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HomeMy WebLinkAbout1.7 Application Part 8APPENDIX B COTTONWOOD-WEBSTER MESA PIPELINE STORM WATER APPLICATION FORM AND PERMIT STATE OF COLORADO GENERAL PERMIT APPLICATION FORM ONLY AND STORMWATER MANAGEMENT PLAN GUIDANCE FOR STORMWATER DISCHARGES ASSOCIATED WITH CONSTRUCTION ACTIVITY ATTENTION This document contains only the two-page application form for the CDPS Stormwater Construction Permit. You must follow the application instructions and the process for developing a Stormwater Management Plan (SWMP). The complete application document is on the Division's web page at www.cdphe.state.co.us/wq/permitsunit/S WConstructionApplication. pdf DO NOT SUBMIT YOUR SWMP Updated 3/2006 NEW FOR THIS APPLICATION REFER TO THE COMPLETE APPLICATION AND INSTRUCTION FOR FURTHER INFORMATION • Site Map/Legal Description — A site map or legal description (subdivision/block/lot) indicating the site boundaries is now required. • Applicant and Operator Liability — An applicant under this permit agrees to assume liability for compliance with the requirements of the Construction General Permit for the entirety of the construction site/project described and applied for, until such time as the applicant takes the necessary actions to amend, transfer, or inactivate their certification, or the permit expires. The Application Certification language has been revised to clarify this requirement. It is the applicant's responsibility to be familiar with the requirements of the permit and ensure compliance with those requirements. • Restrictions on Who May Apply for and Maintain the Permit — The applicant must be either the owner and/or operator of the construction site. An operator at a construction site who is not covered by a certification held by an appropriate entity may be held liable for operating without the necessary permit coverage. Refer to Parts B and C of the Instructions. • Stormwater Management Plan Guidance — The guidance which was previously available as a separate document has now been added as Appendix A to the application. The guidance has been revised and updated. Additional Guidance Additional information, including further discussion on permittee and operator liability, is available in the Stormwater Fact Sheet for Construction, available from the Division's web site at www.cdphe.state.co.us/wq/PermitsUnit. If you have questions on completing this application, you may contact the Division at cdphe.wgstorm@state.co.us or (303) 692-3517. Application Completeness: All items of the application must be completed accurately and in their entirety or the application will be deemed incomplete, and processing of the application will not begin until all information is received. (Do not include a copy of the Stormwater Management Plan, unless requested by the Division.) One original copy of the completed application (no faxes or e-mails) shall be submitted, only to: Colorado Department of Public Health and Environment Water Quality Control Division WQCD-Permits-B2 4300 Cherry Creek Drive South Denver, Colorado 80246-1530 3/06/Const STATE OF COLORADO Bill Ritter, Jr., Governor James B. Martin, Executive Director Dedicated to protecting and improving the health and environment of ihe people of Colorado 4300 Cherry Creek Dr. S. Laboratory Services Division Denver, Colorado 80246-1530 8100 Lowry Blvd. Phone (303) 692-2000 Denver, Colorado 80230-6928 TDD Line (303) 691-7700 (303) 692-3090 Located in Glendale, Colorado http://www.cdphe.state.co.us 3/20/2007 Tom Fiore, Plant Manager Williams Production RMT Company P.O. Box 370 Parachute, CO 81635 970/285-9377 Colorado Department of Public Health and Environment RE: Final Permit, Colorado Discharge Permit System — Stormwater Certification No: COR -03B587, Garfield County Cottonwood to Webster Mesa Pipeline/Rabbit Brush Compressor Station Local Contact: Tom Fiore, Plant Manager, 970/ 263-2714 Anticipated Activity: 07/01/2007 through 12/31/2008 On 104.37 acres (75.45 acres disturbed) Dear Sir or Madam: Enclosed please find a copy of the permit certification that was issued to you under the Colorado Water Quality Control Act. Your certification under the permit requires that specific actions be performed at designated times. You are legally obligated to comply with all terms and conditions of the permit. Note that the Stormwater permit for construction activities now covers construction sites disturbing down to one acre (the previous threshold was 5 acres). Effective July I, 2002, any construction activity that disturbs at least 1 acre of land (or is part of a larger common plan of development or sale that will disturb at least 1 acre) must apply for permit coverage. Please read the permit and certification. If you have any questions please visit our website at http://www.cdphe.state.co.us/wq/permitsunit/wgcdpmt.html, or contact Matt Czahor at (303) 692-3575. Sincerely, (/n/ Kathryn Dolan Stormwater Program Coordinator Permits Unit WATER QUALITY CONTROL DIVISION Enclosure xc: Regional Council of Governments Garfield County Health Department District Engineer, Technical Services, WQCD Permit File Fee File GENEriAL PERMIT APPLICATION STOR\IWATER DISCHARGES ASSOCIATED WITH: CONSTRUCTION ACTIVITY For Agency Use Only Date Received: / / Month Day Year COR -03 tNo. (COR -030000) Billing Code: 9A 9B 9C(1) 9D(2) 9E(3) 9F(4) ALL APPLICANTS MUST FOLLOW THE DIRECTIONS FOR COMPLETION OF THIS FORM IN PART D OF THE INSTRUCTIONS Please print or type. All items must be completed accurately and in their entirety or the application will be deemed incomplete and the application returned. Processing of the application will not begin until all information is received Please refer to the instructions for information about the required items. Original signatures for Parts 8 and 9 are required. 1. Name and address of the permit applicant: Company Name Williams Production RMT Company Mailing Address P.O. Box 370 City, State and Zip Code Parachute, Colorado 81635 Phone Number ( 970 )285-9377 Who is applying? Owner Local Contact (familiar with facility) Mr. Tom Fiore Developer X Contractor 1-1 Title Plant Manager Phone Number ( 970 ) 285-9377 Local Contact E-mail Address tom.fiore@williams.com Local Contact (familiar with facility) Mr. Michael Gardner Title Senior Environmental Specialist Phone Number (970)263-2714 Local Contact E-mail Address Michael.Gardner@Williams.com 2. Location of the construction site: Street Address (or cross streets) N/A City (if unincorporated, so indicate) Parachute/Rulison County Garfield Name of plan, project, or development Cottonwood to Webster Mesa Pipeline/Rabbit Brush Compressor Station Webster Mesa Compressor Station Latitude/Longitude — use one of the following formats: Latitude / _ / Longitude _ _ _ / / (e.g., 39°42'11", 104°55'57") degrees minutes seconds degrees minutes seconds -or- Latitude 39.508° Longitude -107.931° (e.g., 39.703°, 104.933°') degrees (to 3 decimal places) degrees (to 3 decimal places) 3. Legal Description (subdivision, block, and lot) or Map Indicating Site Location/Boundaries: If a map is attached to provide this information, this must be indicated below. Maps must be folded to 81/4 x 11 inches. Map Attached? 9 Yes, skip to item 4 X No; include legal description per Instructions (use separate sheet if needed): Subdivision(s), Lot(s), Block(s): Legals Include: Township 6 South, Range 95 West, Sections 35, 26, 25, 24 AND Township 6 South, Range 94 West, Sections 14, 15, 16, 19, 20, 21 4. Area of the construction site: Total area of project site (acres) 8.3 miles (linear). 75.45 acres (Pipeline) 28 92 acres (Compressor Stations) Area of project site to undergo disturbance (acres) 75.45 acres Total disturbed area of Larger Common Plan of Development or Sale, if applicable (i.e., total including all phases, filings, lots. and infrastructure not covered by this annlication. SEE INSTRUCTIONS!) 75.45 acres 5: Nature of the construction activity: Check the appropriate box(s) or provide a brief description that indicates the general nature of the construction activities. (The full description of activities must be included in the Stormwater Management Plan.) ❑ Single Family Residential Development 9 Multi -Family Residential Development ❑ Commercial Development XOil and Gas Production and/or Exploration (including pad sites and associated infrastructure) ❑ Highway/Road Development (not including roadways associated with commercial or residential development) ❑ Other, Describe: 6. Anticipated construction schedule: (SEE INSTRUCTIONS! Providing incorrect information may result in violations.) Construction Start Date: 07/01/2007 Final Stabilization Date: Ongoing 7. The name of the receiving waters(s). (If discharge is to a ditch or storm sewer, also include the name of the ultimate receiving water): Several ephemeral streams, with the Colorado River being the ultimate receiving water STOP! A Stormwater Management Plan (see Appendix A) must be completed prior to signing the following certifications! 8. Stormwater Management Plan Certification: "I certify under penalty of law that a complete Stormwater Management Plan, as described in Appendix A of this application, has been prepared for my activity. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the Stormwater Management Plan is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for falsely certifying thompletion of said S WMP, including the possibility of fine and imprisonment for knowing violations." eel Signa tlireofLega R Mr. Michael Gardner Name (printed) ponsi 2-07 le Person (submission must include original signature) Date Signed Storm Water Management Plan Administrator Title 9. Signature of Applicant "I certify under penalty of law that I have personally examined and am familiar with the information submitted in this application and all attachments and that, based on my inquiry of those individuals immediately responsible for obtaining the information, I believe that the information is true, accurate and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine or imprisonment. "I understand that submittal of this application is for coverage under the State of Colorado General Permit for Stonnwater Discharges Associated with Construction Activity for the entirety of the construction site/project described and applied for, until such time as the application is amended or the certification is transferred, inactivated, or expired." 311z Signature of Legally Responsible Person (submission must include original signature) DJte Signed Mr. Tom Fiore Plant Manager Name (printed) Title Permit No. COR -030000 Facility No. COR -03B587 PAGE 1 of 17 CERTIFICATION CDPS GENERAL PERMIT STORMWATER DISCHARGES ASSOCIATED WITH CONSTRUCTION Construction Activity: Oil and Gas Production and/or Exploration This permit specifically authorizes: Williams Production RMT Company to discharge stormwater from the facility identified as Cottonwood to Webster Mesa Pipeline/Rabbit Brush Compressor Station which is located at: Near Parachute , Co latitude 39.508, longitude 107.931 in Garfield County to: Colorado River effective: 03/20/2007 Annual Fee: $270.00 (DO NOT PAY NOW. You will receive a prorated bill.) Dear Sir or Madam: The General Permit for Stormwater Discharges Associated with Construction (COR - 030000) that you have obtained coverage under will be renewed on July 1, 2007. The general permit is written to last five years and you came in at the very end of the five-year cycle. In order for you to maintain coverage for this permit beyond June 30, 2007, the Division will automatically certify your project under the renewed permit. You will therefore be receiving a new certification and permit on or before June 30, 2007 that will replace the enclosed certification. You do not need to do anything additional at this point to continue coverage. If you have any further questions, you may contact our office at cdphe.wgstorm@state.co.us or (303) 692-3517. Page 2 of 17 Permit No. COR -030000 CDPS GENERAL PERMIT STORMWATER DISCHARGES ASSOCIATED WTTH CONSTRUCTION ACTIVITY AUTHORIZATION TO DISCHARGE UNDER THE COLORADO DISCHARGE PERMIT SYSTEM In compliance with the provisions of the Colorado Water Quality Control Act, (25-8-101 et seq., CRS, 1973 as amended) and the Federal Water Pollution Control Act, as amended (33 U.S.C. 1251 et seq.; the "Act"), this permit authorizes the discharge of stormwater associated with construction activities certified under this permit, from those locations specified throughout the State of Colorado to specified waters of the State. Such discharges shall be in accordance with the conditions of this permit. This permit specifically authorizes the facility.listed on page 1 of this permit