude of 3.1 on the Richter scale. The quake was felt in Carbondale and in Glenwood Springs. Of the hundreds of quakes that occurred in the Carbondale area during that time period, 12 were reported as felt. 3.10 Flood Prone Areas The facility is not shown within the FEMA 100 year flood hazard zone based on the Flood Plain Map in the Vicinity of the Town of Rifle, Garfield County, Colorado, or a Firmette Map generated from the FEMA data along the Colorado River. The Site is located approximately two miles south of the Colorado River. The Colorado River lies at an elevation of approximately 5,368 feet amsl, and the Site is located at an elevation of approximately 5,689 feet amsl. Areas along the West Fork of Mamm Creek are potentially prone to flash floods; however, the creek is located at an elevation of 5,589 feet, or 100 feet below the Site. The flood plain along the Colorado River is shown in relation to the Site on the attached F-1 Flood Plain Location Map. 3.11 Collapsible Soils According to the Soil Hazard Profile, Study Areas 1, 2, & 3, Garfield County, prepared by Lincoln-Devore Testing Laboratory in 1975-1976, the area southeast of Rifle was not identified as a soil hazard area. Collapsible soils are another type of subsidence that occurs in parts of western Colorado where unconsolidated sediments are present. This ground settlement can damage man-made structures such as foundations, pavements, concrete slabs, utilities, and irrigation works. Collapsible soils have not been mapped in the area and are not expected to be encountered in the vicinity of the Site. 3.12 Mining Activity There is no mining activity in the immediate area of the Site. There are sand and gravel operations located along the Colorado River, and there are natural gas exploration and production facilities in the area of the Site. 3.13 Radioactivity Naturally occurring radioactive materials are not expected to be an issue at the Site. Colorado oil and gas operations are not known to have a significant problem with naturally occurring radioactive materials (NORM) or technologically enhanced naturally occurring radioactive materials (TENORM); however, there have been some instances where pipe scale has contained radium and associated radon gas. A NORM survey including site specific testing Geologic Hazard Report Encana K19NE Storage Yard Garfield County, Colorado 8 Olsson Associates Golden, Colorado February 2015 could be performed to further assess the radon potential at the Site to serve as a baseline assessment if used pipe or pipe scale is stored and is to be disposed offsite in the future. Olsson reviewed the Colorado Bulletin 40, Radioactive Mineral Occurrences of Colorado which states that nearly all of Garfield County's uranium production came before 1954, and most of that came from the Rifle and Garfield mines. Both of these mines were located along the same ore body northeast of the town of Rifle in Section 34 and Section 35, Township 4 South, Range 92 West, or approximately 10 miles to the north of the Site (Fischer, 1960). These occurrences were all hosted in the Jurassic Morrison and Entrada Formations, and the Triassic-Jurassic Navajo Sandstone, or the Triassic Chinle Formation which are known to contain uranium and vanadium deposits in the county and in the Colorado Plateau in general (Nelson-Moore, Collins, and Hornbaker, 1978). These formations lie at great depth in the vicinity of the Site and are stratigraphically below the depth of the Wasatch Formation. The Colorado Department of Public Health and Environment (CDPHE) has posted a statewide radon potential map on their website based on data collected by the EPA and the U.S. Geological Survey. Garfield County and most of Colorado has been mapped as being within Zone 1 — High Radon Potential, or having a high probability that indoor radon concentrations will exceed the EPA action level of 4 picocuries per liter (pCi/L). Radon is not expected to be a significant problem at the proposed Site, since the development will not include any occupied structures, personnel will not be onsite for extended periods, and the Site will not be developed with structures containing basements or substructures in which radon can accumulate. Geologic Hazard Report Encana K19NE Storage Yard Garfield County, Colorado 9 Olsson Associates Golden, Colorado February 2015 4.0 CONCLUSIONS AND RECOMMENDATIONS The following conclusions and recommendations were made following a review of the available site data for natural and geologic hazards in the vicinity of Site located in Garfield County, Colorado. • The Site is not expected to have any buried or aboveground utilities. • Avalanche conditions are not expected to be a hazard in the area of the Site. • Rockfall areas are not a geological hazard in the area of the Site, but may exist in areas along Mamm Creek and its tributary drainages. • The Site is not in an area of landslides or potential landslides. • The Site is not in an area mapped as an alluvial fan hazard area. • Slope is not a geologic hazard in the vicinity of the site, but is in areas to the north and west along West Mamm Creek and Mamm Creek drainages. • The surface runoff is slow and the soil erosion hazard for the Potts Loam is moderate. • The Site is not located in an area of mapped mud flow or debris fan areas. • The Potts Loam soils are listed as a high risk of corrosion to uncoated steel and a low risk of corrosion to concrete. These soil characteristics are not expected to pose a geologic hazard for the proposed development at the Site. • The shrink -swell potential for the Potts Loam is low to moderate. Therefore, expansive soils are not a geologic hazard at the Site. • Collapsible soils are not present in the vicinity of the proposed Site. • No significant faults have been mapped or are known in the Site. The Site is located to the northwest of the Divide Creek anticline which was formed as a result of movement along a blind thrust fault associated with the uplift of the Colorado Rocky Mountains. • The Site is not mapped as being within the 100 -year flood plain. Flash flooding is a hazard for lower elevations along the West Fork of Mamm Creek, Mamm Creek and its tributaries, and areas along the Colorado River located approximately two miles to the north and at elevations that are 100 feet to 200 feet lower than the Site elevation. Therefore, flooding is not expected to be a natural hazard affecting the Site. • Uranium and Vanadium were mined to the northeast of the town of Rifle; and approximately ten miles north of the Site. However, these mines were developed in Jurassic age geologic formations that lie at great depth stratigraphically below the Wasatch Formation. There are no significant radioactive mineral deposits known in the immediate area of the Site. The presence of NORM may be an issue with exploration and production and could be an issue with used pipe scale or used equipment stored at the site. Radioactive materials are not expected to pose a significant hazard at the Site. Geologic Hazard Report Encana K19NE Storage Yard Garfield County, Colorado 10 Olsson Associates Golden, Colorado February 2015 5.0 REFERENCES • Donnell, J.R., 1969, Paleocene and lower Ecoene Units in the Southern Part of the Piceance Creek Basin, Colorado, 21 p. • Fischer, R.P., 1960, Vanadium -Uranium Deposits of the Rifle Creek Area, Garfield County, Colorado, USGS Bulletin 1101, 52 p. • Grout, M. A. and Verbeek, E.R., 1992, USGS Bulletin 1787-Z, Fracture History of the Divide Creek and Wolf Creek Anticlines and Its Relation to Laramide Basin -Margin Tectonism, Southern Piceance Basin, Northwestern Colorado, 32 p. • Harman, J.B. and Murray, D. J., 1985, Soil Survey of Rifle Area, Colorado, Parts of Garfield and Mesa Counties, Colorado: U.S. Department of Agriculture, Soil Conservation Service, in cooperation with the Colorado Agricultural Experiment Station, 149 p. two plates, and 20 map sheets. • Nelson -Moore, J.L., Bishop Collins, D., Hornbaker, A.L., 2005, Colorado Geologic Survey, Bulletin 40, Radioactive Mineral Occurrences of Colorado, pp 154-158 (CD) • Robson, S.G. and Banta, E.R., 1995, USGS Hydrologic Investigations Atlas 730-C, Groundwater Atlas of the United States, Segment 2, Arizona, Colorado, New Mexico, Utah, 32 p. • Shroba R.R., and Scott, R.B., 2001, Geologic Map of the Silt Quadrangle, Garfield County, Colorado, scale 1:24,000, USGS Miscellaneous Field Studies Map MF -2331 Version 1.0, pamphlet accompanies map • Topper, R., Spray, K. L., Bellis, W.H., Hamilton, J.L., Barkman, P.E., Ground Water Atlas of Colorado, Colorado Geologic Survey, 2003, Special Publication 53, 210 p. • Tweto, 0., Moench, R.H., Reed, J.C., Jr., 1978, Geologic Map of the Leadville 1° x 2° Quadrangle, Northwestern Colorado, USGS 1-999 Online References • Colorado Oil and Gas Conservation Commission http://cogcc.state.co.us/ • Natural Resources Conservation Service - Soil Survey http://www.nrcs.usda.gov/ Slope Hazards: http://garfield-county.com/geographic-information- systems/documents/6439291200422slopehaz.pdf Tax Assessor parcel information http://garfieldco.mygisonline.com Soil Hazards: http://garfield-county.com/geographic-information- systems/documents/64335291200423soilhaz.pdf Surficial Geology of Garfield County: http://garfield-county.com/geographic-information- systems/documents/geologic-hazards/24surfgeo.pdf • Colorado Geological Survey: http://geosurvey.state.co.us/hazards • Colorado Geological Survey: http://geosurvey.state.us/land/Pages/Professional Geologist • Colorado Department of Public Health and Environment: http://co- radon.info/CO radon map.html Geologic Hazard Report Encana K19NE Storage Yard Garfield County, Colorado 11 Olsson Associates Golden, Colorado February 2015 FIGURES ENCANA OIL & GAS (USA) INC PARCEL NO. 217919300128 K1 9NE STORAGE YARD SITE LOCATION Encana Oil & Gas (USA) Inc. Wasatch Surveying Associates 906 Main Street Evanston, Wyoming 82930 Phone No. (307) 789-4545 Fax (307) 789-5722 v 0 N Scale in Feet K19NE Storage Yard Vicinity Map SECTION 19, T6S, R92W, 6th, P.M. GARFIELD COUNTY, COLORADO VICINITY MAP PROJECT No. 14-04-12 DATE: 8/22/2014 SCALE: 1:48,000 Subject Parcel 0 K19NE Storage Yard Parcels 3 Mile Buffer Perennial Stream PROJECT NO: 014-2797 DRAWN BY: DATE: JWH 11/25/2014 VICINITY MAP K19NE STORAGE YARD ENCANA OIL & GAS (USA) INC. GARFIELD COUNTY, COLORADO CAOLSSON ASSOCIATES 760 HORIZON DR., SUITE 102 GRAND JUNCTION, CO 81506 TEL 9702617800 FAX 970.263.7456 FIGURE V-1 O K19NE Storage Yard n K19NE Storage Yard Boundary Subject Parcel N PROJECT NO: 014-2797 DRAWN BY: JWH DATE: 11/25/2014 TOPOGRAPHIC MAP K19NE STORAGE YARD ENCANA OIL & GAS (USA) INC. GARFIELD COUNTY, COLORADO O\OLSSON A5SOCIATE5 760 HORIZON DR., SUITE 102 GRAND JUNCTION, CO 81506 TEL 970.263.7800 FAX 970.263.7456 FIGURE T- 1 iQg Gravels and alluviums (Pinedale and Bull Lake age)4 a mit rr• Qg Gravels and alluviums (Pinedale and Bull Lake age) Two Wasatch Formation includin ( gFort,., yUnion equivalent at base) and Ohio Creek Formation Qg Gravels and alluviums (Pinedale and Bull Lake age) O K19NE Storage Yard n Subject Parcel K19NE Storage Yard Boundary — Perennial Stream W Y E s PROJECT NO: 014-2797 DRAWN BY: JWH DATE: 11/25/2014 GEOLOGY MAP K19NE STORAGE YARD ENCANA OIL & GAS (USA) INC. GARFIELD COUNTY, COLORADO O\OLSSON ASSOCIATES 760 HORIZON DR., SUITE 102 GRAND JUNCTION, CO 81506 TEL 970.263.7800 FAX 970.263.7456 FIGURE G-1 0 K19NE Storage Yard Subject Parcel n K19NE Storage Yard Boundary Perennial Stream W Y E s PROJECT NO: 014-2797 DRAWN BY: JWH DATE: 11/25/2014 SOILS MAP K19NE STORAGE YARD ENCANA OIL & GAS (USA) INC. GARFIELD COUNTY, COLORADO O\OLSSON A 5 SOCIATE 5 760 HORIZON DR., SUITE 102 GRAND JUNCTION, CO 81506 TEL 970.263.7800 FAX 970.263.7456 FIGURE S-1 O K19NE Storage Yard Perennial Stream r Subject Parcel Intermittent Stream 3 Mile Buffer Floodplain W Y E s PROJECT NO: 014-2797 DRAWN BY: JWH DATE: 11/25/2014 FLOODPLAIN MAP K19NE STORAGE YARD ENCANA OIL & GAS (USA) INC. GARFIELD COUNTY, COLORADO O\OLSSON A5SOCIATE5 760 HORIZON DR., SUITE 102 GRAND JUNCTION, CO 81506 TEL 970.263.7800 FAX 970.263.7456 FIGURE F-1 Article 4-203.G.6 Wildlife and Vegetation Impact Analysis Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OAProject No. 014-2797 WILDLIFE AND VEGETATION ASSESSMENT FOR THE K19 LAYDOWN YARD PREPARED FOR ENCANA OIL AND GAS (USA) INC. Parachute, Colorado PREPARED BY Olsson Associates 760 Horizon Drive, Suite 102 Grand Junction, Colorado 81506 970.263.7800 Cinnamon Levi -Flinn — Assistant Scientist Lilly Griffin — Assistant Scientist December 2014 Olsson Associates Project No. 014-2797 O\LOLSSON ® ASSOCIATES PPIPr- Wildlife and Vegetation Assessment for K19 Laydown Yard Encana Oil & Gas (USA) Inc. 014-2797 THIS PAGE LEFT BLANK FOR TWO-SIDED DUPLICATION. O\OLSSON® ASSOCIATES Wildlife and Vegetation Assessment for K19 Laydown Yard Encana Oil & Gas (USA) Inc. 014-2797 Table of Contents 1.0 PROJECT DESCRIPTION 1 2.0 SURVEY METHODS 3 3.0 EXISTING ENVIRONMENTAL CONDITIONS 3 3.1 Wetlands and Other Waters of the U.S. 3 3.2 Vegetation Assessment 3 3.3 Threatened, Endangered, and Sensitive Plant Species 4 3.4 Noxious Weeds 5 3.5 Wildlife Species Considered 5 3.5.1 Federal and Colorado State Threatened, Endangered, Candidate, and Species of Concern 5 3.5.2 Raptors, Birds of Conservation Concern, Migratory, and Non -Migratory Birds 11 3.5.3 Species Considered 12 4.0 SECTION 4-203.G (6)(a) DETERMINATION OF THE LONG-TERM AND SHORT-TERM EFFECT ON FLORA AND FAUNA 13 4.1 Flora 13 4.2 Fauna 14 4.2.1 Federal and Colorado State Listed Threatened, Endangered, Candidate, and Sensitive Wildlife Species 14 4.2.2 Raptors, Birds of Conservation Concern, Migratory and Non -Migratory Birds 14 4.2.3 American Elk and Deer 14 5.0 SECTION 4-203.G (6)(b) DETERMINATION OF THE EFFECT ON DESIGNATED ENVIRONMENTAL RESOURCES CRITICAL WILDLIFE HABITAT 14 6.0 SECTION 4-203.G (6)(c) IMPACTS ON WILDLIFE AND DOMESTIC ANIMALS 15 7.0 SECTION 7-202 MITIGATION OF WILDLIFE HABITATS 15 8.0 REFERENCES 18 List of Tables Table 1. Dominant Plant Species within the Project Area 4 Table 2. Noxious Weeds Observed 5 Table 3. USFWS Federal Threatened, Endangered and Candidate Wildlife Species for Garfield County 6 Table 4. Colorado State Threatened, Endangered, and Sensitive Species List 7 Table 5. Raptors, Birds of Conservation Concern, Migratory and Non -migratory Bird Species in Project Area 12 December 5, 2014 OLSSON ASSOCIATES Wildlife and Vegetation Assessment for K19 Laydown Yard Encana Oil & Gas (USA) Inc. 014-2797 List of Figures Figure 1: Project Vicinity 2 Figure 2: Mule Deer Winter Ranges 16 Figure 3: Elk Winter Ranges 17 December 5, 2014 OLSSON ASSOCIATES Encana Oil & Gas (USA) Inc. Wildlife and Vegetation Assessment for K19NE Laydown Yard 014-2797 1.0 PROJECT DESCRIPTION Olsson Associates (Olsson) was contracted by Encana Oil and Gas (USA) Inc. to develop an impact analysis to fulfill the legal requirements set forth in Section 4-203.G of the Garfield County Land Use and Development Code (amended October 2014). Section 4-203.G requires proposed developments to describe existing conditions and potential changes created by the proposed land use change. This document provides an assessment of impacts on wildlife habitat, the creation of hazardous attractions, the alteration of existing native vegetation, blocking of migration routes, and changes in habitat use or disruption of habitat use by wildlife. The K19NE Laydown Yard is located approximately 1.0 mile south of the Garfield County Airport, in unincorporated Garfield County in the NEY4 of the SW'/4 of Section 19, Township 6 South, Range 92 West of the 6th P.M. Elevation at this site is approximately 5,686 feet (Figure 1). The K19 pad is an existing permitted oil and gas well pad. The proposed laydown storage yard would have no new surface disturbance since the site is a previously disturbed area, and would be operated within the existing footprint of the K19 pad. December 5, 2014 Photo of pad site, and habitat conditions Photo of reclaimed areas adjacent to site \OLSSON ASSOCIATES 1 Encana Oil & Gas (USA) Inc. Wildlife and Vegetation Assessment for K19NE Laydown Yard 014-2797 Figure 1: Project Vicinity Arad ilkinj M2.11 MI' Milli: in MIN MEM 11411` $111 M.. MN II PE I111:42 lin11111111.11=111.1 mr-mdk, mr- FilLrazat rrim-"Ial. swit .rmilig Ipmnillitir lolltizoeffi piffling/II Ali umie;171%.'lliMMar _,Ji. v.mrawari,t414ma yr • , ! t f • lirl 2 prl'Iry .4 6,71:-.ift.1.:611,11111 1111 ' nr°7 di . lailliellig444"" A iFir7AII„11.21111111111 'fm ' — --°"-T7.1111•111.V.!..r. i-- -----:--- l4 i titt norm Irelourift. 