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HomeMy WebLinkAbout3.0 BOCC Staff Report 03.10.2008C G) 74ppra (reoj - Y Ccs - y (4?0\. fer'-reo'7/4/(C) Exhibits for a Public Hearing held on March 10th, 2008 (Chevron Central Prod. Fac.) Exhibit Letter (A to Z) Exhibit A Proof of Mail Receipts B Proof of Publication C Garfield County Zoning Resolution of 1978, as amended D Garfield County Comprehensive Plan of 2000 E Application F Staff Report G Memo from Jake Mall of the Garfield County Road and Bridge Department dated February 27, 2008 11 Memo from Steve Anthony of the Garfield County Vegetation Management Department dated February 27, 2008 I Letter from Dean Riggs of the Colorado Division of Wildlife, dated February 25, 2008 J Preliminary Noise Study from Paul Kiteck of Hoover and Keith K Memo from Steve Anthony of the Garfield County Vegetation Management Department dated February 28, 2008 L Letter from Chris Hale, PE of Mountain Cross Engineering, dated February 28, 2008 M Email from Sally Cuffin of Washington Group International dated February 29, 2008 trizotle e ras rbc Cca ra / P/a M(''tr�'J/:q Ia ' j'C(. ✓'o(9 4 Cr ace" ;: » • co,' ` , ! PC �We- � V V D pA,..7 ar V�� 't/7,7 pt- " Pc4 Kc'ej Sr' 147,,* ca,xe,f ,y,e,-7f- 0 /-) C ?/" c r {( �lV. -Ark.,u, gn. . I��� Ar ai 06cj /ee I V .3/7(0e P(,ceat e, eve ^/7 804 ( S).1 c-,7 y *,--p• 74 - so c, c sii-o ! s rr R7l(�° �` �oQ��G rl/% Cl t S pip e -4.4-r ce. ( Ccfr-t l 17( f(47 - C �jSt'err - C,��b �4Sr 1 cp _/A el reg fa f IC'cl'estile_ 47P -C°41 - /ee4p/fe 4 °o/ /Loci,/,3(77/4___ PROJECT INFORMATION AND STAFF COMMENTS TYPE OF REVIEW APPLICANT/PROPERTY OWNER: LOCATION: SITE INFORMATION: ACCESS: EXISTING ZONING: ADJACENT ZONING: BOCC 03/10/08 DP The Applicant requests a Special Use Permit for an "Industrial Support Facility which would include: material handling, pumping facilities, staging areas, storage areas and processing" in the RL zone district Chevron USA, Inc. Section 36, T5S, R98W, generally described as a tract of land 12.5 miles north of the Town of DeBeque off CR 211. 12 acres (54,289.29 acre total) County Road 211 RL (Resource Lands) — GSLVF (Gentle Slopes & Lower Valley Floor) - RL (Resource Lands) - OS (Open Space) I. DESCRIPTION OF THE PROPOSAL The Building and Planning Department received a Special Use Permit (SUP) application for an "Industrial Support Facility which would include: material handling, pumping facilities, staging areas, storage areas and processing" for a Central Production Facility and Temporary Storage Area on an approximately 54,000 -acre property owned by Chevron USA, Inc. The site is located approximately 2.5 miles past the end of County Road 211 and approximately 12.5 miles north of the Town of Debeque. More specifically, the Applicant requests approval from the Board for a Central Production Facility (3.3 acres) and Temporary Storage Area (1.6 acres). The Applicant has represented the facility in the following manner: Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 2 The purpose of the Central Production Facility is to process raw natural gas coming from the well field for delivery to regional pipelines. Gas coming from the wells contains water, which must he removed to prevent corrosion and hydrate formation in the pipelines. A variety of separation techniques are used to remove the excess water including physical separation and glycol dehydration. Raw gas entering the facility is compressed and then sent through the drying processes prior to introduction into a proposed 30 -inch pipeline. The 30 -inch pipeline connects the facility to regional sales pipelines. The facility also will separate natural gas condensate (a mixture of low-density hydrocarbons) from the produced water. The separated condensate will be stored in tanks for off-site shipment. The remaining produced water stored temporarily in a CPF tank prior to being transferred to a proposed onsite treatment system. The project has identified the need for a general storage area to support multiple construction projects associated with proposed facilities. A 1.4 acre area on the cast side of the CPF is proposed for this purpose (see Drawing 2033 -240 -20 -AP -0002.01 Rev. D. The area Calls within the safety radius of the facility flare stack, which means it will only be used until the CPF becomes operational. Required Production Equipment / Storage Items The current CPF equipment list includes the following: • Gas Separator (two phase) • Liquid Separator (three phase) • 3 Compressor Skids complete with: o Compressor o Natural Gas Engine o Bottles o Scrubbers o Coolers o Interconnect Piping (ICP) o Programmable Logic Controller (PLC) o Lubrication system • Glycol Dehydration Tower • 2 Glycol Regeneration Skids • Volatile Organic Compound Recovery Skid for Glycol Dehydration System Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 3 • Water Surge Tank & Transfer Pumps • Condensate Settling Tank • Produced Water Tank • 6 Condensate Tanks • Flare Scruhber / Pump Skid • Flare Stack • 2 Gas Pipeline Scrapper (Pig) Receivers - Gathering Line Cleaner • 2 Liquid Pipeline Scrapper (Pig) Receiver - Gathering Line Cleaner • Chemical Injection Points • Emergency Shutdown / Fire & Gas System (ESD! F&G) • Vapor Recovery Unit Skid for Off -Gas Recovery • Instrument Air Compressor Skid • Power Generation / Distribution • Compressor Building (53 ft x 154.3 ft) • Instrument Air Building (20 fl x 20 ft) • Power House Building (Electrical, Instrumentation & Controls, Warehouse) (16 ft x 65 ft) • Programmable Logic Controllers & Infield Ethernet Ring • Associate Piping and Control Cables II. BACKGROUND Chevron USA Inc. is now underway with their gas extraction operations north of the Town of DeBeque. Chevron USA Inc. owns over 100,000 acres within Garfield County and this particular parcel is approximately 54,000 acres. Chevron USA Inc. is currently operating several natural gas drill rigs in the area and has obtained approval for multiple Temporary Employee Housing facilities, pipelines and temporary office facilities, among others on the subject property. Referral to Planning Commission The BOCC voted 3-0 not to refer this application to the Planning Commission on January 14, 2008 for the following reasons: 1) the limited nature of potential impacts to surrounding properties, 2) the remote location of the property such that it is situated at the end of a dead-end county road which is used primarily for industrial traffic serving the existing industrial uses in the area with very limited general population traffic. III. SITE DESCRIPTION The proposed site where the Central Production Facility (CPF) and Temporary Storage Area are to be located is situated on stream river basin land that is situated at the general confluence of Tom Creek and Clear Creek. The CPF site is proposed to be located on approximately 4.8 acres (12 acres of disturbance) of the total 54,000 acre parcel owned by Chevron USA Inc. The area where the CPF is to be located is surrounded by steep slopes and canyons forming the confluence of the two creeks. Dense mature riparian vegetation exists along the creeks as they pass through the area. There is an old cabin on the property (See photos below) which is to be relocated to the Town of DeBeque. Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 4 General Site Location within Garfield County Central Production Facility Pointer 39°34'3280" 11 105'20'44,07' W oleo 681011 ilea go Stream Google ., Eye alt 119161t Aerial View of Proposed CPF Site Chevron USA Inc. - Central Production Facility BOCC - 03/10/2008 Page 5 ■ sIMIR 111111M risszlip I Subject Site ,iIitpi 1.6211111111129/ ra 11 Ming r rostrepan ratipparoratilil 1 111 1; rdli V:elinik 3 1 rrittlifiati El ;191 iza ff'iI�;�. tramst; ��t�w.l�� r ';;''fir �,�lwl ' aipTiril .;:"; lf ..���al�is€we maySPIV ItisairldzilleMEMIUMEtarmilradamsElmelliNtratirallINIEffigts ? Wareji, werivaLtin i "SA..ttaarm...1.5a Pleala sr Nwc4 is 0 Clersaan igetrami Isaaanuor Pita aratni 9 Pau* Chevron - Central Production Facility 0 2,000 4,000 8,000 Feet 1 1 1 i i Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 6 Right: View of CPF Site looking SE Right: View of CPF Site looking NW Right: View of CPF Site looking NE (Small cabin to berelocated to DeBeque. Access road to be relocated to the north where cabin is currently located). Chevron USA Inc. — Central Production Facility BOCC— 03/10/2008 Page 7 Right: View of CPF Site looking NW (Access road to be relocated to the north). Right: View of CPF Site looking E (Access road to be relocated to the north). IV. ZONING & ADJACENT USES The subject property is zoned Resource Lands (Gentle Slopes and Lower Valley Floor). The type of use requested falls under the definition of an "Industrial Support Facility which would include: material handling, pumping facilities, staging areas, storage areas and processing" which are contemplated as special uses in the Resource Lands (Gentle Slopes and Lower Valley Floor) zone district. The CPF and temporary storage area are to be located on 4.8 acres (12 acres of disturbance) of an approximately 54,000 acre property which is surrounded by properties also owned and utilized by the energy industry such as EnCana, Shell, Oxy, Berry Petroleum Company, Kerogen Oil Company, Puckett Land Company, ExxonMobil, etc. Other neighboring land owners include the Colorado Nature Ranch, the BLM, EV Ranch, and the State of Colorado. Neighboring uses on those lands include rangeland grazing, farming, and resource extraction (natural gas drilling). Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 8 V. AUTHORITY & APPLICABILITY Pursuant to Section 9.03.04 of the Zoning Resolution, an application for a Special Use Permit shall be approved or denied by the Board of County Commissioners after holding a public hearing thereon in conformance with all provisions of the Zoning Resolution. VI. REVIEW AGENCY AND OTHER COMMENTS Comments have been received from the following agencies / community groups and are integrated throughout this memorandum as applicable. 