to discharge stormwater associated with construction activity, as of this date, in accordance with permit requirements and conditions set forth in Parts I and II hereof All discharges authorized herein shall be consistent with the terms and conditions of this permit. This permit and the authorization to discharge shall expire at midnight, June 30, 2007. Issued and Signed this 21st day of May, 2002 COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT S.Gr.?. ,u - Frt. J. David Holm, Director Water Quality Control Division DATE SIGNED: MAY 21, 2002 EFFECTIVE DATE OF PERMIT: JULY 1, 2002 TABLE OF CONTENTS (cont.) GENERAL REQUIREMENTS - - 11 1. Signatory Requirements 11 2. Retention of Records 12 PART II A. MANAGEMENT REQUIREMENTS 12 I. Change in Discharge 12 2. Special Notifications - Definitions 12 3. Noncompliance Notification 13 4. Submission of Incorrect or Incomplete Information 13 5. Bypass 13 6. Upsets 13 7. Removed Substances 14 8. Minimization of Adverse Impact 14 9. Reduction, Loss, or Failure of Treatment Facility 14 10. Proper Operation and Maintenance 14 B. RESPONSIBILITIES 14 1. Inspections and Right to Entry 14 2. Duty to Provide Information 15 3. Transfer of Ownership or Control 15 4. Modification, Suspension, or Revocation of Permit By Division 15 5. Permit Violations 16 6. Legal Responsibilities 16 7. Severability 16 8. Renewal Application 17 9. Confidentiality 17 10. Fees 17 11. Requiring an Individual CDPS Permit 17 -2b- A. COVERAGE UNDER THIS PERMIT (cont.) c) Permit Coverage Termination: When a site has been finally stabilized, coverage under this permit is automatically terminated. PART I Page 4 Permit No. COR -030000 d) Compliance with Qualifying Local Program: A construction site operator that has authorization to discharge under this permit under Part LA.3 shall comply with the requirements of the Qualifying Local Program with jurisdiction over the site. e) Full Permit Applicability: The Division may require any owner or operator within the jurisdiction of a Qualifying Local Program covered under this permit to apply for and obtain coverage under the full requirements of this permit. The owner or operator must be notified in writing that an application for full coverage is required. When a permit certification under this permit is issued to an owner or operator that would otherwise be covered under Part LA.3 of this permit, the full requirements of this permit replace the requirements as per Part LA.3 of this permit, upon the effective date of the permit certification. A site brought under the full requirements of this permit must still comply with local stormwater management requirements, policies or guidelines as required by Part I.C.1.h of this Permit. 4. Application, Due Dates a) Application Due Dates: At least ten days prior to the commencement of construction activities, the operator of the construction activity shall submit an application form as provided by the Division, with a certification that the Stormwater Management Plan (SWMP) is complete. One original completed discharge permit application shall be submitted, by mail or hand delivery, to: Colorado Department of Public Health and Environment Water Quality Control Division WQCD-P-B2 4300 Cherry Creek Drive South Denver, Colorado 80246-1530 b) Summary of Application: The application requires, at a minimum, the following: 1) The operator's name, address, telephone number, tax payer identification number (or employer identification number), and the status as Federal, State, private, public or other entity; 2) Name, county and location of the construction site, including the latitude and longitude to the nearest 15 seconds of the approximate center of the construction activity; 3) A brief description of the nature of the construction activity; 4) The anticipated starting date of the project and the anticipated schedule of completion 5) Estimates of the total area of the site, the area of the site that is expected to be disturbed, and the total area of the larger common plan of development or sale to undergo disturbance; 6) The name of the receiving water(s), or the municipal separate storm sewer system and the ultimate (Le., named) receiving water(s); 7) Certification that the SWMP for the construction site is complete (see Part I.B. below); and 8) The signature of the applicant signed in accordance with Part I.E.1 of this permit. 5. Permit Certification Procedures If the general permit is applicable to the applicant's operation, then a certification will be developed and the applicant will be authorized to discharge stormwater under this general permit. A. COVERAGE UNDER THIS PERMIT (cont.) PART I Page 6 Permit No COR -030000 a) Permit certification number. b) Name, location, and county for the construction site for which the application is being submitted. c) The current permittee's name, address, telephone number and the status as Federal, State, private, public or other entity. d) The new permittee's name, address and telephone number and the status as Federal, State, private, public or other entity. e) Certification that the new permittee has reviewed the permit and SWMP and accepts responsibility, coverage and liability for the permit. t) Effective date of transfer. If the new responsible party will not complete the transfer form, the permit may be inactivated if the permittee has no legal responsibility, through ownership or contract, for the construction activities at the site. In this case, the new operator would be required to obtain permit coverage separately. 8. Permit Expiration Date Authorization to discharge under this general permit shall expire on June 30, 2007. The Division must evaluate and reissue this general permit at least once every five years and must recertify the applicant's authority to discharge under the general permit at such time. Any permittee desiring continued coverage under the general permit must reapply by March 31, 2007. The Division will determine if the applicant may continue to operate under the terms of the general permit. An individual permit will be required for any facility not reauthorized to discharge under the reissued general permit. 9. Individual Permit Criteria Aside from the activity type, the Division may use other criteria in evaluating whether an individual permit is required instead of this general permit. This information may come from the application, SWMP, or additional information as requested by the Division, and includes, but is not limited to, the following: a) the quality of the receiving waters (i.e., the presence of downstream drinking water intakes or a high quality fishery, or for preservation of high quality water); b) the size of the construction site; c) evidence of noncompliance under a previous permit for the operation; d) the use of chemicals within the stormwater system. In addition, an individual permit may be required when the Division has shown or has reason to suspect that the stormwater discharge may contribute to a violation of a water quality standard. B. CONTENTS OF THE STORMWATER MANAGEMENT PLAN The SWMP shall be prepared in accordance with good engineering, hydrologic and pollution control practices. (The SWMP need not be prepared by a registered engineer.) The main objective of the plan shall be to identify Best Management Practices (BMPs) which when implemented will meet the terms and conditions of this permit (see Part I.C., below). The plan shall identify potential sources of pollution (including sediment) which may reasonably be expected to affect the quality of stormwater discharges associated with construction activity from the facility. In addition, the plan shall describe and ensure the implementation of BMPs which will be used to reduce the pollutants in stormwater discharges associated with construction activity. Construction operations must implement the provisions of the SWMP required under this part as a condition of this permit. The SWMP shall include the following items, at a minimum: B. CONTENTS OF THE STORMWATER MANAGEMENT PLAN (cont.) PART I Page 8 Permit No. COR -030000 b) Materials Handling and Spill Prevention. The SWMP shall identify any procedures or significant materials (see definitions at Part I.D.) handled at the site that could contribute pollutants to runoff. These could include sources such as: exposed storage of building materials, fertilizers or chemicals; waste piles; and equipment maintenance or fueling procedures. Areas or procedures where potential spills can occur shall have spill prevention and response procedures identified. Measures to control stormwater pollution from dedicated concrete batch plants or dedicated asphalt batch plants covered by this certification, must be identified in the SWMP. 4. Final Stabilization and Longterm Stormwater Management The plan shall include a description of the measures used to achieve fmal stabilization and measures to control pollutants in stormwater discharges that will occur after construction operations have been completed. Final stabilization is reached when all soil disturbing activities at the site have been completed, and uniform vegetative cover has been established with a density of at least 70 percent of pre -disturbance levels, or equivalent permanent, physical erosion reduction methods have been employed. For purposes of this permit, establishment of a vegetative cover capable of providing erosion control equivalent to pre- existing conditions at the site can be considered final stabilization. The permittee will be responsible for providing to the Division the documentation to make this comparison. The Division may, after consultation with the permittee and upon good cause, amend the fmal stabilization criteria for specific operations. 5. Other Controls The plan shall include a description of other measures to control pollutants in stomtwater discharges, including plans for waste disposal and limiting off-site soil tracking. 6. Inspection and Maintenance The plan shall include a description of procedures to inspect and maintain in good and effective operating condition the vegetation, erosion and sediment control measures and other protective measures identified in the SWMP. C. TERMS AND CONDITIONS I. General Limitations The following limitations shall apply to all discharges covered by this permit: a) Stormwater discharges from construction activities shall not cause or threaten to cause pollution, contamination or degradation of State waters. b) Concrete wash water shall not be discharged to state waters or to storm sewer systems. c) Bulk storage structures for petroleum products and other chemicals shall have adequate protection so as to contain all spills and prevent any spilled material from entering State waters. d) No chemicals are to be added to the discharge unless permission for the use of a specific chemical is granted by the Division. In granting the use of such chemicals, special conditions and monitoring may be addressed by separate letter. e) The Division reserves the right to require sampling and testing, on a case-by-case basis, in the event that there is reason to suspect that compliance with the SWMP is a problem, or to measure the effectiveness of the BMPs in removing pollutants in the effluent. Such monitoring may include Whole Effluent Toxicity testing. C. TERMS AND CONDITIONS (cont.) PART 1 Page 10 Permit No. COR -030000 2) Based on the results of the inspection, the description of potential pollutant sources, and the pollution prevention and control measures that are identified in the SWMP shall be revised and modified as appropriate as soon as practicable after such inspection. Modifications to control measures shall be implemented in a timely manner, but in no case more than 7 calendar days after the inspection. 3) The operator shall keep a record of inspections. Any: incidence of non-compliance; such as uncontrolled releases of mud or muddy water or measurable quantities of sediment found off the site; shall be recorded with a brief explanation as to the measures taken to prevent future violations, as well as any measure taken to clean up the sediment that has left the site. After adequate measures have been taken to correct any problems, or where a report does not identify any incidents of non-compliance, the report shall contain a signed certification indicating the site is in compliance. 