7111111411h -al 1 36 01 12 Subject Parcel 0 K19NE Storage Yard I=1 Parcels — Perennial Stream L..1 3 Mile Buffer WE 8 PROJECT NO: 014-2797 DRAWN BY JWH DATE 11/2512014 VICINITY MAP K19NE STORAGE YARD ENCANA OIL & GAS (USA) INC. GARFIELD COUNTY, COLORADO CAOLSSON ASSOCIATES 700 HORIZON DR.. SUITE 102 GRAND JUNCTION, CO 81506 TEL 070.263.7800 FAX 970203 7450 FIGURE v-1 December 5, 2014 O\OLSSON ASSOCIATES 2 Wildlife and Vegetation Assessment for K19NE Laydown Yard Encana Oil & Gas (USA) Inc. 014-2797 2.0 SURVEY METHODS A preliminary review of the K19NE laydown yard was conducted to determine the presence/absence of threatened, endangered, or sensitive wildlife and plant species and their habitats. The review utilized aerial photographs and a review of GIS data from the U.S. Fish and Wildlife Service's (USFWS) Information, Planning, and Conservation System (IPAC) for listed species in Garfield County (USFWS 2014). Additionally, sensitive or rare wildlife or plant species were reviewed from Colorado Parks and Wildlife's (CPW) Natural Diversity Information source (NDIS) ArcGIS website. Colorado Oil and Gas Conservation Commission (COGCC) GIS data for wildlife habitat was also utilized (COGCC 2013). Species located in the range of the project site were further reviewed for suitable habitats in the vicinity of the project area. On November 4, 2014, Olsson biologists conducted surveys of the project area as well as the surrounding area to assess potential impacts to wildlife and wildlife habitat. Field data collected during the survey were documented and/or recorded using a GPS (NAD83 map datum, UTM coordinate system in Zone 12). Vegetation types were determined during an on-site visit. Photographs of the site location, as well as the surrounding area, were taken to record general biological communities, site conditions, and terrain. As this survey was conducted late in the growing season, some plant species and noxious weeds may not have been identifiable. 3.0 EXISTING ENVIRONMENTAL CONDITIONS 3.1 Wetlands and Other Waters of the U.S. A desktop assessment of waterbodies and wetlands was evaluated by reviewing areas that could potentially be identified as jurisdictional wetlands and other (non -wetland) waters of the U.S. (WoUS). Impacts to potentially jurisdictional WoUS require permitting through Section 404 of the Clean Water Act (CWA). Section 404 of the CWA authorizes the U.S. Army Corps of Engineers (USACE) to issue permits for the discharge of dredge or fill materials into WoUS. Based on the desktop review and on-site surveys, there currently are no wetlands or drainages conveying WoUS that would be affected by the proposed project. 3.2 Vegetation Assessment The K19NE laydown yard is located in an area where the primary land uses include agricultural activities and natural gas development. The project area is located on an existing natural gas well pad, and the surrounding cut and fill slopes are dominated by interim reclamation grasses and forb species. The area of the proposed laydown yard is not surrounded by a fence; however, a fence does border the south side of the location but is maintained by the adjacent landowner. Encana maintains the access road, and December 5, 2014 Photo of sparse native vegetation near site OLSSON 9 ASSOCIATES 3 Wildlife and Vegetation Assessment for K19NE Laydown Yard Encana Oil & Gas (USA) Inc. 014-2797 currently has no plans for future fencing or gates The proposed facility exists in a disturbed vegetation community dominated by grasses. The site appears to have been dominated previously by sagebrush/greasewood shrublands. Scattered patches of greasewood (Sarcobatus vermiculatus) and big sagebrush (Artemesia tridentata), rabbitbrush (Ericameria nauseosa), fourwing saltbush (Atriplex canescens), and shadscale (Atriplex confertifolia) still persist in some areas. The understory is not diverse, and was dominated by downy brome (Anisantha tectorum) with scattered patches of galleta grass (Hilaria jamesii), and weedy annuals. Additional species occurred in lesser coverage and amounts. The pad location has been kept mostly clear of vegetation. The berms, cut slopes, and fill slopes support weedy species and seeded grasses. The dominating vegetation includes downy brome, crested wheatgrass (Agropyron cristatum), slender wheatgrass (Elymus trachycaulus), and scattered shrubs ncluding big sagebrush, rabbitbrush, greasewood, and saltbush species (A. confertifolia and A. canescens). Table 1. Dominant Plant Species within the Project Area Common Name Scientific Name Cheatgrass (Downy Brome) Anisantha tectorum Crested wheatgrass Agropyron cristatum Big Sagebrush Artemesia tridentata Rabbitbrush Ericameria nauseosa Slender wheatgrass Elymus trachycaulus Greasewood Sarcobatus vermiculatus Fourwing saltbush Atriplex canescens Shadscale Atriplex confertifolia Russian Thistle Salsola iberica Tall tumblemustard Sisymbrium altissimum Clasping pepperweed Lepidium perfoliatum Redstem Filaree Erodium cicutarium 3.3 Threatened, Endangered, and Sensitive Plant Species The vegetation survey included an assessment to identify potential habitat for the following plant species, which may occur in the area (USFWS 2014): Colorado hookless cactus (Sclerocactus glaucus) DeBeque phacelia (Phacelia submutica) Parachute beardtongue (Penstemon debilis) Ute ladies' -tresses (Spiranthes diluvialis) None of the above mentioned species or potential habitats was located within the project area. December 5, 2014 4 OLSSON o ASSOCIATES Encana Oil & Gas (USA) Inc. Wildlife and Vegetation Assessment for K19NE Laydown Yard 014-2797 3.4 Noxious Weeds Two Colorado State C -list weed species were found on the cut and fill slopes of the project area: downy brome (Anisantha tectorum) and redstem filaree (Erodium cicutarium). The presence of downy brome is prolific in the surrounding area, and will likely be difficult to control. It is possible that other weed species occur on the project site and in the nearby area but were not detected due to the time of inspection. Table 2. Noxious Weeds Observed Common Name Scientific Name Growth Cycle/Weed List Comment Redstem Filaree Erodium cicutarium Biennial/Colorado C list Worldwide; crowds out more desirable crop species. Cheatgrass (Downy brome) Anisantha tectorum Annual/Colorado C list Highly adaptable to many environments; promoted by fire; highly competitive and early emergent.. As outlined in Encana Oil & Gas (USA) Weed Management Effort Summary, the weed conditions will be assessed on an individual basis, such that the best, site-specific weed management techniques may be executed. Please reference Encana Oil & Gas (USA) Weed Management Effort Summary. 3.5 Wildlife Species Considered 3.5.1 Federal and Colorado State Threatened, Endangered, Candidate, and Species of Concern The K19NE Laydown Yard was evaluated for threatened, endangered, or sensitive wildlife species and their habitats potentially occurring on or adjacent to the project area. According to the USFWS IPAC, there are ten federally listed threatened, endangered, and candidate wildlife species that have the potential to occur in Garfield County (Table 3). Additionally, CPW's list of Threatened, Endangered and Species of Concern was reviewed to determine if any of those species had potential habitat on or adjacent to the proposed laydown yard (Table 4). December 5, 2014 5 OLSSON ASSOCIATES Encana Oil & Gas (USA) Inc. Wildlife and Vegetation Assessment for K19NE Laydown Yard 014-2797 Table 3. USFWS Federal Threatened, Endangered and Candidate Wildlife Species for Garfield County Common Name Scientific Name Habitat Status Habitat Present Birds Greater Sage Grouse Centrocercus urophasianus Large sagebrush shrublands, north of 1-70 in Colorado Candidate No Mexican Spotted owl Strix occidentalis lucida Canyons with mixed conifer old growth mostly in Southwestern Colorado and east of Colorado Springs Threatened No Yellow -Billed Cuckoo Coccyzus americanus Large cottonwood stands along large Rivers; found along North Fork of Gunnison, Colorado, Dolores, Yampa and Rio Grande Rivers Threatened No Fish Bonytail chub Gila elegans Large, swift flowing waters of the Colorado River system Endangered No Colorado pikeminnow Ptychocheilus lucius Large, swift -flowing muddy rivers with quiet warm backwaters in the Green, Yampa, White, Colorado, Gunnison, San Juan, and Dolores Rivers Endangered No Greenback Cutthroat Trout Oncorhynchus clarki stomias Clear, cold mountain streams on the Front Range of Colorado, recently found to occur on the west slope Threatened No Humpback chub Gila cypha Prefers deep, fast-moving, turbid waters often associated with large boulders and steep cliffs in the Green, Yampa, and Colorado Rivers Endangered No Razorback sucker Xyrauchen texanus Deep, clear to turbid waters of large rivers and reservoirs, with silt and gravel substrates in the lower Yampa and lower Colorado Rivers Endangered No Mammals Canada lynx Lynx canadensis Spruce/fir and lodgepole pine forests, sometimes aspen, and shrublands Threatened No Black -Footed ferret Mustela nigripes Associated with prairie dog colonies. Found to occur in Rio Blanco and Moffat Counties Endangered No Nine of the listed species in the above table do not have mapped habitat occurring within or near the site (CPW-NDIS 2013). Potential habitat is not present for the Mexican spotted owl, Yellow -billed cuckoo, Greenback cutthroat trout, Canada lynx, the Black -Footed ferret, or for the four federally listed endangered fish species. The greater sage -grouse (GrSG) has CPW mapped Historic Habitat overlaying the site. GrSG mapped Production Area (includes majority of nesting habitat), Overall Range, Brood Areas, and Winter Range habitats all occur greater than 20 miles northwest of the site, north of the town of Parachute. The proposed Iaydown yard is not within the GrSG habitat areas as depicted in the Garfield County Greater Sage -Grouse Conservation Plan. December 5, 2014 6 OLSSON ASSOCIATES Encana Oil & Gas (USA) Inc. Wildlife and Vegetation Assessment for K19NE Laydown Yard 014-2797 Table 4. Colorado State Threatened, Endangered, and Sensitive Species List Common Name Scientific Name Habitat Status Potential Habitat present within Project Area? Mammals Black -Footed Ferret Mustela nigripes Associated with prairie dog colonies. Found to occur in Rio Blanco and Moffat Counties FE,SE No Black -Tailed Prairie Dog Cynomys ludovicianus Shortgrass steppe on the eastern plains of Colorado SC No Botta's Pocket Gopher Thomomy bottae rubidus Occurs mostly in riparian areas with sandy soils along lower elevations of the Utah border and the Arkansas Valley SC No Gray Wolf Canis lupus Mountains, woodlands and plains of the Northern Rockies FE,SE No Grizzly Bear Ursus arctos Woodlands, forests, alpine meadows and riparian areas near streams and rivers FT,SE No Kit Fox Vulpes macrotis Semi -desert shrublands; found to occur in Colorado and Lower Gunnison River Valleys SE No Canada Lynx Lynx canadensis Spruce/fir and lodgepole pine forests, sometimes aspen, and shrublands FTSE No Northern Pocket Gopher Thomomys talpoides macrotis Occurs in meadows and along streams in mountain areas along the Front Range of Colorado SC No Preble's Meadow jumping mouse Zapus hudsonius preblei Foothills riparian areas and along front range streams of Colorado into northern Wyoming FT,ST No River Otter Lontra Canadensis Widespread in large montane river systems ST No Swift Fox Vulpes velox Shortgrass prairie and riparian woodlands on eastern plains of Colorado SC No Townsend's Big- eared Bat Corynorhinus townsendii pallescens Semi -desert shrublands, Pinyon/juniper, open montane forests, caves and abandoned mines SC No Wolverine Gulo gulo Boreal forests and tundra SE No Birds American Peregrine Falcon Falco peregrines anatum Nest on cliffs, forages over forests and shrublands throughout Colorado SC No Bald Eagle Haliaeetus leucocephalus Forages by roosting along larger rivers, stream and waterbodies, also around big game winter ranges throughout Colorado SC No Burrowing Owl Athene cunicularia Arid grasslands and shrublands on the eastern slope of Colorado; some occurrences in western Colorado ST No Columbian Sharp-Tympanuchus Tailed Grouse phasianellus columbianus High mountain shrub -grassland communities and associated edges in Northwestern Colorado SC No December 5, 2014 7 OLSSON ASSOCIATES Encana Oil & Gas (USA) Inc. Wildlife and Vegetation Assessment for K19NE Laydown Yard 014-2797 Common Name Scientific Name Habitat Status Potential Habitat present within Project Area? Ferruginous Hawk Buteo regalis Grasslands and semi -desert shrublands, winter resident in Colorado SC No Greater Sage Grouse Centrocercus urophasianus Large sagebrush shrublands, north of 1-70 in Colorado SC No Gunnison Sage- Grouse Centrocercus minimus Large sagebrush shrublands with diversity of grasses and riparian areas; occurs in Gunnison basin and a small population south of Grand Junction SC No Greater Sandhill Crane Grus canadensis tabida Wetlands, marshes and large waterbodies; Colorado migrant but the Rocky Mountain Population breeds in northwestern Colorado SC No Least Tern Sterna antillarum Migratory in Colorado, found in large reservoirs and rivers in southeastern Colorado FE,SE No Lesser Prairie- Chicken Tympanuchus pallidicinctus Great plains grasslands and shrublands in southeastern Colorado FT,ST No Long -billed Curlew Numenius americanus Larger reservoirs and river systems in Colorado, mostly on eastern plains SC No Mexican Spotted Owl Strix occidentalis lucida Canyons with mixed conifer old growth mostly in Southwestern Colorado and east of Colorado Springs FT,ST No Mountain Plover Charadrius montanus Summers on eastern plains in Colorado in native short -grass steppe; winters in Southern California & Mexico SC No Plains Sharp -Tailed Grouse Tympanuchus phasianellus jamesii Grasslands and river canyons in northeastern Colorado SE No Piping Plover Charadrius melodus circumcinctus Sandbars and beaches along larger rivers in eastern Colorado FT,ST No Southwestern Willow Flycatcher Empidonax traillii extimus Dense lower elevation riparian habitats FE,SE No Western Snowy Plover Charadrius alexandrines Sandy beaches and barrens in eastern Colorado plains SC No Western Yellow Billed Cuckoo Coccyzus americanus Large cottonwood stands along Targe Rivers; found along North Fork of Gunnison, Colorado, Dolores, Yampa and Rio Grande Rivers SC No Whooping Crane Grus Americana Migratory through Colorado; found to occur in wetlands, marshes and salt flats FE,SE No Fish Arkansas Darter Etheostoma cragini Shallow, clear, sandy streams with spring fed pools in the Arkansas drainage in eastern Colorado ST No December 5, 2014 8 OLSSON o ASSOCIATES Encana Oil & Gas (USA) Inc. Wildlife and Vegetation Assessment for K19NE Laydown Yard 014-2797 Common Name Scientific Name Habitat Status Potential Habitat present within Project Area? Bonytail Gila elegans Large, swift -flowing waters of the Colorado River system FE,SE No Brassy Minnow Hybognathus hankinsoni Moderately clear tributary streams with sand or gravel bottoms; native to Republican and South Platte river basins ST No Colorado Pikeminnow Ptychocheilus lucius Large, swift -flowing muddy rivers with quiet warm backwaters in the Green, Yampa, White, Colorado, Gunnison, San Juan, and Dolores Rivers FE,ST No Colorado River Cutthroat trout Oncorhynchus clarki pleuriticus Headwater streams and lakes in widespread localized reaches SC No Colorado Roundtail Chub Gila robusta Large rivers in the Colorado River system through Glenwood Canyon, downstream on White River, Milk and Divide Creeks SC No Common Shiner Luxilus cornutus Lakes, rivers and streams, common in pools of streams and small rivers in the South Platte River Basin ST No Flathead Chub Platygobio gracilus Main branches of turbid streams and rivers, fast currents with sand/gravel substrates in the Arkansas River basin SC No Greenback Cutthroat trout Oncorhynchus clarki stomias Clear, cold mountain streams on the Front Range of Colorado, recently found to occur on the west slope FT,ST No Humpback Chub Gila cypha Prefers deep, fast-moving, turbid waters often associated with large boulders and steep cliffs in the Green, Yampa, and Colorado Rivers FE,ST No Iowa Darter Etheostoma exile Clear, slow flowing streams and lakes with undercut banks and some vegetation or algal mat in Northeastern plains streams, Eleven Mile Reservoir and Shadow Mountain Reservoir SC No Lake Chub Couesius plumbeus Lakes and large pools in Boulder Creek and the Cache la Poudre River SE No Mountain Sucker Catostomus playtrhynchus Throughout west on both sides of Continental Divide -prefer clear cold creeks and small to medium rivers with rubble, gravel, or sand substrate SC No Northern Redbelly Dace Phoxinus eos Small slow -flowing streams and connected lakes with vegetation in the South Platte basin SE No Plains Minnow Hybognathus placitus Main channels of rivers in the Arkansas and Platte River basins SE No December 5, 2014 9 OLSSON ASSOCIATES Encana Oil & Gas (USA) Inc. Wildlife and Vegetation Assessment for K19NE Laydown Yard 014-2797 Common Name Scientific Name Habitat Status Potential Habitat present within Project Area? Plains Orangethroat Darter Etheostoma spectabile Found in small streams with shallow riffles and gravel substrate in the Republican basin SC No Rio Grande Chub Gila Pandora Pools and streams with gravel substrate and overhanging banks and brush in the Rio Grande basin SC No Rio Grande Cutthroat trout Oncorhynchus clarki virginalis Clear, cold isolated headwater streams and lakes in the Rio Grande basin SC No Rio Grande Sucker Catostomus plebeius Slow moving reaches of streams in the Rio Grande basin FE,SE No Razorback Sucker Xyrauchen texanus Deep, clear to turbid waters of large rivers and reservoirs, with silt and gravel substrates in the lower Yampa and