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HomeMy WebLinkAboutApplication.. Garfield County Community Development Department 108 81h Street, Suite 401 Glenwood Springs, CO 81601 (970) 945-8212 www.garfield-countv.com .. Pleas e contact!Phil Va ughan a t 970-625-5350 with .ques tions an TYPE OF GRADING INVOLVED PARTIES Property Owner: Eva C . Uphoff Trust dated August 7, 2013_ Phone: ( 970 ) 625-5350 Mailing Address: and Timothy James Uphoff c/o PVCMI 1038 County Road 323 Rifle, CO 81650 Contractor: TEP Rocky Mountain LLC Phone: ( 970 ) 263-2736 Mailing Address: c/o Jeff Kirtland-P.O. Box 370 Parachute, CO 81635 Architect: Jeff Johnson Architectural, PC c/o Jeff Johnson Phone: ( 970 } 625-0580 Malling Address: 136 East 3rd St. Rifle, CO 81650 Engineer: Sopris Engineering , LLC c/o Yancy Nichol Phone:( 970 ) 704-0311 Mailing Address : 502 Main Street Carbondale, CO 81623 PROJECT NAME AND LOCATION Project Name: Terra Energy Partners Trail Ridge Employee Housing Facility Describe Work: Overlot excavation and access roadway widening Job Address: Section 3 , Township 5 South, Range 97 West of the 6th P.M . Garfield County, CO Latitude 39a38'57.931"N Longitude 108°15'43.878"W Assessor's Parcel Number: 2137-012-00-001 Sub. Lot _Block Earthwork (square feet): 20,037= 0 .46 acres Earthwork (Cubic Yards): 3 ,500 cubic yds. prox. ALL UTILITIES MUST BE LOCATED PRIOR TO ANY GRADING NOTICE Authority. This application for a Building Permit must be signed by the Owner of the property, described above, or I an authorized agent. If the signature below is not that of the Owner, a separate letter of authority, signed by the Owner, must be provided with this Application. Legal Access. A Building Permit cannot be issued without proof of legal and adequate access to the property for I purposes of Inspections by the Building Division. 1 Other Permits. Multiple separate permits may be required: (1) State Electrical Permit, (2) County ISDS Permit, (3) another permit required for use on the property Identified above, e.g. State or County Highway/ Road Access or a State Wastewater Discharge Permit. Vold Permit. A Building Permit becomes null and void if the work authorized is not commenced within 180 days of the date of issuance and if work is suspended or abandoned for a period of 180 days after commencement. CERTIFICATION I hereby certify that I have read this Appllcation and that the information contained above ls true and correct. I understand that the BuUdlng Division accepts the Appllcation, along with the plans and specifications and other data submitted by me or on my behalf (submittals), based upon my certification as to accuracy. Assuming completeness of the submittals and approval of this Application, a Bullding Permit will be issued granting permission to me, as Owner, to construct the structure(s) and facilities detailed on the submittals reviewed by the Building Division. In consideration of the issuance of the Build Ing Permit, I agree that I and my agents will comply with provisions of any federal, state or local Jaw regulating the work and the Garfield County Building Code, ISDS regulations and applicable land use regulations (County Regulation(s)). I acknowledge that the Building Permit may be suspended or revoked, upon notice from the County, if the location, construction or use of the structure(s) and facility(ies), described above, are not in compliance with County Regulation(s) or any other applicable law. I hereby grant permission to the Bulldlng Division to enter the property, described above, to inspect the work. I further acknowledge that the Issuance of the Bullding Permit does not prevent the Building Official from: (1) requiring the correction of errors In the submittals, if any, discovered after issuance; or (2) stopping construction or use of the structure(s) or facility(ies) if such is in violation of County Regulation(s) or any other appllcable law. Review of this Application, Including submlttals, and inspections of the work by the Building Division do not constitute an acceptance of responsiblllty or llabllity by the County of errors, omissions or discrepancies. As the Owner, I acknowledge that responsibility for compllance with federal, state and local laws and County Regulations rest with me and my authorized agents, including without limitation my architect designer, engineer and/ or builder. I hereby acknowledge that I have read and understand the Notice and Certification above as well as have provided the required information which is correct and accurate to the best of my knowledge. t:1 A o~"" ~ -Philip B. Vaughan-Agent 11/17/16 \j~'?\)?~ Property Owner Print and Sign Date OFFICIAl 'USE ONbY Permit Fee: Misc Fees: Total Fees: Fees Paid: DO--oo- 11-IB· 7.Q~ Date r . Project Information Project# 267-14 Title Terra Energy Partners-Trail Ridge Employee Housing Facility Address City, State, Zip Garfield County, CO Country USA From Contact Philip Vaughan Company Phil Vaughan Construction Inc. Address 1038 County Road 323 City, State, Zip Rifle, CO 81650-8607 Country United States of America Phone (970) 625-5350 Fax (970) 625-4522 I Remarks Andy, I hope that you are doing well today. Management, To Contact Company Address City, State, Zip Country Phone Fax Transmittal Transmittal # Date: 11/17116 Due Date Sender Subject Andy Schwaller Transmittal Hand Grading Permit Documents Garfield County Community Development- Building Division 108 8111 St. Glenwood Springs, CO 81601 USA (970) 945-8212 1. Please find attached the documents for permit review for a grading permit for the Terra Energy Partners Trail Ridge Employee Housing Facility. This is the same application and materials that we submitted in Fall of 2014 for the WPX Energy Trail Ridge Employee Housing Facility. WPX Energy Rocky Mountain, LLC has had a name change to TEP Rocky Mountain LLC. Supporting documents have been attached. 2. Revegetation. Please find attached page 21 of Dave Pesnichak's 618/15 Staff Report indicating that revegetation security is not required. I have also attached 5fl8115 email correspondence with Steve Anthony and Dave Pesnichak confirming this. 3. Cattle guard installation. As per my 11/17/16 letter to Tamra Allen, and the attached reply from Dave Pesnichak, we are requesting that the cattle guard installation be delayed until 611/17. Thank you for your assistance and please contact me with questions. Sincerely, Phil Vaughan 3 4 5 6 7 8 9 11117116 1 1 1 1 0 Review 0 Review 0 Review 0 Review 0 Information 0 Information 0 Review Page 1 of2 Transmittal 10 0 Review 11/t7/t6 Page2of2 . --I \ ( Delaware The First State CONFORMED CAJflY z, JJUJl'JOJr "· ~, &CRl:!'ARr or mn: or n:s ssm °' mLAJJARIJ, DO m:RDr CllR!l'UY !l'1flJ Ar.l'ACDD :rs A DOii MD ~ a:u>r or 1'& Cl:R1'p-:rCAs OE ~ or •rn>.it ZBRGr aoc:2r ornCB OB nm :t'WWW!l'r-acorm DAY 01' APRIL, ..l,J), 2016, M 3:12 O'CLOCK P.JI. 3388640 8100 SR# 20162502586 You "'IY ftfffy this Clftlllcate onllne 1t mrp.dellwarqav/authver .shtml AuthentJcatlon:202199006 Date: 04-22-16 IUI 1~.1l:DIMHH.Hr11Wrifllt'~N:.W~W 11111 Ree~UonM: 8711U3 0610312018 10i 31t:rl Aft Jean AlMl'loa 2 Of 2 tea F .. :11e .oo Dao FH ;0 .00 GARFIELD COUNTY co s111a 1r Dtlln" lalalJ' ,, 11111 DltWm .. c..,m ... Dllnnd ll:U RI K'll/Jtl' flLED U1U RI041JJ1111' a 211masil -i.MaMtr mH4I STATEOFDE~WARE CERTD'ICATE OF AMENDMENT 1. Name of Limited LlabHltyCompany. WPX Energy Rocky Mountain, LLC 2. The Cadftcato of Pormlllon of the limited Uablllty company is hereby 1111aded 11fbllows: ~he name of the limited liability company ia maended to TBe Rocky Mountain LLC. IN wnNB8S WBDEOr, tho undersigned havo executed this CertlfiClfc on tho z1; day of April A.D. 201.6 • By: .,/./< t,. r{ Authorized Penon(s) Name: Mj,chael S. Land Print or Type ·' January 27. 2015 Garfield County Building and Planning Department Mr. Fred Jarman 108 81h Street , Suite 40 I Glenwood Springs, CO 80601 RB : Limited Impact Review -Trail Ridge Employee Housing Facility Section 3, Township 5 South, Range 97 West, 61h P.M. Garfield County. Colorado Dear Mr. Jarman, Per that certain Trail Ridge Employee Housing Facility Site Lease and Agreement effective November 30, 2014, by and between The Eva C. Uphoff Trust dated August 7, 2013 and Timothy James Uphoff ("Uphofl's") and WPX Energy Rocky Mountain, LLC ("WPX"), Uphoffs have granted WPX the right to access, construct, operate, and remove Lessee's Facilities at the Trail Ridge Employee Housing Facility in Section 3, Township 5 South, Range 97 West. Uphoffs authorize WPX, at WPX's sole cost, to obtain any permits, licenses, permissions, or approvals, including, but not limited to, driveway permits, highway access permits, building permits, and land use permits which WPX deems necessary or convenient to conduct, certify, confirm, evidence, facilitate, or effectuate the Permitted Use. Sincerely, Eva C. Uphoff Trust dated August 7, 1013 By:~~ Name:TIJl10thYJphoff Title: Trustee By: a::..£Z ,?' ~ Name: TimothYJpfi(eSUPt10 Title: Individual By· _....-y_ Name: Eva. C Upho Title: Trustee £1hlbll "A" Allac:hc:d to and made a part hcreor that certain Trail Ridge Employee Housing Facilily Site Lcmc and Agreement dated cfTcctivc the JD"' day of November, 2014, by and between The Eva C. UphofTTrust doted August 7, 2013 and Timothy James UpholT, l.essor, and WPX Energy Rocky Mountnin, I.LC, Lessee Legend -EJlstinO Road WPX Energy Rocky Mountain , LLC -Ploposed f.l•n Camp Proposed Man Camp P.t1cel O•ntnll1p (l1om G1rfield Cotn\IJ) TSS R97W, Secllon 3 l'ngc 5 ors .POWER OF ATTORNEY KNOW ALL PERSONS BY TIIESE PRESENTS: CONF U~dv•~i.i COPY THAT TEP ROCKY MOUNTAIN LLC, a Delaware limited liability company, hereby nominates, constitutes, and appoints Jeffrey D. Kirtland, as its true and lawful Attorney-in-Fact to execute .and deliver in the name and on behalf of TEP ROCKY MOUNTAIN LLC ("Principal") any of the following designated instruments or docwnents in connection with the Principal's operations in exploring for and producing oil, gas, or other minerals from lands, or interests in lands, owned, held, or claimed by the United States, any state or political subdivision thereot any person, corporation, partnership or other legal entity: A. (1) Applications for pennits or Jcascs; (2) consents, stipulations, or agreements in connection with the issuance of permits or leases; (3) acceptances of leases, subleases, or pennits; (4) acceptances of all instruments 1ransferring leases, offers to lease, permits, applications for pcnnits, or subleases, or an interest in any of these (including assignments of working or royalty interests) to Principal. B. Applications for extensions or renewals of leases and pennits. C. (1) Prospecting, seismic, or exploration pennits; (2) instruments in connection with the acquisition or maintenance of prospecting, seismic, or exploration pennits. D. lnstnunents withdrawing applications for leases or pennits. E. (1) Requests for rights-of-way and surface use pennits; (2) acceptance of grants of rights-of-way and surface use pennits. including any stipulation or condition in the grants; (3) any statements that may be required in connection with applications for rights-of-way and surface use pennits. F. Requests for extension of time in which to drill wells. Principal agrees to be bound by all representations the Attorney-in-Fact may make in any instrument or document be or she is authorized to execute and deliver under this Power of Attorney. Principal hereby wa~ves any defenses available to it to contest, negate, or disaffirm the actions of its Attorney-in-Fact under this Power of Attorney. This Power of Attorney is effective July J, 2016, and sbaJl continue in full force and effect until revoked in writing, and has the same force and effect as if the Principal granted separate special authority to the named Attorney-in-Fact to execute and deliver each such instrument or document separately for each and every such instrument or document so executed and delivered. EXECUTED by Principal on this 13 111 day of July, 2016 . Terra Energy Partners LLC as sole member or TEP Rocky Mountaia LLC AGREED TO AND ACCEPTED BY: BY:Mieha;l S. Land ITS: President and CEO ~ Attorney-in-Fact ACKNOWLEDGEMENT State of Texas County of Harris This instrument was acknowledged before me on-1./~ /3 . 2016 by Michael S. Land, known to me to be the President and CEO of Terra Energy Partne LLC, a Delaware corporation. on behalf of the corporation. (Notary Seal) TIFFANY CUELL POLLOCK Notorv Public. State of Texas Mv commlsalOn Expires April 26, 2019 ,. No\'cmber 16, 20 I 6 To Whom It May Concern, TEP Rocky Mountain LLC 1058 County Road 215 Parachute, CO 81635 Phil Vaughan" ith Phil Vaughan Constniclion Management, Inc ., has permission to represent Terra Energy Partners (TEP Roch.··y Mountain LLC) on nil mntlers related to lhe Tra il Ridge Housing Facility and Man camp in Garfield County, including communicnlion with county personnel and elected officials. If you have further questions regarding our response , please conlact me nt 970-263-2736. ~~:..