1. Town of DeBeque: 2. Mesa County Planning Department: 3. Colorado Division of Wildlife: 4. Colorado Department of Public Health and Environment: 5. Bureau of Land Management: 6. Garfield County Road and Bridge Department: 7. Garfield County Vegetation Management: 8. Garfield County Oil and Gas Auditor: 9. Mountain Cross Engineering: No Comments Received No Comments Received See Exhibit I No Comments Received No Comments Received See Exhibit G See Exhibit H No Comments Received See Exhibit L Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 9 � F \ $g \SpR yYn4 „cl..kateii \ \\ t/l! E r\\( ? Li i4 g Lfl` lF II 4£ !I: Ill J 2 1. I \ o&en tips a -/ Oil IC Oi[ —a `er d. It Q_ II 's ILJSS E p L ag` 0` E 'u u if 2 'E \!» K L\I: 1E 16 Proposed Site Plan Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 10 VII. REVIEW CRITERIA FOR SPECIAL USE PERMITS (SECTION 5:03) Pursuant to Section 5.03, as listed under the Zone District Regulations, special uses shall conform to all requirements listed there under and elsewhere in the Zoning Resolution, as well as the following standards: 1. Utilities adequate to provide water and sanitation service based on accepted engineering standards and approved by the Board of County Commissioners shall either be in place or shall be constructed in conjunction with the proposed use. Response The Applicant is proposing occupancy of approximately 20 people using the offices identified within the temporary lay down area (Staging Area) followed by occupancy of up to 10 people in the permanent control building for the Central Production Facility. Initially, the temporary construction and office trailers are to be served by hauled potable water and a vault -and -haul sewage disposal system for the initial 20 workers and potentially up to 75 workers during the peak points of construction. During this time, Chevron is to develop and construct the permanent Central Production Facility which is expected to take 6 to 8 months and will include an ISDS capable of supporting up to 10 employees. Water is to be initially supplied with hauled potable water for the initial 6 to 8 months of construction (20 to 75 employees) and the Applicant has supplied an affidavit from Down Valley Septic for this service. During the time of construction, the Applicant has indicated that the number of employees at the site could reach 75 for a very short period. At the time the flare is operational, the control building has obtained the necessary Building Permits and the ISDS is installed, the office trailers are to be removed from the Flare Safety Zone (aka Laydown Area or Staging Area) along with the portable vault -and -haul sewage tanks and potable water tanks. In summary, the Applicant is requesting temporary facilities for the office/construction trailers within the lay down area (Staging Area) until the permanent control building and ISDS are constructed and the flare is operational. At the time the flare is operational all equipment must be removed from the flare safety zone (See Site Plan on previous page). To this end, the Applicant is proposing the following methods of water and sanitation service to the facilities: Temporary Lay Down Area (Staging Area) — First 6 to 8 Months (Until Flare is Operational) Potable Water 2 - 3,025 gallon potable water storage tanks (Total capacity of 6,050 gallons). Water service is to be provided by Down Valley Septic, who purchases water from the Town of Silt. Water tanks are to be refilled a minimum of every three (3) days. With 20 employees at the site, this storage is expected to provide approximately 100 gallons of water per day per employee. Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 11 - With 75 employees at the site, this storage is expected to provide approximately 27 gallons of water per day per employee. Wastewater Disposal 2 — 4,030 gallon wastewater storage tanks (Total capacity of 8,060 gallons). Wastewater disposal service to be provided by Down Valley Septic, who disposes of waste at the South Canyon Landfill. Wastewater tanks are to be emptied a minimum of every three (3) days. According to CDPHE, Water Quality Control Division, Guidelines for Individual Sewage Disposal Systems recommends capacity of 15 gallons/person/day/8-hour shift. Assuming there are 20 employees at the site each working 5 — 8 hour shifts per week, the proposed 8060 gallon capacity of wastewater is expected to be an approximately 26 day supply of storage. Assuming there are 75 employees at the site each working 5 — 8 hour shifts per week, the proposed 8060 gallon capacity of wastewater is expected to be an approximately 7 day supply of storage. Permanent Control Building Potable Water Water is to be stored in a Cistern/Water Storage Container Water service is to be provided by Down Valley Septic, who purchases water from the Town of Silt. Staff understands that the Applicant is working to obtain a well permit for the subject property. Staff recommends that the Applicant obtain an approved well permit prior to issuance of the Special Use Permit. The proposed water tank is to be 3,025 gallons. Water tanks are to be refilled a minimum of every three (3) days. With 10 employees at the site, this storage is expected to provide approximately 100 gallons of water per day per employee. Wastewater Disposal The Applicant is proposing to install an ISDS capable of handling a capacity of 10 employees. The Applicant will need to obtain an ISDS permit from Garfield County prior to installation of this system. In summary, Staff finds that the proposed water supply and wastewater disposal methods are adequate as long as a condition is placed on the Special Use Permit requiring that the Applicant Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 12 submit an approved and adequate well permit to serve the permanent control building prior to issuance of the Special Use Permit. 2. Street improvements adequate to accommodate traffic volume generated by the proposed use and to provide safe, convenient access to the use shall either be in place or shall be constructed in conjunction with the proposed use. Response The Applicant has represented the following regarding traffic to and from the site: Initial traffic associated with the CPF construction will include the delivery and transfer of earthmoving equipment (e.g_, graders, backhoes, loaders) and construction materials (e.g., concrete, gravel, storm -water controls) plus the associated workers. Additional deliveries / installations will be required for the compressors, separators, vapor recovery unit, glycol dehydration & regeneration suds, volatile organic compound recovery skid, tanks, piping, valves, generators, controllers, instrumentation, control electrical & instrumentation/warehouse buildings, and communication equipment_ Vehicles required for the construction will range from heavy duty pickup trucks to oversized vehicles for transporting equipment such as the tasks and compressors. The majority of the traffic will be sized to meet posted weight restrictions but a number of heavy and wide loads will be required to place major equipment (e.g., compressors, generators, etc_). An estimated 75 vehicles will be required to deliver construction and site equipment with an additional 150 vehicles for construction materials and 75 vehicles for concrete delivery (may be larger number depending on compressor foundation design). The construction is expected to take about six months (up to eight depending on weather delays) requiring a workforce of between 75 and 150 employees. Efforts will be made to reduce workforce vehicle trips by the use of carpooling, vans, and / or buses. Start-up operations will begin at the completion of the C2Pt' construction. Start up will involve bringing the systems on line and ensuring that all mechanical / electrical / control & instrumentation systems are operational and properly interface. About 30 employees will be required for start-up operations, but they will divide their time between the CPF and other field systems (e.g., well pad equipment). All equipment and structures will be removed from the temporary storage area prior to start-up operations_ Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 13 Following start up about 4 or 5 individuals will be required for normal operations. These personnel will perform regular system checks, routine maintenance, and coordinate condensate transport. The CPF will not be manned on a continuous basis. Associated personnel will rotate • throughout the project area performing multiple operations. Additional traffic associated with the CPF will include subcontractors providing wastewater servicing, supplying bottled water, and providing trash collection. The number of trips required for these services will be dependent on the capacity of Down Valley Septic but the site will be serviced at least twice a week. All vehicles working within Garfield County Right of Ways will be licensed and registered in the State of Colorado. Vehicles hauling equipment and materials will abide by Garfield County Road and Bridge Departments oversize / overweight regulations. All oversize / overweight vehicles will obtain the necessary permits and carry a letter showing proof that they can operate under a known bond holder on file with Garfield and Mesa County Road and Bridge Departments. The road to the Central Production Facility site is an existing road that meets the County's standards. Staff understands that Garfield County is in negotiations with Chevron USA Inc. to improve County Road 211 and portions of County Road 204. All of the roads past Hiner Gate are private roads owned and maintained by Chevron USA, Inc. The Applicant has indicated that Chevron USA, Inc. has contracted with Hyland Enterprises, Inc. to maintain the internal roads and to supplement the County's maintenance of County Road 211 through the winter months. Chevron USA Inc. also contracted with Ken Small Industries to supplement Hyland's services. Further, this application has been reviewed by the Garfield County Road and Bridge Department who have made the following comments (See Exhibit G): Garfield County Road & Bridge Department has no objections to this application with the following comments. As this in on private land with a permitted driveway access to the property no further requirements to meet the driveway access permit is necessary. All vehicles hauling equipment and materials for the building of the facility will abide by Garfield Counties oversize/overweight system. Vehicles requiring oversize/overweight permits operating under Chevrons bond will have a letter on file with Garfield County Road & Bridge Department prior to the issuing of any permits. As Chevron has already committed to road repair and road maintenance no further commitment is required from them for the roads they will be using. To this end, it is Staff's opinion that the roads to the facility are adequate and that no further improvements associated with this application are necessary. 3. Design of the proposed use is organized to minimize impact on and from adjacent uses of land through installation of screen fences orlandscape materials on the periphery of the lot and by location of intensively utilized areas, access points, lighting and signs in such a manner as to protect established neighborhood character. Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 14 Response The property is located in an extremely secluded portion of the property which is practically screened by adjacent steep topography and is located several miles from the nearest residence (see maps and photos on previous pages). It cannot be seen from CR 204 or CR 211. As noted earlier, the proposed use will have relatively limited impact to surrounding properties. It is situated in a remote private location on the property such that it is situated at the end of a dead-end county road which is used primarily for industrial traffic serving the existing industrial uses in the area with very limited general population traffic. Further, the site itself is situated in an industrial area already characterized by increasingly intense industrial activity from the gas industry as well as previous oil shale exploration activities. No screening is necessary as it is already screened by steep topography. In accordance with the Garfield County Industrial Standards, the "lighting of the storage area shall be pointed downward and inward to the property center and shaded to prevent direct reflection on adjacent property". The Applicant plans to paint all the equipment in accordance with the Bureau of Land Management (BLM) Gold Book standards in order to better blend in with the surrounding environment. The Applicant has made the following representation regarding the visibility of this site: The CPF is located in a remote region of Garfield County and will have 110 visual effects on adjacent landowners. Visual effects include the physical presence of the facility, building lighting, and operational traffic. Outdoor lighting will be positioned downward to ntitimi7e lighting the canyon walls. Additional mitigation measures identified by the Chevron ES}UA process will be implemented as determined by project management. Facilities will be painted in accordance with best management practices such as those recommended in the Bureau of Land Management (BLI'vf) Gold Book. To this end, it is Staff's opinion that the topography of the area sufficiently screens this facility from adjacent uses and public rights-of-way. Staff recommends a condition of approval that all equipment be painted in accordance with the BLM Gold Book standards. Section 5.03.07 !Industrial Operationsj Pursuant to Section 5.03.07 of the Zoning Resolution, a permit for Industrial Operations requires the submittal of an impact statement on the proposed use describing its location, scope, design and construction schedule, including an explanation of its operational characteristics. The impact statement is required to address the following: (A) Existing lawful use of water through depletion or pollution of surface run-off, stream flow or ground water. Response The facility site has been designed to insure protection of ground water and nearby streams through the development and implementation of a Storm Water Management Plan for the general Skinner Ridge area. Further, containment facilities are designed into the facility for any hazardous material stored or used during operations. Staff recommends a Condition of Approval that all construction and operation of the site occur in accordance with the Storm Water Management Plan as submitted. Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 15 The Applicant has also submitted a Certification to Discharge — Stormwater Discharges Associated with Construction for "Tom Creek in the Skinner Ridge Area". This permit is for a total disturbance of 18 acres and expires in 2012. A Spill Prevention, Control, and Countermeasure Plan (SPCC) has been submitted. This plan is general to the "Picaence Basin Field" for Chevron USA, Inc. and is dated 2004. Staff recommends a Condition of Approval that all construction and operation of the site occur in accordance with the SPCC. The Applicant has conducted a floodplain study for the "Picaence Basin Development — Central Production Facility". The study concludes that the Central Production Facility as proposed is not within the 100 -year floodplain. In addition, the study recommends that rip -rap slope protection be provided along the embankments adjacent to the floodplain limits to prevent erosion on the embankment slopes. Staff recommends that this be added as a Condition of Approval. All vault -and -haul wastewater storage containers and ISDS's will need to obtain an ISDS permit from the Garfield County Building Department prior to installation. (B) Impacts on adjacent land from the generation of vapor, dust, smoke, noise, glare or vibration, or other emanations. Response Compressors and other equipment at this facility will produce considerable volumes of noise and vibration but whose acceptable levels are regulated by the Colorado Revised Statutes. The Applicant has submitted a preliminary noise study (see Exhibit J) which predicts that the noise generated on the subject site is anticipated to comply with State Statute. However, staff recommends that as a condition of approval, the Applicant be required to submit a final noise study for the proposed facility which indicates that the facility will not cause noise levels which exceed the state statute. If the facility does undermine the State statutes regarding noise generation, the applicant will need to submit a plan for mitigating this noise. If this plan requires amendments to the submitted and approved Special Use Permit, however, it is possible that the Applicant will need to submit for a new Special Use Permit for this facility if the mitigation measures require changes to the approved plan. Generally, it is Staffs opinion that noise generated will have very little impact on adjacent properties since the compressor is located in a canyon -like area that will prevent any sound from traveling as well as being located well within the boundaries of the subject property far from adjacent properties. In any event, Chevron USA, Inc. shall adhere to the noise standards specified by the Colorado Revised Statutes and the Colorado Oil and Gas Conservation Commission rules. As power to the facility is to initially be provided by on-site diesel generators, the facility will produce diesel fumes. In addition, the facility will generate fumes from the flare. The Applicant has represented the following information regarding these installations: Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 16 1.7.4 Flare An important component of the CPF is the flare system, which is located about 200 feet from the facility (see Drawing 2033 -240 -20 -AP -0002-01, Rev. L). Flaring will be required during start-up operations and potentially into early production. Almost continuous flaring may be required for the first three months and intermittent flaring may be required for up to a year. However, flaring operations will be kept to a minimum because of lost revenue. Because no equipment is 100 -percent efficient, a small amount of hydrocarbons will need to be vented from the system on a continuing basis (no visible flame) The flare system also is designed to handle emergency situations when an equipment failure or other system upset results in an over -pressurization of the system In these situations larger quantities of gas will be vented and flared until corrective action can be taken. The 200 -ft safety radius is provided around the flare to protect personnel and equipment from radiant heat during one of these upset situations. The flare operation will conform to all appropriate federal and state regulatory requirements. There will be no visible flames or emissions from the flare system during normal operations. L9 Electrical Utilities / Regulatory Requirements Grand Valley Power is currently working to provide 5 MW of service to the facilities in Clear Creek valley, but initial operations will require the use of on-site power generation. Operational power will initially be provided the generators described in Section 1.75 These units will be used until a new Grand Valley Power line is routed to the site. Initial plans are to upgrade power to the Clear Creek basin to 5 MW with ultimate plans to upgrade the system to 240 MW service. Grand Valley Power is currently scheduling the 5 MW upgrade for some time 2008 or early 2009_ A 2,000 gallon diesel fuel tank will be used to supply fuel to the onsite generators. The tank installation will comply with the Oil Pollution Prevention regulations (40 CFR 112) of the Clean Water Act, National Fire Prevention Association guidance, and International Fire Code regulations. Information about this tank will be incorporated into the site SPCC plan (see SPCC attachment) during the next review cycle (October, 2007). The tank installations shall be in accordance with manufacturer and SPCC plan specifications, local fire codes, National Fire Protection Association requirements, and International Fire Code. A copy of the site SPCC plan will be available to the De Beque fire chief for review_ The Synthetic Minor permit application submitted to CDPHE on May 1, 2007, included emissions from these generators. Copies of the penult approval notifications will be provided to the County when the CDPHE review has been completed. Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 17 Staff understands that the Synthetic Minor permit for emissions from the generators was submitted to CDPHE on May 1, 2007. However, this permit has not been issued to date. The Applicant has requested that the Special Use Permit be issued so that construction can begin without CDPHE issuing this permit. The Applicant understands that this permit will need to be obtained from CDPHE prior to starting any equipment which is governed by this permit. Staff suggests that if the BOCC is amenable to this request that a limited time frame of six (6) months from the date of issuance of the Special Use Permit be added as a condition of approval to allow for Chevron USA Inc. to obtain and be approved for this permit from CDPHE. If Chevron USA, Inc. fails to either obtain a permit within the specified timeframe or if the permit is denied by CDPHE, the approved Special Use Permit from Garfield County become null and void. At this point, Chevron USA, Inc. will need to reapply for a new Special Use Permit from Garfield County for this facility. The Applicant is proposing to layer the surface of the site with 6 -inches of 1 -inch gravel to create an all weather surface. Staff recommends that as a condition of approval, the Applicant agree to treat this surface periodically with an approved dust suppressant to control fugitive dust. To this end, it is Staffs opinion that considering the topography of the area in conjunction with the distances between the proposed site and existing residences, that the impacts to adjacent property owners is limited to diffuse airborne contaminants associated with the combustion of diesel fuel, gasoline and natural gas (flare). (C) Impacts on wildlife and domestic animals through the creation of hazardous attractions, alteration of existing native vegetation, blockade of migration routes, use patterns or other disruptions. Response The proposed site where the Central Production Facility (CPF) and Temporary Storage Area are proposed to be located is situated on stream river basin land that is situated at the general confluence of Tom Creek and Clear Creek. The CPF site is proposed to be located on approximately 12 acres (plus 0.2 acres of disturbance for the relocation of the access road) of the total 54,000 acre parcel owned by Chevron USA Inc. The area where the CPF is to be located is surrounded