lower Colorado Rivers FE,SE No Southern Red Belly dace Phoxinus erythrogaster Clear, streams and rivers with sand and gravel substrates in the South Platte and Arkansas River drainages SE No Stonecat Noturus flavus Large creeks and small rivers with fast moving riffles and rocky substrates; occurs in the South Platte and Republican basins SC No Suckermouth Minnow Phenacobius mirabilis Clear, shallow riffles with sand and gravel substrates in the South Platte and Republican basins SE No Amphibians Boreal Toad Anaxyrus boreas boreas Subalpine forest meadows, wetlands, beaver ponds and margins of lakes in distinct populations within 8,500- 12,000 feet elevation SE No Couch's Spadefoot Scaphiopus couchii Occurs in pools and stock ponds in the prairie grasslands of Southeastern Colorado SC No Great Plains Narrowmouth Toad Gastrophryne olivacea Grassy areas on rocky slopes and in rock -rimmed canyons in southeastern Colorado SC No Northern Cricket Frog Acris crepitans Margins and edges of permanent and semi-permanent ponds and wetlands of the eastern plains of Colorado SC No Northern Leopard Frog Lithobates pipiens Wetlands, beaver ponds, marshes, and wet meadows throughout mid -to lower - elevations of Colorado SC No Plains Leopard Frog Rana blairi Wetlands, marshes, and ponds on eastern plains SC No Wood Frog Rana sylvatica Subalpine wetlands, beaver ponds, lakes, and wet meadows in eastern Grand, northern Larimer, and Jackson Counties SC No December 5, 2014 OLSSON o ASSOCIATES 10 Encana Oil & Gas (USA) Inc. Wildlife and Vegetation Assessment for K19NE Laydown Yard 014-2797 Common Name Scientific Name Habitat Status Potential Habitat present within Project Area? Reptiles Triploid Checkered Whiptail Cnemidophorus neotesselatus Hillsides, arroyos, and canyons associated with the Arkansas River valley SC No Midget Faded Rattlesnake Crotalus viridis concolor Semi -arid shrublands and rocky arroyos in lower elevations in western Colorado SC No Longnose Leopard lizard Gambelia wislizenii Flat or gently sloping shrublands and desert plains in western Colorado along the Utah border SC No Yellow Mud Turtle Kinosternon flavescens Permanent and intermittent streams, ponds and marshes bordering grasslands and sand hills in eastern Colorado SC No Common King Snake Lampropeltis getula Low elevation, semi desert shrublands near waterways in extreme southwest and southeast Colorado SC No Texas Blind Snake Leptotyphlops dulcis Canyon slopes and bottoms in Pinyon/juniper and shrub habitats in extreme southeastern Colorado SC No Texas horned lizard Phrynosoma cornutum Plains grassland with large patches of bare ground in southeastern Colorado SC No Roundtail Horned lizard Phrynosoma modestum Dry grasslands and shrubland in southeastern Colorado SC No Massasauga Sistrurus catenatus Dry plains grassland and sand hill areas with sandy soils in southeastern Colorado SC No Common Garter Snake Thamnophis sirtalis Wetlands and aquatic and riparian habitats in northeastern Colorado SC No Mollusks Rocky Mountain Capshell Acroloxus coloradensis Cold water lakes in mid -to -low elevations with high amounts of calcium and other ions; occurs in north central Colorado SC No Cylindrical Papershell Anodontoides ferussacianus Headwater creeks and streams with silty/muddy substrates in Boulder County SC No FE= Federally Endangered, FT=Federally Threatened, SE=State Endangered, ST=State Threatened, SC= State Special Concern (not a statutory category) 3.5.2 Raptors, Birds of Conservation Concern, Migratory, and Non -Migratory Birds Olsson evaluated the site for raptor species that could potentially occur in the area (Andrews & Righter 1992, Kingery 1998, and Righter et al. 2004, CPW NDIS 2013). Olsson conducted a habitat survey on November 4, 2014 to determine if any potential raptor nesting habitat was present. The typical raptor nesting season occurs from February 15 -August 15, depending on the species (Table 4). In addition to raptors, Olsson evaluated the site for bird species which could potentially be affected by the proposed laydown yard. Birds of Conservation Concern (BCC) have been identified by the USFWS for priority conservation management in an attempt to prevent or December 5, 2014 OLSSON 9 ASSOCIATES 11 Encana Oil & Gas (USA) Inc. Wildlife and Vegetation Assessment for K19NE Laydown Yard 014-2797 remove the need to list additional species under the Endangered Species Act (USFWS 2008). A literature review was conducted to identify the potential presence of BCC species that could occur in mixed grasslands and sagebrush habitats near the site. Table 5 shows the BCC species for the Southern Rockies/Colorado Plateau that may have potential to occur within the habitats adjacent to the site. The site has been cleared of all vegetation from the previous disturbance of the K19NE gas well pad; therefore, the site does not provide suitable nesting habitat for some species. Habitat surrounding the proposed laydown yard may provide potential foraging habitat for raptors and nesting and foraging habitat for various, migratory and non -migratory bird species. Table 5. Raptors, Birds of Conservation Concern, Migratory and Non -migratory Bird Species in Project Area Common Name Scientific Name Preferred Habitat BCC Cassin's Finch Carpodacus cassinii Associated with pinyon/ juniper woodlands, Douglas -fir trees, and lodgepole and ponderosa pine forests. May breed in open sagebrush and shrubland with scattered juniper (Juniperus scopulorum) Yes Northern Harrier Circus cyaneus Prefers wetlands in both summer and winter; however, these habitats are uncommon in western CO so they will generally nest in sagebrush, montane shrub, grasslands, and hayfields with abundant cover. No Brewer's Sparrow Spizella breweri Primarily nests in sagebrush shrublands but may occasionally nest in greasewood and rabbitbrush or other shrublands in desert valleys. During migration may uses a variety of riparian and desert shrubs. Yes Sage thrasher Oreoscoptes montanus Primarily nests in sagebrush and at low elevations may nest in greasewood, shadscale saltbush, fourwing saltbush and rubber rabbitbrush intermixed with sagebrush. May nest in mountain mahogany or serviceberry at higher elevations. No 3.5.3 Species_Considered In addition to the review of USFWS and CPW Sensitive species and local species of interest, the following species were evaluated for impacts from the proposed laydown yard. No other listed species have suitable habitats or occupied range within the project area. Elk Mule Deer 3.5.3.1 American Elk and Mule Deer Mule deer (Odocoileus hemionus) utilize montane forests and pinyon -juniper woodlands with good shrub understory during winter. They rely on sagebrush and shrubs as their primary food December 5, 2014 OLSSON ASSOCIATES 12 Encana Oil & Gas (USA) Inc. Wildlife and Vegetation Assessment for K19NE Laydown Yard 014-2797 source. Mule deer may utilize the habitat surrounding the site for wintering grounds and will migrate up to higher elevations in the spring (Fitzgerald et al. 1994). Elk (Cervus elaphus) are found in semi -open forests or forest edges adjacent to parks, meadows, and alpine tundra and rely primarily on available grasses and browse for food (Fitzgerald et al. 1994). Elk prefer areas that are less disturbed and generally prefer areas away from roads (Fitzgerald et al. 1994). The proposed laydown yard is located within CPW Game Management Unit (GMU) 42 and Data Analysis Units (DAU) D-12 and E-14. The site location does not occur within CPW mapped migration corridors or wildlife habitat linkages for either species. The site occurs within CPW mapped mule deer Overall Range, Severe Winter Range, Winter Range and Winter Concentration Area. The site occurs within CPW mapped elk Overall Range, Winter Range, Severe Winter Range, and Winter Concentration Area (Figures 2 and 3). During 2014, no elk or mule deer sign was noted during the survey. Photo of more effective native habitats south of site 4.0 SECTION 4-203.G (6)(A) DETERMINATION OF THE LONG-TERM AND SHORT-TERM EFFECT ON FLORA AND FAUNA 4.1 Flom The continued use and redevelopment of the existing laydown yard would not adversely affect federally listed plant species. No additional vegetation removal is associated with the laydown yard. Vegetation communities and conditions will not be affected on a long- or short-term basis and would remain in their present condition. At this time, it is recommended that noxious weed management be focused on preventing the spread of Redstem filaree, and to prevent any new weed infestations. Please reference Colorado Noxious Weed and Garfield County Weed Lists. As outlined in Encana Oil & Gas (USA) Weed Management Effort Summary, the above mentioned weed conditions will be assessed on an individual basis, such that the best, site- specific weed management techniques may be executed. Please reference Encana Oil & Gas (USA) Weed Management Effort Summary. December 5, 2014 13 OLSSON 9 ASSOCIATES Wildlife and Vegetation Assessment for K19NE Laydown Yard Encana Oil & Gas (USA) Inc. 014-2797 4.2 Fauna 4.2.1 Federal and Colorado State Listed Threatened, Endangered, Candidate, and Sensitive Wildlife Species The continued use of the existing site as a laydown yard would not adversely affect federally listed wildlife species due to the lack of suitable habitat within or surrounding the project area. No federally designated critical habitat occurs within or near the site. Colorado State listed Threatened, Endangered or Sensitive wildlife species would not be impacted by the proposed laydown yard due to the lack of suitable habitat available for those species within or surrounding the proposed project area. 4.2.2 Raptors, Birds of Conservation Concern, Migratory and Non -Migratory Birds No additional vegetation removal would be associated with the proposed laydown yard; therefore no suitable raptor, BCC, or other migratory or non -migratory bird species nesting habitat would be impacted. Long- or short-term effects related to the project area would be minimal due to the area being previously disturbed from activities associated with the operation and maintenance of the existing oil and gas well pad, and a lack of suitable nesting habitat in proximity to the site. Loud noises and human activities at the site during the breeding and nesting season may have limited indirect impacts on habitat effectiveness around the pad site, possibly reducing the suitability or effectiveness for nesting activities in the native shrubland habitats; but as mentioned, a lack of suitable nesting habitat in proximity to the pad limits the amount of potential impacts. Foraging and other habitat use would likely continue within adjacent habitats, as available. 4.2.3 American Elk and Deer The existing site is absent of any vegetation, and no additional direct impacts to elk or deer habitats would occur. Elk and deer may be indirectly impacted during the winter months by increased noise and human presence and increased traffic along the access road, which may cause elk and deer to avoid this area during certain times of day or during times of more intense human activities. The winter months are a critical time of year for big game species, when deer and elk are more likely to be utilizing lower elevations and disturbance can have a larger relative impact due to poor foraging opportunities and already stressed animals. Intensive use of the laydown yard during the winter months may force deer and elk away from the area, which could increase energy expenditures for the individuals impacted. During the summer and fall months, most deer and elk are at higher elevation habitats, and therefore use of the pad site outside of the winter would likely have no impact on deer or elk. The use of the laydown yard would not block or impede migration corridors for elk or mule deer. Long-term, reclamation of the site is recommended in order to improve winter range habitat effectiveness in the area. 5.0 SECTION 4-203.G (6)(B) DETERMINATION OF THE EFFECT ON DESIGNATED ENVIRONMENTAL RESOURCES CRITICAL WILDLIFE HABITAT The K19NE Laydown Yard is not expected to affect any critical habitat for any wildlife species, as no federally designated critical habitat or species were identified within or near the site. According to the CPW GIS data, the project area occurs within Overall, Severe Winter Range, Winter Concentration Areas and Winter Range for elk and mule deer. No additional vegetation December 5, 2014 14 OLSSON ASSOCIATES Wildlife and Vegetation Assessment for K19NE Laydown Yard Encana Oil & Gas (USA) Inc. 014-2797 removal or new construction is associated with the site that would further decrease habitat. The site would not impede any natural migration or movement through the area, but use of the site during the winter months may temporarily cause animals to avoid habitats around the site. Given the limited size and temporary nature of activities associated with laydown yard use, these impacts would likely be short-term in nature, and no measureable impact to mule deer or elk herds would be expected from this project. Activities in the winter months would have a relatively larger potential effect given the condition of animals in the winter months, and reduced availability of forage and security habitats. As mentioned, some individual animals may be indirectly impacted by moving away from the site, but no significant impacts to herds, or long- term impacts to critical wildlife habitat would be expected. 6.0 SECTION 4-203.G (6)(C) IMPACTS ON WILDLIFE AND DOMESTIC ANIMALS The laydown yard would not create hazardous attractions to avian or mammalian wildlife species or domestic animals, alter additional native vegetation, block migration routes, or cause a change in habitat use. Wildlife species may be indirectly impacted by increased noise and human presence while equipment is being transferred and stored. Use of habitats by wildlife would still likely occur on or adjacent to the pad and storage yard site during the nighttime hours, and during times when there are no human activities at the laydown yard. The majority of the species occurring within the area have widespread habitats; therefore, most wildlife species that may be indirectly affected would have other habitats in the greater area that are still available for foraging, reproduction, dispersal and shelter. The proposed project may impact individuals indirectly but would not likely impact populations. No impacts to domestic animals would be expected. 7.0 SECTION 7-202 MITIGATION OF WILDLIFE HABITATS There would be no direct loss of wildlife habitat from a change in use of the site. At this time, there are no recommendations for seasonal restrictions, mitigations or special requirements due to the previous disturbance of the existing oil and gas pad. Ongoing noxious weed management will be required to maintain existing vegetation and wildlife habitat quality, and to control any spread of existing noxious weeds. If larger elk or deer herds begin to congregate around the site during the winter months, Encana should consider consulting with CPW to minimize potential impacts to wintering big game species. December 5, 2014 15 OLSSON ASSOCIATES Encana Oil & Gas (USA) Inc. Wildlife and Vegetation Assessment for K19NE Laydown Yard 014-2797 Figure 2: Mule Deer Winter Ranges O K1 9N E Storage Yard K19NE Storage Yard Boundary Subject Parcel Perennial Stream 11101 Mule Deer Severe Winter Range Mule Deer Winter Concentration Area E PROJECT NO. 014-2797 DRAWN BY: JWH DATE 11/25/2014 MULE DEER HABITAT MAP K19NE STORAGE YARD ENCANA OIL & GAS (USA) INC. GARFIELD COUNTY, COLORADO O'OLSSON® ASSOCIATES 700 HORIZON DR.. SUITE 102 GRAND JUNCTION, CO 81606 TEL 970 2607800 FAX 970203.7456 FIGURE MD -1 December 5, 2014 O\OLSSON R, ASSOCIATES 16 Encana Oil & Gas (USA) Inc. Wildlife and Vegetation Assessment for K19NE Laydown Yard 014-2797 Figure 3: EIk Winter Ranges i K19NE Storage Yard Subject Parcel EM EIk Severe Winter Range Q K19NE Storage Yard Boundary Perennial Stream __ _ EIk Winter Concentration Area PROJECT NO: 014-2797 DRAWN EY JWH DATE. 11125!2014 ELK HABITAT MAP K19NE STORAGE YARD ENCANA OIL & GAS (USA) INC. GARFIELD COUNTY, COLORADO Li OLSSON ASSOCIATES 760 HORIZON DR., SUITE 102 GRAND JUNCTION. 00 8151]8 TEL 970.283.7800 FAX 970283.7458 FIGURE E-1 December 5, 2014 O\OLSSON ASSOCIATES 17 Encana Oil & Gas (USA) Inc. 8.0 REFERENCES Wildlife and Vegetation Assessment for K19NE Laydown Yard 014-2797 Andrews, R., and R. Righter. 1992. Colorado Birds: A Reference to Their Distribution and Habitat. Denver Museum of Natural History. Denver. Colorado Bat Working Group 2014. Online website sponsored by the Colorado Natural Heritage Program, Colorado State University, Fort Collins CO. 80523. Accessed on November 19, 2014. http://www.cnhp.colostate.edu/teams/zoology/cbwg/index.asp CPW-NDIS. 2013. Colorado Parks and Wildlife Natural Diversity Information Source-. http://ndis.nrel.colostate.edu/wildlife.asp. Accessed on September 6, 2013 (http://www.arcgis.com/home/search.html?q=Colorado%20Parks%20and%20Wildlife&t=groups ). CWMA. 2013 A. Doran, S. Anthony, C. Shelton. Noxious Weeds of Colorado, Eleventh Edition. Colorado Weed Management Association, Centennial. Fitzgerald, J.P.; C. A. Meaney; D.M. Armstrong. 