-..=:=:;:::=-;;::===::::;;;.- Jeffrey D. Kirtland Regulatory Lend •Ill trl1Jll1'.'111&1MtY,lrlJ.lllU Hl "B I' ~r.,Jl lltf 11\1 11~1. •111 1 Recepti on~: 853193 0 91 0 2 •201 4 12 5 7 15 PM Jean ~lberico 1 of 1 Rec F11e $11 00 Do c Fee 0 00 GRRF I ELD COU'lil' CO L@ Garfield County STATEMENT OF AUTHORITY Pursuant to C.R.S. §38-30-172, the undersigned executes this Statement of Authority on behalf of Phil Vaughan Construction Management, Inc. a Corporation (corporation, ltmlted liability company, general partnership, registered llmlted liability partnership, registe red 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 Phll Vaughan Construction Managemenl Inc. and is formed under the laws of C<*ndo -------------------------------The malling address for the Entity ls _10_38_eou_nty""--Ro-•_d_323_R1_n_ •• _c_o_a_1850 ____________ _ The name and/or position of the person authorized to execute Instruments conveying, encumbering, or otherwise affecting title to real property on beha If of the Entity Is Ph illp e. Vaughan· President The !Imitations upon the authority of the person named above or holding the position described above to bind the Entity are as follows (If no llmitatlons, Insert "None"): _N_one ___________ _ 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 of _Se_ptembe __ r ______ __, 2014 Signature~~~ Name (printed): Phi&p e. vau;ll8n Title (If any): _P_,._s1c1_1H1_t ____________ _ STATE OF _Co1o_rac1_0 _____ ) )SS. COUNTYOf_G_a~_ia_~ ______ ~} The foregoing Instrument was acknowledged before me this~ day of September 20.1!_ by Philip B. Vaughan on behalf of Phil Vaughan Conslnldion Management, Inc. a Coloredo Corporation Witness my hand and official seal. My commission expires : ~4' . (Date) \I ······· .. · ./ (SEAL) : noT :..:J.: !. ?:J 3 _1c : · .. '•••······ (Notary Public) y cTL I THOMPSON I N C 0 • P 0 R A T i 0 October 24, 2014 Phil Vaughan Construction Management, Inc. 1038 County Road 323 Rifle, CO 81650 Attention: Mr. Phil Vaughan Subject: Geologic Hazard Evaluation and Geotechnical Investigation WPX Energy Trail Ridge Employee Housing Facility Garfield County, Colorado Project No . GS05884-115 Revised This letter presents the results of our geologic hazard and geotechnical investigation for the proposed Trail Ridge Employee Housing Facility in Garfield County, Colorado. Our geologic hazard evaluation consisted of literature review and a field reconnaissance by our geologist. The purpose of our geotechnical investigation was to evaluate the subsurface conditions at the site and provide geotechnical engineering recommendations. Recommendations were developed from information obtained during our field exploration, laboratory testing, engi- neering analysis and our experience with similar conditions. Site Conditions The site is about 22 miles north of DeBeque, Colorado . Access is via Rio Blanco County Road 5 and Trail Ridge Road, which is aligned with Parachute Creek. The turnoff to the site is near mile marker 20 at the West Fork of Para- chute Creek. The site location is 39°38' 58" N and 108° 15' 45" W . A relatively flat area is in the northern quadrant of the site. To the south and west of the flat area, slopes drop down steeply to the south. Vegetation is sage and natural grasses and weeds. A vicinity map is shown on Figure 1. The site is shown on Figure2. Anticipated Construction The Trail Ridge Employee Housing Facility will include five factory built units placed together. The individual unit dimensions are 58 feet long and 13 feet wide. The final building footprint will be approximately 75 feet by 62 feet 234 Center Drive I Glenwood Springs. Colorado 81601 Telephone: 970-945-2809 Fax: 970 -945-7411 The building frame Is three 12 x 26 steel beam skids. The skids will bear on a layer of compacted gravel. The storage building will likely be 60 feet by 125 feet in plan dimension and 50 feet high. Building construction will be a prefabricated steel truss skele- ton with a soft membrane cover tensioned over the framework . The membrane material will likely be a coated polyolefin fabric. The steel frame will be welded truss arches. The steel frame will be supported on microplles . We expect maximum foundation excavation depths of 3 to 5 feet, for frost protection and to provide positive earth pressure resistance. Vertical downward foundation loads for the structures are expected to be less than 1,000 pounds per lineal foot of foundation. The lateral and uplift loads on the foundation from wind loads may be the controlling factor relative to foundation design . Site Geology and Geologic Hazards Site geology and geologic hazards on this parcel were evaluated by David A. Glater, P.E., C.P.G ., using field reconnaissance on October 3, 2014 and a re- view of available literature. The ground surface at the time of our visit was snow- free. Literature references are cited at the end of this section . The Trail Ridge Employee Housing Facility will be situated at about 8500 feet elevation along the top of a south -facing slope on an east-trending ridge above the West Fork of Parachute Creek. Aerial photos from Google Earth indi- cate that sometime between April of 2006 and August of 2010, the current site was formed by excavation that resulted in a nearly-level pad about 450 feet long (east-west) by 150 feet wide (north-south). Since there Is little downslope fill em- bankment and the uphill cut slope is about 20 feet high, we assume the approx- imately 25,000 cubic yards of excavated materials were used as fill off-site . The excavation slopes expose light brown, fine-grained marlstone and sandstone from the Eocene-age Unit E of the Uinta Formation (Reference 1 ). Little soil has formed on the bedrock and outcrops are common outside the excavated area. The structural dip is nearly level in this area . No significant structural faulting is mapped in the area . We performed a radiation survey. Our survey cons isted of walking along lines the length of the site in a north-south direction . Lines were spaced approx- imately 50 feet apart. We observed radiation measurements that were taken with a Ludlum Instruments, Inc. Model No . 19 Mlcro-R-Meter carried at arms length (approximately 2 feet above the ground surface). Radiation readings were observed by continuously glancing back and forth from the Micro-R-Meter to the line of travel. We observed radiation measurements averaging approxi- mately 1 microroentgen per hour. Some areas had readings as low as O microroentgens per hour and as high as 2 microroentgens per hour. In our opin- PHIL VAUGHAN CONSTRUCTION MANAGEMENT, INC::. WPX ENERGY TRAIL RIDGE EMPLOYEE HOUSING FACLITY PROJl!CT NO. GSOSIM-121 REVISED S:IGSOllM.000\UN. l.derw\GSOIMC 111 Lt R~ 2 ion, these readings on the site are very low, indicative of nonnal background ra- diation for this area of Garfield County. Subsurface Conditions To investigate subsurface conditions, we directed the drilling of five ex- ploratory borings (TH-1 and TH-5) at the approximate locations shown on Figure 2. The borings were drilled with 4-inch diameter, solid-stem, continuous flight auger and a track-mounted drill rig. Drilling operations were directed by our la- boratory/field manager who logged the soils encountered in the borings and ob- tained samples. Graphic logs of the soils encountered In our exploratory borings are shown on Figure 3. Subsurface conditions encountered in our exploratory borings TH-1 through TH-5 consisted of hard to very hard, moist marlstone and sandstone bedrock with interbedded claystone layers. Our boring TH-5 was located on the top of a stockpile placed on the existing bench. Boring TH-5 penetrated 12 feet of stockpiled sandstone from previous excavation. Atterberg limits on the sand- stone were liquid limits of non-liquid (NL), 30 or 32 percent and plastic indices were non-plastic to 11 percent. Samples tested contained between 4 and 27 percent silt and clay size particles (passing the No. 200 sieve). A sample select- ed for one dimensional swell/consolidation testing was wetted under an applied load of 1,000 psf and the resulting volume change measured. The sample ex- hibited 0.2 percent consolidation. Laboratory test results are shown on Figure 4 and 5 and summarized on Table I. Free groundwater was not found in our bor- ings at the time of drilling. Earthwork A plan that we reviewed shows a 540 to 600 feet long by 120 feet wide pad. This pad will require cuts of up to 20 feet deep at the east one-third of the pad footprint. Fill (if required) to construct the pad and below buildings can be broken down sandstone free of organics and rock fragments larger than 3 inches in diameter. Fill should be moisture treated within 2 percent of optimum moisture content. Fill to construct the pad outside of an area 3 feet beyond the building footprints should be compacted to 95 percent of standard Proctor (ASTM D 698) maximum dry density. Fill placed below and within 3 feet of building footprints should be compacted to at least 100 percent of ASTM D 698. Placement of fill should be checked by a representative of our firm. Excavations at the site will be into sandstone bedrock. The sandstone bedrock will likely classify as a Type A soil based on OSHA standards governing excavations. Temporary slopes deeper than 4 feet should be no steeper than 3/4 to 1 (horizontal to vertical) in Type A soils. The contractor's personnel should PHIL VAUGHAN CONSTRUCTION MANAGEMENT, INC . WPX ENERGY TRAIL RIDGE EMPLOYEE HOUSlfG FACILITY PROJECT NO. GSOlll4-121 REVISED l :IOIOAMCIOllttN. LeftMSIGSClllM 111 L1 Rnlffd.Hc: 3 check that the soils in excavations are laid back in accordance with OSHA re- quirements, where applicable . Foundations We understand the temporary housing buildings are framed with structural steel runners. The runners are commonly referred to as skids. The skids will bear on a layer of compacted gravel placed on the sandstone bedrock. We be- lieve a compacted gravel layer on sandstone bedrock will provide good support The housing building complex will resist lateral loads with tie downs. Plans show helical pier tie downs. The subgrade soils will be hard to very hard sandstone bedrock. The specialty contractor should opine on the ability to helix the hard sandstone. Micropiles could also be used as tie down elements, if desired. Microplles can be installed into the sandstone. We understand the storage building will likely be founded on micropiles. We are providing recommendations for micropiles and helical piers. Our representative should be called to test the placement of fill and ob- serve conditions exposed in the completed foundation excavations to confirm that the exposed soils are as anticipated and suitable for support of the founda- tion as designed. Design and construction criteria for micropiles and helical piers are presented below. Micropiles 1. Commonly available micropile systems have a maximum working capacity in the range of 20 to 100 kips. 2. Micropiles should be designed and installed in accordance with re- quirements as specified in USDOT publication number FHWA-NHl- 05-039. We recommend load tests be performed prior to the start of production microplle installation to check bond stress and instal- lation methods. We can assist in the design of micropiles, if re- quested. 3. We believe micropiles should be designed using grout/ground inter- face bond strength of 20 psi in the sandstone bedrock. Soil above the bedrock should not be included in capacity calculations. The in- stallation contractor should verify this strength is appropriate for their installation method and experience based on load testing. Higher bond stresses based on contractors experience and load tests may be appropriate. 4. Micropiles should have a total length of at least 20 feet PHIL VAUGHAN CONSTRUCTION MANAGEMENT, INC. WPX ENERGY TRAIL RIOGE EMPLOYEE HOUSING FACILITY PROJECT NO. GSOllM-125 REVISED S:'GSOllkOOll\t1N. LM!eralGSDllM 111 U Rft!MCl.doc: 4 5. We recommend that the upper 10 feet of casing be permanent. This upper section of permanent casing will likely be required for lateral load considerations . 6. Micropiles should be reinforced their full length. The area of rein- forcing steel should be sufficient to withstand uplift. 7. Micropiles should have a minimum diameter of 5 inches. Helical Piers 1. In general, manufactured helical piers are available with allowable mechanical capacities between 30 and 50 kips. Helical pier bear- ing capacity shall be verified in the field using manufacturer rec- ommended capacity/torque ratios. A minimum factor of safety of 2.0 Is required. 2. Contractor shall use the number and size of helical blades required to achieve the required depth and capacity. However, the ratio of design bearing capacity specified by the structural engineer and the total area of helical blades used by the contractor shall not exceed 30,000 pounds per square foot. 3. Helical piers should have a minimum shaft cross sectional dimen- sions of 1.75 inches per side, and solid for square shafts or 3 inch diameter, schedule 80 for round shafts. 