'This record shall be made available to the. Division upon request. b) Completed Sites - For sites where all construction activities are completed but final stabilization has not been achieved due to a vegetative cover that has been planted but has not become established, the permittee shall make a thorough inspection of their stormwater management system at least once every month. When site conditions make this schedule impractical, permittees may petition the Division to grant an alternate inspection schedule. These inspections must be conducted in accordance with paragraphs 1), 2), and 3) of Part I.C.5.a. above. c) Winter Conditions - Inspections, as described above in a) and b), will not be required at sites where snow cover exists over the entire site for an extended period, and melting conditions do not exist. This exemption is applicable only during the period where melting conditions do not exist. Regular inspections, as described above, are required at all other times. 6. Reporting No regular reporting requirements are included in this permit; however, the Division reserves the right to request that a copy of the inspection reports be submitted. 7. SWMP Submittal Upon Request Upon request, the permittee shall submit a copy of the SWMP to the Division, EPA or any local agency in charge of approving sediment and erosion plans, grading plans or stormwater management plans. All SWMPs required under this permit are considered reports that shall be available to the public under Section 308(b) of the CWA. The owner or operator of a facility with stormwater discharges covered by this permit shall make plans available to members of the public upon request, unless the SWMP has been submitted to the Division. However, the pemnttee may claim any portion of a SWMP as confidential in accordance with 40 CFR Part 2. D. ADDITIONAL DEFINITIONS For the purposes of this permit: 1. BAT and BCT: (Best Available Technology and Best Conventional Technology) Technology based federal water quality requirements covered under 40 CFR subchapter N. 2. Best management practices (BMPs): schedules of activities, prohibitions of practices, maintenance procedures, and other management practices to prevent or reduce the pollution of waters of the State. BMPs also include treatment requirements, operating procedures, and practices to control site runoff, spillage or leaks, waste disposal, or drainage from material storage. 3. Dedicated asphalt plants and concrete plants: portable asphalt plants and concrete plants that are located on or adjacent to a construction site and that provide materials only to that specific construction site. PART I Page 12 Permit No. COR -030000 E. GENERAL REQUIREMENTS (cont.) 3) In the case of a sole proprietorship, by the proprietor; 4) In the case of a municipal, state, or other public facility, by either a principal executive officer, ranking elected official, or other duly authorized employee. b) Changes to authorization. If an authorization under paragraph a) of this section is no longer accurate because a different individual or position has responsibility for the overall operation of the facility, a new authorization satisfying the requirements of paragraph a) of this section must be submitted to the Division, prior to or together with any reports, information, or applications to be signed by an authorized representative. c) Certification. Any person signing a document under paragraph a) of this section shall make the following certification: "I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather -and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information; the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations." 2. Retention of Records a) The pemnttee shall retain copies of the SWMP and all reports required by this permit and records of all data used to complete the application to be covered by this permit, for a period of at least three years from the date that the siteis finally stabilized. b) The pennittee shall retain a copy of the SWMP required by this permit at the construction site from the date of project initiation to the date of final stabilization, unless another location, specified by the permittee, is approved by the Division. . PART II A. MANAGEMENT REQUIREMENTS 1. Change in Discharge The permittee shall inform the Division (Permits Unit) in writing of any intent to significantly change activities from those indicated in the permit application (this does not include changes to the SWMP). Upon request, the permittee shall furnish the Division with such plans and specifications which the Division deems reasonably necessary to evaluate the effect on the discharge and receiving stream. The SWMP shall be updated within 30 days of the changes. The permittee shall submit this notice to the Division within two weeks after making a determination to perform the type of activity referred to in the preceding paragraph. Any discharge to the waters of the State from a point source other than specifically authorized by this permit is prohibited. 2. Special Notifications - Definitions a) Spill: An unintentional release of solid or liquid material which may cause pollution of state waters. b) Upset: An exceptional incident in which there is unintentional and temporary noncompliance with permit effluent limitations because of factors beyond the reasonable control of the permittee. An upset does not include noncompliance to the extent caused by operational error, improperly designed treatment facilities, inadequate treatment facilities, lack of preventative maintenance, or careless or improper operation. A. MANAGEMENT REQUIREMENTS (cont.) PART II Page 14 Permit No. COR -030000 4) The permittee complied with any remedial measures required under Section 122.7(d) of the federal regulations. c) Burden of Proof In any enforcement proceeding the permittee seeking to establish the occurrence of an upset has the burden of proof. 7. Removed Substances Solids, sludges, or other pollutants removed in the course of treatment or control of wastewaters shall be properly disposed of in a manner such as to prevent any pollutant from such materials from entering waters of the State. 8. Minimization of Adverse Impact The permittee shall take all reasonable steps to minimize any adverse impact to waters of the State resulting from noncompliance with any effluent limitations specified in this permit, including such accelerated or additional monitoring as necessary to determine the nature and impact of the noncomplying discharge. 9. Reduction, Loss, or Failure of Treatment Facility The permittee has the duty to halt or reduce any activity if necessary to maintain compliance with the permit • requirements. Upon reduction, loss, or failure of the treatment facility, the permittee shall, to the extent necessary to maintain compliance with its permit, control production, or all discharges, or both until the facility is restored or an alternative method of treatment is provided. It shall not be a defense for a permittee in an enforcement action that it would be necessary to halt or reduce the permitted activity in order to maintain compliance with the conditions of this permit. 10. Proper Operation and Maintenance The permittee shall at all times properly operate and maintain all facilities and systems of treatment and control (and related appurtenances) which are installed or used by the permittee to achieve compliance with the conditions of this permit. Proper operation and maintenance includes effective performance, adequate funding, adequate operator staffing and training, and adequate laboratory and process controls, including appropriate quality assurance procedures. This provision requires the operation of back-up or auxiliary facilities or similar systems only when necessary to achieve compliance with the conditions of the permit. B. RESPONSIBILITIES I. Inspections and Right to Entry The permittee shall allow the Director of the State Water Quality Control Division, the EPA Regional Administrator, and/or their authorized representative, upon the presentation of credentials: a) To enter upon the permittee's premises where a regulated facility or activity is located or in which any records are required to be kept under the terms and conditions of this permit; b) At reasonable times to have access to and copy any records required to be kept under the terms and conditions of this permit and to inspect any monitoring equipment or monitoring method required in the permit; and c) To enter upon the permittee's premises to investigate, within reason, any actual, suspected, or potential source of water pollution, or any violation of the Colorado Water Quality Control Act. The investigation may include, but is not limited to, the following: sampling of any discharge and/or process waters, the taking of photographs, interviewing permittee staff on alleged violations, and access to any and all facilities or areas within the permittee's premises that may have any effect on the discharge, permit, or alleged violation. B. RESPONSIBILITIES (cont.) PART II Page 16 Permit No. COR -030000 c) This permit, or certification under this permit, may be modified in whole or in part to include new effluent limitations and other appropriate conditions where data submitted pursuant to Part I indicates that such effluent limitations and conditions are necessary to ensure compliance with applicable water quality standards and protection of classified uses d) At the request of the permittee, the Division may modify or inactivate certification under this permit if the following conditions are met: 1) In the case of inactivation, the permittee notifies the Division of its intent to inactivate the certification, and certifies that the site has been finally stabilized; 2) hi the case of inactivation, the permittee has ceased any and all discharges to state waters and demonstrates to the Division there is no probability of further uncontrolled discharge(s) which may affect waters of the State. 3) The Division fords that the permittee has shown reasonable grounds consistent with the Federal and State statutes and regulations for such modification, amendment or inactivation; 4) Fee requirements of Section 61.15 of State Discharge Permit System Regulations have been met; and 5) Requirements of public notice have been met. For small construction sites covered by a Qualifying Local Program, coverage under this permit is automatically terminated when a site has been finally stabilized. 5. Permit Violations Failure to comply with any terms and/or conditions of this permit shall be a violation of this permit. Dischargers of stormwater associated with industrial activity, as defined in the EPA Stormwater Regulation (40 CFR 122.26(b)(14), which do not obtain coverage under this or other Colorado general permits, or under an individual CDPS permit regulating industrial stormwater, will be in violation of the federal Clean Water Act and the Colorado Water Quality Control Act, 25-8-101. Failure to comply with CDPS permit requirements will also constitute a violation. Civil penalties for such violations may be up to $10,000 per day, and criminal pollution of state waters is punishable by fines of up to $25,000 per day. 6. Legal Responsibilities The issuance of this permit does not convey any property or water rights in either real or personal property, or stream flows, or any exclusive privileges, nor does it authorize any injury to private property or any invasion of personal rights, nor any infringement of Federal, State or local laws or regulations. Nothing in this permit shall be construed to preclude the institution of any legal action or relieve the permittee from any responsibilities, liabilities, or penalties to which the permittee is or may be subject to under Section 311 (Oil and Hazardous Substance Liability) of the Clean Water Act. 7. Severability The provisions of this permit are severable. If any provisions of this permit, or the application of any provision of this permit to any circumstance, is held invalid, the application of such provision to other circumstances and the application of the remainder of this permit shall not be affected. COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT Water Quality Control Division r9CD-P-B2 0 Cherry Creek Drive South - - uenver, Colorado 80246-1530 RATIONALE STORMWATER DISCHARGES ASSOCIATED WITH CONSTRUCTION ACTIVITY GENERAL PERMIT IN COLORADO SECOND RENEWAL COLORADO DISCHARGE PERMIT NUMBER COR -030000 CONTENTS PAGE I. Introduction 1 II. Background 2 III. Stormwater Discharges Associated with Construction Activity 3 IV. Coverage Under this Permit 4 V. Application and Certification 4 VI. Qualifying Local Programs 4 VII. Terms and Conditions of Permit 5 VIII. Changes Made After Public Notice 7 I INTRODUCTION This permit is for the regulation ofstormwater runofffrom construction activities. The term "construction activity" includes clearing, grading and excavation operations. "Stormwater" is precipitation -induced surface runoff This Rationale will explain the background of the Stormwater program, activities which are covered under this permit, how to apply for coverage under this permit, and the requirements of this permit The forms discussed in the Rationale and Permit are available on the Division's website at: http:/Avww.cdphe.state.co.ushvg/permitsunitlwqcdpmthtml A. Changes in this General Permit Several notable changes from the previous General Permit for Construction Activities have been incorporated into this permit. Most of the changes are related to the Phase II revision to the stormwater regulation in the Colorado Discharge Permit System Regulations (SCCR 1002-61), effective March 2, 2001. Significant changes are listed below: 1. Permit coverage is now required for construction sites that disturb 1 to 5 acres (i.e., small construction activities). Allowances have been made for small construction activities to comply with the requirements ofa Division -approved Qualifying Local Program (refer to section VI below for a discussion of Qualifying Local Programs) in place of many specific requirements in the Permit, including requirements to submit an application, inactivation notice, and fees to the Division. Refer to Part LA.3 of the Permit and section VILA of the Rationale for more details. 