1994. Mammals of Colorado. Denver Museum of Natural History. Denver. Kingery, H. E. 1998. Colorado Breeding Bird Atlas. Colorado Bird Atlas Partnership, Colorado Division of Wildlife, Denver. Mutel, C.F. and J.C. Emerick. 1992. From Grasslands to Glacier: The Natural History of Colorado and the Surrounding Region. Johnson Printing. Boulder, CO Righter, R., R. Levad, C. Dexter, and K. Potter. 2004. Birds of Western Colorado Plateau and Mesa Country. Grand Valley Audubon Society, Grand Junction. USFWS. 2008. Birds of Conservation Concern 2008. U.S. Fish and Wildlife Service, Division of Migratory Bird Management, U.S. Fish and Wildlife Service, Arlington, Virginia. USFWS. 2014. U.S. Fish and Wildlife Service Information, Planning, and Conservation System. Endangered Species List — Western Colorado Ecological Services Field Office County List. Accessed November 18, 2014. Available online: http://ecos.fws.gov/ipac/wizard/chooseLocation!prepare.action Weber, William A., and Ronald C. Wittman. 2012 Colorado Flora, Western Slope. Third Edition, University Press of Colorado, Boulder. Whitson, T.D. (editor), L.C. Burrill, S.A. Dewey, D.W. Cudney, B.E. Nelson, R.D. Lee, and R. Parker. 2001. Weeds of the West — 9th edition. Western Society of Weed Science in cooperation with Cooperative Extension Services, University of Wyoming, Laramie. December 5, 2014 18 O\OLSSON ASSOCIATES Article 4-203.G.7 Fugitive Dust Control Plan Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OA Project No. 014-2797 ENCANA U.S.A. Inc. Piceance Unit Fugitive Dust Control Plan Piceance Basin Natural Gas Development Projects Scope The scope of these guidelines is to outline some basic principles to minimize and control fugitive dust emissions during land development. Requirements Encana places the highest priority on the health and safety of our workforce and protection of our assets and the environment. Applicable Documents Department of Public Health and Environment Air Quality Control Commission Regulation 1 5CCR 1001-3 Quality These guidelines will be reviewed periodically and will be shared with employees and contractors to ensure that they have adequate knowledge to minimize fugitive dust emissions. 1.0 Introduction Land development activities, including clearing, excavating, and grading, release fugitive dust, a pollutant regulated by the Air Pollution Control Division (Division) at the Colorado Department of Public Health and Environment. However, small land development activities that are less than 25 contiguous acres and less than 6 months in duration do not need to report air emissions to the Division, but must use appropriate control measures to minimize the release of fugitive dust from the site. This Fugitive Dust Control Plan addresses how dust will be kept to a minimum at the Encana's Project sites. This plan focuses action on: 1. Identifying specific individual sources of fugitive dust. 2. Control options for unpaved roadways. 3. Control options for disturbed areas. 4. Control options for transport, storage and handling of bulk materials. 5. Contingency Plan for alternative action in the event that control strategies are not adequate, effective, or practicable. 2.0 Specific Sources Specific types of fugitive dust sources may appear to have negligible dust emissions, but when combined with other specific sources underway at the same time can create dust plumes that are visible beyond that which is appropriate for designated speeds and designs and may exceed nuisance emission limitation guidelines. It is important to consider all activities on the site together in determining compliance with federal, state, and local air quality regulations. Task: Provide field personnel and contractors with the information required to limit fugitive particulate matter (fugitive dust) from all specific sources to include: • Unpaved Roadways and traffic areas. • Construction activities including Earth Moving and excavation. • Bulk Material (i.e. gravel and soils). • Storage and handling of materials 3.0 Control Options for Unpaved Roadways Any owner or operator responsible for construction or maintenance of any (existing or new) unpaved roadway is required to use all available, practical methods to minimize dust emissions: Task: Provide guidelines for minimizing fugitive dust emissions from all specific sources on unpaved roadways and traffic areas: • Require that all passenger vehicles, construction equipment, and truck traffic obey the posted speed limits on all unpaved County roads to and from the project site. • Ensure that vehicle speeds on new and existing access roads on the project site do not exceed 15 miles per hour by posting speed limits along these roads. • Restrict vehicle traffic to existing roads by posting signs and/or providing the locations of allowable access routes to all field personnel and visitors. • Encourage carpooling to and from the project site to limit traffic on existing County roads. • Roads and well locations will be surfaced with compacted gravel to protect against wind erosion, to reduce the amount of fugitive dust generated by traffic and other activities, and to reduce carryout/trackout. • Use dust inhibitors (surfacing materials, water, or non -saline dust suppressants) on all unpaved collector, local, and resource roads to prevent fugitive dust problems (ensure that any dust suppressants used are appropriate for road conditions and will not compromise the safety of workers on the project site). • Restrict vehicular access during periods of inactivity using gates, fencing, and/or onsite security personnel. 4.0 Control Options for Disturbed Areas Disturbed areas include new roads, well pads, parking and staging areas, and materials storage areas that have been cleared of vegetation, leveled, or excavated. These areas are susceptible to wind erosion and are a major source of fugitive dust emissions that require the appropriate controls and dust mitigation methods. Note that specific sources are subject to change as project conditions change, and will require an evaluation of current control options to ensure effectiveness and practicality. - 2 Task: Limit the adverse impacts of fugitive dust emissions through control measures and operational procedures designed so that no off -property transport emissions occur at the project site: • Ensure that land clearing, grading, earthmoving, and excavation activities are suspended when wind speeds exceed a sustained velocity of 20 miles per hour. - Surface all bare ground with gravel as soon as practicable after clearing, leveling, and grading. • Use dust inhibitors (surfacing materials, water, or non -saline dust suppressants) on all disturbed areas as necessary to prevent fugitive dust problems. • Identify the water source to be used for dust suppression, and ensure that contract water haulers are available when needed. • Reduce the amount of time between initially disturbing the soil and revegetating or other surface stabilization. • Apply vegetative or synthetic cover to topsoil and spoil piles as soon as practicable following stockpiling to prevent wind erosion and fugitive dust emissions. • Compact the soil on disturbed areas that will not be surfaced with gravel or revegetated immediately following construction. • Minimize surface disturbance to only that necessary for safe and efficient construction and operations. • Use vegetative mulch, reseeding, or other methods of surface stabilization on all areas adjoining development to include shoulders, borrow ditches, and berms if practical. • Restrict vehicular access during periods of inactivity using gates, fencing, and/or onsite security personnel. • Identify any new sources of fugitive dust emissions and evaluate and implement the appropriate control methods for that source. - Incorporate fugitive dust controls in all lands projects. 5.0 Control Options for Transport, Storage and Handling of Bulk Materials Transporting bulk materials, such as gravel and fill material, can result in off -property dust emissions and other impacts (i.e. broken windshields) over some distance if the appropriate control measures are not implemented. Storage and handling of bulk materials once they arrive at the project site also requires that controls are in place to ensure that these materials do not exceed regulated nuisance dust emissions. Task: Use control measures and operational procedures designed so that no off -property transport emissions occur along public roadways to and from the project site: • Enclose, cover, water, or otherwise treat loaded haul trucks to minimize the loss of material to wind and spillage. • Require that all contract haul vehicles obey the posted speed limits on all public roadways to and from the project site. • Ensure that haul truck speeds on new and existing access roads on the project site do not exceed 15 miles per hour by posting speed limits along these roads. • Restrict haul trucks to existing roads and pad locations. - Do not attempt to load/unload haul trucks when wind speeds exceed a sustained velocity of 20 miles per hour. • Promptly remove dust -forming material from haul trucks to minimize entrainment of fugitive particulate matter. - Avoid storage and handling of bulk material any more than necessary to complete construction. - Use covers, enclosures, wind breaks, or watering to prevent fugitive dust emissions from material storage piles • Restrict access to construction areas and storage piles during periods of inactivity using gates, fencing, and/or onsite security personnel. -3- 6.0 Contingency Planning Alternative control measures may become necessary in the event that the current dust control strategy is not adequate or effective for conditions. An alternative plan may require addition planning, permitting, or other regulatory compliance requirements to implement. In this case, the current activities at the project site would necessarily be suspended until such time as the alternate dust control methods could be put into place. Task: Implement alternative action to fugitive dust control plan and to each specific source if deemed necessary to comply with federal, state, and local air quality regulations: • Provide field personnel and contractors with contact information for responsible individuals in cases where control measures need to be escalated in response to weather conditions (i.e. increased windiness). - Use an appropriate alternative dust inhibitor if water does not prove to be effective under normal circumstances, and obtain all regulatory permissions for the use of chemical suppressants on the project site. • Use vegetative blankets or other methods for cover of topsoil, spoil, and bulk material storage piles if immediate cover becomes necessary. • Attempt to locate alternative sources of bulk material closer to the project site if fugitive dust emissions or other impacts from contract haul trucks on state or federal highways become an issue with public safety or regulatory compliance. -4 Appendix A Contacts 5 ENCANA PERSONNEL Name Title Office CeII CONTRACT CONSTRUCTION 6 Article 4-203.L Traffic Study Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OA Project No. 014-2797 BASIC TRAFFIC ANALYSIS ENCANA OIL & GAS K19NE LAYDOWN YARD GARFIELD COUNTY, COLORADO O6's(' OLSSON ASSOCIATES OA Project No. 014-2797 January 2015 760 Horizon Dr., Suite 102 1 Grand Junction, CO 81506 1 970.263.7800 1 Fax 970.263.745 K19NE Laydown Yard January 2015 Encana Oil & Gas INTRODUCTION & OBJECTIVE This document summarizes findings of a Basic Traffic Analysis performed for the Encana Oil & Gas K19NE Laydown Yard. The current permitted use of the site is as a well pad. Although the site is also being used for some equipment storage today, the laydown yard is proposed to be permitted as an additional use on the property. The laydown yard will be used to store equipment and material associated with natural gas operations. It is expected that the lifespan of the site will be approximately 30 years. The site is approximately one mile south of the Garfield County Regional Airport. The facility is located on Lot 3 of Section 19, Township 6 South, Range 92 West of the 6th Principal Meridian in unincorporated Garfield County. The subject site encompasses approximately 5.17 acres. The property is owned and operated by Encana Oil & Gas. The objective of this analysis is to provide traffic data for the additional land use, review the existing road network, and provide traffic projections for public roads impacted by site traffic. EXISTING ROAD NETWORK Regional trips to this facility will use the 1-70 exit near the Garfield County Regional Airport (Exit 94). Vehicles traveling to the site will drive south for approximately 4 miles along CR 315 to the intersection of CR 315 & CR 333 and make a right turn. They would then travel approximately 2.8 miles to the private access road where they would turn right to access the site. It should be noted that the private access drive is shared with a well pad. Table 1 tabulates roadway geometry and characteristics for the county roads used by vehicles visiting this site. An alternate route is to travel west along CR 346 (Rifle -Silt Rd) for approximately 2 miles to CR 352. Vehicles will then turn east onto CR 352 (Airport Road) and travel approximately 1.3 miles to CR 333 (Hunter Mesa Rd). Vehicles will then turn south onto CR 333 and travel approximately 0.8 miles to a private access road, turn left, and drive 0.5 miles to access the site. Both routes follow Garfield County preferred haul routes. Table 1: Roadway Geometry and Characteristics Roadway Lanes Road Width Roadway Type Speed Limit Condition Year of Impmt. Functional Classification CR 352 2 40' Asphalt 35 mph Good ('02) 2004 Minor Collector CR 333 2 16' Gravel 35 mph Fair ('02) - Local CR 346 2 24' Asphalt 35 mph Good ('02) 2005 Minor Collector CR 315 2 24' Asphalt 35 mph Good ('05) 2005 Minor Collector Basic Traffic Analysis Page 1 K19NE Laydown Yard January 2015 Encana Oil & Gas BACKGROUND TRAFFIC Background traffic volumes were obtained from the Garfield County Road & Bridge department. The count data included 2014 counts at all roadways planned to be used by traffic traveling to the K19NE Laydown Yard. The background traffic volumes are shown in Table 2 below. Table 2: Background Traffic Roadway 2014 CR 352 975 CR 333 125 CR 346 755 CR 315 805 TRIP GENERATION AND DISTRIBUTION Trip generation is generally determined using rates found in the ITE Trip Generation manual. Rates from this publication are applied to values related to the size of the proposed site to estimate the trips expected to enter and exit the site. In this case, no rates are provided for facilities similar to these. To estimate trips expected for this site, information was gathered regarding the expected traffic based on the existing operations. Existing vehicle activities during daily operations consist of one (1) pickup truck (two trips per day) for daily well inspections. Based on the new use of the site, it is expected that an additional two trips will visit the site daily. The site may also experience one additional heavy truck every two months. The pickup and heavy truck trips related to the storage use will store or remove materials that will be used in daily operations or during drilling and completing wells in the area. The majority of vehicles accessing this facility will originate from other activities in the immediate area. Many of the existing trips to this site occurring over the public road system are associated with the daily monitoring of the site and are within background traffic projections. The same personnel, in fact, monitor multiple sites on a daily basis. The trips associated with the storage use will also originate from the surrounding natural gas operations in the general area. They would include existing trips that haul materials and equipment in and out of the greater field. These are trips that would now be contained within the general area. Aside from public roads in the immediate vicinity of the site, the storage use is not expected to generate additional traffic and has the potential to reduce traffic on some roadways by providing a place for extra materials and equipment that would otherwise be hauled in or out of the larger field. Basic Traffic Analysis Page 2 K19NE Laydown Yard January 2015 Encana Oil & Gas ROADWAY ANALYSIS Existing Parcel Current land use on the subject parcel is natural gas development. The majority of existing traffic on area county roads south of the airport is related to natural gas development activities and very limited agricultural activities. Roadways near the Garfield County Regional Airport including CR 346, CR 352, and portions of CR 315 also serve the airport as well as other municipal uses like the Colorado Mountain College, Garfield County Sheriff and Road & Bridge offices, and the Tri- State Generation and Transmission generating station. State Highway Crossings and Access There are no state highway crossings along the haul routes. Similarly, there will be no access to the site from a state highway. Intersection of CR 352 & CR 346 The intersection of CR 352 & CR 346 is a "T" intersection with CR 346 as the stop -controlled