4. Helical piers should have a minimum length of 15 feet. Helical piers should be placed as close to vertical as possible. 5. At a minimum, helical piers bearing on bedrock should be spaced apart a distance equal to three times the average helix diameter to avoid group efficiency effects. 8. Installation of helical piers should be observed by a representative of our firm to confirm the depth and installation torque of the helical piers are adequate . Surface Drainage Surface drainage is critical to the performance of foundations. The ground surface around the structures should be sloped to direct runoff away from the structures. Backfill adjacent to foundation walls should be moisture condi- tioned and compacted as recommended in the Earthwork section. PHIL VAUGHAN CONSTRUCTION llANAG!MENT, INC. WPX ENERGY TRMt. RIDGE EMPLOYEE HOUSING FACLJTY P~CT NO. GSOllM-121 REVISED 1.-GRWl.Wlttll3. LM18'1\Glll .. 11fl L1 9'ftlwldoc 5 Access Road and Parking Lot The proposed parking areas subgrade is sandstone bedrock. Access road and parking lots are to be gravel. We anticipate that the majority of vehicle traffic will be light trucks. Heavy trucks will be limited to those required to provide sup- plies. If the anticipated traffic loads are considerably different than those as- sumed. we should be Informed so that we can review our recommendations. Aggregate Base Course (ABC) 1. A Class 5 or 6 Colorado Department of Transportation (Coon specified aggregate base course should be used . A recycled con- crete alternative which meets the Class 5 or 6 designation is also acceptable. 2. Aggregate base course or recycled concrete should be laid in thin lifts not to exceed 8 inches, moisture treated to within 2 percent of optimum moisture content, and compacted to at least 95 percent of maximum modified Proctor dry density (ASTM D 1557. AASHTO T 180). 3. Placement and compaction of aggregate base course or recycled concrete should be observed and tested by a representative of our firm. Placement should not commence until the underlying sub- grade is properly prepared and tested. Drives and parking lots at the facility can be constructed with a 6 inch lay- er of Class 6 aggregate base course placed on the prepared natural sandstone bedrock surface. A primary cause of eariy driving surface deterioration Is water infiltration into the subgrade. The addition of moisture usually results in softening of sub- grade and the eventual failure of the drive surface. We recommend drainage be designed for rapid removal of surface runoff from drives and parking areas. Fi- nal grading should be carefully controlled so that design cross-slope is main- tained and low spots in the subgrade which could trap water are eliminated. Final Design Consultation and Construction Observation This report has been prepared for the exclusive use of Phil Vaughan Con- struction Management. Inc. and the design team for the purpose of providing ge- otechnical criteria for the proposed project The information and the conclusions and recommendations presented herein are based upon the considerations of many factors including, but not limited to. the type of structure proposed. the configuration and location of the structure, the geologic setting. and the subsur- PHIL VAUGHAN CONSTRUCTION MANAGEMENT, INC. 6 WPX ENERGY TRAIL RIOOE EMPLOYEE HOUSING FACILITY PROJECT NO. GSOllM-121 REVlSED S:IOIOllM '°"'UN. L.-.IGSOllM 111 Lt fteol!Md.doc face conditions encountered. The conclusions and recommendations contained in the report are not valid for use by others. Standards of practice continuously change in the area of geotechnical engineering. The recommendations provided are appropriate for about three years. If the proposed project is not constructed within about three years, we should be contacted to determine if we should up- date this report. It is recommended that CTL I Thompson, Inc. be retained to provide gen- eral review of the final construction plans prior to construction. Our firm should also be retained to provide geotechnical engineering and material testing during construction. The purpose is to observe the construction with respect to the ge- otechnical design concepts, specifications or recommendations, and to facilitate design changes in areas where the subsurface conditions differ from those antic- ipated prior to start of construction. Limitations Our exploratory borings were located to obtain a reasonably accurate pic- ture of subsurface conditions. Variations In the subsurface conditions not indi- cated by our borings will occur. A representative of our firm should be called to observe the completed foundation excavations to check fill moisture content and density. This investigation was conducted in a manner consistent with that level of care and skill ordinarily exercised by geotechnical engineers currently practicing under similar conditions in the locality of this project. No warranty, express or im- plied, Is made. If we can be of further service in discussing the contents of this report or in the analysis of the influence of the subsoil conditions on the planned construction, please call. cc: Via email to phll@pvcmi.com PHIL VAUGHAN CONSTRUCTION MANAGEMENT, INC. WPX ENERGY TRAIL RIOGE EMPLOYEE HOUSING FAClt.ITY PROJECT NO. GSOSll4-1ZI REVllED S :'DSOllMDOll111U. IAttlNIGSlllM 111 U Rew!Md.doc: 7 SCALE: 1" • 60,000' lFIAIL RIDGE EMPLOYEE HOUSING FAOIUTY PHI.. VAUGHAN CCIN8fAUCT10N MANAOl!MEM', NO. ProjectNo.GS05884-125 Vicinity Map Fig. 1 ---li--- SCAl.E: 1 • -200' TRAIL RIDGE EMPLOYEE HOUSING FACILITY l'HIL VAUG~ CCINSlflUCIT10N MANMJ&&n: INC. Project No. 0$05884-125 · • T Locations of Exploratory Borings Fig. 2 i l!l ~ I j i ~ I • i I Tff.1 TH·2 0 -..r.on -5 10 511110 15 20 1-25 SQl4 30 l-35 40 fllte..YM.ll:MliM~MUllWillElllENr.JC ,._,.. .... Dftowtll......,UDUrr ..... CUD a...111 TH ·3 TH-4 .OCll12 1- 50l4 TH-5 0 5 10 15 1-20 25 30 35 40 LEGEND : BS FU. STOCKPllE8ANOSTON£ I SANDliTONE BEDROCK INJER8EllDED W!TtiC:V.l'S10NE, HMIDTO llERY HMO, SUGKTLY MOIST, BROWN. ~ ~ ~ Dlll\IE SAMPU.. TM; SYMICL SOI,, ""7 INOICATES BOllLOWS OF A l~HAMMER FAWNCI 30 INCHES WERIE REQUIMI> ltl ORM! AUINCH 0.0. llAMPl.ER 7 INCHES. Dlll\IE SAM'LI!. TtlESYllBCL50l•tHDICATES SDILOWSOl'A 140-l'OUNDIWSER FAWNO 30 INCHES WERE REQUIRED TO ORJ\IEA ~NCH 0.D. SAM'LER 4 INOtES. IUU< SAMPLE l'llOM AUOEll cumNOS. NOTES: 1. EJIPl.OllAlORY IORINOS FOR lHS INllESTKIATIDll WSIE DRllUD ON SU'1"EJ.mER 11. 201• wmt '-llCH OWIETER, COHTI~ 80UD.sttM NJOER N#J A TIW:IC~CllllllllG. 2. LOCATIONS OF ElCl'LORAlORY IORIHOS ARE N'PROICIMATE. 3.. NO FREE GllOUNOWATER WAS FOINI IN CURElCPl.llRATORY llOIUNOSAT TtlE TIME OF DfUWNG. 4. lltUI: ElCl'LOllAlORY BORINGS ME SU8JECT TO THE ElC!VoNATIOHS, LIMITATIONS N#J CONCUJSIONS AS Cllfn'AINE!I IN lHS AeP'ORT. SUMMARY LOGS OF EXPLORATORY BORINGS T FIG. 3 HYDROMETER ANALVSIS SIEVE ANALYSIS 25 HR. 7 HR. mE READINGS US. STANDARD SERIES CUAR SQUARE OPeMNGS 45 MIN. IS MIN. llO MIN. ISIMIN. OAIN. OUN. '200 •100 '50 •40 ":JO •11 'ID •a •4 311• 314" ,. • • 3• ,.. •• 11· 0 100 IO 30 i 211 -10 0 .001 o 002 .oos .oot .019 .on Cl.AV (PLASTIC) TO SILT CNON-1'1.ASTIC} Sample of SANDSTONE From TH -1 AT 0-10 FEET HYDROMETER ANALYSIS 25 HR. 7 HR. TIME llEADING& / I""" ~ v 10 - ~ ,,.,- ~' .. / / _J' v ,.... 70 ao llO 100 .074 .149 .297 .$90 1.11 2.D 2.31 4.711 0.42 11.52 IU 31.t 76.2 tzt 52zoo DIAMETER OF PARTICU: IN MIWMEMAS SANDS FINE MeOIUM FINE COARSE COlllllES GRAVEL 16 % SANO SILT & CLAY 27 % LIQUID LIMIT PLASTICITY INDEX SIEVE ANALYSIS U.S. STAHOARD SERIES CLEAR SQUARE Ofl9llNGS 57 % 32 % 11 % 45YM. 15W4. &OlilN. llMIH. ODl UllH. '200 •100 -SO •40 ":JO •11 °1D °I •4 3lr 314• 1W 3" S'&• r 100 0 llO -/ ------. ~ -) --~ -. ------ --,_ --/-IO 10 211 J -/ ----,_ -t --· / -,_ -- I/ v - ~ -- I/ ,,,,..- - 30 20 10 ID . I ' I I 10 0 ..001 o.ooz .1119 1137 .149 .2970.42 .590 1.111 2J) 2.31 4 .11i 1.52 36 .1 toa 712 12f 52211G DIAMETER OF PARTIClE IN Mll..UETERS a.AV (Pl.ASTICI TO SILT (NON-Pl.ASTICI FINE Sample of SANDSTONE From TH - 4 AT 0-10 FEET PHIL VAUGHAN CONSTRUCTION MANAGEMENT, INC. TRAIL RIDGE EMPLOYEE HOUSING FACILITY PROJECT NO. 6905884-125 S ;IGSOSIM.I00\11,.. C•la'tGSOSIM Gr.cl.alan.als GRAVEL FINE GRAVEL 29 % SAND SILT & CLAY 20 % LIQUID LIMIT PLASTICITY INDEX Gradation Test Results 51 % 30% 9% FIG.4 7 I I 1111 l I I l I [ I I I ! 1 I I I I I ' I I ITT ADDITIONAL COMPRESSION UNDER IT I CONSTANT PRESSURE DUE TO 11-----r1-,·~)n·-·-· · ·---·11- 6 5 I I 11 ----I I J ,_ I I ' ' T ·-/-1 -I n -! T --,_ 4 3 2 0 'i T_JI~ ,-~JfL v·1--_____ ,_ ~ ·1 !K --. 1 f \ I l\ I --__ I ........ I l -I ,, __ -r I ·2 -3 -:~ -l l - I (,:1 I 11Tf I I I T--r--r I Tn-Tl-1 ·1 I I I 0 .1 1.0 APPLIED PRESSURE • KSF Sample of SANDSTONE --· From TH-5 AT 24 FEET ---- PHIL VAUGHAN CONSTRUCTION MANAGEMENT, INC. TRAIL RIDGE EMPLOYEE HOUSING FACIUIY PROJECT NO. GSD5114e125 l ;IOSHl14.ICICll 11511. CalcalGS05114 SweH..ata 10 100 DRY UNIT WEIGHT= 101 PCF MOISTURE CONTENT.: 12.6 % Swell Consolidation Test Results Fl G.6 MOISTURE DRY EXPLORATORY DEPTH CONTENT DENSITY BORING (FEET) 1%1 IPCF) .... 1 0-1Q nR TH-1 9 14.11 TH-1 29 111.9 TH-2 14 15.2 108 TH-3 4 14.2 TH-4 4 15.11 TH-4 0-10 12.11 TH-5 4 20.11 TH-5 24 12.11 101 A ,L-o<> LIQUID PLASTICfrY LIMIT INDEX 1%) 1%) :J2 11 32 7 NL NP JO 9 NL NP TABLE I stJllllMY OF UllORATORY TESTlNG PROJECT NO. GSOAM-125 SWELl ri::.r -ll_TS• APPLIED UNCONFINED SWELl PRESSURE COMPRESSION 1%1 ro~ IPSFl 8.200 .(1.2 1,000 • SWaJ. MEASURED WITH 1000 PSF APPLIEtJ PREsauRE. OR ESTIMATED IN-SITU OVERllURD!H PRESSURE. NEOATN'E VALUE INDICATES CO~IOtl .... • ~ PASSING SOLUBLE PERCENT PERCENT N0.200 SULFATES GRAVEL SANO SEVE f'lltl ('Wt) l'llol 1%1 DESCRIPTION 111 DI 21 .. SANDSTONE 23 SANDSTONE SANDSTONE 0.000 SANDSTONE 0.000 SANDSTONE 29 51 2D SANDSTONE II SANDSTONE SANDSTONE P11g&1 of1 SEJqb No. 14180 Trgil Rjclge Employee Housing Facilitv Nqyember2S. 2014 Drainage Report for WPX Energy Rocky Mountain, LLC Trail Ridge Employee Housing Facility Garfield County, Colorado Prepared for : Phll Vaughan Construction Management, Inc 1038 County Road 323 Rifle CO, 81650 Prepared by: Soprls Engineering, LLC 502 Main Street Suite A3 Carbondale, Colorado 81623 SE Project Number: 14180.02 November 25, 20 14 SE Job No. 14 ll/O Trail RWec &nmoytc H<1uJ.ja11 fqcj/jp • Norrmhcr 25. 2014 Table of Contents Contents I. Purpose of Drainage Study ......................................................................................................................... 2 II. General Overview & Site Description .......................................................................................................... 2 Ill. Historic Drainage Basins ............................................................................................................................. 2 IV. Developed Onsite Drainage Basins ............................................................................................................ 3 V. Hydrologic & Hydraulic Analysis Methods & Assumptions .......................................................................... 3 VI. Detention Mitigation Analysis & Design ....................................................................................................... 4 VII. Sediment and Erosion Control .................................................................................................................... 5 VIII. Conclusions & Recommendations .............................................................................................................. 5 SE Job No. 141110 Trail Ridge Employee Hmisjng fqcjlity Novernber 25. 