2. The requirements to submit with the application the Township, Range, section and quarter section ofa site and a list of any other environmental permits for the site have been removed. 3. Inactivation requirements have been changed to allow small construction activities that submit applications indicating a completion date 12 months or less from the start of construction activity to be authorized for a predetermined period from 3 to 12 months. The permit certification will include the automatic expiration date for permit coverage. This expiration date will be in place of the requirement to submit an Inactivation Notice. If permit coverage beyond the expiration date is needed (t.e., the site has not been finally stabilized), the permittee must submit an extension request form to the Division at least 10 days prior to the expiration. COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Rationale - Page 3. Permit No. COR -030000 III. STORMWATER DISCHARGES ASSOCIATED WITH CONSTRUCTION ACTIVITY The Stormwater regulations require that stormwater discharges associated with certain industrial activities be covered under the permit program. Construction activity that disturbs one acre or more during the life of the project is specifically included in the listed industrial activities. A. Construction Activity Construction activity includes clearing, grading and excavation activities. Construction does not include routine maintenance performed by public agencies, or their agents to maintain original line and grade, hydraulic capacity, or original purpose of the facility. Definitions of additional terms can be found in Part I.D of the Permit Stormwater discharges from construction activity require permit coverage, except for operations that result in the disturbance of less than one acre of total land area which are not part ofa larger common plan of development or sale. A larger common plan of development or sale is a contiguous area where multiple separate and distinct construction activities may be taking place at different times on different schedules under one plan. B. Types ofActivities Covered This permit is intended to cover most new or existing discharges composed entirely of stormwater from construction activities that are required by State regulation to obtain a permit. This includes stormwater discharges associated with areas that are dedicated to producing earthen materials, such as soils, sand, and gravel, for use at a single construction site. These areas may be located at the construction site or at some other location. This permit does not authorize the discharge of mine water or process waterfom such areas. This permit also includes stormwater discharges associated with dedicated asphalt plants and concrete plants located at the construction sites. C. Types ofActivities NOT Covered This permit does not cover stormwater dischargedf •om construction sites that is mixed with stonnwater from other types of industrial activities, or process water of any kind. Other types of industrial activities that require stormwater discharge permits pursuant to different sections of the regulations (Regulation 5 CCR 1002-61, Section 61.2(e)(iii)(A-I, K)j, are not covered by this permit. This permit also does not cover the discharge of process water. If the construction activity encounters groundwater, a Construction Dewatering Discharge Permit (Permit Number COG -070000) must also be obtained in order to discharge this groundwater from the excavation site. An application for this permit can be obtained from the Division at the address listed in Part 1.A.4.a of the Permit. D. Exemptions for Small Municipalities The Intermodal Surface Transportation Efficiency Act of 1991 (Section 1068(c)) added an exemption to the stormwater regulations for municipalities with less than 100,000 population. The term "municipality" includes cities, towns, counties, special districts or any entity created by or pursuant to State law. Stormwater discharges associated with construction activity for facilities or sites that are owned or operated by a small municipality are not required to apply for or obtain a stormwater permit until March 10, 2003. (Note: This exemption does not apply to other, privately owned construction sites within the same small municipality) COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Rationale - Page 5. Permit No. COR -030000 WI. TERMS AND CONDITIONS OF PERMIT A. Coverage under a Qualifying Local Program — For Small Construction Sites Only For small construction sites (disturbing less than 5 acres) covered under a Qualifying Local Program (see Section VI above), only certain permit requirements apply, as outlined below. The local program must have been formally designated by the Division to quay. Most municipalities have some type of local program and may require permits and fees. However, simply having a program in place does not necessarily mean that itis a qualifying program and that a State permit is not required. The local municipality,will be responsible for notifying operators and/or owners that they are covered by a Qualifying Local Program. A list of municipalities with Qualifying Local Programs is also available at http:/hwvw.cdphe.state.co.us/wq/PennitsUnit/wgcdpmt.html. The Division reserves the right to require any owner or operator within the jurisdiction ofa Qualifying Local Program covered under this permit to apply for and obtain coverage under the full requirements of this permit. 1. Permit Coverage: Ifa construction site is within the jurisdiction ofa Qualifying Local Program, the operator of the construction activity is authorized to discharge stormwater associated with small construction activity under this general permit without the submittal of an application to the Division. The permittee also is not required to submit an inactivation notice or payment of an annual fee to the Division. 2. Permit Terms and Conditions: The permittee covered by a Qualifying Local Program must comply with the requirements of that Qualifying Local Program . In addition, the following permit sections are applicable: i. I.A.1, 1.4.2, and 1.4.3: Authorization to discharge and discussion of coverage under the permit. ii. I.C.1: General limitations that must be met in addition to local requirements. LC.2,1.C.3: Prohibition of non-stormwater discharges unless addressed in a separate CDPS permit, and requirements related to releases of reportable quantities. v. ID: Additional definitions. Part II (except for Pans IIA.1, 113.3, II.B.8, and II1310): Specifically includes, but is not limited to, provisions applicable in the case of noncompliance with permit requirement, and requirements to provide information and access. B. Stormwater Management Plans (SWMPs) Prior to commencement of construction, a stonnwater management plan (SWMP) shall be developed and implemented for each facility covered by this permit. A certification that the SWMP is complete must be submitted with the permit application. The SWMP shall identify potential sources of pollution (including sediment) which may reasonably be expected to affect the quality of stormwater discharges associated with construction activityfrom the facility. In addition, the plan shall describe the best management practice (BMPs) which will be used to reduce the pollutants in stormwater discharges from the construction site. Facilities must implement the provisions of their SWMP as a condition of this permit. The SWMP shall include the following items: 1. Site Description 2. Site Map 3. BMPs for Stormwater Pollution Prevention 4. Longterm Stormwater Management 5. Other Controls 6. Inspection and Maintenance 7. Signatory Requirements and Availability 8. SWMP Review/Changes (See Part I.B. of the permit for a more detailed description of SWMP requirements.) COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT Water Quality Control Division Rationale - Page 7. Permit No. COR -030000 TERMS AND CONDITIONS OF PERMIT (cont.) 1. Transfer of Permit When responsibility for stormwater discharges at a construction site changes from one individual to another, the permit shall be transferred in accordance with Part I.A.7 of the permit. The Notice of Transfer form will be mailed to the permittee along with the permit certification. Additional copies are availablefom the Division. If the new responsible party will not complete the transfer form, the permit may be inactivated ifthe permittee has no legal responsibility, through ownership or contract, for the construction activities at the site. In this case, the new operator would be required to obtain permit coverage separately. J Duration of Permit The general permit will expire on June 30, 2007. The permittee's authority to dischargeunder this permit is approved until the expiration date of the general permit. Any permittee desiring continued coverage under the general permit must apply for recertification under the general permit at least 90 days prior to its expiration date. Nathan Moore March 11, 2002 VII CHANGES MADE AFTER PUBLIC NOTICE Several comments were received from the Environmental Protection Agency (EPA). Changes based on these comments and additional internal review are discussed below: A. The EPA commented that language needs to be added to the permit addressing the certification requirements for inspection reports. Part 1.E.1 of the Permit requires that all reports submitted to the Division include specific certification language. Because site inspections required by Part I. C.5 of the permit are not submitted to the Division, they are not covered under Part 1.C.5 of the Permit or Regulation 5 CCR 1002-61, Section 61.4(1)(J), which require specific certification language. However, Regulation 5 CCR 1002-61, Section 61.8(4)(o)(ii)(B) does require that the permittee maintain a record summarizing the inspections that includes a certification that the site in compliance with the plan and the permit. Therefore, language has been added to Part I. C.5 of the Permit, requiring that a signed statement be included with all records of inspection on the status of compliance at the site. B. The EPA recommended that the Permit and Rationale be changed to indicate that the application is due ten days prior to the commencement of construction activities, instead of prior to the anticipated date of discharge. The Division agrees that this wording is preferable and more accurately indicates the Division's existing interpretation of the regulations. These changes have been made. C. The EPA expressed concern with requiring a permittee to transfer permit coverage in cases where the new responsible party may not be cooperative. Language has been added to the Permit and Rationale clarifying that termination of permit coverage is allowed when the permittee no longer has any legal responsibility through ownership or contract for the construction activity. D. The EPA commented on the lack ofa definition for the terms "receiving water" and "ultimate receiving water A definition has been added to the Permit, and the term "ultimate receiving water" clarified to indicate that it means the first named receiving water, if the discharge initially goes to an unnamed ditch or storm sewer. Nathan Moore May 15, 2002 Colorado Department of Public Health & Environment FOR AGENCY USE ONLY Water Quality Control Division WQCD-P-B2 REC 4300 Cherry Creek Drive South EFF Denver, Colorado 80246-1530 YEAR MONTH DAY INACTIVATION NOTICE FOR CONSTRUCTION STORMWATER DISCHARGE GENERAL PERMIT CERTIFICATION Please print or type. Form must be filled out completely. Certification Number: COR -03 Permittee (Company) Name: Permittee Address: Phone No. ( ) Site/Facility Name: Taxpayer ID or EIN Construction Site Address/Location: County: Contact Person: Summary of work performed and description of final site stabilization: I certify under penalty of law that by the date of my signature below, all disturbed soils at the identified construction site have been fmally stabilized; all temporary erosion and sediment control measures have been removed; all construction and equipment maintenance wastes have been disposed of properly; and all elements of the Stormwater Management Plan have been completed. I understand that by submitting this notice of inactivation, I am no longer authorized to discharge stormwater associated with construction activity by the general permit. I understand that discharging pollutants in stormwater associated with construction activities to the waters of the State of Colorado, where such discharges are not authorized by a CDPS permit, is unlawful under the Colorado Water Quality Control Act and the Clean Water Act. I certify under penalty of law that I have personally examined and am familiar with the information submitted herein, and based on my inquiry of those individuals immediately responsible for obtaining the information, I believe that the information is true, accurate and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment. (See 18 U.S.0 1001 and 33 U.S.C. 1319.) Signature of Permit Applicant (Legally Responsible Party) Date Signed Name (printed) Title mm10 ilii ibic fr6 [° y feetW h�s.