minor approach. Sight distance as measured from the stop sign on CR 346 is adequate looking east and west. There is a right -turn deceleration lane leading into a free right (yield -controlled) for the westbound traffic along CR 352. There is also a left -turn deceleration lane for eastbound traffic on CR 352. Southbound CR 346 has a two-lane approach at this intersection. It is not expected site traffic will negatively impact intersection operations. Intersection of CR 352 & CR 333 The intersection of CR 352 & CR 333 is a "T" intersection with CR 333 as the stop -controlled minor approach. Sight distance as measured from the stop sign on CR 333 is adequate looking east and west. There are left -turn deceleration lanes for traffic on CR 352. It should be noted that trucks are not permitted along CR 352 to the east of this intersection. It is not expected site traffic will negatively impact intersection operations. Intersection of CR 315 & CR 346 The intersection of CR 315 & CR 346 is a four leg intersection with CR 346 as the stop -controlled minor approach. Sight distance as measured from the stop sign on CR 346 is adequate looking north and south. The Exit 94 1-70 ramp terminal is located approximately 200 feet north of this intersection. Sight distance photos were taken at the stop -controlled legs of this intersection and can be seen at the end of this document. It is not expected site traffic will negatively impact intersection operations. Basic Traffic Analysis Page 3 K19NE Laydown Yard January 2015 Encana Oil & Gas Intersection of CR 315 & CR 333 The intersection of CR 315 & CR 333 is a "T" intersection with CR 333 as the stop -controlled minor approach. Sight distance as measured from the stop sign on CR 333 is adequate looking north and south along CR 315. It is not expected site traffic will negatively impact intersection operations. RECOMMENDATIONS Based on the expected trip generation rates discussed above, the increase in average daily traffic is not expected to be significant on roads generally used by the public. The county roads discussed will see only a minor increase in traffic. The total traffic volumes will remain very low and can be accommodated by the existing roadways. The addition of traffic generated by the proposed updated site use does not increase existing volumes to levels required for State or County permits. Attachments Vicinity Map and Haul Routes Map Sight Distance Photos Basic Traffic Analysis Page 4 LEGEND - Site Location - Preferred Haul Route - Alternative Haul Route X,XXX - Background ADT Encana K19 Laydown Yard Garfield County, CO OLSSON ® Vicinity Map and Haul Routes ASSOCIATES FIGURE 1 O\OLSSON ASSOCIATES Encana K19 Laydown Yard — Site Roadway Photos OA #14-2797 PHOTO 1: West leg looking north onto County Road 315 from County Road 346. PHOTO 2: West leg looking south onto County Road 315 from County Road 346. Article 4-203.M Water Supply and Distribution Plan Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OAProject No. 014-2797 O LSSO N ASSOCIATES Water Supply and Distribution Plan Encana Oil & Gas (USA) Inc. K19NE Storage Facility (Laydown Yard) SECTION 4-203.M. WATER SUPPLY AND DISTRIBUTION PLAN. The Encana Energy K19NE Storage Facility does not require potable water source for personnel or freshwater for sanitary facilities, landscaping or day to day operations of the facility. The operations of the facility will be similar to other natural gas operations in relatively remote areas of Garfield County. No potable water will be provided at this facility. The proposed use is an unmanned facility with personnel onsite only for short intervals. Personnel provide their own potable water carried in their vehicles. Encana makes potable water available at their field office to staff and contractors. Sanitary facilities will not require a source of water and will be provided by portable toilets located at numerous sites in the field per OSHA standards. Landscaping is not being proposed and a water system is not required to maintain any plantings. The storage facility does not use water in its daily operation. 760 Horizon Drive, Suite 102 TEL 970.263.7800 Grand Junction, CO 81506 FAX 970.263.7456 www.olssonassociates.com THIS PAGE LEFT BLANK FOR TWO-SIDED DUPLICATION. Article 4-203.N Wastewater Management and System Plan Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OAProject No. 014-2797 O LSSO N ASSOCIATES Waste Management and System Plan Encana Oil & Gas (USA) Inc. K19 Storage Facility SECTION 4-203.N. WASTEWATER MANAGEMENT AND SYSTEM PLAN. The operations of the facility will be similar to other natural gas operations in relatively remote areas of Garfield County. Staff will not be assigned to the facility on a regular basis. Personnel will be at the facility only for short periods of time. Workers will be loading and unloading materials and providing facility maintenance and inspections. Sanitary facilities are provided by portable toilets placed at numerous sites in the field per OSHA standards. These portable toilets are maintained by Redi Services of Rifle, Colorado. All waste is hauled to a licensed treatment facility. A "Will Serve" letter is provided documenting the maintenance of these sanitary facilities. 760 Horizon Drive, Suite 102 TEL 970.263.7800 Grand Junction, CO 81506 FAX 970.263.7456 www.olssonassociates.com (............. rleewcr arsveers, ..e dr REDI SERVICES, LLC 2143 AIRPORT RD. RIFLE, CO. 81650 970-625-0233 SUBJECT: WILL SERVE LETTER COMPANY: Encana Oil and Gas LOCATIONS: All Locations Serviced 2/09/2015 Redi Services will provide Encana Oil and Gas with Porta John Units on designated locations Redi Services will service and maintain these units and dispose of the waste at an approved disposal site. At this time we are disposing of the waste at The West Garfield County Landfill. Thanks, Mario Ramirez Redi Services, LLC Trucking / Waste Management Manager This page left blank for two-sided printing. Article 7 Standards Analysis Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OA Project No. 014-2797 OLSSON ASSOCIATES Article 7 — Standards Analysis Encana Oil & Gas (USA) Inc. K19 Storage Facility (Laydown Yard) DIVISION 1. GENERAL APPROVAL STANDARDS FOR LAND USE CHANGE PERMITS SECTION 7-101. ZONE DISTRICT USE RESTRICTIONS The subject property is located in the Rural (R) zone district of Garfield County on Lot 3 of Section 19, Township 6 South, Range 92 West of the 6th Prime Meridian. The proposed use is considered a Storage use according to Table 3-403: Use Table of the Garfield County Unified Land Use and Development Code. This use requires a Limited Impact Review (LIR) to obtain a Land Use Change Permit (LUCP). SECTION 7-102. COMPREHENSIVE PLAN AND INTERGOVERNMENTAL AGREEMENTS The K19 Laydown Yard generally conforms to the Garfield County Comprehensive Plan. The site is designated in the Garfield County Comprehensive Plan 2030 as a Residential Medium High (RMH) area with a residential density of 2 to 6 acres per dwelling unit. According to the Comprehensive Plan, facilities that are appurtenances to oil/ gas development activities (compressors, etc.) are considered appropriate in all land uses so long as they meet the respective mitigation requirements of the Land Use and Development Code to maintain compatibility with surrounding land uses. The existing use is not within an area governed by an intergovernmental agreement. SECTION 7-103. COMPATIBILITY The proposed site is located within the boundaries of an 88.5 acre property. The storage use would be limited to a 5.17 acre area. Rural residential, natural gas development, light industrial, and agriculture are the predominate uses on the subject parcel and surrounding properties. The closest residential use to the proposed laydown yard is approximately 0.75 miles to the north The proposed use is intended to provide a centralized and convenient storage location for the natural gas operations in the immediate area. This proposed use is compatible with and supportive of the adjacent uses. SECTION 7-104. SOURCE OF WATER A source of potable water will not be required for workers utilizing the site. This facility is not manned on a regular basis and does not require a water distribution and wastewater system to properly function. Workers will provide their own potable water in their trucks. Encana will provide personnel bottled or potable water at their field office. A source of water is not required for the 760 Horizon Drive, Suite 102 TEL 970.263.7800 Grand Junction, CO 81506 FAX 970.263.7456 www.olssonassociates.com Encana Oil & Gas (USA) Inc. K19 Laydown Yard operation of the facility. The site will be used as a storage facility. Water will not be required for the operation of sanitary facilities. Portable toilets will be used, and all wastes will be hauled to a licensed treatment facility. Water will not be required for landscaping. No landscaping is proposed at this site. SECTION 7-105. CENTRAL WATER DISTRIBUTION AND WASTEWATER SYSTEMS A. Water Distribution System As stated above, the proposed facility will not require a source of water or a central water distribution system. B. Wastewater Systems As stated above, the proposed facility will not require a centralized wastewater system. Portable toilets will be used and wastes will be hauled to a licensed disposal facility. SECTION 7-106. PUBLIC UTILITIES The facility will not require public utilities in order to operate. SECTION 7-107. ACCESS AND ROADWAYS A. Access to Public Right of Way No new roads are proposed to accommodate the additional storage use. Access to the subject property is from County Road (CR) 333 via a private access road. The existing roadway and access are adequate for the anticipated low traffic volumes. Dust from the private driveway will be mitigated as appropriate. B. Safe Access The road functions adequately for its intended use and is typical of existing roads providing access to natural gas production facilities in Garfield County. C. Adequate Capacity The proposed facility will generate little traffic and the current road system has adequate capacity to support the proposal. See Traffic Analysis and Road Assessment reports included with this application for additional details. D. Road Dedications The road has a 45 foot wide Access Easement (Garfield County Reception Number 650315). This private road does not provide access to residential uses nor is it used by the general public on a regular basis. No new public roads are being built or dedicated as part of this project. Standards Analysis Page 2 Encana Oil & Gas (USA) Inc. K19 Laydown Yard E. Impacts Mitigated County roads will experience minor impacts from this project. The proposed storage use may actually reduce traffic impacts by limiting the need to haul equipment in and out of the area when it is needed. See the Traffic Analysis for further information. F. Design Standards The access driveway meets most of the Primitive Roadway/Driveway standards of Table 7- 107 of the Land Use and Development Code. The private access road does not meet the design standards for road grade, cross slope, or ditches. See Road Assessment report for more information. A Waiver of Standards request is being submitted as part of this submittal. SECTION 7-108. USE OF LAND SUBJECT TO NATURAL HAZARDS According to the Natural and Geological Hazard Assessment Report the project area is not subject to avalanche, rockfall, landslide, alluvial fan, slope, mud flow or debris fan, expansive soils, collapsible soils, faults, or radiation hazards. The Potts Loam soils are listed as having a high risk of corrosion to uncoated steel and a low risk of corrosion to concrete. This should not present a significant hazard. SECTION 7-109. FIRE PROTECTION Encana makes their Emergency Response Plan available to the appropriate fire protection district. If requested, Encana will orientate the appropriate fire protection district regarding this facility. DIVISION 2. GENERAL RESOURCE PROTECTION STANDARDS SECTION 7-201. AGRICULTURAL LANDS A. No Adverse Affect to Agricultural Operations The proposed use will not directly affect any agricultural operation. B. Domestic Animal Controls Dogs and other domestic animals will not be permitted on the property or allowed to interfere with livestock. C. Fences The site will not be fenced. D. Roads No new roads will be constructed to access this facility, and the existing road will be maintained. E. Irrigation Ditches The proposed use will not impact irrigation ditches. Standards Analysis Page 3 Encana Oil & Gas (USA) Inc. K19 Laydown Yard SECTION 7-202. WILDLIFE HABITAT AREAS A. Buffers Visual or sound buffers are not necessary to screen activity areas from habitat areas. According to the Wildlife Assessment accompanying this submittal, it is not likely that the proposed laydown yard would adversely affect federally listed wildlife species. No additional vegetation removal is associated with the laydown yard, since it was previously disturbed. As noted in the Wildlife Assessment, the project site was surveyed for the potential habitat for the greater sage grouse. No potential habitat exists in the area for the greater sage grouse. The greater sage grouse inhabits vast, continuous sagebrush communities. B. Locational Controls of Land Disturbance The project area is currently disturbed. No additional wildlife habitat disturbance will occur. According to the Biological Assessment the site is within CPW Game Management Unit 42 and Data Analysis Units D-12 and E-14. The site does not occur within CPW mapped migration corridors or habitat linkages for elk or deer. The site occurs within CPW mapped mule deer Overall Range, Severe Winter Range, Winter Range and Winter Concentration Area. The site occurs within CPW mapped elk Overall Range, Winter Range, Severe Winter Range, and Winter Concentration Area. C. Preservation of Native Vegetation The site will be reclaimed after the facility is no longer utilized and will be revegetated with native plant species. Noxious weeds will be controlled during the life of the facility and during the re-establishment of native plants. D. Habitat Compensation No critical wildlife habitat will be disturbed at this site. E. Domestic Animal Controls Domestic animals will not be kept on the site. SECTION 7-203. PROTECTION OF WATERBODIES A. Minimum Setback The proposed laydown yard is located approximately 500 feet from an unnamed drainage to the west, and 757 feet from an unnamed drainage to the east. The project area will be more than 35 feet from the Typical and Ordinary High Water elevation of this stream. B. Structures Permitted in Setback There will not be any structures located in this setback area. C. Structures and Activity Prohibited in Setback There will not be any structures or activities located in the buffer zone. Standards Analysis Page 4 Encana Oil & Gas (USA) Inc. K19 Laydown Yard D. Compliance with State and Federal Laws The facility will comply with all applicable state and federal laws. SECTION 7-204. DRAINAGE AND EROSION The site is an existing disturbed surface area. Minor additional surface disturbance may be required to accommodate the Grading and Drainage Plan. BMPs will be used to protect water bodies from stormwater runoff during the operation of this facility. This facility is more than 100 feet from a water body, and it does not create more than 10,000 square feet of impervious area. SECTION 7-205. ENVIRONMENTAL QUALITY A. Air Quality This facility will not cause air quality to be reduced below acceptable levels established by the Colorado Air Pollution Control Division and will comply with appropriate Colorado air emissions regulations as applicable. The equipment and materials proposed to be stored on site will not require an APEN. B. Water Quality This facility will be operated in compliance with all applicable State and Federal hazardous material regulations. There will be no hazardous materials stored at this proposed site. Implementation and adherence to Encana's Stormwater Management Plan (SWMP) BMPs and Spill Prevention Control and Countermeasures Plan (SPCC) will assure that water quality is protected. SECTION 7-206. WILDFIRE HAZARDS A. Location Restrictions The site is in a low wildfire hazard area according to the Garfield County on-line GIS map resources. F. Development Does Not Increase Potential Hazard The facility will not increase the potential intensity or duration of a wildfire, or adversely affect wildfire behavior or fuel composition. G. Roof Materials and Design No structures are being proposed. This standard is not applicable. SECTION 7-207. NATURAL AND GEOLOGIC HAZARDS A Natural and Geological Hazard Assessment Report is included with this application under a separate tab. A. Utilities B. Trenches for water pipelines, natural gas pipelines, and electrical lines are not expected to be associated with the proposed development of the K19 Storage Yard. The laydown Standards Analysis Page 5 Encana Oil & Gas (USA) Inc. K19 Laydown Yard yard will be used to store sections of pipe and equipment above grade for use elsewhere in the area and region. C. Development in Avalanche Hazard Areas The site is not located in a known avalanche hazard area. Winters are cold in the mountainous