2014 I. Purpose of Drainage Study The purpose of this Drainage Study is to: • Evaluate the historic drainage conditions to compare historic drainage conditions versus post development drainage conditions. • Evaluate the drainage impacts of the proposed improvements along with peak runoff rates associated with a 2-year, 25·year, and 100·year rainfall event. • Evaluate detention volumes to verify the detention system has adequate capacity such that post development runoff rates do not exceed historic peak runoff rates for the 25-year event; determine that the flow of the 2-Year event continues through the site, as to not harm downstream users. Evaluate that a 100-year storm event will not wet building floors. • Ensure that ultimate stormwater infrastructure is adequately sized for the proposed improvements. • Provide Best Management Practice (BMP) recommendations to minimize sediment transport offsite. II. General Overview & Site Description The specific site being developed is approximately 3 acres of a disturbance within a 596 acre parcel, which is less than 1.0%. The development of this site consists of a future storage building, employee housing, water storage, and generator for electrical power, refrigeration storage, and parking. The parking and general site will consist of a gravel surface and areas outside of the gravel are planned to be reclaimed with vegetation. The drainage report has been prepared as a part of the Limited Impact Review Permit (LIRP), for the proposed Trail Ridge Employee Housing Facility in Garfield County, Colorado. The purpose of this report is to evaluate the historical site conditions, and verify how the proposed improvements will affect the drainage conditions . This report presents our findings and recommendations for stormwater mitigation associated with the site improvements of the project. The existing site is located in Northern Garfield County . The site existing topography, Existing Topographic Map (Exhibit A) prepared by Sopris Engineering, LLC in October of 2014: Even though the site is currently disturbed, the site is evaluated at its historical topography with natural vegetation . The site generally slopes to the South from all points on the site. The surrounding areas are native sage and oak brush. Ill. Historic Basins The historic drainage conditions were analyzed in order to understand the peak stormwater flow rates affecting the site and were based on historic topography. The resultant basins are described in greater detail below and are illustrated in Appendix 8. Historic Basin 1 (HIST-11 is composed of the offsite drainage that flows across the Trail Ridge Employee site from the North and is up gradient of Historical Basin 2. This basin will be intercepted into a swale at the top of the sites north cut slope and will pass through the site via a culvert near the entrance to the site. The analysis of this basin is for sizing of culverts and drainage swale only, no detention is planned for this basin. Historic Basin 1 (HIST-2) is composed of the entire onsite disturbance area of the Trail Ridge site. The Flows are generally North to South. The analysis of this basin is for determining the flow for the continuation of the 2- 21 Pagt: SIUoh No . 14 J 80 Trail Rjdgt En!nlnyte Htmsjng FacW'Y Novtmbtr 25. 2014 year event and the flow of the 25-year event. Historically the waters leave the site in sheet flow and not po int loaded in any defined drainage way . IV. Developed Onsite Drainage Basins The site is graded into 3 separated basins, by high points. The overall grading of the site will move water away from structures and divert to 3 defined detention ponds along the south edge of the site. The detention ponds will be built to collect and release water in accordance with historic flows of a 2-year event and detain the difference between the historical and post development 25-year event. The 1 00 year event will pass without wetting the planned structures. Below is a brief description of each of the onsite post development drainage basins. Post 1-includes the furthermost West basin of the site being developed; flows of this basin generally flow from the north to the south via surface. Design point 1 is found at the South end of the basin where a detention pond will be placed to manage the post development drainage. The basin includes a portion of the proposed future building and primarily a gravel surface, with the northerly portion of the basin being restored with vegetation. Post 2· Is the basin located in the center of the site being developed. This basin encompasses design point 2, which will include a culvert to convey waters from the north to the south to the detention pond on the Southern end of the basin to the second detention basin . The basin includes a portion of the proposed future building , a portion of the employee housing facility and primarily a gravel surface, with the northerly portion of the basin being restored with vegetation. Post 3· this basin is located at the East end of the site being developed and includes design point 3. The drainage will flow from the North to the Southeast via surface and from the Southwest to the Northeast via drainage swale to a third detention basin. The basin includes a portion of the proposed future building, a portion of the employee housing facility and primarily a gravel surface, with the northerly portion of the basin being restored with vegetation. The approximate 0.5 mile of access road to the site is mostly on a ridge and includes a helicopter pad. The disturbance from i mprovement of this road is small compared to the overall parcel size and does not warrant additional disturbance to install detention basins to control a 25 year event. A portion of the road will drain to 2 existing livestock ponds and will be retained. Sediment basins will be constructed and maintained near an exist cattle guard . V . Hydrologic & Hydraulic Analysis Methods & Assumptions Onsite and offsite drainage areas were analyzed using the Rational Method (Equation 1) for the 2-year and 25-year storm even t since the cumulative total of tributary offsite basins and subject property being studied was less than 90 acres. Equation 1: Q = c• I *A Q = Runoff Flow Rate (cfs); C = Runoff Coefficient I = Rainfall Intensity (in/hr); A= Area of Basin (acres) 31 p .'.I~~ SEJnh No. 1418() Trail Rjdgr Employu HmWng Fqcjljry Nomnhcr 25. 2014 The runoff coefficient (C) is a variable that represents the ratio of runoff to rainfall volumes during a storm event. The determination of C mainly depends on the soil type, watershed impervious and storm event frequency . Each drainage basin was stud ied to determine the percent of impervious area. Landscaping and open space areas were assumed to be 0% impervious which correlates to 2-year, 25-year and 100 year runoff coefficients of .0 .55, 0.76 and 0.95, respectively. Gravel surfaces were assumed to be 70% impervious or .85 and for the 2-year, 25-year and 100-year runoff coefficients, respectively. Areas with impervious areas differ from 0% and 100% were estimated using the weighted average method . Supporting information is provided within Appendix A of this report. The design rainfall duration used in the Rational Method is referred to as the time of concentration. The time of concentration is the cumulative travel time, including overland flow and channelized flow, for runoff to get from the furthest point upstream of a basin to a designated design point. A minimum time of concentration of 5 minutes was used for all basins given the short travel distances. Based on the NOAA Mas 14,.Volume 8, Version 2, Latitude 39 .3905 degrees, Longitude-108 . 1550 degrees, Parachute Colorado, Intensity Duration Frequency (IDF) Curve the 2-year, 25-year and 100-year are 2.00 in/hr, 4.55in/hr, and 6.98in/hr respectively. A summary of the 2-year, 25-year and 100-year estimated peak runoff rates analyzed for this project are summarized within Table 1 below: Table 1: Peak Runoff Summary 2-VR PEAK HISTORIC BASINS 25-YR PEAK HISTORIC BASINS BASIN c, 12 (In/hr) AREA Qz(c:fs> (acres) BASIN Cis l:is (In/hi) AREA Ou(cfs) (acres) HIST·l 0.55 2.00 0.81 0 .89 HIST·l 0.55 4.55 0.81 2.02 HST-2 0 .55 2.00 2.24 2.47 HIST-2 0.55 4.55 2.24 5.61 2-VR PEAK POST DEVB..OPMEHT PEAK RUNOF SUMMARY ~YR PEAK POST DEVEl.OPMEHT PEAK RUNOF SUMMARY BASIN c, 12 (lnlhr) MEA(acre1 02 (cflj BASIN Cis f25 (In/hr) AREA (acre1 O:is (cfsl Pl 0.81 2.00 0.56 0.90 Pl 0 .81 4.55 0 .56 2.05 P2 o.n 2.00 1.13 1.75 P2 o.n 4 .55 1.13 3 .99 P3 0 .76 2.00 0.55 0 .83 P3 0.76 4 .55 0 .55 1 .90 100-VR PEAK HISTORIC BASINS BASIN Cioo I 11111 (In/hr) AREA 0 1oo(cfs) (acre I) Hl::.1 ·1 0 .55 6.98 0.81 3 .09 HIST·2 0.55 6.98 2 .24 8 .61 100-VR PEAK POST DEVEl.OPMENT PEAK RUNOF SUMMARY BASIN Cioo 1100 (In/hr) AREA (acre• 0100 (cfs) Pl 0 .81 6.98 0 .56 3 .15 P2 o.n 6.98 1.13 6 .11 P3 0 .76 6.98 0.55 2 .91 Supporting data can be found within Appendix A of this report. VI. Detention Mitigation Analysis & Design Based on the information summarized within Table 1 the peak runoff rates will be developed and therefore stormwater detention/ retention will be required . Required detention will be accomplished through the use of three detention ponds. The Rational Method Detention Volume approach was used to estimate this required volume. Hydraflow Express Software was utilized to calculate these volumes and a receeding limb factor of 1.67 was applied to lengthen the receeding limb of the hydrograph. Precipitation data used within Hydraflow 41 P age SE Jqb No. 14 !RO Trail Rjdee Emnlqvee Housj11g Fqdllrv No11ernber 25. 2014 Express Software was taken from the IDF curve developed for the Town of Parachute, Colorado and is provided within Appendix C of this report. Based on the Information summarized within Table 1 the 2-year historical flow of 2.47 cfs is required to continue. We split this flow into three different basins utilizing the area of the post development basins as to Post 1 basin being 0.61 cfs, Post 2 basin being 1.25 cfs and Post 3 basin being 0.61 cfs. The detention requirements are the difference of the predevelopment to post development runoff of the 25- year event. Post 1, 2 and 3 basins requiring a minimum detention volume of 279, 417 and 196 cubic feet respectively. A copy of the Hydraflow inpuUoutput data is provided within Appendix C of this report. VII. Sediment and Erosion Control This site is located within the area covered by an existing WPX Energy Construction Field Wide Stonnwater Management Plan (SWMP). This Field Wide Stormwater Management Plan was developed in compliance with Colorado Department of Public Health and Environmenta l (CDPHE) Colorado Discharge Permit System (COPS) stormwater discharge permit for general construction activity associated with oil and gas development. VIII. Conclusions & Recommendations The results of this drainage study suggest that no long-term, adverse impacts to drainage are anticipated with the proposed improvements. Although onsite peak runoff rates will increase with the added impervious areas, the detention system will eliminate any increase in stormwater leaving the site. Best Management Practices (BMPs) have been identified and will be implemented during the construction of the improvements. In addition, permanent vegetated cover should be installed in areas outside of the gravel driving surfaces as soon as construction allows. 5l P:i1?e SE Job No. 14180 Troll Ridge Employee Housing Facility November 25. 2014 APPENDIX A Rational Runoff Coefficient Summary SOPRIS ENllNEERING • llC Civil Consultants 502 Main Street Suite A3 carbondale Colorado 8162 3 (970)704.Q311 Fn:(970)704·0313 APPENDIX A -DRAINAGE CALCUl..ATIONS EXISTING DRAINAGE SUBAREAS -RATIONAL METI-100 0-CIA EX. Area(ac) %of Basin Surface uata Oe(cls) Tc (min)• BASIN Area lmoeN (acl % c Pervlous racl % c WeightedC EX01 0.81 26.4% 0.00 0.0% 0.85 0.81 100.0% 0.55 0.55 0.89 5 EX02 2.24 73.6% 0.00 O.O'Y. 0.85 2.24 100.0% 0.55 0.55 2.47 5 Tolal 3.05 DEVELOPED DRAINAGE SUBAREAS RATIONAL METI-100 0-CIA POST Area (ac) %ol sasin Surface -Data Qd(cls) Tc (min)• BASIN Area lmperv l&cl % G Pervious lac1 % -c we111nteac P-1 0.56 24 .9% 0 .47 83.9'Y. 0.86 0.09 16.1% 0.55 0.81 0.90 5 P·2 1.13 50.6% 0.78 68.4% 0 .88 0.36 31 .6% 0.55 o.n 1.75 5 P-3 0.55 24 .5% 0.36 66.3% 0.86 0.19 33.7% 0.55 0.76 0.83 5 Total 2.24 ·ca1culalion based on the 2 year 1 hour storm . The Time of Concentration (Tc) was assumed to be 5 minutes Intensity ol rainfall (in/hr) • 2 (Intensity lor a 2 year 1 hour storm) APPENDIX A· DRAINAGE CALCULATIONS EXISTING DRAINAGE SUBAREAS EX. o/. of Basin BASIN Area(ac) Area Im"""' (ac) I EX01 0.81 26.4% 0.00 I EX02 2.24 73.6% 0.00 I Total 3.05 DEVELOPED DRAINAGE SUBAREAS - -·- POST Area (ac) %of Basin BASIN Area 1mperv (acJ P-1 0.56 24.9% 0.47 P-2 1.13 50.6% 0.78 p.3 0.55 24.5% 0.36 Total 2.24 RATIONAL METHOD O.CIA :sunace uata 'Yo c I t"erv1ous lac) I % 0.0% 0.85 I 0 .81 I 100.0% 0.0% 0.85 I 2.24 I 100.0% RATIONAL METHOD 0.CIA - :sunaca uata 'Yo G t"8IVIOUS (8C) % 83.9% 0 .86 0.09 16.1% 68.4% 0 .88 0.36 31 .6% 66.3% 0 .86 0.19 33.7% ·ca1culation based on the 25 year 1 hour storm . The Time of Concentration (Tc) was assumed to be 5 minutes Intensity ol rainfall (inlhrl • 4.55 (Intensity for a 25 year 1 hour storm) Oe (els) Tc (min)" I c I Waiohlecl C I 0.55 I 0.55 2.02 5 I 0.55 I 0 .55 5.61 5 Od(cfs) Tc(mln)" G WeianteaG 0.55 0.81 2.05 5 0.55 0.77 3 .99 5 0 .55 0.76 1.90 5 APPENDIX A -DRAINAGE CALCULATIONS EXISTING DRAINAGE SUBAREAS ---·--··----....... -------··----- EX. %ofBasln BASIN Area (ac) Area lmperv (BC) I EX01 0.81 26.4% 0.00 I EX02 2.24 73.6% 0.00 I Total 3.05 DEVELOPED DRAINAGE SUBAREAS ~T Area(ac) %of Basin BASIN Area lmperv (SC) P-1 0 .56 24 .9% 0.47 P-2 1.13 50.6% 0.78 p .3 0 .55 24 .5% 0.36 Total 2.24 RATIONAL METHOD O.CIA -.. -------- -- :sunace uata % I c I Pervlous (BC) I % 0.0% I 0.85 I 0 .81 I 100.0% 0 .0% I 0.85 I 2.24 I 100.0% RATIONAL METHOD O.CIA :sunace uata % c Perv1ous 1ac1 % 83.9o/o 0.86 0 .09 16.1% 68.4'Yo 0 .88 0.36 31 .6% 66.3% 0.86 0 .19 33.7% ·ca1cutation based on the 100 year 1 hour storm . The Time ol Concenbation (Tc) was assumed lo be 5 minutes Intensity of rainfall (In/hr) • 6.98 (Intensity for a 100 year 1 hour storm) Qe (els) Tc (min)" I c I WeiahtedC I 0.55 I 0 .55 3.09 5 I 0 .55 I 0.55 8.61 5 Cid (els) Tc (min)" c WeKJntedC 0.55 0 .81 3 .15 5 0.55 0 .77 6.11 5 0.55 0.76 2 .91 5 SEJob No. 14180 Trail Rldqt Emplovtt Housing Facility Novtmbtr 25. 