�S Pori rillIr�'°of \NAT �i a�^iU �a`G' 2 � � � 1�- �i" � �,���C, tic frfuffliTcs qiikokigw IS=� I � W 4"t i{XPi*C ©sivottiabCC,['o ),IHSS tC ' B ' 0 ' SoX9> p eon , yam}(Y O��� lin°J�q •, � "4y so `'S� ry�{�.��{ ���� %tvd✓a'Y��ti©�`+.l`u APPENDIX C STORM WATER INSPECTION FORM Williams Storm Water Inspection Checklist Project Name Project ID Unique ID Field Name Site Type Permit Name Permit Date Proposed Start Date Pipeline Description Latitude Longitude Township Range Section Description 2 Inspection Date Inspector Inspection Type Comments Comment 1 Acres Disturbed Acres Subject to Interim Reclamation Acres Restored Distance to Receiving Water Name of Receiving Water(s) Type Estimated Runoff Coefficient Comment 1 Best Management Practices B M P Type Maintenance Required Date Maintenance Completed Comment 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 # of Separators Freeboard in Secondary Containment Storm Water in Secondary Containment Comment 21 N/A N/A N/A None 22 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 Processing Epuiament # of Tanks # of Separators Freeboard in Secondary Containment Storm Water in Secondary Containment Comment N/A N/A N/A N/A None Secondary Wells On Site None None None None None None None None None None Other Equipment Type of Equipment Comment None None None None None None Housekeeping/Site Trash Materials Handling Spills or Leaks Veeetation Seed Mix Date Planted 70% Revegetated Comment TBD TBD TBD TBD Files Type of File Location Site Complies With Storm Water Standards (Yes or No) Comments: APPENDIX D SWMP DAILY LOG Date: Storm Water Management Plan (SWMP) Daily Log Name of Person Completing Form: Project Activities Detailed Description Meetings: Date: Purpose: Attendees: Comments: Items Discussed: Instructions Given: Maintenance Activities Contractor: Phone: Comments Items Completed Spills and Discharge Record Description of Spill or Discharge (type, qty, etc) Describe Mitigation Activities Record of Reporting Describe nature of report and to whom it was made APPENDIX E BMP DESCRIPTIONS AND INSTALLATION DETAILS Silt Fence Description and Purpose A silt fence is made of a filter fabric that has been entrenched, attached to supporting poles, and sometimes backed by a plastic or wire mesh for support. The silt fence detains sediment -laden water, promoting sedimentation behind the fence Implementation A silt fence is a temporary sediment barrier consisting of filter fabric stretched across and attached to supporting posts, entrenched, and, depending upon the strength of fabric used, supported with plastic or wire mesh fence. Silt fences trap sediment by intercepting and detaining small amounts of sediment -laden runoff from disturbed areas in order to promote sedimentation behind the fence. Silt fences are preferable to straw bale barriers in many cases. Laboratory work at the Virginia Highway and Transportation Research Council has shown that silt fences can trap a much higher percentage of suspended sediments than can straw bales. While the failure rate of silt fences is lower than that of straw bale barriers, there are many instances where silt fences have been improperly installed. The following layout and installation guidance can improve performance and should be followed: • Use principally in areas where sheet flow occurs. • Don't use in streams, channels, or anywhere flow is concentrated. Don't use silt fences to divert flow. • Don't use below slopes subject to creep, slumping, or landslides. • Select filter fabric that retains 85% of soil by weight, based on sieve analysis, but that is not finer than an equivalent opening size of 70. • Install along a level contour, so water does not pond more than 1.5 ft at any point along the silt fence. • The maximum length of slope draining to any point along the silt fence should be 200 ft or less. The maximum slope perpendicular to the fence line should be 1:1. Silt Fence Implementation Continued • Provide sufficient room for runoff to pond behind the fence and to allow sediment removal equipment to pass between the silt fence and toes of slopes or other obstructions. About 1200 ft2 of ponding area should be provided for every acre draining to the fence. • Turn the ends of the filter fence uphill to prevent storm water from flowing around the fence. • Leave an undisturbed or stabilized area immediately down slope from the fence where feasible. • Silt fences should remain in place until the disturbed area is permanently stabilized. Materials • Silt fence fabric should be woven polypropylene with a minimum width of 36 in. and a minimum tensile strength of 1001b force. The fabric should conform to the requirements in ASTM designation D4632 and should have an integral reinforcement layer. The reinforcement layer should be a polypropylene, or equivalent, net provided by the manufacturer. The permittivity of the fabric should be between 0.1 sec -1 and 0.15 sec -1 in conformance with the requirements in ASTM designation D4491. • Wood stakes should be commercial quality lumber of the size and shape shown on the plans Each stake should be free from decay, splits or cracks longer than the thickness of the stake or other defects that would weaken the stakes and cause the stakes to be structurally unsuitable. • Staples used to fasten the fence fabric to the stakes should be not less than 1.75 in. long and should be fabricated from 15 gauge or heavier wire. The wire used to fasten the tops of the stakes together when joining two sections of fence should be 9 -gauge or heavier wire. Galvanizing of the fastening wire will not be required. • There are new products that may use prefabricated plastic holders for the silt fence and use bar reinforcement instead of wood stakes. If bar reinforcement is used in lieu of wood stakes, use number four or greater bar. Provide end protection for any exposed bar reinforcement. Straw Bale Barrier Description and Purpose A straw bale barrier is a series of straw bales placed on a level contour to intercept sheet flows. Straw bale barriers pond sheet- flow runoff, allowing sediment to settle out. Implementation A straw bale barrier consists of a row of straw bales placed on a level contour. When appropriately placed, a straw bale barrier intercepts and slows sheet flow runoff, causing temporary ponding. The temporary ponding provides quiescent conditions allowing sediment to settle. Straw bale barriers also interrupt the slope length and thereby reduce erosion by reducing the tendency of sheet flows to concentrate into rivulets, which erode rills, and ultimately gullies, into disturbed, sloped soils. Straw bale barriers have not been as effective as expected due to improper use. These barriers have been placed in streams and drainage ways where runoff volumes and velocities have caused the barriers to wash out. In addition, failure to stake and entrench the straw bale has allowed undercutting and end flow. Materials • Straw Bale Size: Each straw bale should be a minimum of 14 in. wide, 18 in. in height, 36 in. in length and should have a minimum mass of 50 lbs. The straw bale should be composed entirely of vegetative matter, except for the binding material. • Bale Bindings: Bales should be bound by steel wire, nylon or polypropylene string placed horizontally. Jute and cotton binding should not be used. Baling wire should be a minimum diameter of 14 -gauge. Nylon or polypropylene string should be approximately 12 -gauge in diameter with a breaking strength of 80 lbs force. • Stakes: Wood stakes should be commercial quality lumber of the size and shape shown on the plans. Each stake should be free from decay, splits or cracks longer than the thickness of the stake, or other defects that would weaken the stakes and cause the stakes to be structurally unsuitable. Steel bar reinforcement should be equal to a #4 designation or greater. End protection should be provided for any exposed bar reinforcement. Check Dams Description and Purpose A check dam is a small barrier constructed of rock, gravel bags, sandbags, straw bales, fiber rolls, or reusable products, placed across a constructed swale or drainage ditch. Check dams reduce the effective slope of the channel, thereby reducing the velocity of flowing water, allowing sediment to settle and reducing erosion. Implementation General Check dams reduce the effective slope and create small pools in swales and ditches that drain 10 acres or less. Reduced slopes reduce the velocity of storm water flows, thus reducing erosion of the swale or ditch and promoting sedimentation. Use of check dams for sedimentation will likely result in little net removal of sediment because of the small detention time and probable scour during longer storms. Using a series of check dams will generally increase their effectiveness. A sediment trap may be placed immediately upstream of the check dam to increase sediment removal efficiency. Design and Layout Check dams work by decreasing the effective slope in ditches and swales. An important consequence of the reduced slope is a reduction in capacity of the ditch or swale. This reduction in capacity must be considered when using this BMP, as reduced capacity can result in overtopping of the ditch or swale and resultant consequences. In some cases, such as a "permanent" ditch or swale being constructed early and used as a "temporary" conveyance for construction flows, the ditch or swale may have sufficient capacity such that the temporary reduction in capacity due to check dams is acceptable. When check dams reduce capacities beyond acceptable limits, there are several options: • Don't use check dams. Consider alternative BMPs. • Increase the size of the ditch or swale to restore capacity. Maximum slope and velocity reduction is achieved when the toe of the upstream dam is at the same elevation as the top of the downstream dam. The center section of the dam should be lower than the edge sections so that the check dam will direct flows to the center of the ditch or swale. Check dams are usually constructed of rock, gravel bags, sandbags, and fiber rolls. A number of products manufactured specifically for use as check dams are also being used, and some of these products can be removed and reused. Check dams can also be constructed of logs or lumber, and have the advantage of a longer lifespan when compared to gravel bags, sandbags, and fiber rolls. Straw bales can also be used for check dams and can work if correctly installed; but in practice, straw bale check dams have a high failure rate. Check dams should not be constructed from straw bales or silt fences, since concentrated flows quickly wash out these materials. Rock check dams are usually constructed of 8 to 12 in. rock. The rock is placed either by hand or mechanically, but never just dumped into the channel. The dam must completely span the ditch or swale to prevent washout. The rock used must be large enough to stay in place given the expected design flow through the channel. Log check dams are usually constructed of 4 to 6 in. diameter