by steep slopes and canyons forming the confluence of the two creeks. Dense mature riparian vegetation exists along the creeks as they pass through the area. The Applicant has submitted an "Integrated Vegetation and Noxious Weed Management Plan" for the Chevron Clear Creek 8 inch pipeline which was conducted in December2006. Steve Anthony of Garfield County Vegetation Management had the following comments regarding vegetation and weed management for this site (See Exhibit H): Thanks for the opportunity to comment on this project. My comments are as follows: Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 18 Integrated Vegetation and Weed Management • The submitted vegetation and weed management plan is for an area outside of the project site. Staff requests that the applicant submit a plan for the project area. This includes weed inventory, weed management, and revegetation. • Before leaving the site, all off road major construction equipment (graders, dozers, etc) working in areas of mapped noxious weeds should be power washed to remove seeds, soil, and vegetative matter. • The comments below are excerpted from a memo from Vegetation Management staff to Building and Planning regarding the Piceance Gathering Pipeline Project (July20, 2007): The noxious weed, tamarisk, is located in within 200 feet of the pipeline in many points along the pipeline. The applicant shall cut and treat the tamarisk prior to construction activities. Please forward a copy of the application records to the below address. Garfield County Vegetation Management POB 426 Rifle CO 81650 To date, this office has not received records indicating that the tamarisk work was done. Reclamation The applicant has quantified the surface area to be disturbed and subsequently reseeded. Temporary office area = 1.4 acres Production facility (including road) = 3.5 acres The recommended security for the office area is $3500 (1.4 acres x $2500/acre). The recommended security for the production facility acre is $14,000 (3.5 acres x $4000/acre). Since the production facility may be in place for 20 years or longer the per acre rate is higher. These securities should be done separately since the time frame for security release is in the short term for the temporary office area. The applicant shall provide the Vegetation Management Department with the original tags from each seed bag. The seed mix in the Plan shall match the seed mix used in the field. Do not use a seed mix containing yellow sweet clover (Melilotus offcinalis) or annual yellow Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 19 sweetclover (M. indicus). The amount of seed specified to be planted in the Plan shall match the quantity of seed used in the field. The security shall be held by Garfield County until vegetation has been successfully reestablished according to the Reclamation Standards in the Garfield County Weed Management Plan. It is the responsibility of the applicant to contact the County, upon successful revegetation establishment, to request an inspection for security release consideration. Erosion control Any straw or hay bales used in erosion control shall be certified weed free. In addition, the Applicant has also submitted a biological inventory which is in relation to the 6.25 mile long 8 -inch pipeline running parallel to County Road 211. In addition, the Applicant has submitted a "Clear Creek Biological Survey". This survey does include the subject property. It appears that items of significant biological interest near the site are an active American Kestral nest and a probable Accipiter nest. Further, the Applicant has made the following representations related to impacts on wildlife and domestic animals through the creation of hazardous attractions, alteration of existing native vegetation, blockade of migration routes, use patterns or other disruptions. Available topsoil will be stockpiled and stabilized for the eventual site reclamation in accordance with specific SWMP requirements. Seed mixes used for site stabilization and revegetation will be in compliance with Garfield County Reclamation Standards. The stockpile will be monitored and controlled for noxious weeds throughout the operation of the CPF. General information concerning the area reclamation plan for the area is provided iii Section 8.4. 8.4 Reclamation and Revegetation Plan Operations at the CPF are expected to continue throughout the duration of the project. When the gas field is depleted the CPF equipment, gravel pad, and foundations will be removed. The area then will be graded to the original contours, stockpiled topsoil will be replaced, and the area will be planted with native vegetation. Reclamation and revegetation activities will be in accordance with requirements outlined in Garfield County Zoning Resolution 5.02.21 (11). General details of the re -vegetation activities are provided in the IVNWM Plan and Storm Water Management Plan (SWMP) and will be included in the final revegetation plan. Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 20 A recently completed study has identified portions of CR 204 to be a wildlife corridor for mole deer. Vehicle traffic to and from the site will affect these populations, but mitigation treasures are currently being studied and evaluated. Mitigation recommendations will be provided to project management, who will evaluate the alternatives and implement appropriate measures. A bond for the site reclamation after the cessation of activities will be provided as an addendum to this application upon detenuutation of the total site disturbance_ In accordance with the comments received from Steve Anthony of Garfield County Vegetation Management, Staff recommends that a condition of approval be added to the Special Use Permit requiring that the Applicant submit a new Integrated Vegetation and Weed Management plan which incorporates that area which is to be disturbed by the proposed Central Production Facility. This plan shall be reviewed and deemed adequate by the Garfield County Vegetation Management Department prior to issuance of the Special Use Permit. In addition, in order to maintain the validity of the plan, the site shall not be graded or otherwise disturbed prior review and acceptance of the plan by the Vegetation Management Department. Staff requests this document no later than June 1, 2008. Further, Staff recommends that a revegetation and rehabilitation security be put in place for 1) the area to be disturbed for the placement of the temporary office and staging area (1.6 acres) and general construction disturbance (5.6 acres) which shall be in place for up to one year from the date of issuance of the Special Use Permit ($21,750); and 2) the area to be disturbed for the Central Production Facility (3.3 acres) which shall be in place for at least a 20 year timeframe ($13,200). Further, this revegetation security shall be subject to the comments as submitted by the Garfield County Vegetation Management Department (Exhibit H) and clarification on acreages in Exhibit M. This Application was also referred to and reviewed by Dean Riggs of the Colorado Division of Wildlife (CDOW) who provided extensive comments. Below are excerpts of the comments which are particularly relevant to this application (See Exhibit I): The proposed CPP and the assoetated temporarystorage area locations lie in an area where native vegetation provides'foragmg,.nesting, Thermal and escape habitatsfor_riumerousspeciesofwtidltfe. The removal and disturbiuiee of native vegetation fbr tine constntctiion of the CPP, temporary.storage area and associated roads Will negatively impact the native wildlife species associated with this project area. Upon rehabilitation of this location and roads, negative impacts to native wildlife can be offset by planting a suitable mixture of native grass/forb/ahrub seed. Seed plantings on disturbed soils will have greater germination and survival rates when the soil surface has been prepared to hold moisture and runoff precipitation. Soils will exhibit increased moisture retention capabilities when the soil surface has been loosened with a "ripping toot" that creates a rough and uneven soil surface and seed bed. This treatment will increase seed germination, and, will reduce the amount of surface runoff and soil erosion. Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 21 Roads Bears The Division of Wildlife notes and supports that minimal new roads are proposed with this new development. Minimizing the number of roads will benefit wildlife, as building of multiple roads in an area increases fragmentation of habitat, inhibits the natural movement of wildlife across the landscape, increases mad -kill mortality, and broadens the opportunity for poaching. Minimizing roads and road use will also decrease fugitive dust, which can become severe during dry summer months. The Division of Wildlife recommends that Chevron strictly enforce speed limits on new and existing roads, and employ dust control measures as needed. The proposed CFF and the associated temporary storage area locations lie within year-round black bear habitat fncreased human use of the proposed development area may increase the potential for conflicts with black bears during the summer and early fall, particularly during years of drought. The potential for human/bear conflicts within this project area would be greatly reduced by placing and utilizing "bear proof" trash containers at worksite/camping locations. These trash containers should be emptied weekly at a minimum. The Division of Wildlife has information on the design and purchase of"bear proof' trash containers, and, will provide this information to anyone who is interested in preventing conflicts with bears. To this end, Staff makes the following recommendations based on the comments submitted by the Colorado Division of Wildlife: 1. Staff recommends that a "ripping" process for the soil be incorporated into the revegetation and rehabilitation plan. 2. Staff recommends that a condition of approval be added requiring that all solid waste be handled within a wild -life proof refuse container which is emptied at least once per week. 3. Staff recommends that a condition of approval be added requiring that the gravel surface within the CPF be periodically treated with an approved dust suppressant when needed. (D) Affirmatively show the impacts of truck and automobile traffic to and from such uses and their impacts to areas in the County. Response The Applicant has represented the following regarding traffic to and from the site: Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 22 Initial traffic associated with the CPF construction will include the delivery and transfer of earthmoving equipment (e.g., graders, back -hoes, loaders) and construction materials (e.g., concrete, gravel, storm -water controls) plus the associated workers. Additional deliveries t installations will be required for the compressors, separators, vapor recovery unit, glycol