2014 APPENDIX B Historic and Post Development Basin Map, Existing Topography SOPRIS ENGINEERIN8 • llC Civil Consultants 502 M1ln Strut Suite Al Carbondale Colorado 11623 (970)704-0311 Fa•:(970)704-0313 5 :~y;11/1~ 0</ / / / ,/ / ,---"\!iii ·1 !; II I/ /;;-/ / / / / --M l 0 X// / ; I II I / ~ If>~ / I I '\ : .. '!/;; !1. ~ ,-1 / / / / ~/ --~ / 'i( \ ~~I ~ / 1 /, "' "" ( ~:::s _ .(--,,, ~---/::\:\ ~ i .. ;f-~ / r , \. /. --__ -.... _ / i1 1. . i ro I// I 111 I t ,, ----_ -_:>\ 11 --'--:::',, 1 \ \I \ \ l E I I( I ( .,. ',2 ~~---,J I\ \ \\ I r . , , ,\~ ~ \ \ \\\ \\\\ ~ :c -I ,111 ,111 '\ ,\1\ g c ~ 1/I I / ~ \ \ ~\ \ \ )) ) ~ r-I / / l ""' I 1: I Z:5! \ 111 11 I i I ( ( I 1111 ~ g 1 I I 11 J I ~ '-"' \I ,, i )> m 11 I I "-.1 I . I nm I rl 1· I l'l '/I 1111 c ~ ii 111 I ' I ,,---"-"-I\-\ n ~ ! i 11 11 f '-! 51 1111 11111 / / ,,---_ :_ 1~, , p ~ 11 JI 111 i 1 m ~ 1 I I I 11' I / / ,,---------J ' IJ; / ) /// /ji //i / / ~ \Ir ;;/ Ji ~ \o '111/i/i //( / -- I/ I ~f1I ~[r )f\ )j \// II/ / I r "'i/~_ ~ / I ~ lt ~lr, \-1>~z_~JJ; . ~~ ~ IU '\ ~ \ ~{j =r--:P 1 ~ uin \ ,\:\ \ ' ; ~ ~ \\~ ~. ~""~ ~~R ~. , ' ~""'~"-'---~' ~ ~~ : ~ ~ ~" "~"I ' ~ k 0 • • NO REVISION av DATE s !l! a; ~ Trail Ridge Employee Housing Fac1hty OPRIS NG INEERING, LLC. :;i ~ • GARFIELDCOUNTY,COLORAOO CIVILCONSULTANTS • • -: 502 MAIN STREET ll. i QI EXISTINGTOPOGRAPHY CAReONOALE,coa1e23 ... "' !:!! (970) 704-0311 2 ~ EXHIBIT A FAX: ~970}-704-0313 / l&S6 2_ '---=-=-·-.:. -....:. ·_--:--·_:. ~...;. ·...:-= ·.....:.-=-.....:. ·..:=- --.......... , ,;~~---''\ // ~ ' ,.,...,/ \ \ \ / // . \ " ' 1.' // / I \ \ . I \ I // // \ ( '1 \/ \ .-··-I"-"··-~ .. ----1--,--:r:-1 -_:::: :-:. ;:;.:-: :-:-= ~ __.--_.J=_ / I I \ \ \ HlST-1 ....__ ~. ' ~ :.E __:: -... "" ' • . >< '·. --- ti ~ ' --:==~==~=-=-========~~~ I \ J\ /j j\ j \:'"C = _ ~~ ~ \, --M~~~--~~~~~~~/ ----• • =--b-' "'-f,' ; I , f ~~- b. """ 11 ' . , , . ) I . \_ ' L= ' -/------~ ------. ·--==- . ...._ --~ ------------~ -~.. ..._ EXISTING LEGEND PROPOSED LEGEND EXISTING COHTOUR PROPOSED COHroUll '1'00 EXISTING CONTOUR INTERVAi. 191111--PROPOSE!> COHTOUll llnERVAI. GRAPHIC SCALE JOO ~ .... CJ°; l:J z ii:~ "' ... wZ t;-w< .,_~- Z ~ ~sJ-{3 Iii,.; z~ z;t 6' wu ~i~e 111 5 ~2-~ a: c ~ "' CL U 0 Vl w ~ ~ a ~ ~ ~ 'G i~ :> .... z ~~ ~ G> i!::: ID G> z 0 >-:;;) a: -20 0 ~u t; W O -.... :I: G> !!! CJ>IA-~ ~ ~ Clto-t>Ot-<OLBI 'XV.I UCD-m(OUI) aeur oo 'i'l't'ONOlnlv:> L3i!US NMll Z:0S I S.LNv.nnsNo:> i 1Ao I ·:>11 '9Nlll33Nl9N 3 SllldO S \. ' \', ,,,.. '"" ' ' ' ' ' ' ' ' ' ' :i l.llHHX3 ;!: s t--+--+--------+--4-----_..:;.:;;;;;~--------llil ii ... NISV8 !SOd :(! ; '15 t--+--+--------+--4-------~--------1 .:. -"' OOWOlOO 'A.ltmoo 0131:1~ ~ g ~ Aim:>e,:16u1snoH ea.<01dw3 e6p1ij Ue.Jl ~ ~ i i.LVO AS NOISIAi~ ·oN SE Job No. 14180 Troll Ridge Employee Housing Facilitv APPENDIXC Hydraflow Detention Output SDPllS ENBINEEllNC • llC 502 Main Stn1et Suite A3 Carbondale Colorado 81623 (970)704-0311 fa.:(970)704-0313 November 25. 2014 Civil Consultants Hydrology Report Hydranow Express Extension for Autodesk® AutoCAD® Civil 30® by Autodesk , Inc. Trail Ridge Employee Housing Historic 1 Hydrograph type Storm frequency (yrs) Drainage area (ac) Rainfall lnten (in/hr) IDF Curve = Rational = 2 = 0.810 = 1.996 = North Parachute.IDF Peak discharge (cfs) Time interval (min) Runoff coeff. (C) Tc by User (min) Rec limb factor Thursday, Nov 20 2014 = 0.889 = 1 = 0.55 = 5 = 1.67 Hydrograph Volume = 356 (cuft); 0.008 (acft) Runoff Hydrograph a (cfs) 2-yr frequency a (cfs) 1.00 .....----------~-----------,.-------------.-1.00 0 .90 -+-----------+----------~-----------+-0 .90 0 .60 ..,_------+-----+-----~,...------+------------+ 0 .60 0.50 +------#------+-------~---+----------+ 0.50 0 .30 ---------------------------------0.30 0.20 +---+--------+-----------t------'~-------T 0.20 0 .00 .,._ .__ _________ .__ _________ ....__ ___________ _.._ 0.00 0 5 10 15 Time (min) -Runoff Hyd • Qp = 0.89 (cfs) Hydrology Report Hydrafiow Express Extension for Autodesk® AutoCAD® Civil 30® by Autodesk, Jnc. Trail Ridge Employee Housing Historic 1 Hydrograph type Storm frequency (yrs) Drainage area (ac) Rainfall lnten (in/hr) IDF Curve = Rational = 25 = 0.810 = 4.549 = North Parachute.IDF Peak discharge (cfs) Time interval (min) Runoff coeff. (C) Tc by User (min) Rec limb factor Thursday, Nov 20 2014 = 2.026 = 1 = 0.55 = 5 = 1.67 Hydrograph Volume= 812 (cuft); 0.019 (acft) a (cfs) 3.00 2.00 1.00 0.00 / / / / / / / / 7 v 0 -Runo ff Hyd -Qp = 2.03 (cfs) Runoff Hydrograph 25-yr frequency ~ I ' ' " ' " ~~ ' ' ' 5 10 Q (cfs) 3 .00 .2..00 1.00 0.00 15 Time (min) Hydrology Report Hydrallow Express Extension (or Autodesk® AutoCAO® Civil 30® by Autodesk, Inc. Trail Ridge Employee Housing Historic 2 Hydrograph type Storm frequency (yrs) Drainage area (ac) Rainfall lnten (in/hr) IDF Curve = Rational = 2 = 2.240 = 1.996 = North Parachute.IDF Peak discharge (cfs) Time interval (min) Runoff coeff. (C) Tc by User (min) Rec limb factor Thursday, Nov 20 2014 = 2.460 = 1 = 0 .55 = 5 = 1.67 Hydrograph Volume"' 985 (curt); 0.023 (acft) a (cfs) 3.00 2.00 1.00 0.00 .... I I I I I I I I I I I I 0 5 -Runoff Hyd -Qp = 2.46 (cfs) Runoff Hydrograph 2-yr frequency ' ' ' ' ' ~ ""' ~ ' ' ' ' 10 a (cfs) 3.00 2.00 1.00 0 .00 15 Time (min) Hydrology Report Hydranow Express Extension for Autodesk®AutoCAD® Clvll 30® by Autodesk, Inc. Trail Ridge Employee Housing Historic 2 Hydrograph type Storm frequency (yrs) Drainage area (ac) Rainfall lnten (in/hr) IDF Curve = Rational = 25 = 2.240 = 4.549 = North Parachute.IDF Peak discharge (cfs) Time interval (min) Runoff coeff. (C) Tc by User (min) Rec limb factor Thursday, Nov 20 2014 = 5.604 = 1 = 0.55 = 5 = 1.67 Hydrograph Volume "'2,244 (cuft); 0.052 (acft) Q (cfs) 6.00 5.00 4 .00 3.00 2.00 1.00 0.00 Runoff Hydrograph 25-yr frequency '·' I '\. I ' I ' I '\. I ' I '\. I ' I " I " I " I " I " I ' I '\. I '\. I ' I ~ .. I ~ I ~ I I ' I " I " I " I " I '\. I '\. i ' 0 5 10 -Runoff Hycl -Op= 5.60 (cfs) Q (cfs) 6.00 5.00 4 .00 3 .00 2 .00 1.00 0.00 15 Time (min) Hydrology Report Hydraflow Express Extension for Autodesk® AutoCAD® Civil 30® by Autodesk, Inc. Trail Ridge Employee Housing Post P1 Hydrograph type Storm frequency (yrs) Drainage area (ac) Rainfall lnten (in/hr) IDF Curve = Rational = 25 = 0.560 = 4.549 = North Parachute.IDF Peak discharge ( cfs) Time interval (min) Runoff coeff. (C) Tc by User (min) Rec limb factor Thursday, Nov 20 2014 = 2 .063 = 1 = 0.81 = 5 = 1.67 Hydrograph Volume= 826 (cuft); 0.019 (acft) Runoff Hydrograph a (cfs) 25-yr frequency a (cfs) 3.00 ~---------~---------_,,...-----------,... 3.00 0 .00 ....:;.. _________ __._ _________ __._ _____ ~----"'-0 .00 0 5 10 15 T ime (min) -Runoff Hyd -Qp = 2.06 (cfs) -Outflow Hyd * nTnT Req. Stor = 279 (cuft) • •Estimated Hydrology Report Hydraflow Express Extension for Autodesk® AutoCAD® Civil 30® by Autodesk, Inc. Trail Ridge Employee Housing Post P2 Hydrograph type Storm frequency (yrs) Drainage area (ac) Rainfall lnten (in/hr) IDF Curve = Rational = 25 = 1.130 = 4.549 = North Parachute.IDF Peak discharge (cfs) Time interval (min) Runoff coeff. (C) Tc by User (min) Rec limb factor Thursday, Nov 20 2014 = 3.958 = 1 = 0.77 = 5 = 1.67 Hydrograph Volume= 1,585 (cuft); 0.036 (acft) Q (cfs) 4 .00 3.00 2.00 1.00 0.00 Runoff Hydrograph 25-yr frequency i ' I '\. I \ .. L '\. Ii '\. I =tz ~ I ., "-.. I 7 ~ J / '-~ I 7 ~ ... I L '\. ~ I / '-"-.. j / ." \. ' I v ~ " I / '\. -t // '\. '\. p '\. '\. '\. 0 5 10 -Runoff Hyd -Qp = 3 .96 (cfs) -Outflow Hyd • JIII[L Req. Stor = 417 (cuft) * •Estimated ! Q (cfs) 4.00 3.00 2 .00 1.00 0.00 15 Time (min) Hydrology Report Hydranow Express Extension for Autodesk® AutoCAD® Civil 30® by Autodesk, Inc. Trail Ridge Employee Housing Post P3 Hydrograph type Storm frequency (yrs} Drainage area (ac} Rainfall lnten (in/hr} IDF Curve = Rational = 25 = 0.550 = 4.549 = North Parachute.IDF Peak discharge (cfs} Time interval (min} Runoff coeff. (C) Tc by User (min) Rec limb factor Thursday, Nov 20 2014 = 1.901 = 1 = 0.76 = 5 = 1.67 Hydrograph Volume= 762 (curt); 0.017 (acft) Runoff Hydrograph a (cfs) 25-yr frequency a (cfs) 2.00 --------------------------------------.-2.00 0 .00 ____________ _._ _________ __._ _____ __,.. ___ ~ 0 .00 0 5 10 15 Time (min) -Runoff Hyd -Qp = 1.90 (cfs) -Outflow Hyd • OTillJJ Req. Stor"" 196 (cuft) • •Estimated SE Job No. 14180 Trail Rfdqe Employee Housing Foc{/{ty November 25. 2014 APPENDIX D NOAA Point Precipitation Frequency Estimates Web Soil Survey SOPllS ENGINEEllNI • llC Civil Consultants 502 Main Strttt Suite A3 <:&rbondale Colorado 81623 (970}704.Q311 Fa•:(970)704-0313 10/27/2014 PreclpltaUon Frequency Data Server NOAA Atlas 14, Volume 8, Version 2 Location name: Parachute, Colorado, US* Latitude: 311.31105•, Longitude: ·108.1550° Elevation: 5398 ft* • 1ource: Google Mapa POINT PRECIPITATION FREQUENCY ESTIMATES Se nje Pericll, Oebo11h Martin , Sandra Pe'lto'k, l1hanl Roy, Mic:hHI SI. l aumnt, Ca~ Trypa._,k, Dela Unruh, Michael Yelda. Geolfery Bonnin NOM, Nallonal Weather Service , Sliver SpMg, Maiyland PE tabular I PE graphical I Maos & aerials PF tabular I PDS-based point precipitation frequency estimates with 90% confidence Intervals (In Inches/hour) 1 lourationll Average nicumnce lnt.rval (years) 1 II 2 II 5 II 10 25 50 II 100 II 200 II 500 l 1000 I s-m1n II (1 .~/:22, I (1 .:o~2~58) II (2.~3~40) II (2.:3.a:.32, 4.55 5.89 II 11.18 II 8.50 II 10.8 12.7 (3.58-6.43) (4 .30~.03) :: (5.08-10.11 :: (5 .89-12~ :: (7.15-18.3) {8.09·19.1) 10-mln I 1.27 u1 II 1.13 2M 3.33 4 .16 II 5.12 II 8.22 II 7.88 11.2a I {1.00-1 .62) (1.16-1.88) :: (1.53-2.491 (1.92·3.16) (2.62-4 .701 (3.14-5.871 :: (3.72·7.38) :: (4.32-9.191 .. (5.23 ·11 .9) {5.92-1•4.0) 15-mln 1.03 1.19 II 1.57 1.119 2.71 3.38 4.18 I 5.06 uo 7.54 (0.816-1 .32) {0.948-1 .53) :: {1.24-2.02) (1.58·2.57! !2.13-3.83) {2.56-4.78) {3.02·8.00) : p .51-7.4rl (4.25-9.88 ) (4.82 ·1 1.3) 1 30-mln I 0.838 0.118 II 1.u 1..45 1.111 2.31 2.74 3.21 3.88 I 4.43 0.508·0.8181 (0.848·1 .05) .. (0.906-1 .47) (1.14·1.8!) (1 .47·2.83) (1 .72-3.20) {1.97·3.88) (2.21-4 .67) (2.56-5.80) . (2.83-6 .65) I so-min I 0.400 0.511 0.708 0.879 1.14 1.35 I 1.57 I u1 2.15 II 2.42 0.318-0.513' '0.~·0 .657' 0.559-0.910 {0 .692·1 .14) (0.868-1 .54) (1 .00·1.65) : (1.13·2.21) : (1.24·2.62) (1.41 ·3.20) :: (1.54 ·3 83) B 0.240 0.307 0.420 0.518 D.858 0.770 I o.887 II 1.01 I 1.18 II 1.31 0.194-0.304 0.246-0 .388' 0.336-0.534 0.412-0 .880 0.506-0.876 (0.578·1 .04) : (0.842·1.23 ) :: !0.700 ·1.43 ) . (0.784-1.72! :: !0.848-1 .94! B 0.183 0.225 0.297 lio~!!ssil 0.451 0.525 o.803 I D.885 I o.799 0.889 0.149-0.230' 0.182-0.283 0.239-0.3741 0.350-0.596' 0.396-0.703 110.441 ·0.627 :,0.479-0.966): (0,537-1.16) (0.580-1 .31 ) El 0.114 0.135 0.170 0.201 0.246 0.282 lio:!:!~ill10.~~ill(0.~~~2I OMO 0.094·0.141 0.1 10-0 .187 0.139-0.211 ll0.163-0.251\I 0.193-0.319 1(0.216-0 .371 '0 .304-0.665 El l1 0 .~~1ae il 0.081 0.100 I 0.118 I 0.140 0.1511 0.1711 0 .201 110.1~~3 !1 0.253 0.067-0 .099 (0.083·0 .122 :10.096-0.1431: 0.112-0.179 0.124-0.206 0.135-0.238 IC0.1 44-0.274 11 0.170-0.380 I 24-tu I 0.043 0.049 0.080 I 0.069 II o.083 I 0 .094 0.105 I 0 .111 I o .133 0.146 0.036-0.052' 0.041-0 .05911 0.050-0.072 ' :,0.058-0.084)::,0.067-0 .104 ): 0.074-0 .119 0.080-0 .137 :,0.065-0.157) : 0.093-0.184) 0.100-0.204 I 2-d•Y I 0.025 lio.o~~35!1 0.038 I o.041 II 0.049 II 0.055 I 0.082 I o.088 II 0 .018 I 0.085 0.022-0.030 0.030-0.042' :10 .