logs. The logs should be embedded into the soil at least 18 in. Logs can be bolted or wired to vertical support logs that have been driven or buried into the soil. Gravel bag and sandbag check dams are constructed by stacking bags across the ditch or swale, shaped as shown in the drawings at the end of this fact sheet. Manufactured products should be installed in accordance with the manufacturer's instructions. If grass is planted to stabilize the ditch or swale, the check dam should be removed when the grass has matured (unless the slope of the swales is greater than 4%). The following guidance should be followed for the design and layout of check dams: • Install the first check dam approximately 16 ft from the outfall device and at regular intervals based on slope gradient and soil type. • Check dams should be placed at a distance and height to allow small pools to form between each check dam. • Backwater from a downstream check dam should reach the toes of the upstream check dam. • A sediment trap provided immediately upstream of the check dam will help capture sediment. Due to the potential for this sediment to be re -suspended in subsequent storms, the sediment trap must be cleaned following each storm event. • High flows (typically a 2 -year storm or larger) should safely flow over the check dam without an increase in upstream flooding or damage to the check dam. • Where grass is used to line ditches, check dams should be removed when grass has matured sufficiently to protect the ditch or swale. • Gravel bags may be used as check dams with the following specifications: Materials Gravel bags used for check dams should conform to the requirements of gravel bag berms. Sandbags used for check dams should conform to sandbag barrier guidelines. Fiber rolls used for check dams should conform to fiber roll requirements. Straw bales used for check dams should conform to straw bale barrier requirements. Fiber Rolls Description and Purpose A fiber roll consists of straw, flax, or other similar materials bound into a tight tubular roll. When fiber rolls are placed at the toe and on the face of slopes, they intercept runoff, reduce its flow velocity, release the runoff as sheet flow, and provide removal of sediment from the runoff. By interrupting the length of a slope, fiber rolls can also reduce erosion. Implementation Fiber Roll Materials • Fiber rolls should be either prefabricated rolls or rolled tubes of erosion control blanket. Assembly of Field Rolled Fiber Roll • Roll length of erosion control blanket into a tube of minimum 8 in. diameter. • Bind roll at each end and every 4 ft along length of roll with jute -type twine. Installation • Locate fiber rolls on level contours spaced as follows: o Slope inclination of 4:1 (H:V) or flatter: Fiber rolls should be placed at a maximum interval of 20 ft. o Slope inclination between 4:1 and 2:1 (14:V): Fiber Rolls should be placed at a maximum interval of 15 ft. (a closer spacing is more effective). o Slope inclination 2:1 (H:V) or greater: Fiber Rolls should be placed at a maximum interval of 10 ft. (a closer spacing is more effective). • Turn the ends of the fiber roll up slope to prevent runoff from going around the roll. • Stake fiber rolls into a 2 to 4 in. deep trench with a width equal to the diameter of the fiber roll. o Drive stakes at the end of each fiber roll and spaced 4 ft maximum on center. o Use wood stakes with a nominal classification of 0.75 by 0.75 in. and minimum length of 24 in. • If more than one fiber roll is placed in a row, the rolls should be overlapped, not abutted. Culvert Inlet/Outlet Protection a. Normal metal culvert installation using riprap around the inlet and outlet of culverts. Also use geotestile (filter fabric) or gravel filter beneath the riprap for tuost installations. (Adaptedfrom iflsconsht s Forestry Best Management Practice for Water Quality, 1995) Description and Purpose Culvert inlet/outlet protection typically consists of gravel riprap that act as energy dissipation features, thus allowing for the settling of sediments, while preventing piping form occurring at the inlet or outlet. Riprap should consist of small to medium gravels that layered to achieve uniform density. Inspection and Maintenance • Inspect BMPs prior to forecast rain, daily during extended rain events, after rain events, weekly during the rainy season, and at two-week intervals during the non - rainy season. • Repair or fill any unnecessary gaps or holes in the inlet/outlet of culverts. Erosion Control Blankets Description and Purpose Made out of environmentally friendly, biodegradable material, erosion control blankets are installed on disturbed slopes that are requiring stability. They stabilize slopes, and provide for an increased water holding capacity, which ultimately increased the rate and establishment of desired vegetative cover. Implementation Erosion control blankets should installed smoothly on the surface of the soil, loose enough to allow for vegetation establishment. The blankets are to be in complete contact with the soil to prevent any tenting. The upslope end of the blanket should be buried in a trench with ideal dimensions of 6"x6". Where one blanket ends and another begins, there should be 4-6 inches of overlap. Inspection and Maintenance • Inspect blankets prior to forecast rain, daily during extended rain events, after rain events, weekly during the rainy season, and at two-week intervals during the non - rainy season. • Repair any unnecessary gaps or holes in the blankets. • Inspect to make sure that there is uniform contact with the soil. PVCMI Land Planning Division 1038 County Road 323 Rifle, CO 81650 Ph. 970-625-5350 Fax 970-625-4522 Email: pvcm@hughes.net Project: Cottonwood Compressor Station to Webster Hill 24" Gathering Line. Submittal Item Tab 23- Response letter regarding Development Plan Review Standards and Criteria for Approval. 9.07.06 Please find below a response to each of the checklist items that are required to be reviewed by the Garfield County Building and Planning Department. A. Right-of-way locations related to perimeters of surface property ownerships. 9.07.06 (1) Please see Tab 2- Vicinity Map- 9.07.04 (1) B. Colorado Oil and Gas Conservation Commission Rules and Regulations, Section 802, Noise Abatement. 9.07.06 (2) Please see attached a "Computer Noise Model Prediction and COGCC Compliance Report for New Gas Compression Equipment at Webster Hill Compressor Station" and "Computer Noise Model Prediction and COGCC Compliance Report for New Gas Compression Equipment at Rabbit Brush Compressor Station". These reports are dated 4/30/07 and were prepared by HFP Acoustical Consultants, Inc. The reports account for the Phase 2 expansion of the compressor stations as well. In regards to the pipeline installation, we will follow the COGCC regulations in regards to rule 802 and maximum noise levels. Important Note: Via this application to Garfield County, we are applying for approval for the expansion of the compressor building at both Webster Hill and Rabbit Brush Compressor Stations to a maximum size of 75'-0" wide x 275'-0" long. This would allow for the building/compressor expansion to occur without further Garfield County Page 1 of 3 land use approvals. A Garfield County building permit would, of course, need to be applied for and obtained. C. Minimize visual impact and disturbance of the land surface. 9.07.06 (3) We have located the new 24" line in existing, disturbed right-of- way to limit surface disturbance to previously disturbed areas. All equipment, above -ground piping and exterior materials on the buildings will be painted in "Desert Brown" color. An 8 ft. chain link fence with three strands of barbwire at the top will be installed at the exterior of the compressor stations for security purposes. The Rabbit Brush Compressor Station is located approximately ''A mile North from I-70 and U.S. Highway 6 & 24 at an elevation higher than both. The painting scheme will camouflage this facility in an effective fashion. The Webster Hill Compressor Station is located on Webster Mesa. This location is not visible from I-70 or U.S. Highway 6 & 24. The painting scheme will camouflage this facility in an effective fashion. D. Access Points to public roads. 9.07.06 (4) Please see Tab 16- Traffic Impact- 9.07.04 (15) E. Impact on endangered species. 9.07.06 (5) Please see Tab 11- Sensitive Area Survey- 9.07.04 (10) F. Air contaminant emissions. 9.07.06 (6) Bargath, Inc. agrees to meet the control provisions set forth by the Colorado Air Quality Control Program, Title 25, Article 7, C.R.S. Please see the APCDs and the Fugitive Dust Permit in Tab 7- 9.07.04 (6). Page 2 of 3 G. Compliance with Colorado State Public Health and Environment, Water Quality Control standards. 9.07.06 (7) Please see Tab 7- Regulatory Permit Requirements- 9.07.04 (6). Bargath, Inc. has received a CDPS permit from the CDPHE for the project. H. Compliance with Garfield County Individual Sewage Disposal System regulations. 9.07.06 (8) There will not be ISDS installed at this project. Please see Tab 22 - Construction Management Plan- Page 23- Waste Disposal and sanitation to note the use of portable chemical toilets for human waste during the construction of the pipeline. I. Reclamation plan. 9.07.06 (9) Please see Tab 13- Revegetation Plan- 9.07.04 (12) J. Abandoned pipeline removal. 9.07.06 (10) Abandoned pipeline will be abandoned as per the most current Colorado Oil & Gas Conservation Commission regulations at the time of abandonment. Please contact me with any questions. Sincerely, Philip B. Vaughan President PVCMI Page 3 of 3 ACOUSTICAL CSULTANTS II FlC. Submitted by: HFP Acoustical Consultants Inc. HFP File 6260-1 April 30, 2007 6001 Savoy Drive, Suite 115 Phone: 713.789.9400 #1140, 10201 Southport Road S.W. Phone: 403.259.6600 Houston, Texas 77036 Fax: 713.789.5493 Calgary, Alberta, Canada T2W 4X9 Fax: 403.259.6611 Computer Noise Model Prediction and COGCC Compliance Report for New Gas Compression Equipment at Webster Hill Compressor Station (Williams) Prepared for Enviro Noise Control Group Submitted by: HFP Acoustical Consultants Inc. HFP File 6260-1 April 30, 2007 6001 Savoy Drive, Suite 115 Phone: 713.789.9400 #1140, 10201 Southport Road S.W. Phone: 403.259.6600 Houston, Texas 77036 Fax: 713.789.5493 Calgary, Alberta, Canada T2W 4X9 Fax: 403.259.6611 April 30, 2007 Williams — Webster Hill CS HFP File 6260-1 Page 2 1 INTRODUCTION Williams Production RMT Co. (Williams) plans to install two gas engine driven gas compressors at Webster Hill Compressor Station (CS), a new facility in Garfield County, Colorado. The project goal is that the total sound level be less than or equal to 65 dB(A) at a distance of 350 feet from noise sources or at the property line, whichever is greater. This is in accordance with the Colorado Oil and Gas Conservation Commission (COGCC) nighttime noise limit for a light industrial zone. HFP Acoustical Consultants Inc. (HFP) was asked to create a computer noise model of the compressor station for the planned conditions. A Phase 2 case was also modeled for a potential build -out condition with four total compressors at the site. Based on data provided and using the noise mitigation treatments listed, results show that the sound level contribution from the planned equipment will be less than 65 dB(A) at a distance of 350 feet from the noise sources or at the property line, as applicable for both Phase 1 and Phase 2 conditions. 2 COMPUTER NOISE MODELING A three-dimensional computer noise model was constructed in order to predict the sound level impact of the proposed equipment. The compressor station noise model was developed using CadnaA, version 3.6.119, a noise modeling package developed by DataKustik GmbH. The software takes into account spreading losses, ground and atmospheric effects, shielding from barriers and buildings, and reflections from surfaces. The computer noise model calculations are based on "ISO 9613-2: Acoustics — Attenuation of sound during propagation outdoors." 