areas of Garfield County, and valleys are colder than the lower parts of adjacent mountains due to cold air drainage. Average seasonal snowfall in Garfield County is 50 inches. The greatest snow depth at any one time during the period of record from 1951 to 1974 was 29 inches recorded at Rifle, Colorado approximately 30 miles to the east of the proposed site. Much of the Rifle area is at a higher elevation than the town of Rifle and is somewhat cooler and receives more precipitation. Avalanches are not expected to affect the proposed laydown yard, since it is located at elevations between 6000 feet and 8000 feet. D. Development in Landslide Hazard Areas The Site is not in an area of landslides or potential landslides. E. Development in Rockfall Hazard Areas Rockfall areas are not a geological hazard in the area of the Site, but may exist in areas along Mamm Creek and its tributary drainages. F. Development in Alluvial Fan Hazard Area The Site is not in an area mapped as an alluvial fan hazard area. G. Slope Development Slope is not a geologic hazard in the vicinity of the site, but is in areas to the north and west along West Mamm Creek and Mamm Creek drainages. H. Development on Corrosive or Expansive Soils and Rock The Potts Loam soils are listed as a high risk of corrosion to uncoated steel and a low risk of corrosion to concrete. These soil characteristics are not expected to pose a geologic hazard for the proposed development at the K19NE Storage Yard. The shrink -swell potential for the Potts Loam is low to moderate. Therefore, expansive soils are not a geologic hazard at the K19NE Storage Yard. I. Development in Mudflow Areas The Site is not located in an area of mapped mud flow or debris fan areas. J. Development Over Faults No significant faults have been mapped or are known in the K19NE Storage Yard. The Site is located to the northwest of the Divide Creek anticline which was formed as a result of movement along a blind thrust fault associated with the uplift of the Colorado Rocky Mountains. Standards Analysis Page 6 Encana Oil & Gas (USA) Inc. K19 Laydown Yard SECTION 7-208. RECLAMATION After the completion of Encana's natural gas production in the area, the facility will be decommissioned and reclaimed in accordance with the reclamation plan provided in this submittal and COGCC Series 1000 Rules. All of Encana's surface disturbances (final reclamation requirements) are covered under a statewide bond. DIVISION 3. SITE PLANNING AND DEVELOPMENT STANDARDS SECTION 7-301. COMPATIBLE DESIGN A. Site Organization The site was designed to accommodate the functional and efficient operations, monitoring and maintenance of the facility. B. Operational Characteristics Operation of the proposed storage facility will be consistent with nearby uses. Adjacent lands will not be impacted by the generation of vapor, dust, smoke, glare, noise or vibration. Noise will not exceed standards established by the COGCC. The facility will be unmanned but accessible to Encana personnel 24 hours a day. There will be minimal impacts, if any, to the existing roadway system during the operational phase. C. Buffering The site and the surrounding properties areas located in a Rural (R) zone district. Additional buffering is not required. D. Materials Buildings are not being proposed. This standard is not applicable. SECTION 7-302. OFF-STREET PARKING AND LOADING STANDARDS Adequate parking will be made available to accommodate Encana's personnel during regular operation, inspection and maintenance of the facility. All activities on this site will be conducted out of any public right-of-way. SECTION 7-303. LANDSCAPING STANDARDS This type of industrial use is exempt from the landscape standards of the Development Code. SECTION 7-304. LIGHTING STANDARDS A. Downcast Lighting Any lighting will be directed inward, towards the interior of the site. B. Shielded Lighting Any exterior lighting will be shielded so as not to shine directly onto other properties. Standards Analysis Page 7 Encana Oil & Gas (USA) Inc. K19 Laydown Yard C. Hazardous Lighting Light from the site will not create a traffic hazard or be confused as traffic control devices. D. Flashing Lights The facility will not contain flashing lights. E. Height Limitations There will be no light sources exceeding 40 feet in height on the site. SECTION 7-305. SNOW STORAGE STANDARDS Snow will be stored in a vacant section of the existing disturbed area. SECTION 7-306. TRAIL AND WALKWAY STANDARDS The proposed site is located in a rural area of Garfield County. Multimodal connections are not appropriate or feasible. DIVISION 10. ADDITIONAL STANDARDS FOR INDUSTRIAL USES SECTION 7-1001. INDUSTRIAL USE A. Residential Subdivisions This site is not located in a platted residential subdivision. B. Setbacks The laydown yard will maintain at least a 100 foot setback from adjacent property lines. C. Concealing and Screening The site is concealed from neighboring properties by a combination of topography and distance. The majority of equipment and materials stored on site will be low -profile in nature. D. Storing The site is not in a flood zone or other natural hazard zone that would transfer the materials off site. All products will be stored according to all national, state and local codes. The laydown yard will maintain at least a 100 foot setback from adjacent property lines. E. Industrial Wastes All industrial wastes will be disposed of in a manner consistent with Federal and State statures and requirements of the CDPHE. F. Noise Noise levels will not exceed state noise standards pursuant to C.R.S., Article 12, Title 25. The site will be used as a storage facility/laydown yard and any operational stationary equipment is associated with the Oil and Gas Drilling and Production uses located in the area. No Standards Analysis Page 8 Encana Oil & Gas (USA) Inc. K19 Laydown Yard additional equipment will be permanently installed on the site that could potentially create a noise nuisance. G. Ground Vibration This facility will not generate ground vibrations perceptible beyond the boundary line of the property. H. Hours of Operation The facility will not generate noise, odors, or glare beyond the property boundaries greater than what is allowed under the Land Use Development Code. Activities that do generate these impacts within the established standards will occur between the hours of 7:00 a.m. and 7:00 p.m. Monday through Saturday. I. Interference, Nuisance, or Hazard This facility will not emit heat, glare, radiation or fumes which will interfere with uses on adjacent properties or constitute a public nuisance. The proposed use will not exceed the standards established by Garfield County or the COGCC. Standards Analysis Page 9 Encana Oil & Gas (USA) Inc. K19 Laydown Yard THIS PAGE LEFT BLANK FOR TWO-SIDED DUPLICATION. Standards Analysis Page 10 Article 7-1003.0 Emergency Response Plan Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OA Project No. 014-2797 encana.. natural gas ethos "f vAxi9'.inL E,.;icriycE Emergency Response Plan U.S. Division Quick Reference Guide ethos C:.NE aTIONAl E%CEALICoa CE (Condensed copy for permit submittals) Encana's complete Emergency Response Plan is on file with all applicable Fire Districts and updates are provided as necessary Updated Sep 2012 safe36 ji encana ENIERGENCY RESPONSE PLAN U.S.A. DIVISION SRBU EMERGENCY RESPONSE REPORTING TEMPLATE Document No: ERP -0042 SRBU Revised By'Date: Reviewed Ilytnate: ERPComm105.26.2010 Approved Ey/Date: ERPComm/05.26.2010 SBU: Narne of Event: Date:2010 Location: Secured [Yes No Town, State: _:1 , 1. Time of the call. {Military Time) 2. What is the location of the emergency? What has happened? Location?: What Happened?: 3. Has anyone been hurt? ❑No ❑Yes If so, Who? How? 4. Who is the most senior Encana or Company representative on location? 5. Who is the most senior Encana or company representative on location who will be the INCIDENT COMMANDER? Do they have the proper Incident Commander Training? ~6. Incident Commander Trained? No Yes Based on your assessment, what Level of Emergency are you declaring? Level 1 ® Level 2 ❑ Level 3 ❑ 7. Who are you appointing as OPERATION CHIEF? 8. Do not respond to a man down, or to the emergency, until you have completed a Risk Assessment, gained control and understanding of the emergency, and can assure life safety of the responders. Have you completed a Risk Assessment? N ❑ Y ❑ 1lINcoon roiled Document ent %Viten 1'rin i J 1'a1i i 1 of 2 encana. PoKira/ tras EMERGENCY RESPONSE PLAN U.S.A. DIVISION SRBU EMERGENCY RESPONSE REPORTING TEMPLATE Document No: ERP -0042 SRBU Revised By/Date: Reviewed By)Date: ERPCommJ05.262010 Approved By/Date: ERPConmtl05.262010 9. Are there FIRST RESPONDERS on location? No ❑Yes Time of Arrival: Who arrived? 10. Have you set up an INCIDENT COMMAND POST, if so, where? No Yes Location of the Incident Command Center? 11. Based on your initial assessment, what is your proposed preliminary response strategy? 12. I will act as EMERGENCY MANAGER, and activate the EOC. Plan on calling in to the EOC, using the Emergency Notification Conference Call Number, within 15 minutes. Emergency Manager Activated at: Emergency Operations Center Activated at: We will be using EOC Conference Line: EOC 1 and EOC 2: 1-877-445-2224 EOC 1: • Profile # '•1211113 Password 10131 EOC 2: Profile # 242 i o I.4 Password 10141 EOC 3: ❑ 120 or more incoming calls} NDIIII American Dial-ln: 1-866-4U0-1788 International Dial -lo: (647) 427-2433 Conference code: 835 2'18 48.06 Leader PIN: 2846 13. I will notify EXECUTIVE LEAD, EHS OFFICER, and put together the EMERGENCY MANAGEMENT TEAM. Executive Lead Notified: — No ❑ Yes ❑ Time: EHS Officer Notified: No ❑ Yes ❑ Time: EMT Notified: No [] Yes ❑ Tirne: 14. Start to put together a local INCIDENT COMMAND TEAM. Incident Deputy Safety Officer: Liaison Public Information Operations Planning Lo . istics Commander: Incident Commander: _ Officer: Officer: Section Chief: Section Chief: Section Chief: l ncootrolled Document When Printed face 2 of 2 Eraser• enc Classification / Levels Definition 1 Criteria EMERGENCY LEVELS Examples ina not re eel area -s + eci tc risks or threats} LEVEL 1 - Onsite incidents where control of the hazard has been obtained but the potential exists for the imminent loss of control due to deteriorating conditions. o Immediate control of the hazard has been established using available resources, however, conditions are not improving and/or resources are being depleted. o Injuries to onsite personnel of a moderate that are impact. o Public safety is not threatened, however there is, or may be, a public perception of moderate risk to human health or the environment. o Environmental impacts are confined to the site and have limited potential to impact offsite. o All control and relief systems are functioning normally. o Any controlled situation, outside of normal operation conditions, where the ability to maintain control using onsite resources is in question or offsite resources are required to maintain control such as a fire or explosion where imminent control of the fire is probable. o Injuries to personnel requiring offsite medical attention. - o Spills and releases that are contained onsite but have the potential to extend offsite. o Any incident requiring the advisory notification of the public of a non -routine, onsite occurrence. o Weather conditions (i.e., tornado) which may threaten personnel and operations. o Potential social / political unrest, labor disputes Uncontrolled I]ocumen i When Printed 3 LEVEL 2 - An Incident where control,of the hazard has been lost but where {oj,mtermittent control of the hfjr'd is possible. -. o Control of the hazard has been lost, however, through the application of available resources intermittent control is being obtained or hazard control is imminent. a Injuries to onsite personnel that are of a major impact. o Public safety is not threatened, however, there is or may be a public perception of significant risk to human health or the environment o Environmental effects extend offsite and are resulting in minor or short- term detrimental impacts. o Some control and relief systems are not o.erational. m minent o Any uncontrolled hazard where the ability to regain control using available resources is imminent or intermittent control is being achieved using available resources such as pipeline integrity failure_ o Injuries to personnel which have or are likely to result in a lost time (beyond the day of the occurrence) injury or short term health impact. o Spills or releases that extend offsite and are, or will, result in minor or short-term detrimental impacts. o Any incident requiring the notification of the public of a potential or imminent threat to human health or the environment, such as or pipeline rupture. o Some control and/or relief systems are not operational. o Imminent security threats, social / political unrest, and labor disputes_ o Severe weather threats which threatens personnel and/or operations. o Overdue vehicle or aircraft. o LEVEL 3 - An incident where control of the hazard has been lost, imminent control is not possible and public safety is, or has the potential, to be threatened. • o Control of the hazard has been lost and regaining control is not imminently possible. o Onsite personnel have sustained injuries with a serious impact. o Public safety is being, or has the imminent potential to be, jeopardized. o Environmental impacts are significant, extend offsite and have the potential to result in long-term environmental degradation. o Key control and relief functions have failed and are not o • eratin. correctl . o Any situation where control of a hazard has been lost and regaining control is not imminently possible such as loss of well control or failure of essential well control equipment. o Injuries to personnel which have or are likely to result in permanent disability, long term health impacts or death o Any incident that has necessitated the evacuation or sheltering of public such as or a catastrophic facility fire or loss of process control. o Spills or releases that have extended off site and are, or likely to, result in significant and substantial detrimental impact to the environment. o Key control and relief systems are not operational. o Act of terrorism, violence, social/political unrest. o Severe weather impacting personnel and/or operations. o Overdue vehicle or aircraft, missing .erson. Ir lr..I 14 un'. 4 1 ACTIVATION AND NOTIFICATION REQUIREMENTS Receiving an Emergency Call - Typical Notification First Responder to notify Incident Commander Level 1 - as soon as possible Level 2 or 3 - IMMEDIATELY Report direct or via 24 Hr Emergency Number 1-877-386-2200 Encana local Incident Commander (IC), notified (Reception / Answering Service will initiate call -down. The first person contacted establishes the Incident Commander position, until delegated) • Notify/dispatch Operator to Investigate - Sr. Operator Or Representative establishes the First Responder position - Two operators (buddy system) required when i-I2S 2 10 ppm known to be present First Responder determines if the inciden involves an Encana facility? Incident Commander - Contact individual who reported the incident to advise outcome First Responder Initiate standard operating/ maintenance procedures 4I—NO Yes Incident Commander and First Responder will assess the incident. Is it an Emergency? Yes Determine Level of Emergency (see Emergency Levels in this Section) 0 'Incident Commander - Contact Operating Company - Contact individual who reported the incident to advise outcome First Responder - Provide assistance, if possible, until relieved by Operating Company. - Maintain contact with operating company and Incident Commander until relieved of duties Identify Scope/Area affected (exposure zone) and: - Activate ERP, notify support personnel (field and Region), emergency services, initiate regulatory notifications. - First Responder establishes Command Post (CP) and initiates response actions. - Incident Commander notifies authorities and contacts Encana's Emergency Manager. - Incident Commander contacts persons who reported incident to advise them of outcome. - RECORD YOUR ACTIONS! Uncontrolled Document When Printed 5 First Responder Actions 6 Protect Yourself 71 Approach the incident from upwind and uphill, if possible. ❑ Position vehicle far enough away from the release, allowing for a safe retreat, ifnecessaty. ❑ Resist the urge to rush in, others cannot be helped if you are injured. ❑ Avoid any contact with liquids, mists, sludge's, gases, vapors and smoke. Sound the Alarm ❑ Announce level of emergency. ❑ Direct others to safe areas and alert other personnel. Call for Help ❑ Notify control room, local office and or the on-call supervisor. ❑ Confirm emergency services has been dispatched. ❑ Activate Emergency Response Plan. Assume Command ❑ Size up incident and make report. ❑ Confirm location (if necessary). ❑ Situation found. ❑ Make assignments (as necessary). Summon additional help and technical assistance as required. Do not hesitate to summon assistance; it can always be canceled if not needed. ❑ Tactical considerations: o Life safety, 0 Environmental protection, and o Incident stabilization, 0 Property conservation. ❑ Zoning: o Utilize, with caution, the U.S. DOT Emergency Response Guidebook for recommended actions if MSDSs are unavailable for released material, a Establish hazard / hot zone (use fire line tape for hot line), o Establish and mark warm zone (decontamination corridor), and o Establish cold zone (set security line). ❑ Immediately provide for proper decontamination of responders and/or injured. ❑ Transfer command (as necessary). Assess Hazard ❑ If immediate rescue is required, it should only be attempted when the rescuers are fully aware of the risks posed to them, they are wearing protective clothing, as required, utilizing a bare minimum number of personnel. If the hazards are unknown or exceptionally life-threatening, the rescuer should consider waiting until the situation has been assessed by the IC, SO, and the EHS/HazMat Unit. Secure the Area 171 Restrict access to location or area. ❑ Utilize law enforcement agencies (Emergency Alert System) and any other available resources to evacuate or shelter in-place exposed victims. 