~.04Bl::10 .040-0.oe1 1::10 .044-0.oe91: 0.047-0.079' :,0.051-0.090)::,0 .055-0.1!!fil: l<0.058-0.117 I J-day I 0.019 0.021 0.021 I o.030 II 0.031 I 0.041 I o.045 II o.oso I 0.057 0.082 0.016-0.022 0.018-0.025) 0.022-0 .031 :10.026-0.03B )::10.030-0.044 !: 0.033-0.051 :(0.035-0.058)::10.038-0.066): ll0.041-0.0ml 0.043-0.0651 I 4-day I 0.015 0.017 0.021 0.024 0.029 0.033 0.037 0.041 I o.048 I 0.050 (0 .013-0.018' (0 .015-0.020) (0.018-0.025' l0.021-0.029) (0.024-0.035) 0.026-0 .040 (0.029-0.048' 110.030-0.053) :,0.033-0.061 l: (0.035-0 .088) 7-c:lay 0.010 0.012 0.014 0.011 I 0.019 I 0.021 0.024 I 0.026 II o.o3o I 0.032 0.009-0.012 0.010-0.013 0.012-0.018' 0.014-0.0191 :,0.016-0.023): 0.018-0.026 0.019-0.030 :10.0ZO.O.o34)::10.022-0.0391: 0.023-0 .043' 10-day 0.008 0.009 0.011 0.013 0.015 0.011 ~~8 0.020 110 .0~::29)1 0.024 0.007-0.009 0.008-0.010 0.010-0.013 0.011-0.0151 '0.012-0.018 0.014-0 .020 .022 0.015-0.0251 0.017-0 .032' 8l 0.005 II 0.008 II 0.001 II 0.008 I 0.009 0.010 0.011 0.012 0.013 0.014 :io.oos-0.0081::10.00S-0.0011::10.008-0.008!::10.001-0.009): (0.008-0.011 0.008-0.012] '0.009-0 .013 0.009-0.015' (0.010-0.017 0.010-0.019 ~I 0.004 II 0.005 II 0.008 I 0.008 I 0.001 I 0.008 0.009 0.009 0 .010 0.011 :10.004-0 .oos1::10.004-0.oosi::10.oos-o.ooe2: o.ooe-0.007) :10.ooe-o.ooa1: 0.007-0 .009' 0.007-0010 0.007-0.012 10.008-0 .013 110.008-0.014 ~I 0.004 II 0.004 II 0.005 II 0.005 II 0.008 ll 0.001 II 0.001 I 0.008 I o.ooa I 0.0011 :10.003-0.004)::10.004-0 .004!::10.004-0 .005!::10.005-0 .006 !::1 0.00S-0.007 !::10.006-0.008)::10.006-0.008!: 0.006-0.009' :10.006-0.0101: 0.006-0.011 8l 0 .003 II 0 .003 II 0.004 II o.oos II o.oos II 0 .0011 II 0.001 I 0.001 I 0.001 I 0.007 :10.003-0.003l::10.00J-0.004!::10.004-0.005!::10.004-0 .00S)::io.OOS-0.006 )::10.oos-o.0011::10.00S-0.0012: lro.005-0.ooa' :,0.005-0.009): 0.006-0.009 1 Pnlclpltallon frequency (PF) estimates In this table 1111 based on frequency analysis of panial duration aerias (POS). Numbers In parenthesis are PF estimttes at lowat and llPP8f' bounds of the 90% conlldence Interval. The probablty that precipitation frequency ntmatas (for a given duration and average recurrence Interval) wl be greate r than the upper bound (or lesa than the lower bound) Is 5%. Esllmates at upper bounds ere not checked against probable maxmum precipitation (PMP) estimates and may be higher than currenttf veld PMP vakles . Please refer to NOAA Alles 14 document for more Information. Back lo Too PF graphical hltp://hdsc.nws.noaa.gavlhdsc/prds/prds_plntpage.h!ml?lat=39.3905&lai=·108.1550&data=lntenslty&unlts=engllsh&serles=pds#top 114 10l27/2014 Precipitation Frequency Data Server .-. '-~ .~ Ill c .fl .5 ~ .... .!!I 'i5. ·~ 100.000 10.000 1.000 0.100 0.010 0.001 c ·e . Ill PDS·based intensity-duration·frequency (IDF) curves Latitude: 39.3905•. Longitude: -108.1550• . . . . . ....... ·····-............... ·-............ -· ..... -.... -- . . ' ... -~ ... ~ . . .. : .. . . . .. ..... -.... __ .,,., -... ·-............. --- 0 I • 0 0 f . . . • I 0 f f . . . . . . P o ' I I o o o o 0 • t f .. 4 • . . ' ... ·:-. -. : .... -~ . -. -. ~ ..... ~ ... ! ... -. -!• • ---·::: .. -• + -: •• + --~ -• -.~ -~ --- - 0 0 0 0 0 I 0 0 0 I I 0 0 0 I ' I 0 0 0 I p . .. . . . . . . . .. . . . . . . . ... • I o 0 o O I I ' • o I • o • c c c c ... ... ... ... ... >. >. >. > >. > >-·e -~ ·e ·e .c .c .c .c .c Ill Ill Ill Ill Ill Ill ra N i+i oD ~ ~ ,, 'ti "T:I "ljl "9 '9 "ljl I ~ s N m .t ~ :!I ,... 0 ~ ~ Duration ~ >> ,. Ill 'tl"T:I ~~ 100 .000o--~ ...... !~~~~!,__~-~ •. ~~~~!~~---~~~~~..-~~~~~­ ' . . . .. . . 10.000 -·· .•.. ~-··· ..... --:-----... ; .......... -~ ....... -~·· ..... ~··· ..... : ... . . . .. . . . . 1.000 ~ ......... . .. --.. ·-· --...... ---... . . - I 0 0 .... • •- 0.100 -······-~··· -----......... -............. " .. ., ... ' 2 Average recurrence interval (years) NOAA Atlas 14, Volume 8, Version 2 Created (GMT): Mon Oct 27 18~48:51 2014 htlp'J/hdsc.nws.noaa.gov/hdsc/pfds/pfds_Jll'lntpage.hlrnl?lal=39.3905&lai=-10B.1550&data=lntenslty&units=engllsh&serles=pds#tcp Awraga r.cummc:e ineertal (yaansJ -1 ~2 -5 -10 -25 -50 -100 -200 -500 -1000 10/27/2014 Precipitation Frequency Data Server -5-inln -2-day -10-inln -3-day -15-mln -4-day -:'ID-min -7-day -eo-min -10-day -2.f1r -20-day -:i~r -30-day -~r -45-day -12-hr -60-day -2~ Back to Top Maps & aerials Large scale terrain h!lp'Jl1ldsc.nws.noaa.ggv/hd5c/plds/pfds_prlntpage.html?lat=39.3905&Jon=-108.1550&data=lntenslty&units=engllsh&serles:pds#tcp 1 Cl/27/2014 Precipitation Frequency Data Server Bads lo Too US Deoar!menl pf Commerce National Oceanic and AlmpBDhedc Admlnl111m11pn NaHpnal Waal!Jer SeMca Oft!ca pf Hvdmloolc Qavelgomant 1325 East Wast Highway Sliver Spring, MD 20910 Questions?: HQSC.CU111!onsCnoaa.gpv Dlaclalmer hllp://hdscJTNs.noaa.gov/hdsc/pfds/pfds_prlntpage.html?lat=39.3905&lm=· 108.1550&da1a=llUnsl!y&unlts=engllsh&serles=pds#top MMlt..- .... JI ... . .. • • ; • • ~ Hydrologic Soll Group-Douglas-Plateau Area, Colorado, Parts or Garfield and Mesa Counties (Trial Ridge Employee Housing Facility) MAP LEGEND Area of Interest (AOI) O Area of Interest (AOI) Soll1 SoH Rallng Potygon1 D A D AID D B D BID D c D CID D D D Not raled or not available Soll Rating LlnH -A -AID -B .,,,.,,, BID -c -CID ,,,..,,,. D . ,, Not raled or not available Soll Rallng Points Cl A C ND • B • BID Natural Resources ConservaUon Service Cl c CJ CID • D IJ Not rated or nol avBilable Water Fealunis ,....__ Streams and Canals Tran1portatlon +++ Ralls .,,,., Interstate Highways ,...,, US Routes Major Roads local Roads Background • Aerial Photography Web Soil Survey National Cooperative Soil Survey MAP INFORMATION The soil surveys lhat 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 or mapping can cause misunderstanding or the detail or mapping and accuracy of soil line placemenL The maps do not show the small areas of conlrasting soils that could have been shown al 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 Soll Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soll 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. Soll Survey Area: Douglas-Plateau Area, Colorado, Parts of Garfield and Mesa Counties Survey Area Data: Version 7, Sep 22, 2014 Soil map units are labeled (as space allows)formap scales 1 :50,000 or larger. Date(s) aerial images were photographed: Jun 22, 2010-Sep 2, 2010 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs rrom the background imagery displayed on these maps. As a result. some minor shifting of map unit boundaries may be evident. 1012412014 Page 2 of 4 Hydrologlc So il Group-Douglas-Plateau Area, Colorado, Parts of Garfiel d and Mesa Counties Trial Ridge Employee Housing Facility Hydrologic Soil Group Hydrologlc Soll Group-Summary by Map Unit -Dougla1°Plateau Araa, Colorado, Parts of Garfield and Mesa CountlH (C0682) Map unit symbol I Map unit name Rating I Ac1'81lnAOI I Percent of AOI 56 I Parachute-lrigul·Rhone c I 3.2 I association, 25 to 50 percent slopes Total• for Area of Interest Description Hydrologic soil groups are based on estimates of runoff potential. Soils are ass igned 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 (ND, 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 dra ined 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 (ND, BID, 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 . Rating Options Aggregation Method: Dominant Condition Natul"llll Resources Conservation Service Web Soil Survey National Cooperative Soll Survey 100.0% 100.0% 10(24/2014 Page 3of4 Hydrologlc Soll Group-Douglas-Plateau Area, Colorado, Parts of Garfield and Mesa Counties Component Percent Cutoff: None Specified Tie-break Rule: Higher Natural Resources ConservaUon Service Web So il Survey Nati onal Cooperative Soil Survey Trial Ridge Employee Housing Facility 10/24/2014 Page4 of 4 I WPXEnergy Trail Ridge Employee Housing Facility Integrated Vegetation and Noxious Weed Management Plan Garfield County, Colorado Cover photo: View of existing conditions at the proposed employee housing facility location. Prepared for: WPX Energy Rocky Mountain, LLC 1058 County Road 215 Parachute, CO, 81635 Prepared by: Westwater Engineering 2516 Foresight Circle #1 Grand Junction, CO 81505 (970)241~7076 October 2014 1.0 INTRODUCTION 1.1 Project Description On behalf of WPX Energy Rocky Mountain, LLC (WPX), Phil Vaughan Construction Management, Inc. requested WestWatcr Engineering (WcstWate r) to prepare this Integrated Vegetation and Nox ious Weed Management Plan for the proposed Trail Ridge Employee Housing Facility . Th is project would be located on private lands on the ridge dividing West Fork Parachute Creek and West Fork Stewart Gulch in Section 3, Township 5 South, Range 97 West, Sixth Principal Me ri dian in Garfield County, Colorado (Figure J). The current primary uses of the project area arc rangeland , natural gas development , and wildlife habitat. 1.2 General Survey Information Pedestrian surveys of the project area were conducted on September 16, 2014. Identification of plant species was aided by using pertinent published field guides (Kershaw ct al. 1998, Whitson ct al. 2001, CWMA 2007, Weber and Wittmann 2012). Mapped soil types , as published by the Natural Resources Conservation Service (NRCS), U. S. Department of Agriculture (USDA), were reviewed to determine the soil types and vegetation characteristics at the project site (NRCS 2014). 2.0 LANDSCAPE SETTING 2.1 Terrain The terrain near the project consists primarily of gently rolling ridges typical of upper elevations of the Roan Plateau. Elevation in the project area is approximately 8,450 feet. 2.2 Vegetation Vegetation is dominated by a mixture of mountain big sagebrush (Artemisia tridentata vaseyana), Gambel oak (Quercus gambe/ii), serviccberry (Amelanchier alnifolia), antelope bitterbrush (Purshia tridentata), snowbcrry (Symphoricarpos rotundifolius), and aspen (Popu/us tremuloides). Groves of aspen prefer northern exposures where soil moisture and temperatures arc suitable. A variety of grasses and forbs arc distributed throughout the undcrstory in the project area. A few common species include various whcatgrass species (Elymus or Pascopyrum spp.), bluegrass (Poa spp .), Indian riccgrass (Achnatherum hymenoides), western yarrow (Achillea lanu/osa), dandelion (Taraxacum spp), lupine (lupinus spp), and sulphur-flower buckwheat (Eriogonum umbellatum). 2.3 Soils Soil types in the general project area include loams and sandy loams that overlay broken shale derived from the Green River Formation . This formation is visible in the sheer canyons of Ronn and Parachute Creek and the Roan Cliffs overlooking the towns of Rifle, Parachute, and DeBeque, Colorado . In many areas , soil profiles arc shallow, with only 12-24 inches of soil overlying deep, broken shale deposits. So il types and the vegetation supported vary with elevation and slope aspect. Mapped soil types, as published by the Natural Resources Conservation Service (NRCS), U.S . Department of Agriculture (USDA), were reviewed to determine the soil types and vegetation characteristics of the project site and surrounding property (NRCS 2014). One soil type is found in the project area and includes the following : Parachute -lrigul-Rhonc association has slopes ranging from 25 to 30 percent. Vegetation on this soil type includes a mix of aspen and deciduous mountain shrubs including serviccbcrry, with an understory of sagebrush. 3 .0 NOXIOUS WEEDS 3.1 Introduction to Noxious Weeds WestWatcr Engineering Page 1 of8 October 20 14 Most noxious weed species in Colorado were introduced, mostly from Eurasia, either unintentionally or as ornamentals that established wild populations . These plants compete aggressively with native vegetation and tend to spread quickly because the environmental factors that normally control them arc absent. Disturbed soils, altered native vegetation communities, and areas with increased soil moisture often create prime conditions for weed infestations. The primary vectors that spread noxious weeds include humans, animals, water, and wind. The Colorado Noxious Weed Act (State of Colorado 2005) requires local governing bodies to develop noxious weed management plans. Both the State of Colorado and Garfield County maintain a list of plants that arc considered to be noxious weeds . The State of Colorado noxious weed list segregates noxious weed species based on priority for control: I. List A species must be eradicated whenever detected. 2. List B species' spread should be halted; may be designated for eradication in some counties. 3. List C species arc widespread and the State will assist local jurisdictions which choose to manage those weeds. The Garfield County Weed Advisory Board has compiled a list of 21 plants from the State list considered to be noxious weeds within the county (Garfield County 2013) (Appendix A). The Garfield County Weed Advisory Board has duties to: 1. Develop a noxious weed list; 2. Develop a weed management plan for designated noxious weeds; and, 3. Recommend to the Board of County Commissioners that identified landowners submit an integrated weed management plan for their properties (Garfield County 2002). 3.2 Observations The current noxious weed control efforts on the site appear to be effective and only one noxious weed species, cheatgrass, was observed thinly scattered in the project area. Several unlisted nuisance weed species were noted in small quantities on disturbed soils near the site. The presence of these plants can negatively affect desirable native plant species resulting in decreased reclamation success. Plants in this category include kochia (Bassia scoparia), prostrate knotwecd (Polygonum aviculare), western sticktight (lappula occidentalis), and Russian thistle (Sa/so/a spp.). 