dehydration & regeneration skids, volatile organic compound recovery skid, tanks, piping, calves, generators; controllers, instrumentation control / electrical & iastnunentation / warehouse buildings, and communication equipment. Vehicles required for the construction will range from heavy duty pickup trucks to oversized vehicles for transporting equipment such as the tanks and compressors. The majority of the traffic will be sized to meet posted weight restrictions but a number of heavy and wide loads will be required to place major equipment (e.g., compressors, generators, etc.). An estimated 75 vehicles will be required to deliver construction and site equipment with an additional 150 vehicles for construction materials and 75 vehicles for concrete delivery (may be larger number depending on compressor foundation design). The constriction is expected to take about six months (up to eight depending on weather delays) requiring a workforce of between 75 and 150 employees. Efforts will be made to reduce workforce vehicle trips by the use of carpooling, vans, and / or buses. Start-up operations will begin at the completion of the CPF construction. Startup will involve bringing the systems on line and ensuring that all mechanical / electrical / control & instrumentation systems are operational and properly interface. About 30 employees will be required for start-up operations, but they will divide their time between the CPF and other field systems (e. g., well pad equipment). All equipment and structures will be removed from the temporary storage area prior to start-up operations. Following start up about 4 or 5 individuals will be required for normal operations. These personnel will perform regular system checks, routine maintenance, and coordinate condensate transport. The CPF will not be maimed on a continuous basis. Associated personnel will rotate throughout the project area performing multiple operations. Additional traffic associated with the CPF will include subcontractors providing wastewater servicing, supplying bottled water, and providing trash collection. The number of trips required for these services will be dependent on the capacity of Down Valley Septic but the site will be serviced at least twice a week. All vehicles working within Garfield County Right of Ways will be licensed and registered in the State of Colorado. Vehicles hauling equipment and materials will abide by Garfield County Road and Bridge Departments oversize / overweight regulations. All oversize / overweight vehicles will obtain the necessary permits and carry a letter showing proof that they can operate under a known bond holder on file with Garfield and Mesa County Road and Bridge Departments. The road to the Central Production Facility site is an existing road that meets the County's standards. Staff understands that Garfield County is in negotiations with Chevron USA Inc. to improve County Road 211 and portions of County Road 204. All of the roads past Hiner Gate are private roads owned and maintained by Chevron USA, Inc. The Applicant has indicated that Chevron USA, Inc. has contracted with Hyland Enterprises, Inc. to maintain the internal roads and to supplement the County's maintenance of County Road 211 Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 23 through the winter months. Chevron USA Inc. also contracted with Ken Small Industries to supplement Hyland's services Further, this application has been reviewed by the Garfield County Road and Bridge Department who have made the following comments (See Exhibit G): Garfield County Road & Bridge Department has no objections to this application with the following comments. As this in on private land with a permitted driveway access to the property no further requirements to meet the driveway access permit is necessary. All vehicles hauling equipment and materials for the building of the facility will abide by Garfield Counties oversize/overweight system. Vehicles requiring oversize/overweight permits operating under Chevrons bond will have a letter on file with Garfield County Road & Bridge Department prior to the issuing of any permits. As Chevron has already committed to road repair and road maintenance no further commitment is required from them for the roads they will be using. To this end, it is Staff's opinion that the roads to the facility are adequate and that no further improvements associated with this application are necessary. (E) That sufficient distances shall separate such use from abutting property which might otherwise be damaged by operations of the proposed use(s). Response The proposed site where the Central Production Facility (CPF) and Temporary Storage Area are proposed to be located is situated on stream river basin land that is situated at the general confluence of Tom Creek and Clear Creek. The CPF site is proposed to be located on approximately 4.8 acres (12 acres of disturbance) of the total 54,000 acre parcel owned by Chevron USA Inc. The area where the CPF is to be located is surrounded by steep slopes and canyons forming the general confluence of the two creeks. The nearest residence to the proposed site is approximately 6 miles away. Dense mature riparian vegetation exists along the creeks as they pass through the area. There is an old cabin on the property which is to be relocated to the Town of DeBeque. The CPF and temporary storage area are to be located on 4.8 acres of an approximately 54,000 acre property which is surrounded by properties also owned and utilized by the energy industry such as EnCana, Shell, Oxy, Berry Petroleum Company, Kerogen Oil Company, Puckett Land Company, ExxonMobil, etc. Other neighboring land owners include the Colorado Nature Ranch, the BLM, EV Ranch, and the State of Colorado. Neighboring uses on those lands include rangeland grazing, farming, and resource extraction (natural gas drilling). To this end, it is Staffs opinion that considering the topography of the area in conjunction with the distances between the proposed site and existing residences, that the impacts to adjacent property owners is limited to diffuse airborne contaminants associated with the combustion of diesel fuel, gasoline and natural gas (flare). Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 24 (F) Mitigation measures proposed for all of the foregoing impacts identified and for the standards identified in Section 5.03.08 of this Resolution Special Use Permits may be granted for those uses with provisions that provide adequate mitigation for the following: Visual Mitigation: Staff recommends a condition of approval that all equipment be painted in accordance with the BLM Gold Book standards. Dust: Staff recommends that as a condition of approval, the Applicant agree to treat this surface periodically with an approved dust suppressant to control fugitive dust. Air Pollution: Staff understands that the Synthetic Minor permit for emissions from the generators was submitted to CDPHE on May 1, 2007. However, this permit has not been issued to date. The Applicant has requested that the Special Use Permit be issued so that construction can begin without CDPHE issuing this permit. The Applicant understands that this permit will need to be obtained from CDPHE prior to starting any equipment which is governed by this permit. Staff suggests that if the BOCC is amenable to this request that a limited time frame of six (6) months from the date of issuance of the Special Use Permit be added as a condition of approval to allow for Chevron USA Inc. to obtain and be approved for this permit from CDPHE. If Chevron USA, Inc. fails to either obtain a permit within the specified timeframe or if the permit is denied by CDPHE, the approved Special Use Permit from Garfield County become null and void. At this point, Chevron USA, Inc. will need to reapply for a new Special Use Permit from Garfield County for this facility. Noise: Staff recommends that as a condition of approval, the Applicant be required to submit a final noise study for the proposed facility which indicates that the facility will not cause noise levels which exceed the state statute. The Applicant has submitted a preliminary noise study which indicates that noise at the property lines is expected to be in compliance with the State Statute. However, if the facility does undermine the State statutes regarding noise generation, the applicant will need to submit a plan for mitigating this noise. If this plan requires amendments to the submitted and approved Special Use Permit, however, it is possible that the Applicant will need to submit for a new Special Use Permit for this facility if the mitigation measures require changes to the approved plan. Groundwater Protection, Riparian Area Protection and Stream Protection: Staff recommends a Condition of Approval that all construction and operation of the site occur in accordance with the Storm Water Management Plan (SWMP) as submitted. In addition, as represented in the application, Chevron USA Inc. shall conduct bi-weekly SWMP to ensure site stabilization measures are adequate and/or identify areas that need repair or improvement. Soil Contamination, Groundwater Contamination, Stream Protection, and Riparian Area Protection: A Spill Prevention, Control, and Countermeasure (SPCC) plan has been submitted. This plan is general to the "Picaence Basin Field" for Chevron USA, Inc. and is dated 2004. Staff recommends a Condition of Approval that all construction and operation of the site occur in accordance with the most up-to-date SPCC for this site. Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 25 Stream Protection and Riparian Protection: The Applicant has conducted a floodplain study for the "Picaence Basin Development — Central Production Facility". The study concludes that the Central Production Facility as proposed is not within the 100 -year floodplain. In addition, the study recommends that rip -rap slope protection be provided along the embankments adjacent to the floodplain limits to prevent erosion on the embankment slopes. Staff recommends that this be added as a Condition of Approval. Soil Contamination, Groundwater Protection, and Stream Protection: All vault -and -haul wastewater storage containers and ISDS's shall obtain an ISDS permit from the Garfield County Building Department prior to installation. Water Rights: Staff finds that the proposed water supply and wastewater disposal methods are adequate as long as a condition is placed on the Special Use Permit requiring that the Applicant submit an approved and adequate well permit to serve the permanent control building prior to issuance of the Special Use Permit. In order to maintain consistency with the proposed ISDS, this well permit should be adequate in terms of rights and quantity to serve a workforce of up to ten (10) employees. Noxious Weeds and Vegetation Management: In accordance with the comments received from Steve Anthony of the Garfield County Vegetation Department, Staff recommends that a condition of approval be added to the Special Use Permit requiring that the Applicant submit a new Integrated Vegetation and Weed Management plan which incorporates that area which is to be disturbed by the proposed Central Production Facility. This plan shall be reviewed and deemed adequate by the Garfield County Vegetation Management Department prior to issuance of the Special Use Permit. In addition, in order to maintain the validity of the plan, the site shall not be graded or otherwise disturbed prior review and acceptance of the plan by the Vegetation Management Department. Staff requests this document no later than June 1, 2008. Noxious Weeds and Vegetation Management: Staff recommends a condition of approval requiring that before leaving the site, all off-road major construction equipment (graders, dozers, etc) working in areas of mapped noxious weeds should be power washed to remove seeds, soil, and vegetative matter. Revegetation and Reclamation Security: The applicant has quantified the surface area to be disturbed and subsequently reseeded. Temporary office area and Construction Site = 8.7 acres Production facility = 3.3acres The recommended security for the office area and const. area is $21,750 (8.7 acres x $2500/acre). Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 26 The recommended security for the production facility acre is $13,200 (3.3 acres x $4000/acre). Since the production facility may be in place for 20 years or longer the per acre rate is higher. These securities should be done separately since the time frame for security release is in the short term for the temporary office area. The applicant shall provide the Vegetation Management Department with the original tags from each seed bag. The seed mix in the Plan shall match the seed mix used in the field. Do not use a seed mix containing yellow sweet clover (Melilotus offcinalis) or annual yellow sweetclover (M. indicus). The amount of seed specified to be planted in the Plan shall match the quantity of seed used in the field. The security shall be held by Garfield County until vegetation has been successfully reestablished according to the Reclamation Standards in the Garfield County Weed Management Plan. It is the responsibility of the applicant to contact the County, upon successful revegetation establishment, to request an inspection for security release consideration. Erosion Control: Any straw or hay bales used in erosion control shall be certified weed free. Rehabilitation: Staff recommends that a "ripping" process for the soil be incorporated into the revegetation and rehabilitation plan. Wildlife Protection: Staff recommends that a condition of approval be added requiring that all solid waste be handled within a wild -life proof refuse container which is emptied at least once per week. (A) A plan forsite rehabilitation must be approved by the County Commissioners before a permit for conditional or special use will be issued; Response In accordance with the comments received from Steve Anthony of Garfield County Vegetation Management, Staff recommends that a condition of approval be added to the Special Use Permit requiring that the Applicant submit a new Integrated Vegetation and Weed Management plan which incorporates that area which is to be disturbed by the proposed Central Production Facility. In accordance with this Section of the Zoning Resolution of 1978, this plan shall be reviewed and deemed adequate by the Garfield County Vegetation Management Department prior to issuance of the Special Use Permit if this action is deemed appropriate by the BOCC. Further, Staff recommends that a revegetation and rehabilitation security be put in place for 1) the area to be disturbed for the placement of the temporary office and staging area (1.6 acres) and general construction disturbance (5.6 acres) which shall be in place for up to one year from the date Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 27 of issuance of the Special Use Permit ($21,750); and 2) the area to be disturbed for the Central Production Facility (3.3 acres) which shall be in place for at least a 20 year timeframe ($13,200). Further, this revegetation security shall be subject to the comments as submitted by the Garfield County Vegetation Management Department (Exhibit H) and clarification on acreages in Exhibit M. (8) The County Commissioners may require security before a permit for special or conditional use is issued, if required. The applicant shall furnish evidence of a bank commitment of credit, bond, certified check or other security deemed acceptable by the County Commissioners in the amount calculated by the County Commissioners to secure the execution of the site rehabilitation plan in workmanlike manner and in accordance with the specifications and construction schedule established or approved by the County Commissioners. Such commitments, bonds or check shall be payable to and held by the County Commissioners; Response In the past, the Board has required, as a condition of approval that "A sufficient monetary security, determined by the Board of County Commissioners, to ensure rehabilitation of the site once operation has ceased shall be provided by the Applicant." Staff is recommending the following guidelines for revegetation and rehabilitation of the subject site: Revegetation and Reclamation Security: The applicant has quantified the surface area to be disturbed and subsequently reseeded. Temporary office area and Construction Site Production facility = 8.7 acres = 3.3 acres The recommended security for the office area and const. area is $21,750 (8.7 acres x $2500/acre). The recommended security for the production facility acre is $13,200 (3.3 acres x $4000/acre). Since the production facility may be in place for 20 years or longer the per acre rate is higher. These securities should be done separately since the time frame for security release is in the short term for the temporary office area. The applicant shall provide the Vegetation Management Department with the original tags from each seed bag. The seed mix in the Plan shall match the seed mix used in the field. Do not use a seed mix containing yellow sweet clover (Melilotus offcinalis) or annual yellow sweetclover (M. indicus). The amount of seed specified to be planted in the Plan shall match the quantity of seed used in the field. Following further clarification from the Applicant (See Exhibit M), the total disturbance area is actually 12 acres (8.7 to be reclaimed following construction and 3.3 acres to be disturbed over the Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 28 life of the facility). The security shall be held by Garfield County until vegetation has been successfully reestablished according to the Reclamation Standards in the Garfield County Weed Management Plan. It is the responsibility of the applicant to contact the County, upon successful revegetation establishment, to request an inspection for security release consideration. Section 5.03.08 !Industrial Performance Standardsl Pursuant to section 5.03.08 of the Zoning Resolution, all Industrial Operations in the County shall comply with applicable County, State, and Federal regulations regulating water, air and noise pollution and shall not be conducted in a manner constituting a public nuisance or hazard. Operations shall be conducted in such a manner as to minimize heat, dust, smoke, vibration, glare and odor and all other undesirable environmental effects beyond the boundaries of the property in which such uses are located, in accord with the following standards: (1) Volume of sound generated shall comply with the standards set forth in the Colorado Revised Statutes at the time any new application is made. (2) Vibration generated: every use shall be so operated that the ground vibration inherently and recurrently generated is not perceptible, without instruments, at any point of any boundary line of the property on which the use is located. (3) Emissions of smoke and particulate matter: every use shall be operated so as to comply with all Federal, State and County air quality laws, regulations and standards. (4) Emission of heat, glare, radiation and fumes: every use shall be so operated that it does not emit heat, glare, radiation or fumes which substantially interfere with the existing use of adjoining property or which constitutes a public nuisance or hazard. Flaring of gases, aircraft warning signals, reflective painting of storage tanks, or other such operations which may be required by law as safety or air pollution control measures shall be exempted from this provision. (5) Storage area, salvage yard, sanitary landfill and mineral waste disposal areas: (A) Storage of flammable or explosive solids or gases shall be in accordance with accepted standards and laws and shall comply with the national, state and local fire codes and written recommendations/comments from the appropriate local protection district regarding compliance with the appropriate codes; (B) At the discretion of the County Commissioners, all outdoor storage facilities may be required to be enclosed by fence, landscaping or wall adequate to conceal such facilities from adjacent property; (C) No materials or wastes shall be deposited upon a property in such form or manner that they may be transferred off the property by any reasonably foreseeable natural causes or forces; (D) Storage of Heavy Equipment will only be allowed subject to (A) and (C) above and the following standards: 1. The minimum lot size is five (5) acres and is not a platted subdivision. 2. The equipment storage area is not placed any closer than 300 ft. from any existing residential dwelling. Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 29 3. All equipment storage will be enclosed in an area with screening at least eight (8) feet in height and obscured from view at the same elevation or lower. Screening may include berming, landscaping, sight obscuring fencing or a combination of any of these methods. 