1. lilonlii,1 ,.1 Naimoli imoli 1I lig r hint Transfer of Command The process of moving the responsibility for incident command from one Incident Commander (IC) to another is called "transfer of command." It should be recognized that transition of command on an expanding incident is to be expected. It does not reflect on the competency of the current IC. The most important steps in effectively assuming command of an incident in progress are: Assessment & Briefing O Perform assessment of incident situation with existing IC. ▪ Receive adequate briefing by the current IC in face-to-face meeting. The briefing must cover the following items: o Lricident history (what has happened), o Priorities and objectives, o Current plan, o Resource assignments, o Incident organization, o Resources ordered/needed, o Facilities established, o Status of communications, o Any constraints or limitations, o Incident potential, and o Delegation of Authority. Written Summary Report L7 Incoming IC to receive written summary to assist in incident briefings. This form contains: o Incident objectives, o A place for a sketch map, o Summary of current actions, o Organizational framework, and o Resources summary. Notice of Command Change I 1 Determine an appropriate time for transfer of command. O Provide notice of a change in incident command to: o Emergency Management Team (through dispatch), o General Staff members (if designated), o Command Staff members (if designated), and o All incident personnel and agencies. The incoming IC may give the out -going IC another assignment on the incident. O There are several advantages of this: o The out -going IC retains first-hand knowledge at the incident site, and o This strategy allows the out -going IC to observe the progress of the incident and to gain experience. iilri,lled 7 encana Western Operations Emergency Notification Chart Piceance FIRST RESPONDER 1. Evacuate: Account for all personnel 2. Call for help: Quick Reference Guide / Notification Charts 3. Secure the scene: Establish IC Command INCIDENT COMMANDER SAFETY & HEALTH Brad Ankrum Clyde Marks W 970-285-2630 W 970-285-2681 C 435-260-1673 C 970-309-3061 Operations Control Center Doug Rosa (Parachute) W 970-285-2686 W 970-285-2615 C 970-210-2073 C 970-301-1319 Parachute OCC Alternate Operations Control Center (Denver) W 866-244-0062 Mitch Steinke W 970-285-2654 C 303-918-3844 Ryan Tompkins W 970-285-2685 C 970-640-3294 EMERGENCY MANAGER HUMAN Jeff Johnson W 720-876-5091 C 303-881-7666 Ken Retzlaff W 720-876-5231 C 303-301-4176 Level 1 Level 2 Level 3 EHS On Call Number 1-855-759-1855 Axiom Injury Case Management 877-502-9466 USA Security Watch Center 1-855-822-01 F9 SAFETY & HEALTH FINANCE ENVIRONMENTAL Laura Lancaster W 970-285-2617 C 970-216-1251 HUMAN Lindsey Kruckenberg W 970-285-2711 C 970-456-3229 MEDIA EHS OFFICER John Keil W 720-876-3705 C 214-755-2081 EXECUTIVE LEAD COMUNICATIONS EXECUTIVE MANAGEMENT Jeff Balmer C 720-206-6382 RELATIONS Byron Gale EMERGENCY MANAGEMENT TEAM LEGAL FINANCE LOSS CONTROL & CORPORATE HUMAN SECURITY MEDIA COMMUNITY RELATIONS, INSURANCE COMUNICATIONS RESOURCES RELATIONS LAND, REGULATORY Matt Baskind Kelly Vandamme David Platt Alicia Olson Chris Casebolt Ken Jackson Doug Hock Jason Oates W 720-876-3403 W 720-876-3829 W 403-645-7514 W 720-876-5486 W 720-876-3622 W 970-285-2830 W 720-876-5096 W 720-876-3228 C 303-653-4308 C 303-829-0573 C 403-606-2877 C 720-412-6802 C 303-898-6501 C 970-309-2655 C 303-328-7048 C 720-785-4806 Corporate HQ — Calgary — Security Desk CORPORATE PRESIDENT & CHIEF OPERATING OFFICER On Call 24 Hours — (402) -645 - 7777 CHIEF EXECUTIVE OFFICER Mike McAllister Doug Suttles TACTICAL SUPPORT TEAM AGENCY CONTACTS EMERGENCY CONTACTS BLM (Grand Junction) 970-244-3050 National Response Cntr 800-424-8802 Grand River Hospital (rifle) 970-625-1510 EMS, Fire, Police 911 BLM (Silt) 970-876-9000 Federal OSHA 800-321-6742 Garfield County 970-625-8095 BLM (Meeker) 970-878-3800 CO One -Call 800-922-1987 Mesa County 970-242-6707 COGCC (Rifle) 970-625-2497 Pipeline ref. 811 Rio Blanco County 970-878-9600 CDPHE 877-518-5608 Colorado State Patrol 970-824-6501 Cisco Meeting Place Express Toll Free: 1-877-445-2224 Long Distance: 1-403-645-2224 Meeting ID to start the meeting 2421013# Date Reviewed: 10/31/2014 Date Revised: 10/31/2014 Password 10131# Uncontrolled Document if Printed To join the meeting 2421013# Password 10131# Article 7-107 Roadway Assessment Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OA Project No. 014-2797 O\OLSSON ASSOCIATES ROAD ASSESSMENT ENCANA OIL & GAS (USA) INC. K19NE STORAGE FACILITY (LAYDOWN YARD) The following road assessment is to address Garfield County's Policy 04-01 waivers for roads and demonstration of compliance. The purpose of the road assessment is to assess the subject road for the Garfield County roadway standards listed within Table 7-107 of the Land Use Development Code. The Encana Oil & Gas (USA) Inc. (Encana) K19NE Storage Facility (Laydown Yard) Road Assessment begins where the road turns off of County Road (CR) 333 in the SESE quarter of Section 24, Township 6 South, Range 93 West of the 6th P.M. and terminates in Lot 3 of Section 19, Township 6 South, Range 92 West of the 6th P.M. at the Encana K19NE Laydown Yard. This road is approximately 0.5 miles in length from CR 333 to the Laydown Yard. Included in the road assessment is a road through private land shared for access to Encana Pad K19CNE, which is approximately 0.2 miles in length. The remaining 0.3 miles is on Encana property and is used solely to access the K19NE Laydown Yard. Encana performs the maintenance on the entire road. Field observations and data gathering were conducted on November 18, 2014. The observations are summarized as an attachment to this assessment. Statement of Adequacy This road is typical of roads providing access to natural gas production facilities in Garfield County. The roadway is adequate for the intended use. Geometry of Road The following table compares this road to the Garfield County roadway standards found in Table 7-107 of the Land Use and Development Code for Primitive Road/Driveway. 760 Horizon Drive, Suite 102 Grand Junction, CO 81506 TEL 970.263.7800 FAX 970.263.7456 www.olssonassociates.com Table 7-107: Roadway Standards Design Standards Design Capacity (ADT) Primitive/Driveway = Road Assessment 0-20 4-6 Minimum ROW Width (Feet) 15 to 301 45 Lane Width (Feet) Single Lane 12 13.2 to 23 Shoulder Width (Feet) 0 0.6 to 5.5 Ditch Width (Feet) 32 0 to 7.5 Cross Slope 2% 0.6% to 7.3% Shoulder Slope n/a 0.6% to 7.3% Design Speed n/a n/a Minimum Radius (Feet) 40 50 Maximum % Grade 12% 14.4% Surface Native Material Gravel 760 Horizon Drive, Suite 102 Grand Junction, CO 81506 TEL 970.263.7800 FAX 970.263.7456 www.olssonassociates.com K19NE Storage Yard January 2015 Encana Oil & Gas (USA) Inc. 1 As determined adequate in an engineering review. Primitive road shall be dedicated ROW, driveway can be dedicated as either an easement or ROW. 2 If determined necessary for adequate drainage. The road is across private land, and there is a 45 ft. wide Access Easement (Garfield County Reception Number 650315). The road width varies between 13.2 and 23 feet. This meets the minimum requirement. Where ditches are present, they range in width from 2.0 to 7.5 feet. The ditches are fairly shallow. The cross slope varies between 0.6% and 7.3%. In some places, the road slopes toward the side of the road without a ditch, including some areas where the road is crowned. There is no posted speed limit on the road. The horizontal radii range from 50 feet to 310 feet. All the turns meet the minimum 40 foot standard radius. The grade for the road varies between 0.4% and 14.4%. The areas where the grade is greater than 12% occur in short sections. The road is surfaced with gravel. The road geometry changes occasionally with maintenance activities. Cross slopes change during maintenance operations. The road was built to follow the general topography of the area with minimal change to the natural grade. Safety/Structural Issues A significant drop off adjacent to the road was observed on the right side of the road approximately from stations 13+50 to 19+00 and on the left side of the road approximately from stations 16+70 to 24+00. Mitigation methods should be evaluated during maintenance operations. Overall the roadway did not exhibit obvious safety or structural issues during the date of the field observation, November 18, 2014. Maintenance Encana does all of the maintenance on the road. The road is inspected on a regular basis for maintenance issues. Maintenance includes grading as needed to remove washboard and repair potholes. The road surface is graveled as needed to maintain the road base with attention to dust control. Speeds are low to promote safety and reduce road damage. Travel Demand Average Daily Traffic (ADT) for the proposed project is expected to be less than 20 vehicles per day (VPD) as shown in the Basic Traffic Study prepared by Olsson Associates, dated January 2015 (study). As a result, this roadway is being assessed according to the standards for a Primitive Road/Driveway. Access Road Assessment Page 2 K19NE Storage Yard January 2015 Encana Oil & Gas (USA) Inc. As mentioned within the study, traffic associated with the use as a storage facility at the site is primarily pickup trucks, 4 trips per day. Additionally, a heavy truck will access the site one time every two months. Typical daily volumes will be approximately 4 trips per day with the potential for 6 trips. Other Evidence of Compliance Section 7-107.A Access to Public Right -of -Way The private road to the site has direct access to CR 333. A copy of the driveway permit is included at the end of this section. Section 7-107.8 Safe Access Access to the site is consistent with other similar uses. Section 7-107.0 Adequate Capacity Traffic congestion is not anticipated as a result of the proposed use. The roadway capacity is expected to be sufficient for the intended use. Section 7-107.D Road Dedications The road has a 45 foot wide Access Easement (Garfield County Reception Number 650315). Section 7-107.E Impacts Mitigated Based on the expected trip generation rates discussed in the Basic Traffic Study, the increase in average daily traffic is not expected to increase on County Roads such that a modification of the existing access permit would be required. The total traffic volumes are expected to remain very low and are anticipated to be accommodated by the existing roadway. Conclusions The road assessment identified areas that deviate from the Design Standards in Table 7-107 for ditch width, cross slope, and maximum grade. Where there are discernible ditches along the road, the ditch width varies. Locations 1, 2, 4-7 have ditch widths less than 3 feet. Some of the road has ditches on one side only or no ditches at all. In some areas, the cross slope inclines toward the side of the road where there is no ditch. As a result, areas will have ponding water that could lead to the need for additional maintenance over time. There are no defined shoulders though most areas of the roadway are wide enough to consider shoulders as an extension of the lane width. There is a dedicated turn -out at station13+25 with a width of 24.5 feet. The cross slope varies from 0.6% to 7.3% along the road. The road geometry changes occasionally with maintenance activities. While ponding may occur in areas of shallow cross slope, the road is inspected on a regular basis for maintenance issues, which are addressed in a timely manner. The grade for the road varies between 0.4% and 14.4%. The areas where the grade is greater than 12% occur in short sections. Access Road Assessment Page 3 K19NE Storage Yard January 2015 Encana Oil & Gas (USA) Inc. The road functions adequately for its intended use and is typical of existing roads providing access to natural gas production facilities in Garfield County. Wyatt E. Popp, PE Access Road Assessment Page 4 USER: alheritier a U) E 0) 0) 0 Q O 0 0 00 00 0) 1 00 L_ x 00 00 X 0 J 0 r0 00 o CN N ,- 0I-0 0 N 0 0 00 iC CD I- 00 CULVERT CROSSING NOTE: INFORMATION SHOWN ON THIS EXHIBIT IS APPROXIMATE. DATA REFLECTED WITHIN THE TABLE IS NOT BASED ON A TOPOGRAPHIC SURVEY. INFORMATION SHOWN IS BASED ON MEASUREMENTS TAKEN DURING A SITE VISIT ON NOVEMBER 18, 2014. LOCATION STATION CROSS SLOPE GRADE ROAD WIDTH LEFT DITCH RIGHT DITCH 1 6+50 6.8% -9.4% 23.0' NONE 2.0' 2 8.20 7.2% - 19.0' NONE NONE 3 11+80 5.8% -11.5% 13.2' 3.5' 5.0' 0' 150' 300' 600' SCALE IN FEET PROJECT NO: 014-2797 DRAWN BY: ABL DATE: 12/01/2014 ENCANA K19NE STORAGE FACILITY (LAYDOWN YARD) ROADWAY ASSESSMENT GARFIELD COUNTY, COLORADO O\OLSSON® ASSOCIATES 760 Horizon Dr. Suite 102 Grand Junction, CO 81506 TEL 970.263.7800 SHEET 1 USER: alheritier CULVERT CROSSING PC: 16+22.32 PT: 16+16.12 R51' PC: 16+02.76 i► LOCATION 6 0' 100' 200' 400' SCALE IN FEET NOTE: INFORMATION SHOWN ON THIS EXHIBIT IS APPROXIMATE. DATA REFLECTED WITHIN THE TABLE IS NOT BASED ON A TOPOGRAPHIC SURVEY. INFORMATION SHOWN IS BASED ON MEASUREMENTS TAKEN DURING A SITE VISIT ON NOVEMBER 18, 2014. LOCATION STATION CROSS SLOPE GRADE ROAD WIDTH LEFT DITCH RIGHT DITCH 4 16+70 2.2% —14.4% 16.5' 2.5' NONE 5 19+10 0.6% 1.7% 16.0' NONE NONE 6 23+00 7.3% 10.3% 18.0' NONE 7.5' 7 27+00 4.8% 4.7% 23.0' NONE NONE PROJECT NO: 014-2797 DRAWN BY: ABL DATE: 12/01/2014 ENCANA K19NE STORAGE FACILITY (LAYDOWN YARD) ROADWAY ASSESSMENT GARFIELD COUNTY, COLORADO O\OLSSON® ASSOCIATES 760 Horizon Dr. Suite 102 Grand Junction, CO 81506 TEL 970.263.7800 SHEET 2 Garfield County Application for Driveway Permit Person Obtaining Permit: Encana Oil and Gas(USA), Inc. Application Date: 5/18/2005 County Road Number: 333 District: Silt Permit Number: GRB05 D-38 Termination Date: 6/18/2005 Inspector: Jake Mall hereby requests permission and authority from the Board of County Commissioners to construct a driveway approach (es) OD the right-of-way off of County Road, 333, 1 mite South of Intersection of CR 333 and CR 352 on CR 333, located on the East side of road for the purpose of obtaining access to property. Applicant submits herewith for the consideration and approval of the Board of County Commissioners, a sketch of the proposed installation showing all the necessary specification detail including: 1. Frontage of lot along road. 2. Distance from centerline of road to property line. 3. Number of driveways requested 4. Width of proposed driveways and angle of approach. 5. Distance from driveway to road intersection, Warty. 6. Size and shape of area separating driveways if more than one approach. 7. Setback distance of building(s) and other structure improvements. 8. No unloading of equipment on county road, any damage caused to county road will be repaired at subdivision expense. 9. Responsible for two years from the date of completion. General Provisions 1) The applicant represents all parties in interest, and affirms that the driveway approach (es) is to be constructed by him for the bona fide purpose of securing access to his property and not for the purpose of doing business or servicing vehicles on the road right of way. 2) The applicant shall furnish all labor and materials, perform all work, and pay all costs in connection with the construction of the driveway(s). All work shall be completed within thirty (30) days of the permit date. 3) The type of construction shall be as designated and/or approved by the Board of County Commissioners or their representative and all materials used shall be of satisfactory quality and subject to inspection and approval of the Board of County Commissioners or their representative. 4) The traveling public shall be protected during the installation with proper warning signs and signals and the Board of County Commissioners and their duly appointed agents and employee shall be held harmless against any action for personal injury or property damage sustained by any reason of the exercise of the Permit. 