3.3 Integrated Weed Management Control of invasive species is a difficult task and requires intensive on-going control measures. Care must be taken to avoid negatively impacting desirable plant communities and inviting infestation by other pioneer invaders. Weed management is best achieved by employing varied methods over several growing seasons, including inventory (surveys), direct treatments, prevention through best management practices, monitoring of treatment efficacy, and subsequent detection efforts. Weed management is often limited to controlling existing infestations and prevention of further infestations, rather than eradication, but through effective weed management practices eradication can be possible in small to medium sized weed populations . Assessment of the existence and extent of noxious weeds in an area is essential for the development of an integrated weed management plan . Th is report provides an initial assessment of the occurrence of noxious weeds for the project area. In order to continue effective management of noxious weeds , further inventory and analysis is necessary to I) determine the effectiveness of the past treatment strategics; 2) modify the treatment plan, if necessary; and 3) detect new infestations early, which would result in more economical and effective treatments. 3.4 Prevention of Noxious Weed Infestations Westwater Engineering Page 2 of8 October 2014 I Weed management can be costly, and heavy infestations may exceed the economic threshold for practical treatment. Prevention is an especially valuable and economical strategy for noxious weed management. Several simple practices should be employed to prevent weed infestations . The following practices will help prevent infestation and thereby reduce costs associated with noxious weed control : • Prior to delivery to the site, all equipment and vehicles, including maintenance vehicles, should be thoroughly cleaned of soils from previous sites which may be contaminated with noxious weeds. • If working in sites with weed-seed contaminated soil, equipment should be cleaned of potentially seed-bearing soils and vegetative debris at the infested area prior to moving to uncontaminated terrain. • A void driving vehicles through areas where weed infestations exist. • Use of weed free materials such as mulch and seed. 3.5 Treatment and Control of Noxious Weed Infestations The treatment method and timing will be detennined by the company and their contracted licensed pesticide applicators. The recommendations provided in this report should be considered when developing annual treatment plans . General control methods for the species detected in the project area arc provided for reference in Table I. a e . T bl 1 G en era nox ous wee d con ro me 0 s or SDCCICS m t I th d i . th . t e pro1ec area. -Common Name Scientific N@me USDA Symbol ---Type* Control Methods ~ Prevent seed production. Apply herbicides in fall and spring in large monoculturcs where there arc few if any Cheatgrass desirable grasses. Till when plants arc in the seedling Bromus tectorum A stage followed by seeding with native cool-season BRTE grasses . Avoid overgrazing. Best management practices arc most effective in preventing and controlling infestations . • Type: A 12 annual 3.6 Recommended Treatment Strategies The following treatment strategics arc presented for reference . It is important to know whether the weed species being managed is an annual, biennial, or perennial to select strategics that effectively control and eliminate the target. Treatment strategics vary depending on plant type, which arc summarized in Tables 2 and 3. Herbicides should not always be the first treatment of choice when other methods can be effectively employed. Table 2. Treatment Strategies for Annual and Biennial Noxious Weeds Target: Prevent Seed Production I. Hand grub (pull), hoc, till, cult ivate in rosette s tage and before flowering or seed maturity. If flowers or seeds develop, cut and bag seed heads . WcstWater Engineering Page 3of8 October 2014 ·' 2. Cut roots with a spade 2"-3" below soil level. 3. Treat with herbicide in seedling, rosette or bolting stage, before flowering. 4. Mow biennials after bolting stage but before seed set. Mowing annuals will not prevent flowering but can reduce total seed production. (Sirota 2004) Table 3. Treatment Strategies for Perennials af'Tlet: D l ' ' d d epi ete n11tr1ent reserves m root system, prevent see pro 11ct1on I. Allow plants to expend as much energy from root system as possible. Do not treat when first emerging in spring but allow growth to bud/bloom stage. If seeds develop cut and bag if possible. 2. Herbicide treatment at bud to bloom stage or in the fall (recommended after August 15 when natural precipitation is present). In the fall plants draw nutrients into the roots for winter storage. Herbicides will be drawn down to the roots more efficiently at this time due to translocation of nutrients to roots rather than leaves. lf the weed patch has been present for a long period of time another season of seed production is not as important as getting the herbicide into the root system. Spraying in fall (after middle August) will kill the following year's shoots, which arc being fonned on the roots at this time. 3. Mowing usually is not recommended because the plants will flower anyway, rather, seed production should be reduced. Many studies have shown that mowing perennials and spraying the regrowth is not as effective as spraying without mowing. Effect of mowing is species dependent therefore it is imperative to know the species and its basic biology. Timing of application must be done when biologically appropriate, which is not necessarily convenient. 4. Tillage may or may not be effective or practical. Most perennial roots can sprout from pieces only 0. 5 inch -1. 0 inch long. Clean machinery thoroughly before leaving the weed patch. 5. Hand pulling is generally not recommended for perennial species unless you know the plants arc seedlings and not established plants. Hand pulling can be effective on small patches but is very labor intensive because it must be done repeatedly. (Sirota 2004) Some weeds, particularly annuals and biennials, can develop resistance to herbicides. The ability to quickly develop immunity to herbicides, especially when they arc used incorrectly, makes it imperative to use the proper chemicals at the correct time in the specified concentration according to the product label. Excessive application, either in frequency or concentration, can result in top kill without significantly affecting the root system. Repeated excessive applications may result in resistant phenotypes. 3.7 Noxious Weed Management-Best Management Practices Construction: The following practices should be adopted for any construction project to reduce the costs of noxious weed control and aid in prevention efforts. New disturbance for this project is minimal, however these practices will help prevent spread of noxious weeds. The practices include: • Prior to delivery to the site, equipment should be cleaned of soils remaining from previous construction sites which may be contaminated with noxious weeds . • Equipment and material handling should be done on established sites to reduce the area and extent of soil compaction. • In all cases, temporary disturbance should be kept to an absolute minimum. • Top soil, where present, should be segregated from deeper soils and replaced as top soil on the final grade, a process known as live topsoil handling. • If stored longer than one growing season, topsoil stockpiles should be seeded with non-invasive sterile hybrid grasses . WestWat cr Engineering Page 4of8 Octob er 2014 • Wetland vegetation, if encountered, should be live handled like sod, temporarily watered if necessary, and placed over excavated sub-soil relative to the position from which the wetland sod was removed. • Cut-off collars should be placed on all wetland and stream crossings to prevent back washing (seed vector) and to ensure that soil moisture conditions arc not impacted after construction so that native plants can re-establish from the existing seed bank. • If working in weed infested sites, equipment should be cleaned of potentially seed-bearing soils and vegetative debris prior to moving to uncontaminated terrain. • After construction, disturbed areas outside the footprint of the development should be immediately reseeded with an appropriate seed mix . Herbicides: Many of the listed noxious weed species in Colorado can be controlled with commercially available herbicides . Annual and biennial weeds arc best controlled at the pre-bud stage after gcnnination or in the spring of the second year. Selective herbicides arc recommended to minimize damage to desirable grass species. It is important that applicators adhere to concentrations specified on herbicide containers. Herbicides generally do not work better at higher concentrations. Herbicide failures arc frequently related to high concentrations that result in top kill before the active ingredient can be transported to the roots through the nutrient translocation process . If directed on the herbicide label, a surfactant or other adjuvant should be added to the tank. Grazing: In the event grazing is allowed in the project area, it should be deferred in reclaimed areas until revcgctation of desirable species has been successfully established and seeded plants have had the opportunity to reproduce. Monitoring: Areas where noxious weed infestations arc identified and treated should be inspected over time to ensure that control methods arc working to reduce and suppress the identified infestation. The sites should be monitored until the infestations arc eliminated . These inspections can then be used to prioritize future weed control efforts. 3.8 Commercial Applicator Recommendations A certified commercial pesticide applicator licensed in rangeland and/or right-of-way/industrial weed control (depending on site characteristics) is a necessary choice for herbicide control efforts . An applicator has the full range of knowledge, skills, equipment, and experience desired when dealing with tough noxious weeds. In addition , the purchase and use of restricted use herbicides requires a Colorado pesticide applicator license. 4.0 REVEGETATION -RECLAMATION Based on the soils and vegetative communities present, the following reclamation recommendations arc provided. Soil Preparation Special soil preparation techniques may be needed as soil compaction may be an issue on the housing facility location . Compaction can reduce water infiltration and also hinder the penetration of the sprouting seed . Practices that will reduce compaction and prepare the seedbed include: scarification, tillage, or harrowing (Colorado Natural Areas Program ct al. 1998). Soil Amendments West Water docs not recommend the use of soil amendments for reclamation for this project due to the likelihood that fertilizer containing nitrogen will disproportionately benefit undesirable annual plants WcstWater Engineering Page 5of8 October 2014 ,J (Perry ct al. 2010). If the company detennines the use of soil amendments to be beneficial, the type and rate should be based on soil samples near the site. With proper topsoil handling, these soils should rcvegetate well with native plant species. The addition of soil amendments in rangeland reclamation projects can create more optimal growing conditions for non- native or invasive plant species, with which native plants compete poorly. A potentially beneficial alternative method to enhance reclamation success, particularly where there is poor or destroyed topsoil, is the application of vesicular-arbuscular mycorrhizal fungi (AMF). These fungi, mostly of the genus G/omus, arc symbiotic with about 80 percent of all vegetation. Endo- mycorrhizal fungi arc associated mostly with grasses and forbs and could be helpful in reclamation. In symbiosis, the fungi can increase water and nutrient transfer capacity of the host root system (Barrow and McCaslin 1995). Over-the-counter commercial products arc available, and the best products should contain more than one fungus species. Seed Mixture The recommended seed mix (Appendix B) is adapted from the Bureau of Land Management's Colorado River Valley Field Office seed menu recommendations (BLM 2012). This seed mix is well suited for mountain shrublands similar to the project area, and includes perennial native grasses and forbs that should establish well, protect topsoil, and provide a basis for rehabilitation for the site upon reclamation. Locally collected sagebrush seed would be a benefit to sage-grouse in the area, as it has a higher chance of success and would eliminate the potential for introducing another non-local species into sage-grouse habitat. Seeding Methods Drill seeding would be the most appropriate and economical method for seeding the majority of the project area. Hydroseeding or hand-broadcast seeding at twice the recommended drill seed rate is recommended for steep slopes or for smaller areas where drill seeding would be impractical or dangerous. Mulching Crimped straw mulch would be the most cost effective and practical method of mulching areas prone to erosion after drill seeding this site. No mulching is recommended for areas that arc hydrosceded. Potential detrimental effects of mulching include the introduction of weed species and the establishment of non- native cereal grains . Use of a certified weed-free sterile wheat hybrid straw mulch would limit these effects. BMPs Excelsior wattles or straw bales at the toe of steep slopes and water discharge points arc appropriate to help control water velocity flowing off the alignment during stonn runoff. Terracing slopes near or exceeding 3: 1 will reduce erosion, benefitting topsoil and seed retention and thereby improving revegctation success. 