4. Any repair and maintenance activity requiring the use of equipment that will generate noise, odors or glare beyond the property boundaries will be conducted within a building or outdoors during the hours of 8 a.m. to 6 p.m., Mon. Fri. 5. Loading and unloading of vehicles shall be conducted on private property and may not be conducted on any public right-of-way. (E) Any storage area for uses not associated with natural resources shall not exceed ten (10) acres in size. (F) Any lighting of storage area shall be pointed downward and inward to the property center and shaded to prevent direct reflection on adjacent property. (6) Water pollution: in a case in which potential hazards exist, it shall be necessary to install safeguards designed to comply with the Regulations of the Environmental Protection Agency before operation of the facilities may begin. All percolation tests or ground water resource tests as may be required by local or State Health Officers must be met before operation of the facilities may begin. Staff Response Should the Board approve the request for the Compressor Station, Staff suggests the industrial performance standards be considered conditions of approval as they are specifically intended to ensure that any industrial use such as the proposed Central Production Facility function in accordance with the proper best management practices and within the parameters of the State Statutes. Section 9.03.05!Periodic Review of SUPT Pursuant to section 9.03.05 of the Zoning Resolution: Any Special Use Permits maybe made subject to a periodic review not less than every six (6) months if required by the County Commissioners. The purpose of such review shall be to determine compliance or noncompliance with any performance requirements associated with the granting of the Special Use Permit. The County Commissioners shall indicate that such a review is required and shall establish the time periods at the time of issuance of a Special Use Permit. Such review shall be conducted in such manner and by such persons as the County Commissioners deem appropriate to make the review effective and meaningful. Upon the completion of each review, the Commissioners may determine that the permit operations are in compliance and continue the permit, or determine the operations are not in compliance and either suspend the permit or require the permittee to bring the operation into compliance by a certain specified date. Such periodic review shall be limited to those performance requirements and conditions imposed at the time of the original issuance of the Special Use Permit. Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 30 VIII. RECOMMENDED FINDINGS 1. Proper posting and public notice was provided as required for the meeting before the Board of County Commissioners. 2. The meeting before the Board of County Commissioners was extensive and complete, that all pertinent facts, matters and issues were submitted and that all interested parties were heard at that meeting. 3. The above stated and other reasons, the proposed special use permit has been determined to be in the best interest of the health, safety, morals, convenience, order, prosperity and welfare of the citizens of Garfield County. 4. The application has met the requirements of Special Use (Sections 5:03, 5:03:07, 5:03.08 and 9:03) the Garfield County Zoning Resolution of 1978, as amended. IX. STAFF RECOMMENDATION Due to 1) the limited nature of potential impacts to surrounding properties, 2) the remote location of the property such that it is situated at the end of a dead-end county road which is used primarily for industrial traffic serving the existing industrial uses in the area with very limited general population traffic, 3) and the fact that the site itself will be situated in an industrial area already characterized by industrial activity from the oil shale and natural gas exploration activities, Staff recommends the Board approve the request for a Special Use Permit for Processing and Material Handling of Natural Resources for a Central Production Facility for Chevron USA, Inc. with the following conditions: 1. That all representations of the Applicant, either within the application or stated at the hearing before the Board of County Commissioners, shall be considered conditions of approval unless explicitly altered by the Board. 2. The Applicant shall comply with all standards as set forth in §5.03.08 "Industrial Performance Standards" of the Garfield County Zoning Resolution of 1978 as amended and included here as follows: a. Volume of sound generated shall comply with the standards set forth in the Colorado Revised Statutes. b. Every use shall be so operated that the ground vibration inherently and recurrently generated is not perceptible, without instruments, at any point of any boundary line of the property on which the use is located. c. Emissions of smoke and particulate matter: every use shall be operated so as to comply with all Federal, State and County air quality laws, regulations and standards. d. Every use shall be so operated that it does not emit heat, glare, radiation or fumes which substantially interfere with the existing use of adjoining property or which Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 31 constitutes a public nuisance or hazard. Flaring of gases, aircraft warning signals, reflective painting of storage tanks, or other such operations which may be required by law as safety or air pollution control measures shall be exempted from this provision. e. Storage of flammable or explosive solids or gases shall be in accordance with accepted standards and laws and shall comply with the national, state and local fire codes and written recommendations/comments from the appropriate local protection district regarding compliance with the appropriate codes. f. No materials or wastes shall be deposited upon a property in such form or manner that they may be transferred off the property by any reasonably foreseeable natural causes or forces. g• Any repair and maintenance activity requiring the use of equipment that will generate noise, odors or glare beyond the property boundaries will be conducted within a building or outdoors during the hours of 8 a.m. to 6 p.m., Mon. -Fri. h. Loading and unloading of vehicles shall be conducted on private property and may not be conducted on any public right-of-way. i. Any storage area for uses not associated with natural resources shall not exceed ten (10) acres in size. j. Any lighting of storage area shall be pointed downward and inward to the property center and shaded to prevent direct reflection on adjacent property. 3. That the operation of the facility be done in accordance with all applicable federal, state, and local regulations governing the operation of this type of facility. 4. That the Applicant shall comply with the fire protection provisions included in the rules and regulations of the Colorado Oil and Gas Conservation Commission (COGCC) and the International Fire Code as the Code pertains to the operation of this facility. 5. The total area of disturbance shall not exceed 12 acres in size. The Central Production Facility and Flare Safety Zone at completion shall have a footprint no larger than 4.8 acres. 6. That all proper building permits and ISDS permits are obtained for the structures and wastewater disposal systems, including vault -and -haul systems, associated with the operation of the Central Production Facility. 7. Sewage systems shall to be installed and maintained in accordance with the Garfield County ISDS regulations with all pipes and connections water tight and lids kept securely in place at all times except during normal cleaning operations. 8. The facility shall have a minimum total capacity of 6,050 gallons of potable water storage which shall be refilled a minimum of every three days in connection with 1.4 acre temporary Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 32 storage (staging) area. These tanks shall be removed at the point that the flare is operational and the lay down yard (Staging Area) is decommissioned. The permanent Control Building shall be connected to a permanent water supply system. 9. The facility shall have a minimum total capacity of 3,025 gallons of potable water storage capacity which shall be refilled a minimum of every three days from either well water produced on the subject property as demonstrated within this application or from water purchased from a water supplier in connection with the permanent Control Building. 10. The facility shall have a minimum total capacity of 8,060 gallons of sewage and wastewater storage capacity which shall be emptied a minimum of every three days. These tanks shall be removed at the point that the flare is operational and the lay down yard (Staging Area) is decommissioned. The permanent Control Building shall be connected to the ISDS and shall not be served by sewage vault tanks. 11. Wildlife -proof refuse and/or recycling containers must be provided for trash. At least one thirty (30) cubic yard container shall be provided for the facility. Said container(s) must be durable, washable, non-absorbent metal or plastic with tight -fitting lids. Refuse shall be disposed of not less than once weekly. 12. All equipment and structures must be painted in accordance with the BLM Gold Book standards. 13. The Applicant shall treat the gravel surfaces within the facility periodically as needed with an approved dust suppressant to control fugitive dust. 14. The Applicant shall have six (6) months from the date of issuance of the Special Use Permit for Chevron USA Inc. to obtain and be approved for the Synthetic Minor permit from CDPHE. If Chevron USA, Inc. fails to obtain a permit within the specified timeframe, the permit is denied by CDPHE, or the conditions of the permit modify the site plan as approved under this Special Use Permit, the approved Special Use Permit from Garfield County shall become null and void. At this point, Chevron USA, Inc. will need to reapply for a new Special Use Permit from Garfield County for this facility. 15. The Applicant is required to submit a final noise study for the proposed facility which indicates that the facility will not cause noise levels which exceed the state statute. If the facility does not conform to the State statutes regarding noise generation, the applicant will need to submit a plan for mitigating this noise. If this mitigation plan requires amendments to the submitted and approved Special Use Permit or any representations made the Applicant however, the Applicant shall submit for a new Special Use Permit from Garfield County for this Central Production Facility. 16. All construction and operation of the site shall occur in accordance with the Storm Water Management Plan (SWMP) as submitted. In addition, as represented in the application, Chevron USA Inc. shall conduct bi-weekly SWMP inspections to ensure site stabilization measures are adequate and/or identify areas that need repair or improvement. Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 33 17. All construction and operation of the site shall occur in accordance with the most up-to-date SPCC plan for this site. 18. The embankments adjacent to the floodplain limits shall have rip -rap slope protection in order to prevent erosion on the embankment slopes. 19. The Applicant shall submit an approved and adequate well permit to serve the permanent control building prior to issuance of the Special Use Permit. In order to maintain consistency with the proposed ISDS, this well permit shall be adequate in terms of rights and quantity to serve a workforce of up to ten (10) employees. 