2.1 Phase 1 — Two Compressors Two compressor units and associated lube oil coolers are modeled. Each compressor/cooler unit consists of the following equipment: • CAT G3612, 3550 hp engine • Ariel JGZ-4 compressor • Air -X -Changer model 156-2Z lube oil cooler (two 156" fans per cooler) The two units will share two total process gas coolers, one interstage and one after cooler: • Air -X -Changer model 132-2Z process gas cooler (two 132" fans per cooler) The engines and compressors will be inside a metal building. The modeled octave band sound pressure levels (SPL) inside the building due to the two engines and compressors are shown in Table 1. Also shown are the sound power levels (PWL) of other modeled noise sources. ACOUSTICAL CONSULTANTS April 30, 2007 Williams — Webster Hill CS HFP File 6260-1 Page 3 Table 1: Compressor Building interior sound pressure level (SPL) and source sound power level (PWL) values assumed for planned equipment. Equipment Noise Source 31.5 63 125 250 500 1000 2000 4000 8000 dB(A) Engine Exhaust (Unsilenced) 109 125 123 121 123 128 133 139 140 143 Sound Pressure Level SPL in Compressor Building - Walls and Roof 92 103 106 97 97 96 98 97 89 104 (SPL) in Compressor Building - East Wall only 94 105 111 102 102 99 100 99 92 107 Compressor Building Ventilation Fan, PWL 97 97 98 98 97 93 89 84 80 98 Horizontal Lube Oil Cooler Fan, PWL 106 106 105 102 97 95 89 83 77 100 Horizontal Interstage Process Gas Cooler, PWL 106 106 105 102 97 95 89 83 77 100 Horizontal Process Gas After Cooler, PWL 107 107 106 103 98 96 90 84 78 101 The sound transmission loss (TL) values of the building walls, roof, doors and translucent panel are shown in Table 2. Also shown are the required minimum dynamic insertion loss (DIL) values for the engine exhaust silencer. Figure 1 (attached) shows the results of the computer noise model. The sound level at a distance of 350 feet from the noise sources in the north, east and south directions is shown to be less than 65 dB(A). The sound level at the west property line is also shown to be less than 65 dB(A). Table 4 (attached) shows a rank -ordered list of source sound contributions at each of the four receiver locations. Planned new equipment noise sources are grouped into the following categories: • Engine Exhausts • Building Walls and Roof • Building Ventilation — Ridge Vent Exhaust • Building Ventilation — Intakes • Building Doors • Building Translucent Panel • Horizontal Lube Oil Coolers • Horizontal Process Coolers ACOUSTICAL CONSULTANTS April 30, 2007 Williams — Webster Hill CS HFP File 6260-1 Page 4 Table 2: Required noise control treatments to meet 65 dB(A) at 350 feet from noise source or at the property line, as applicable for Phase 1. Noise Source Treatment Required Minimum Dynamic Insertion Loss (DIL) or Transmission Loss (TL) by Octave Band (Hz) 31.5 63 125 250 500 1000 2000 4000 8000 Engine Exhaust Stack Outlets (2) Phase 1 Engine Exhaust Silencer, DIL 0 3 11 15 22 27 30 31 28 Compressor Building Walls and Roof Required Minimum TL 10 8 14 16 17 23 23 27 29 Compressor Building Translucent Panel 1/4" Lexan 0 17 21 22 26 32 37 41 41 Equipment Door STC -21 Roll -up Door, TL 2 7 12 17 18 19 22 30 35 Personnel Door TLC -32 Door, 20 17 23 27 32 32 31 41 41 The compressor building is assumed to be constructed of 24 gage sheet metal. Building ventilation was considered in the model, including seven wall inlet fans and roof ridge gravity relief vent. No special acoustical treatments are required for building ventilation. No special acoustical treatments are required on the lube oil or process gas coolers, which have cooling fans with relatively low sound power levels. Above ground piping associated with metering, scrubbers, pig launchers, receivers, etc. will be minimized to the extent practical. It is possible that some aboveground piping will need to be acoustically lagged, but lagging can be installed after operations begin if necessary. Noise from process gas pipes and valves were not included in the noise analysis. 2.2 Phase 2 — Potential Build -out Condition There is the potential to add two additional compressors to the Webster Hill Compressor Station, bringing the total number of compressors at the site to four. The build -out condition was modeled to determine the sound level impact under this build -out condition. The model assumes that the same source sound levels listed in Table 1 will apply for the Phase 2 equipment. The noise control treatments listed in Table 3 are assumed for the Phase 2 build -out equipment. All treatments are the same as Phase 1 except for the engine exhaust silencers. The Phase 1 engine exhaust silencers must be replaced with Phase 2 silencers so that all four silencers have the minimum DIL performance shown in Table 3. ACOUSTICAL CONSULTANTS April 30, 2007 Williams — Webster Hill CS HFP File 6260-1 Page 5 Table 3: Required noise control treatments to meet 65 dB(A) at 350 feet from noise source or at the property line, as applicable for Phase 2. Noise Source Treatment Required Minimum Dynamic Insertion Loss (DIL) or Transmission Loss (TL) by Octave Band (Hz) 31.5 63 125 250 500 1000 2000 4000 8000 Engine Exhaust Stack Outlets (4) Phase 2 Engine Exhaust Silencer, DIL 0 7 14 18 25 35 39 45 39 Compressor Building Walls and Roof Required Minimum TL 10 8 14 16 17 23 23 27 29 Compressor Building Translucent Panel 1/4" Lexan 0 17 21 22 26 32 37 41 41 Equipment Door STC -21 Roll -up Door, TL 2 7 12 17 18 19 22 30 35 Personnel Door TLC -32 Door, 20 17 23 27 32 32 31 41 41 Figure 2 (attached) shows the results of the computer noise model with the build -out condition. The sound level contribution due to the combined Phase 1 and Phase 2 equipment is shown to be less than 65 dB(A) at a distance of 350 feet from the noise sources in the north, east and south directions, as well as at the west property line. 3 SUMMARY AND CONCLUSIONS A computer noise model of the Williams Webster Hill Compressor Station was created to determine the noise contribution of the planned compression equipment — two gas engine compressors. Based on data provided and using the noise mitigation treatments listed in Table 2, sound level contributions from the planned equipment will be less than 65 dB(A) at a distance of 350 feet from the noise sources or at the property line, as applicable. A potential Phase 2 build -out condition was modeled with four total compressors. Based on data provided and using the noise mitigation treatments listed in Table 2, the total sound level contribution due to Phase 1 and Phase 2 equipment will be less than 65 dB(A) at a distance of 350 feet from the noise sources or at the property line, as applicable. ACOUSTICAL CONSULTANTS April 30, 2007 Williams — Webster Hill CS 8 L63.5 0 rittitattnythnte 380 ft Process Gas Coolers Compressor Building = Lube Oil Coolers 61.9 380 ft. Control Building 0) M A 63.2 HFP File 6260-1 Page 6 �u 100 R. 350 ft 350 R 63.8 Figure 1: 3-D Computer Noise Model Results, dB(A) Williams Webster Hill Compressor Station - Phase 1 Noise Contribution for Planned Equipment is Below 65 dB(A) at a Distance of 350 ft. from Equipment or at the Property Line. ACOUSTICAL CONSULTANTS April 30, 2007 Williams — Webster Hill CS 0 62.8 lRrrptctitM tto 380 R Process Gas Coolers t 64.1 380 ft. 63.8 -88.0 Process Gas Coolers - Phase 2 Control Building Compressor Building Ilding = Lube 0I1 Cooler: l3 HFP File 6260-1 Page 7 100tL 350 ft. 0 350 ft. 64.5 01 62.0 Lube 011 Coolers Phase 2 64.5 Figure 2: 3-D Computer Noise Model Results, dB(A) Williams Webster Hill Compressor Station - Phase 2 Noise Contribution for Planned Equipment is Below 65 dB(A) at a Distance of 350 ft. from Equipment. ACOUSTICAL CONSULTANTS April 30, 2007 Williams - Webster Hill CS HFP File 6260-1 Page 8 Table 4: Phase 1 Source Group Contribution List at Receiver Locations Rank -ordered by dB(A). Octave band values are linear. NORTH RECEIVER: Source Group Contribution Rank -ordered List Source Group dB(A) 31.5 63 125 250 500 1000 2000 4000 8000 Engine Exhausts 60.6 62.7 75.1 64.4 56.7 51.5 52.8 53.5 54.5 45.6 Building Walls and Roof 56.9 58.7 71.5 67.9 54.8 54.1 47.2 47.6 38.8 16.5 Lube Oil Coolers 53.3 62.0 61.8 59.2 53.9 50.4 49.2 42.4 32.1 12.6 Process Gas Coolers (Interstage and After) 53.1 61.8 61.7 58.9 53.7 50.1 49.0 41.9 31.5 11.0 Building Ventilation - Ridge Vent 49.9 41.4 51.6 54.6 43.3 46.2 43.8 44.4 37.6 16.4 Building Ventilation - Intakes 49.2 50.5 56.1 58.3 46.0 42.8 45.7 39.8 31.5 10.8 Building Doors 39.7 49.8 55.4 51.9 35.0 34.2 32.5 29.4 15.3 -11.2 Building Translucent Panel 32.1 54.3 48.0 44.9 32.2 28.4 20.7 14.5 4.0 -18.2 Total 63.5 67.9 77.0 70.7 61.2 58.3 56.7 55.5 54.8 45.6 EAST RECEIVER: Source Group Contribution Rank -ordered List Source Group dB(A) 31.5 63 125 250 500 1000 2000 4000 8000 Engine Exhausts 60.5 62.6 75.0 64.3 56.6 51.4 52.7 53.4 54.4 45.1 Building Walls and Roof 57.7 58.4 71.5 68.8 55.7 55.2 48.0 48.2 39.1 15.7 Lube Oil Coolers 56.0 62.8 62.7 61.1 56.6 53.0 52.0 45.1 35.0 16.0 Building Ventilation - Intakes 50.6 50.2 56.5 59.7 46.6 43.8 47.1 41.5 33.1 11.3 Building Ventilation - Ridge Vent 49.4 41.3 52.4 57.4 44.6 45.3 42.9 43.4 36.2 13.7 Process Gas Coolers (Interstage and After) 48.3 58.6 58.0 54.6 49.0 45.2 44.0 36.7 24.9 0.4 Building Doors 45.0 53.6 59.6 56.3 39.1 39.1 38.7 36.8 23.8 -2.6 Building Translucent Panel 22.0 48.8 41.1 35.7 20.3 14.1 4.5 -2.4 -12.5 -36.1 Total 63.8 67.4 77.0 71.4 61.6 58.9 57.1 55.6 54.7 45.1 ACOUSTICAL CONSULTANTS April 30, 2007 Williams - Webster Hill CS HFP File 6260-1 Page 9 SOUTH RECEIVER: Source Group Contribution Rank -ordered List Source Group dB(A) 31.5 63 125 250 500 1000 2000 4000 8000 Engine Exhausts 60.6 62.7 75.1 64.4 56.7 51.5 52.8 53.5 54.5 45.5 Building Walls and Roof 56.9 58.7 71.5 67.9 54.8 54.1 47.2 47.6 38.8 16.5 Lube Oil Coolers 53.4 62.1 61.9 59.3 54.0 50.4 49.3 42.5 32.3 12.9 Building Ventilation - Ridge Vent 49.9 41.4 51.6 54.6 43.3 46.2 43.8 44.4 37.6 16.4 Building Ventilation - Intakes 49.3 50.5 56.1 58.2 46.0 42.8 45.8 40.0 31.8 11.2 Process Gas Coolers (Interstage and After) 48.5 61.0 60.1 56.8 50.8 45.6 42.7 33.8 21.5 0.5 Building Doors 39.9 49.9 55.5 52.1 35.1 34.4 32.8 29.9 16.2 -9.9 Building Translucent Panel 31.9 54.2 47.9 44.8 32.0 28.2 20.4 14.1 3.2 -19.8 Total 63.2 67.7 77.0 70.6 60.8 57.9 56.2 55.3 54.8 45.5 WEST RECEIVER: Source Group Contribution Rank -ordered List Source Group dB(A) 31.5 63 125 250 500 1000 2000 4000 8000 Process Gas Coolers (Interstage and After) 57.4 65.1 65.0 62.5 58.0 54.4 53.3 46.6 37.3 21.2 Building Walls and Roof 56.4 58.4 71.2 66.9 53.9 53.5 47.2 47.9 39.2 16.4 Engine Exhausts 55.6 57.1 69.5 58.9 51.2 46.1 47.6 48.5 49.9 41.9 Building Ventilation - Intakes 50.3 51.4 56.8 58.0 46.2 43.5 47.1 41.9 33.9 12.9 Building Ventilation - Ridge Vent 50.2 42.0 53.1 58.2 45.4 46.1 43.7 44.3 37.4 16.2 Building Translucent Panel 37.7 57.4 51.7 49.4 37.8 35.0 28.6 24.1 15.5 -4.7 Lube Oil Coolers 36.6 55.7 53.4 47.8 39.1 32.1 28.0 18.5 6.4 -16.1 Building Doors 31.1 45.3 49.5 44.0 25.4 22.2 21.2 21.8 6.9 -13.8 Total 61.9 67.5 74.2 69.5 60.4 57.8 56.0 53.4 50.8 41.9 H I:: P ACOUSTICAL CONSULTANTS 4WWLTkt41S INC, Submitted by: HFP Acoustical Consultants Inc. HFP File 6258-1 April 30; 2007 6001 Savoy Drive, Suite 115 Phone: 713.789.9400 #1140, 10201 Southport Road S.W. Phone: 403.259.6600 Houston, Texas 77036 Fax: 713.789.5493 Calgary, Alberta, Canada T2W 4X9 Fax: 403.259.6611 Computer Noise Model Prediction and COGCC Compliance Report for New Gas Compression Equipment at Rabbit Brush Compressor Station (Williams) Prepared for Enviro Noise Control Group Submitted by: HFP Acoustical Consultants Inc. HFP File 6258-1 April 30; 2007 6001 Savoy Drive, Suite 115 Phone: 713.789.9400 #1140, 10201 Southport Road S.W. Phone: 403.259.6600 Houston, Texas 77036 Fax: 713.789.5493 Calgary, Alberta, Canada T2W 4X9 Fax: 403.259.6611 April 30, 2007 Williams — Rabbit Brush CS HFP File 6258-1 Page 2 1 INTRODUCTION Williams Production RMT Co. (Williams) plans to install two gas engine driven gas compressors at Rabbit Brush Compressor Station (CS), a new facility in Garfield County, Colorado. The project goal is that the total sound level be less than or equal to 65 dB(A) at a distance of 350 feet from noise sources or at the property line, whichever is greater. This is in accordance with the Colorado Oil and Gas Conservation Commission (COGCC) nighttime noise limit for a light industrial zone. HFP Acoustical Consultants Inc. (IRP) was asked to create a computer noise model of the compressor station for the planned conditions. A Phase 2 case was also modeled for a potential build -out condition with four total compressors at the site. Based on data provided and using the noise mitigation treatments listed, results show that the sound level contribution from the planned equipment will be less than 65 dB(A) at a distance of 350 feet from the noise sources or at the property line, as applicable for both Phase 1 and Phase 2 conditions. 2 COMPUTER NOISE MODELING A three-dimensional computer noise model was constructed in order to predict the sound level impact of the proposed equipment. The compressor station noise model was developed using CadnaA, version 3.6.119, a noise modeling package developed by DataKustik GmbH. The software takes into account spreading losses, ground and atmospheric effects, shielding from barriers and buildings, and reflections from surfaces. The computer noise model calculations are based on "ISO 9613-2: Acoustics — Attenuation of sound during propagation outdoors." 