5.0 REFERENCES Barrow, J. R., and B. D. Mccaslin. 1995. Role of microbes in resource management in arid ecosystems . In: Barrow, J. R. , E. D. McArthur, R. E. Sosebee, and Tausch , R. J. , comps. 1996. Proceedings: shrubland ecosystem dynamics in a changing environment. General Technical Report, INT-GTR- 338, Ogden, Utah: U.S. Department of Agriculture, U.S. Forest Service, lntermountain Resource Station, 275 pp. BLM . 2012. Revised Revegctation Seed Mix Menus, CRVFO Energy Team. U.S. Bureau of Land Management, Colorado River Valley Field Office. Silt, Colorado. We stWater Enginee ring Page 6of 8 October 20 I 4 Colorado Natural Areas Program , Colorado State Parks, Colorado Department of Natural Resources. 1998. Native Plant Revegetation Guide for Colorado . Available online: http://www . parks. state. co. us/SiteCollcctionlmagcs/parks/Programs/CNAP/CNAPPublications/RevcgetationGuide/rcvegetat ion . pdf. Accessed February 4, 2014 CWMA. 2007. S . Anthony, T . D'Amato, A. Doran, S. Elzinga, J. Powell, I. Schonlc, K. Uhing . Noxious Weeds of Colorado, Ninth Edition. Colorado Weed Management Association, Centennial. Garfield County . 2002. Garfield County Vegetation Management and Garfield County Weed Advisory Board . Garfield County Noxious W ccd Management Plan, Resolution #2002-94, October 21 . Garfield County . 2013 . Vegetation Management Section -Noxious Weed List. Available online: http://www . garficld-county. com/vegetation-management/noxious-weed-list. aspx. Accessed Fcburary 4, 2014 Kershaw, L., A. MacKinnon, and J. Pojar. 1998 . Plants of the Rocky Mounta ins . Lone Pinc Publishing , Auburn, Washington . NRCS. 2013. Web Soil Survey, U.S. Department of Agriculture, Natural Resource Conservation Service, URL : http://websoilsurvey . nrcs. usda . gov Perry , L. G., D. M. Blumenthal , T . A. Monaco, M. W. Paschke , and E. F. Redente. 2010 . Immobilizing nitrogen to control plan invasion. Oecologia: 163 : 12-24. Sirota, J. M. 2004 . Best management practices for noxious weeds of Mesa County. Colorado State University , Cooperative Extension Tri River Arca, Grand Junction, Colorado. URL: http://www. coopcxt. colostate. edu/TRA/Weeds/wecdmgmt. html State of Colorado . 2005 . Rules pertaining to the administration and enforcement of the Colorado Noxious Weed Act, 35-5-1-119, C.R. S. 2003. Department of Agriculture, Plant Industry Division, Denver, 78 pp . Weber, W. A., and R. C. Wittmann . 2012. Colorado Flora, Western Slope. Fourth 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. We eds of the West -~" edition. Western Society of Weed Science in cooperation with Cooperative Extension Services, Unive rsity of Wyoming, Laramie . Wcs tWatcr Enginee ring Page 7 of8 October 2014 c:::J 100 Foot Weeds Suivey Area D Housing Facility LJ BLM ~-' Trail Ridge Employee Housing Facility Integrated Vegetation and Noxious Weed Management Plan ~ 'flestWater Engineering -:;;, Con sulttng Englnffn 6 Scientists ti 2$0 llOO F'Ht .. . - Appendix A ar 1e ountv OXIOUS ee IS G fi Id C t N . W d L" t Species Growth State Soecles Common name Code Form Life Hlstorv Llstin2 Acroptilon repens Russian knapweed ACRE3 Forb Perennial B Aegilops Jointed goatgrass AECY Grass Annual B cylindrica Arctium minus Common (Lesser) ARMI2 Forb Biennial c burdock Cardaria draba Hoary cress, Whitetop CADR Forb Perennial B Carduus Spiny plumeless CAAC Forb Biennial I Winter B aca111hoides thistle Annual Carduus nutans Musk (Nodding CANU4 Forb Biennial B plumeless) thistle Centaurea diffusa Diffuse knapweed CEDl3 Forb Perennial B Centaurea Spotted knapweed CEMA4 Forb Perennial B macu/osa Centaurea Yell ow starthistle CES03 Forb Annual A solstitialis Chrysanthemum Oxeye daisy CH LESO Forb Perennial B /eucanthemum Cichorium Chicory CIIN Forb Perennial c intybus Cirsium arvense Canada thistle CIAR4 Forb Perennial B Cynog/ossum Houndstongue, CYOF Forb Biennial B officinale Gypsyflower Elaeagnus Russian olive ELAN Tree Perennial B angustifolia Euphorbia esu/a Leafy spurge EUES Forb Perennial B Linaria Dalmatian toadflax, LIDA Forb Perennial B dalmatica broad-leaved Linaria vu/garis Yell ow toadflax LIVU2 Forb Perennial B Lythrom salicaria Purple loosestrifc LYSA2 Forb Perennial A Onopordum Scotch thistle ONAC Forb Biennial B acanthium Tamarix Small flower tnmarisk TAPA4 Tree Perennial B parviflora Tamarix Salt cedar, Tamarisk TARA Tree Perennial B ramosissima WestWater Engineering Appendix A October 2014 A d. BR ,ppen 1x . ecommen d d d e see . d menu or m1xe h bl d ' I d' mounta n s ru an , me u ml! oa kb h rus • PLS Common Name _ Scientific Name Variety Season Form lbs/acre* Plant Both of the Followin2 (20% Each, 40% Total) Bottlebrush Squirreltail E/ymus e/ymoides, Sitanion VNS Cool Bunch 2. 7 hystrl"< Pseudoroegneria spicata, Secar, P-7, Bluebunch Wheatgrass Anatone, Cool Bunch 3. 7 Agropyron spicatum Goldar and Two of the Followine 15% Each. 30% Total) E/ymus /anceo/atus ssp. Critana, Sod-Thickspike Wheatgrass lanceo/atus, Agropyron Bannock, Cool fonning 2.5 dasvstachvum Schwendimar Slender Wheatgrass Elymus trachycaulus, San Luis Cool Bunch 2.5 AwoDvron trac/1ycaulum Western Wheatgrass Pascopyrum [Agropyro11] Arriba, Cool Sod-3.6 smith ii Rosana fonning and One of the Followlne 10% Total) Big Bluegrass Poaampla Shennan Cool Bunch 0.3 Canby Bluegrass Poa canbyi, P. secunda Can bar Cool Bunch 0 .3 Muttongrass Poafe11dleriana VNS Cool Bunch 0.3 and One of the Followlne 10% Total) Lettennan Needlegrass Achnathe111m [Stipa] VNS Cool Bunch I. 7 letterman ii Columbia Needlegrass Achnatherum [Stipa] VNS Cool Bunch I. 7 11e/sonii, Stioa co/umbiana Green Needlegrass Nassella [Stipa] viridula Lodorrn, Cool Bunch I. 4 Cucharas and One of the Followin2 10% Total) Achnatherum [Oryzopsis] Nezpar, Indian Ricegrass Paloma, Cool Bunch I. 9 hymenoides Rimrock Koe/eria macrantha, K. VNS (North Junegrass cristata American Cool Bunch 0. I origin) OPTIONAL: Any combination from the following species may be substituted for up to 10% of the above erasses. Silvery Lupine Lupinus a'1(enteus VNS Arrowleaf Balsamroot Balsamorhize saI!itlata VNS Sulfur Flower EriOJ!onum umbe/latum VNS Yarrow Achillea mi//ffolium VNS Utah Sweetvetch Hedvsarum borea/e VNS Rocky Mountain Beeplant C/eome serrolata VNS Utah Serviceberry Amelanchior utahensis VNS Mounlain Snowberry Svmphoricarpus oreoohilus VNS Woods' Rose Rosa woodsii VNS White Sage Artemisia ludoviciana VNS *Based on 60 pure live seeds (PLS) per square foot, drill-seeded. Double this rate (120 PLS per square foot) if broadcast or hydroseeded WestWater Engineering Appendix B October 2014 Grading and Drainage Plan. These plans have been reviewed by referral agencies and appear to meet the requirements in the LUDC. 7-205 Environmental Quality The application includes an SPCC which has been reviewed by the referral agencies and appears to meet the requirements of the LUDC. Permits are required for the diesel generators. The Applicant provided evidence that the permits have been submitted. Except for the generators, the only other air emissions are expected from those typical of motor vehicles accessing the site. 7-206: Wiidfire Hazards The DeBeque Fire Protection District reviewed the application and had no addHional comments. The facility Is not located within a "very high" wildland fire susceptibility designation according to the Community Wildfire Protection Plan. In addition, no buildings will be constructed onsite with shake roofs. 7-207 Natural and Geologic Hazards See Section 7-108, above. The Applicant has Included a reclamation plan that addresses re-vegetation and reclamation. However, it appears that the revegetation and reclamation calculatlon Is only for the newly disturbed areas of the site. The LUDC states that reclamation security is required If the disturbed area outside that of the long-term functioning area of the site -In this case the storage and roadway Improvements -is one acre or greater. The Applicant submitted a drawing from Sopris Engineering on May 28, 2015 (See Exhibit 20) indicating that the area outside 1he storage and roadway functions is 0.68 acres. · I -are . taff.does not n The form and content of the reclamation and revegetation plan has been reviewed by the Garfield County Vegetation Manager and has been found to be adequate. 7-301: Compatible Design See Section 7-103, above. 21 Phil Vaughan From: Phil Vaughan Sent: Thursday, May 28, 2015 7 :20 AM To: Subject: 'Steve Anthony'; Dave Pesnichak (dpesnichak@garfield-county.com) RE: WPX LIPA-8191 Attachments: WPX LIPA-8191.pdf; 1-Tab36-TrailRidgeEHF-MajorEmplHousingFacility.pdf; 05-28-15- CivilSheetS-PVCMI Notes on disturbed area.pdf Steve and Dave, I hope that you are doing well today. I received Steve's voice mails yesterday and I apologize for not getting back with you sooner. Steve, thanks for taking time to speak this morning. The attached Tab 36, Item J notes the following acreages : The area to be revegetated is the following: 1. New are disturbed at the East side of the existing cleared area= 0.40 acres. 2. New disturbance for on-site wastewater system installation= 0 .06 acres Total New On-site disturbance= 0 .46 acres These new on-site disturbance calculations were provided by my civil engineer Sopris Engineering. I have Included civil sheet CS noting these approximate areas in redline format. As Steve Anthony and I discussed in November 2014, the existing disturbance has not been incorporated into the revegetatlon area as this area was disturbed previously by the land owner. Additionally, the roadway widening activity of 1.73 acres is a permanent feature and is not subject to a revegetation bond. Thank you and please contact me with further questions. Sincerely, Phil Vaughan Phil Vaughan Construction Management, Inc. 1038 County Road 323 Rifle, CO 81650 970-625-5350 From: Steve Anthony f ma ilto:san t booy@garfield-countv.coml Sent: Tuesday, May 26, 2015 5:50 PM To: Phil Vaughan Cc: David Pesnichak Subject: RE: WPX UPA-8191 Phi l, 1 Thanks for providing the information rega rding the surface area to be disturbed by the project that would require reseeding, since it is less than an acre, we will not be requesting a revegetation security for the project. Please let me know if you have any further questions . Thank you , Steve Steve Anthony Vegetation Manager Garfield Coun1y Public Works 0375 Coun1y Road 352, Bldg . 2060 Rifle, CO 81650 Phone: (970) 945-1377 Ext. 4305 Email: santhony@garfield-countv .com From: Phil Vaughan [ma ll to:ohil@ovcmi .com ) Sent: Tuesday, May 26, 2015 2:55 PM To: Steve Anthony Cc: David Pesnichak Subject: FW: WPX LlPA-8191 Steve, Thanks for taking time to speak this afternoon . Please call me when you get back to the office and we can discuss my 5/12/15 reply below and attached. My cell phone number is 970-379-0428. Sincerely, Phil Vaughan Phll Vaughan Construction Management, Inc. 1038 County Road 323 Rifle, CO 81650 970.625-5350 From: Phil Vaughan Sent: Tuesday, May 12, 2015 1:00 PM To: Steve Anthony (sa nthony@garfield -county.com ); Dave Pesnichak (doesn lchak@ garfield -county.com) Subject: FW : WPX UPA-8191 Steve and Dave, I hope that you are doing well today. 2 Thank you for the attached 5/12/15 letter. Please find attached Tab 36 of our land use change application. Please see pages 5 -6, Item J-Reclamation and Revegetation plan where I have noted the 0.46 acres of new on-site disturbance. I have also noted our 11/25/14 conversation in regards to not providing a revegetation bond as the on -site new disturbance Is less than 1 acre. Thank you for your assistance and please contact me with questions. Sincerely, Phil Vaughan Phil Vaughan Construction Management, Inc. 1038 County Road 323 Rifle , CO 81650 970-625-5350 From: David Pesnichak [mailto:dp esnichak@garfleld-county.com) Sent: Tuesday, May 12, 2015 10:59 AM To : Phil Vaughan Subject: FW : WPX LIPA-8191 FYI- David Pesnichak, AICP Senior Planner Garfield County Community Development Department 108 81h St Suite 401 Glenwood Spri ngs, CO 81601 (970) 945-8212 dpesnichak@garfield-county.co m http://www.garfield-county.com/com munity-development/ -----..., Garfield Cou11ty From: Steve Anthony Sent: Tuesday, May 12, 2015 10:52 AM To: David Pesnichak Subject: RE : WPX LIPA-8191 Here is the signed copy 3 i •• ___ .... ....... ' ....... ....... \ m a i! WPX ENERGY ROCKY MTN UC , lRAU. RIDGE EMPLOYEE HOUSING FACUTY ~ iii COUHTYOf GARFELD,COlORAOO 1----l-------+--t--I I ! . s OPRIS E NGlNEERING, LLC. "'"""' l>OTE I C!VILCONSULTANTS I 1----"~----I _ ..