5) The Applicant shall assume responsibility for the removal or clearance of snow, ice, or sleet upon any portion of the driveway approach (es) even though deposited on the driveway(s) in the course of the County snow removal operations. Encana Available Credit Credit from 2004 Utility Permit GRB05-U-12 Utility Permit GRBO5-U-2 Utility Permit GRB05-U-5 Driveway Permit GRB05-D-33 Driveway Permit GRB05-D-32 Driveway Permit GRB05-D-38 $(1,181.50) $ 165.00 $ 165.00 $ 202.50 $ 75.00 $ 75.00 $ 75.00 Available Credit as of 513/05 L24 00 Specifications 1. A driveway approach is understood to be that portion of the county road right -of way between the pavement edge and the property line that is designed and used for the interchange of traffic between the roadway and abutting property. 2. At any intersection, a driveway shall be restricted for a sufficient distance from the intersection to preserve the normal and safe movement of traffic. at is recommended for rural residence entrances that a minimum intersection clearance of 50 feet be provided and for rural commercial entrances a minimum of 100 feet be provided.) 3. All entrances and exits shal] be so located and constructed that vehicles approaching or using them will be able to obtain adequate sight distance in both directions along the county road in order to maneuver safely and without interfering with county road traffic. 4. The Applicant shall not be permitted to erect any sign or display material, either fixed or Movable, on or extending over any portion of the county road right-of-way. 5. Generally, no more than one approach shall be allowed any parcel or property the frontage of which is less than one hundred (100) feet. Additional entrances or exits for parcels having a frontage in excess of one hundred 100) feet shal] be permitted only after showing of actual convenience and necessity. 6. All driveways shall be so located that the flared portion adjacent to the traveled way will not encroach upon adjoining property. 7. No commercial driveway shall have a width greater than thirty (30) feet measured at right angles to the centerline of the driveway except as increased by permissible radii. No noncommercial driveway shall have a width greater than twenty (20) feet measured at right angles to the centerline of the driveway, except as increased by permissible radii. 8. The axis of an approach to the road may be at a right angle to the centerline of the county road and of any angle between ninety (90) degrees and sixty (60) degrees but shall not be less than sixty (60) degrees. Adjustment will be made according to the type of traffic to be served and other physical conditions. 9. The construction of parking or servicing areas on the county road right-of-way is specifically prohibited. Commercial establishments for customer vehicles should provide off -the -road parking facilities. 10. The grade of entrance and exit shall slope downward and away from the road surface at the same rate as the normal shoulder slope and for a distance equal to the width of the shoulder but in no case less than twenty (20) feet from the pavement edge. Approach grades are restricted to not more than ten percent (10%). 11. All driveways and approaches shall be so constructed that they shall not interfere with the drainage system of the street or county road. The Applicant will be required to provide, at his own expense, drainage structures at entrances and exits, which will become an integral part of the existing drainage system. The Board of County Commissioners or their representative, prior to installation, must approve the dimensions and types of all drainage structures. Note: This permit shall be made available at the site where and when work is being done. A work sketch or drawing of the proposed driveway(s) must accompany application. No permit will be issued without drawing, blueprint, or sketch. 6) In the event it becomes necessary to remove any right-of-way fence, the posts on either side of the entrance shall be surely braced before the fence is cut to prevent any slacking of the remaining fence and all posts and wire removed shall be turned over to the District Road Supervisor of the Board of County Commissioners. 7) No revisions or additions shall be made to the driveway(s) or its appurtenances on the right-of-way without written permission of the Board of County Commissioners_ 8) Provisions and specifications outlined herein shall apply on all roads under the jurisdiction of the Board of County Commissioners of Garfield County, Colorado, and the Specifications, set forth on the attached hereof and incorporated herein as conditions hereof. 9) Final inspection of driveway will be required upon completion and must be approved by person issuing permit or representative of person issuing permit. The inspection and sign off must be done prior to any CO from the Building and Planning Department being issued. Special Conditions: 1. Driveway Width- Stift 2. Culvert required? True Size: 15 inch by 80ft 3. Asphalt or concrete pad required? False Size of pad: 4. Gravel portion required? True Length: lOOft 5. Trees, brush and/or fence need to be removed for 'visibility? False 6. Distance and Direction: 7. Certified Traffic Control Required? False 8. Work zone signs required? True In signing this application and upon receiving authorization and permission to install the driveway approach (es) described herein the Applicant signifies That he has read, understands and accepts the foregoing provisions and conditions and agrees to constructthe driveway(s) in accordance with the accompanying specification plant reviewed and approved by the Board of County Commissioners. Signed: Addr ncana3il and Gas(USA), inc. Telephone Number: l` X7 - r `i-21,,: I � Permit granted 511812005, subject to the provisions, specifications and conditions stipulated herein. For Board of County Commissi Iers' of Garfield County, Colorado: Representative of Garfield County Road and Bridge Signature Article 7-202.C.3 Noxious Weed Plan Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OA Project No. 014-2797 encana.. Introduction natural gas Encana Oil & Gas (USA) Weed Management Effort Summary July, 2010 Encana Oil & Gas (USA) (Encana) is currently implementing several integrated weed management techniques in the Piceance Basin. Whenever possible, weed infestations are assessed on an individual basis, such that the best, site-specific weed management techniques may be executed. Encana employs the benefits of chemical, mechanical, biological, cultural or an integration of these methods in everyday weed management throughout the Piceance field. Chemical Management Chemical means of weed control are the most commonly utilized weed management technique at this point in time. The frequency of this treatment method is mostly attributed to the financial feasibility, speed and relative consistency in results associated with herbicide applications. In general, most Encana sites are inventoried, monitored and sprayed a minimum of 3-4 times per year, based upon the accessibility and known infestation status of the site. With every visit, commercial pesticide applicators monitor previous treatments for effectiveness, inventory for new or surviving plants and treat the site. Documentation of this event is recorded into Encana's Noxious Weed Management Database as reported on contractor invoices and daily pesticide application records. The first site visit and herbicide application is done in the early spring of the approaching growing season or in the late fall of the previous year. At this time, non-selective, residual herbicide applications are made as a safety precaution on active sites. This treatment type also prevents annual weed infestations that are commonly observed on fresh and frequently disturbed sites. During this treatment, pesticide applicators inspect the location and surrounding areas for very young newly emerging weeds, or rosette "flushes" in the circumstance that the site is treated in the fall. The second site visit and treatment is done in spring to early summer. This treatment is intended to target early perennials (hoary cress, primarily), biennial rosettes and annual "obnoxious weeds" such as Russian thistle and kochia. Again, pesticide applicators will inventory the area for later maturing plant species such as Russian knapweed. During the third site visit a mid to late summer inventory is conducted with intentions to spray late - bolting biennials and budding perennials; furthermore, mechanical removal of flowers and seed heads on biennial species (most commonly musk thistle) may also be done around this time. Lastly, on many sites, a late -summer to fall herbicide treatment may be applied on creeping perennials such as Canada thistle and Russian knapweed in order to best capture the opportunity for the use of translocated herbicides. Following this step, the non-selective treatments described above will be used where applicable, and the cycle will start again. This treatment plan is highly site -dependent, thus variations inevitably occur based upon individual site characteristics (i.e. elevation, soils, topography, moisture, etc.) and also upon the various label requirements and recommended target growth stages of the herbicides being used. Mechanical Weed Management Second to chemical means of control, Encana utilized mechanical weed management on a frequent basis. Large-scale mowing or "brush -hogging" projects are primarily executed on reclaimed sites that support a desirable plant component, but which also support a significant, spatially -competitive weed community. Generally, these treatments target annual, non -listed weed types. Encana makes a special effort to utilize mechanical weed management techniques in the early stages of reclamation, so as not to disturb newly establishing native and desirable plants. Additionally, Encana will employ mechanical removal as a second resort when chemical weed control means are not an effective option. These treatments are typically goaled towards the removal of weeds when the growth stage of the target specie is not compatible with chemical control (i.e. removal of thistle seed heads following bolt and flower). Additionally, in the case of fuels reduction for safety purposes, mechanical control is preferred with the objective at hand. Generally, mechanical weed removal is conducted throughout the summer and early fall. Biological Weed Management Encana has introduced the presence of biological weed control agents in recent years and is in the early stages of monitoring and considering the continued use of similar resources. At this time, Encana has released a limited number of biological control agents. These have been released at sites that were not candidates for chemical or mechanical control, either based upon topography, infestation size, spatial relativity to potentially impacted wildlife habitat or a combination of these factors. All releases to date have been established near the property boundaries of weed -harboring neighbors and have been incorporated with some chemical and mechanical means. Casual ocular monitoring has been conducted and landscape photographs have been taken and recorded. Due to the youth of these projects and the expected long-term results of biological controls, little change has been observed at this point. Cultural Weed Manaqement As cultural weed management tools, Encana emphasizes on prevention, early detection/ rapid response (EDRR), and grazing monitoring and rotation grazing, where applicable. As prevention, Encana requires Third Party companies and contractors to clean dirt -moving equipment prior to mobilization into new areas. Encana provides annual, in-house weed identification trainings to their Environmental Field Coordinators to assist in early detection. To support rapid response, Environmental Field Coordinators also carry tools and instructions for mechanical weed removal, in the circumstance that a few, isolated weeds are approached during regular field activities. Lastly, where Encana has authority, livestock grazing plans, pasture rotations and monitoring and inventory plans are implemented to assess and minimize the impacts of grazing on weed infestations and wildlife habitat. Conclusion Due to the primarily fragmented, linear structure of the surfaces managed by Encana, successful weed control proves to be challenging and dynamic. Additionally, because Encana's surfaces are relatively small in scale, a great deal of communication and cooperation between landowners, county representatives and federal government agencies is necessary to effectively and sustainably control, isolate and eradicate weed infestations on a local, landscape basis. To meet these challenges, Encana utilizes standardized reporting, invoicing and inspection processes that are all logged and documented in an Access Database. Figures Encana Oil & Gas (USA) Inc K19NE Storage Facility (Laydown Yard) OA Project No. 014-2797 217724100476 BOARD OF COUN COMMISSIONERS 0 GARFIELD COUN 17919100511 ILDSON, SC & LINDA 217919300128 ENCANA OIL'& GAB(USA) INC'" 217725100546 AIRPORT LAND PARTNERS LIMITED 217930100522/ BRYNILDSON, SCOTT W & LINDA S r Subject Parcel 92W O K19NE Storage Yard =I Parcels K19NE Storage Yard Boundary Subject Parcel Perennial Stream WE PROJECT NO: 014-2797 DRAWN BY: JWH DATE: 11/25/2014 ADJACENT LAND OWNERS MAP K19NE STORAGE YARD ENCANA OIL & GAS (USA) INC. GARFIELD COUNTY, COLORADO O\OLSSON ASSOCIATES 760 HORIZON DR., SUITE 102 GRAND JUNCTION, CO 81506 TEL 970.263.7800 FAX 970.263.7456 FIGURE ALO -1 SINGLE SPEC.PURPOSE- FAM.RES.-LAND IMPROVEMENTS MEADOW HAY LAND-AGRICLTRL WASTE LAND EXEMPT -COUNTY -IMPS. 24 35 AC TO UT 100 AC WASTE LAND O 68 93W Subject Parcel • MEADOW HAY LAND-AGRICLTRL • . O K19NE Storage Yard f Subject Parcel T1 K19NE Storage Yard Boundary x,1500 Foot Buffer W Y E s PROJECT NO: 014-2797 DRAWN BY: JWH DATE: 11/25/2014 ADJACENT LAND USE MAP K19NE STORAGE YARD ENCANA OIL & GAS (USA) INC. GARFIELD COUNTY, COLORADO O\OLSSON A5SOCIATE5 760 HORIZON DR., SUITE 102 GRAND JUNCTION, CO 81506 TEL 970.263.7800 FAX 970.263.7456 FIGURE ALU -1 O K19NE Storage Yard L I K19NE Storage Yard Boundary - Subject Parcel yid Elk Severe Winter Range Perennial Stream Elk Winter Concentration Area PROJECT NO: 014-2797 DRAWN BY: JWH DATE: 11/25/2014 ELK HABITAT MAP K19NE STORAGE YARD ENCANA OIL & GAS (USA) INC. GARFIELD COUNTY, COLORADO O\OLSSON ASSOCIATES 760 HORIZON DR., SUITE 102 GRAND JUNCTION, CO 81506 TEL 970.263.7800 FAX 970.263.7456 FIGURE E-1 O K19NE Storage Yard Perennial Stream r Subject Parcel Intermittent Stream 3 Mile Buffer Floodplain W Y E s PROJECT NO: 014-2797 DRAWN BY: JWH DATE: 11/25/2014 FLOODPLAIN MAP K19NE STORAGE YARD ENCANA OIL & GAS (USA) INC. GARFIELD COUNTY, COLORADO O\OLSSON A5SOCIATE5 760 HORIZON DR., SUITE 102 GRAND JUNCTION, CO 81506 TEL 970.263.7800 FAX 970.263.7456 FIGURE F-1 iQg Gravels and alluviums (Pinedale and Bull Lake age)4 a mit rr• Qg Gravels and alluviums (Pinedale and Bull Lake age) Two Wasatch Formation includin ( gFort,., yUnion equivalent at base) and Ohio Creek Formation Qg Gravels and alluviums (Pinedale and Bull Lake age) O K19NE Storage Yard n Subject Parcel K19NE Storage Yard Boundary — Perennial Stream W Y E s PROJECT NO: 014-2797 DRAWN BY: JWH DATE: 11/25/2014 GEOLOGY MAP K19NE STORAGE YARD ENCANA OIL & GAS (USA) INC. GARFIELD COUNTY, COLORADO O\OLSSON ASSOCIATES 760 HORIZON DR., SUITE 102 GRAND JUNCTION, CO 81506 TEL 970.263.7800 FAX 970.263.7456 FIGURE G-1 117709 282954 1411114...- 13 25935 / 25923 / 2&. 160303 272793 -'. ,47135 229121 Subject Parcel 0 K19NE Storage Yard 1 Mile Buffer 0 Water Well Perennial Stream K19NE Storage Yard Boundary Subject Parcel Spring/Seep Intermittent Stream Floodplain W Y E s PROJECT NO: 014-2797 DRAWN BY: JWH DATE: 11/25/2014 HYDROGRAPHY MAP K19NE STORAGE YARD ENCANA OIL & GAS (USA) INC. GARFIELD COUNTY, COLORADO O\OLSSON ,R> A5SOCIATE5 760 HORIZON DR., SUITE 102 GRAND JUNCTION, CO 81506 TEL 970.263.7800 FAX 970.263.7456 FIGURE H-1 O K19NE Storage Yard Subject Parcel ® Mule Deer Severe Winter Range n K19NE Storage Yard Boundary Perennial Stream Mule Deer Winter Concentration Area PROJECT NO: 014-2797 DRAWN BY: JWH DATE: 11/25/2014 MULE DEER HABITAT MAP K19NE STORAGE YARD ENCANA OIL & GAS (USA) INC. GARFIELD COUNTY, COLORADO O\OLSSON ASSOCIATES 760 HORIZON DR., SUITE 102 GRAND JUNCTION, CO 81506 TEL 970.263.7800 FAX 970.263.7456 FIGURE MD -1 0 K19NE Storage Yard Subject Parcel n K19NE Storage Yard Boundary Perennial Stream W Y E s PROJECT NO: 014-2797 DRAWN BY: JWH DATE: 11/25/2014 SOILS MAP K19NE STORAGE YARD ENCANA OIL & GAS (USA) INC. GARFIELD COUNTY, COLORADO O\OLSSON A 5 SOCIATE 5 760 HORIZON DR., SUITE 102 GRAND JUNCTION, CO 81506 TEL 970.263.7800 FAX 970.263.7456 FIGURE S-1 O K19NE Storage Yard n K19NE Storage Yard Boundary Subject Parcel N PROJECT NO: 014-2797 DRAWN BY: JWH DATE: 11/25/2014 TOPOGRAPHIC MAP K19NE STORAGE YARD ENCANA OIL & GAS (USA) INC. GARFIELD COUNTY, COLORADO O\OLSSON A5SOCIATE5 760 HORIZON DR., SUITE 102 GRAND JUNCTION, CO 81506 TEL 970.263.7800 FAX 970.263.7456 FIGURE T- 1 Subject Parcel 0 K19NE Storage Yard Parcels 3 Mile Buffer Perennial Stream PROJECT NO: 014-2797 DRAWN BY: DATE: JWH 11/25/2014 VICINITY MAP K19NE STORAGE YARD ENCANA OIL & GAS (USA) INC. GARFIELD COUNTY, COLORADO CAOLSSON ASSOCIATES 760 HORIZON DR., SUITE 102 GRAND JUNCTION, CO 81506 TEL 9702617800 FAX 970.263.7456 FIGURE V-1