2.1 Phase 1— Two Compressors Two compressor units and associated lube oil coolers are modeled. Each compressor/cooler unit consists of the following equipment: • CAT G3612, 3550 hp engine • Ariel JGZ-4 compressor • Air -X -Changer model 156-2Z lube oil cooler (two 156" fans per cooler) The two units will share two total process gas coolers, one interstage and one after cooler: • Air -X -Changer model 132-2Z process gas cooler (two 132" fans per cooler) The engines and compressors will be inside a metal building. The modeled octave band sound pressure levels (SPL) inside the building due to the two engines and compressors are shown in Table 1. Also shown are the sound power levels (PWL) of other modeled noise sources. ACOUSTICAL CONSULTANTS April 30, 2007 Williams — Rabbit Brush CS HFP File 6258-1 Page 3 Table 1: Compressor Building interior sound pressure level (SPL) and source sound power level (PWL) values assumed for planned equipment. Equipment Noise Source 31.5 63 125 250 500 1000 2000 4000 8000 dB(A) Engine Exhaust (Unsilenced) 109 125 123 121 123 128 133 139 140 143 Sound Pressure Level SPL in Compressor Building - Walls and Roof 92 103 106 97 97 96 98 97 89 104 (SPL) in Compressor Building - East Wall only 94 105 111 102 102 99 100 99 92 107 Compressor Building Ventilation Fan, PWL 97 97 98 98 97 93 89 84 80 98 Horizontal Lube Oil Cooler Fan, PWL 106 106 105 102 97 95 89 83 77 100 Horizontal Interstage Process Gas Cooler, PWL 106 106 105 102 97 95 89 83 77 100 Horizontal Process Gas After Cooler, PWL 107 107 106 103 98 96 90 84 78 101 The sound transmission loss (TL) values of the building walls, roof, doors and translucent panel are shown in Table 2. Also shown are the required minimum dynamic insertion loss (DIL) values for the engine exhaust silencer. Figure 1 (attached) shows the results of the computer noise model. The sound level at a distance of 350 feet from the noise sources in the north, east and south directions is shown to be less than 65 dB(A). The sound level at the west property line is also shown to be less than 65 dB(A). Table 4 (attached) shows a rank -ordered list of source sound contributions at each of the four receiver locations. Planned new equipment noise sources are grouped into the following categories: • Engine Exhausts • Building Walls and Roof • Building Ventilation — Ridge Vent Exhaust • Building Ventilation — Intakes • Building Doors • Building Translucent Panel • Horizontal Lube Oil Coolers • Horizontal Process Coolers 1 F_. ACOUSTICAL CONSULTANTS April 30, 2007 Williams — Rabbit Brush CS HFP File 6258-1 Page 4 Table 2: Required noise control treatments to meet 65 dB(A) at 350 feet from noise source or at the property line, as applicable for Phase 1. Noise Source Treatment Required Minimum Dynamic Insertion Loss (DIL) or Transmission Loss (TL) by Octave Band (Hz) 31.5 63 125 250 500 1000 2000 4000 8000 Engine Exhaust Stack Outlets (2) Phase 1 Engine Exhaust Silencer, DIL 0 3 11 15 22 27 30 31 28 Compressor Building Walls and Roof Required Minimum TL 10 8 14 16 17 23 23 27 29 Compressor Building Translucent Panel 1/4" Lexan 0 17 21 22 26 32 37 41 41 Equipment Door STC -21 Roll -up Door, TL 2 7 12 17 18 19 22 30 35 Personnel Door TLC -32 Door, 20 17 23 27 32 32 31 41 41 The compressor building is assumed to be constructed of 24 gage sheet metal. Building ventilation was considered in the model, including seven wall inlet fans and roof ridge gravity relief vent. No special acoustical treatments are required for building ventilation. No special acoustical treatments are required on the lube oil or process gas coolers, which have cooling fans with relatively low sound power levels. Above ground piping associated with metering, scrubbers, pig launchers, receivers, etc. will be minimized to the extent practical. It is possible that some aboveground piping will need to be acoustically lagged, but lagging can be installed after operations begin if necessary. Noise from process gas pipes and valves were not included in the noise analysis. 2.2 Phase 2 — Potential Build -out Condition There is the potential to add two additional compressors to the Rabbit Brush Compressor Station, bringing the total number of compressors at the site to four. The build -out condition was modeled to determine the sound level impact under this build -out condition. The model assumes that the same source sound levels listed in Table 1 will apply for the Phase 2 equipment. The noise control treatments listed in Table 3 are assumed for the Phase 2 build -out equipment. All treatments are the same as Phase 1 except for the engine exhaust silencers. The Phase 1 engine exhaust silencers must be replaced with Phase 2 silencers so that all four silencers have the minimum DIL performance shown in Table 3. ACOUSTICAL CONSULTANTS April 30, 2007 Williams — Rabbit Brush CS 1 -IFP File 6258-1 Page 5 Table 3: Required noise control treatments to meet 65 dB(A) at 350 feet from noise source or at the property line, as applicable for Phase 2. Noise Source Treatment Required Minimum Dynamic Insertion Loss (DIL) or Transmission Loss (TL) by Octave Band (Hz) 31.5 63 125 250 500 1000 2000 4000 8000 Engine Exhaust Stack Outlets (4) Phase 2 Engine Exhaust Silencer, DIL 0 7 14 18 25 35 39 45 39 Compressor Building Walls and Roof Required Minimum TL 10 8 14 16 17 23 23 27 29 Compressor Building Translucent Panel 1/4" Lexan 0 17 21 22 26 32 37 41 41 Equipment Door STC -21 Roll -up Door, TL 2 7 12 17 18 19 22 30 35 Personnel Door TLC -32 Door, 20 17 23 27 32 32 31 41 41 Figure 2 (attached) shows the results of the computer noise model with the build -out condition. The sound level contribution due to the combined Phase 1 and Phase 2 equipment is shown to be less than 65 dB(A) at a distance of 350 feet from the noise sources in the north, east and south directions, as well as at the west property line. 3 SUMMARY AND CONCLUSIONS A computer noise model of the Williams Rabbit Brush Compressor Station was created to determine the noise contribution of the planned compression equipment — two gas engine compressors. Based on data provided and using the noise mitigation treatments listed in Table 2, sound level contributions from the planned equipment will be less than 65 dB(A) at a distance of 350 feet from the noise sources or at the property line, as applicable. A potential Phase 2 build -out condition was modeled with four total compressors. Based on data provided and using the noise mitigation treatments listed in Table 2, the total sound level contribution due to Phase 1 and Phase 2 equipment will be less than 65 dB(A) at a distance of 350 feet from the noise sources or at the property line, as applicable. ACOUSTICA L CONSULTANTS April 30, 2007 Williams — Rabbit Brush CS HFP File 6258-1 Page 6 L'IRO Control MI Building Process Gas Coolers 380 ft. 63.2 Compressor Building Luba 011 Coolers 150 ft. 100 ft. 61.9 63.5 • 63.7 Figure 1: 3-D Computer Noise Model Results, dB(A) Williams Rabbit Brush Compressor Station - Phase 1 Noise Contribution for Planned Equipment is Below 65 dB(A) at a Distance of 350 ft. from Equipment or at the Property Line. ACOUSTICAL CONSULTANTS April 30, 2007 Williams — Rabbit Brush CS HFP File 6258-1 Page 7 Control Building Process Gas Coolers 380 ft. 62. 63.9 r Process Gas Coolers - Phase 2 63.7 380 ft. Compressor Building ilding Lube Oil Coolers 111 350 ft. 100 ft. [ Lube Oil Coolers Phase 2 t 64.4 350 ft. 62.6 64.4 Figure 2: 3-D Computer Noise Model Results, dB(A) Williams Rabbit Brush Compressor Station - Phase 2 Noise Contribution for Planned Equipment is Below 65 dB(A) at a Distance of 350 ft. from Equipment or at the Property Line. 1-1 F F'• ACOUSTICAL CONSULTANTS April 30, 2007 Williams - Rabbit Brush CS HFP File 6258-1 Page 8 Table 4: Phase 1 Source Group Contribution List at Receiver Locations Rank -ordered by dB(A). Octave band values are linear. NORTH RECEIVER: Source Group Contribution Rank -ordered List Source Group dB(A) 31.5 63 125 250 500 1000 2000 4000 8000 Engine Exhausts 60.6 62.7 75.1 64.4 56.7 51.5 52.8 53.5 54.5 45.6 Building Walls and Roof 56.9 58.6 71.5 67.9 54.8 54.1 47.2 47.6 39.1 16.9 Lube Oil Coolers 53.4 62.0 61.9 59.2 54.0 50.4 49.3 42.5 32.2 12.9 Building Ventilation - Ridge Vent 49.9 41.4 51.6 54.6 43.3 46.2 43.8 44.4 37.6 16.4 Building Ventilation - Intakes 49.3 50.5 56.1 58.3 46.0 42.8 45.7 39.8 33.3 12.8 Process Gas Coolers (Interstage and After) 48.6 60.8 60.1 56.9 50.9 45.8 43.0 34.0 21.7 0.7 Building Doors 39.7 49.8 55.4 51.9 35.0 34.2 32.5 29.4 15.3 -11.2 Building Translucent Panel 32.1 54.3 48.0 44.9 32.2 28.4 20.7 14.5 4.0 -18.2 Total 63.3 67.7 77.0 70.6 60.8 57.9 56.2 55.3 54.8 45.6 EAST RECEIVER: Source Group Contribution Rank -ordered List Source Group dB(A) 31.5 63 125 250 500 1000 2000 4000 8000 Engine Exhausts 60.5 62.6 75.0 64.3 56.6 51.5 52.7 53.4 54.4 45.1 Building Walls and Roof 57.6 58.4 71.5 68.8 55.7 55.2 48.0 48.2 39.1 15.7 Lube Oil Coolers 56.0 62.8 62.7 61.1 56.6 53.0 52.0 45.1 35.0 16.0 Building Ventilation - Intakes 50.5 50.2 56.5 59.7 46.6 43.8 47.1 41.5 33.1 11.3 Building Ventilation - Ridge Vent 49.4 41.3 52.4 57.4 44.6 45.3 42.9 43.4 36.2 13.7 Building Doors 45.0 53.6 59.6 56.3 39.1 39.1 38.7 36.8 23.8 -2.5 Process Gas Coolers (Interstage and After) 43.3 57.3 56.3 52.1 45.3 40.3 37.7 28.8 15.2 -11.3 Building Translucent Panel 22.0 48.8 41.1 35.7 20.3 14.1 4.5 -2.4 -12.5 -36.1 Total 63.7 67.3 76.9 71.3 61.5 58.7 56.9 55.5 54.7 45.1 ACOUSTICAL CONSULTANTS April 30, 2007 Williams - Rabbit Brush CS HFP File 6258-1 Page 9 SOUTH RECEIVER: Source Group Contribution Rank -ordered List Source Group dB(A) 31.5 63 125 250 500 1000 2000 4000 8000 Engine Exhausts 60.6 62.7 75.1 64.4 56.7 51.5 52.8 53.5 54.5 45.5 Building Walls and Roof 56.9 58.7 71.5 67.9 54.8 54.1 47.2 47.6 38.8 16.5 Lube Oil Coolers 53.4 62.0 61.8 59.2 53.9 50.4 49.2 42.4 32.2 12.7 Process Gas Coolers (Interstage and After) 53.1 61.7 61.6 58.9 53.6 50.1 48.9 42.0 31.5 10.9 Building Ventilation - Ridge Vent 49.9 41.4 51.6 54.6 43.3 46.2 43.8 44.4 37.6 16.4 Building Ventilation - Intakes 49.3 50.5 56.1 58.2 46.0 42.8 45.8 40.0 31.8 11.2 Building Doors 39.9 49.9 55.5 52.1 35.1 34.4 32.8 29.9 16.2 -9.9 Building Translucent Panel 31.9 54.2 47.9 44.8 32.0 28.2 20.4 14.1 3.2 -19.8 Total 63.5 67.9 77.0 70.7 61.2 58.3 56.7 55.5 54.8 45.5 WEST RECEIVER: Source Group Contribution Rank -ordered List Source Group dB(A) 31.5 63 125 250 500 1000 2000 4000 8000 Process Gas Coolers (Interstage and After) 57.3 65.0 64.9 62.3 58.0 54.4 53.3 46.5 37.2 20.8 Building Walls and Roof 56.4 58.4 71.2 66.9 53.9 53.5 47.2 47.9 39.2 16.4 Engine Exhausts 55.6 57.1 69.5 58.9 51.2 46.1 47.6 48.5 49.9 41.9 Building Ventilation - Intakes 50.3 51.4 56.8 58.0 46.2 43.5 47.1 41.9 33.9 12.9 Building Ventilation - Ridge Vent 50.2 42.0 53.1 58.2 45.4 46.1 43.7 44.3 37.4 16.2 Building Translucent Panel 37.7 57.4 51.7 49.4 37.8 35.0 28.6 24.1 15.5 -4.7 Lube Oil Coolers 36.6 55.7 53.4 47.7 39.0 32.1 27.9 18.4 6.4 -16.2 Building Doors 31.1 45.3 49.5 44.0 25.4 22.2 21.2 21.8 6.9 -13.8 Total 61.9 67.4 74.2 69.5 60.4 57.8 56.0 53.4 50.8 41.9 { F- P ACOUSTICAL CONSULTANTS PVCMI Land Planning Division 1038 County Road 323 Rifle, CO 81650 Ph. 970-625-5350 Fax 970-625-4522 Email: pvcm@hughes.net Project: Cottonwood Compressor Station to Webster Hill 24" Gathering Line. Submittal Item Tab 24. Contact person for Williams Production RMT Co. for Garfield County to contact for Garfield County inspection. 9.07.11 Bargath, Inc.- Authorized Representative and Project Manager Mr. Tom Fiore P.O. Box 370 Parachute, CO 81635 Phone: 970-263-2743 Cell Phone: 970-210-1641 Email: tom.fiore@williams.com Please contact me with any questions. Sincerely, QVc Philip B. Vaughan President PVCMI Page 1 of 1 PVCMI Land Planning Division 1038 County Road 323 Rifle, CO 81650 Ph. 970-625-5350 Fax 970-625-4522 Email: pvcm@hughes.net Project: Cottonwood Compressor Station to Webster Hill 24" Gathering Line. Submittal Item Tab 25. Colorado Professional Engineer responsible for statement and certification of project, including a digital copy of the surveyed pipeline as -built. 9.07.11 DR Griffin & Associates, Inc: Project Designer and Surveyor Mr. Larry Bodyfelt, PELS Engineering Manager D. R. Griffin & Associates, Inc. Professional Engineers & Land Surveyors 1414 Elk Street, Suite 202 Rock Springs, WY 82901 Phone: 307-362-5028 Fax: 307-362-1056 Cell: 307-389-0371 Email: lbodyfelt@n,drg-wy.com Mr. Bodyfelt and his staff will prepare the information noted in 9.07.11. Please contact me with any questions. Sincerely, Philip B. Vaughan President PVCMI Page 1 of 1