20. The Applicant shall submit a new Integrated Vegetation and Weed Management plan which incorporates that area which is to be disturbed by the proposed Central Production Facility. This plan shall be reviewed and deemed adequate by the Garfield County Vegetation Management Department prior to issuance of the Special Use Permit. The Applicant shall submit this plan by June 1, 2008, shall NOT grade or disturb any portion of the subject site prior to the Integrated Vegetation and Weed Management plan's review and acceptance by the Garfield County Vegetation Management Department and shall incorporate a soil "ripping" process into this revegetation and rehabilitation plan. 21. Before leaving the approved site, all off-road major construction equipment (graders, dozers, etc) working in areas of mapped noxious weeds shall be power washed to remove seeds, soil, and vegetative matter. 22. The Applicant shall provide a security for revegetation in the amount $21,750 to cover the estimated 8.7 acres to be disturbed prior to issuance of the Special Use Permit (using a rate of $2500 per acre for a facility that may be in place for up to one year). The security shall be held by Garfield County until vegetation has been successfully reestablished according to the Reclamation Standards in the Garfield County Vegetation Management Plan. It is the responsibility of the applicant to contact the County, upon successful revegetation establishment, to request an inspection for security release consideration. The applicant shall provide the Vegetation Management Department with the original tags from each seed bag. The seed mix in the Plan shall match the seed mix used in the field. Do not use a seed mix containing yellow sweet clover (Melilotus offcinalis) or annual yellow sweetclover (M. indicus). The amount of seed specified to be planted in the Plan shall match the quantity of seed used in the field. 23. The Applicant shall provide a security for revegetation in the amount $13,200 to cover the estimated 3.3 acres to be disturbed prior to issuance of the Special Use Permit (using a rate of $4000 per acre for a facility that may be in place for up to twenty (20) years). The security shall be held by Garfield County until vegetation has been successfully reestablished according to the Reclamation Standards in the Garfield County Vegetation Management Plan. It is the responsibility of the applicant to contact the County, upon successful revegetation establishment, to request an inspection for security release consideration. Chevron USA Inc. — Central Production Facility BOCC — 03/10/2008 Page 34 The applicant shall provide the Vegetation Management Department with the original tags from each seed bag. The seed mix in the Plan shall match the seed mix used in the field. Do not use a seed mix containing yellow sweet clover (Melilotus offcinalis) or annual yellow sweetclover (M. indicus). The amount of seed specified to be planted in the Plan shall match the quantity of seed used in the field. 24. Any straw or hay bales used in erosion control shall be certified weed free. X. RECOMMENDED MOTION "I move to approve a Special Use Permit for a Central Production Facility and Staging Area for Chevron USA, Inc with the conditions provided by Staff." GARFIELD COUNTY Building & Planning Department Review Agency Form Date Sent: February 27, 2008 Comments Due: February 27, 2008 Name of application: Chevron Storage Handling Facility Sent to: Garfield County requests your comment in review of this project. Please notify the Planning Department in the event you are unable to respond by the deadline. This form may be used for your response, or you may attach your own additional sheets as necessary. Written comments may be mailed, e-mailed, or faxed to: Garfield County Building & Planning Staffs contact: David Pesnichak 109 8th Street, Suite 301 Glenwood Springs, CO 81601 Fax: 970-384-3470 Phone: 970-945-8212 General Comments: Garfield County Road & Bridge Department has no objections to this application with the following comments. As this in on private land with a permitted driveway access to the property no further requirements to meet the driveway access permit is necessary. All vehicles hauling equipment and materials for the building of the facility will abide by Garfield Counties oversize/overweight system. Vehicles requiring oversize/overweight permits operating under Chevrons bond will have a letter on file with Garfield County Road & Bridge Department prior to the issuing of any permits. As Chevron has already committed to road repair and road maintenance no further commitment is required from them for the roads they will be using. Name of review agency: Garfield County Road and Bridge Dept By: Jake B. Mall Date _February 27, 2008 Revised 3/30/00 EXHIBIT MEMORANDUM To: David Pesnichak From: Steve Anthony Re: Comments on the Chevron Piceance Production Facility and Special Use Permit Date: February 27, 2008 Thanks for the opportunity to comment on this project. My comments are as follows: Integrated Vegetation and Weed Management • The submitted vegetation and weed management plan is for an area outside of the project site. Staff requests that the applicant submit a plan for the project area. This includes weed inventory, weed management, and revegetation. • Before leaving the site, all off road major construction equipment (graders, dozers, etc) working in areas of mapped noxious weeds should be power washed to remove seeds, soil, and vegetative matter. • The comments below are excerpted from a memo from Vegetation Management staff to Building and Planning regarding the Piceance Gathering Pipeline Project (July 20, 2007): The noxious weed, tamarisk, is located in within 200 feet of the pipeline in many points along the pipeline. The applicant shall cut and treat the tamarisk prior to construction activities. Please forward a copy of the application records to the below address. Garfield County Vegetation Management POB 426 Rifle CO 81650 To date, this office has not received records indicating that the tamarisk work was done. Reclamation • The applicant has quantified the surface area to be disturbed and subsequently reseeded. Temporary office area = 1.4 acres Production facility (including road) = 3.5 acres The recommended security for the office area is $3500 (1.4 acres x $2500/acre). The recommended security for the production facility acre is $14,000 (3.5 acres x $4000/acre). Since the production facility may be in place for 20 years or longer the per acre rate is higher. These securities should be done separately since the time frame for security release is in the short term for the temporary office area. • The applicant shall provide the Vegetation Management Department with the original tags from each seed bag. The seed mix in the Plan shall match the seed mix used in the field. Do not use a seed mix containing yellow sweet clover (Melilotus offcinalis) or annual yellow sweetclover (M. indicus). The amount of seed specified to be planted in the Plan shall match the quantity of seed used in the field. • The security shall be held by Garfield County until vegetation has been successfully reestablished according to the Reclamation Standards in the Garfield County Weed Management Plan. It is the responsibility of the applicant to contact the County, upon successful revegetation establishment, to request an inspection for security release consideration. Erosion control • Any straw or hay bales used in erosion control shall be certified weed free. STATE OF COLORADO Bill Ritter, Jr., Governor DEPARTMENT OF NATURAL RESOURCES DIVISION OF WILDLIFE AN EQUAL OPPORTUNITY EMPLOYER Thomas E. Remington, Director 6060 Broadway Denver, Colorado 80216 Telephone: (303) 297-1192 wildlife.state.co.us February 25, 2007 David Pesnichak Garfield County Building and Planning Department 108 8th Street, Suite 401 Glenwood Springs, CO 81601 EXHIBIT 1 r r FEB E 2 7 2008 RE: Piceance Basin Natural Gas Development Program — Early Production System Central Production Facility and Temporary Storage Area (Job # 29021-003) Dear Mr. Pesnichak, For Wildlife - For People Thank you for the opportunity to comment on the proposed Central Production Facility (CPF) and Temporary Storage Area. The Division of Wildlife acknowledges Chevron's request to develop a CPF and an associated temporary storage area on land currently zoned as grazing/ agriculture; located in the Clear Creek drainage near the confluence of Tom Creek and Clear Creek, north of the town of De Beque, CO. The proposed development lies at the base of a steep slope with west and south facing aspects. The Division of Wildlife would like to offer the following comments with regard to potential impacts this development may have on wildlife. Habitat The proposed building site is located near the confluence of Tom Creek and Clear Creek. Tom Creek, a tributary to Clear Creek, which provides some riparian habitat as it flows intermittently and periodically disappears under ground. Riparian areas such as this are highly valuable to wildlife, as they provide both permanent habitat and migration corridors allowing movement from one area to another. The riparian vegetation along Tom Creek consists of a few deciduous shrubs and woodland over story comprised of mountain boxelder, locust, willow and cottonwood. Habitat surrounding the proposed site is characterized by sagebrush -steppe, mountain shrub and woodland vegetation, consisting primarily of Gambel's oak, Douglas fir, big sagebrush, rabbitbrush, snowberry, serviceberry, chokecherry, sumac, and several forbs and grasses. This habitat provides critical summer range for mule deer; summer range, severe winter range and winter concentration area for elk; year-round and production range for wild turkey; summer and fall concentration areas for black bears; year-round range for mountain lion; and production areas and winter range for Greater sage grouse. The proposed facility lies in close proximity to at least two active sage grouse leks on Skinner Ridge. The proposed facility also lies in close proximity of sage grouse brood area on Puddin Ridge. The proposed CPF and the associated temporary storage area locations lie in an area where native vegetation provides foraging, nesting, thermal and escape habitats for numerous species of wildlife. The removal and disturbance of native vegetation for the construction of the CPF, temporary storage area and associated roads will negatively impact the native wildlife species associated with this project area. Upon rehabilitation of this location and roads, negative impacts to native wildlife can be offset by planting a suitable mixture of native grass/forb/shrub seed. Seed plantings on disturbed soils will have DEPARTMENT OF NATURAL RESOURCES, Harris D. Sherman, Executive Director WILDLIFE COMMISSION, Tom Burke, Chair • Claire O'Neal, Vice Chair • Robert Bray, Secretary Members, Dennis Buechler • Brad Coors • Jeffrey Crawford • Tim Glenn • Roy McAnally • Richard Ray Ex Officio Members, Hams Sherman and John Stulp greater germination and survival rates when the soil surface has been prepared to hold moisture and runoff precipitation. Soils will exhibit increased moisture retention capabilities when the soil surface has been loosened with a "ripping tool" that creates a rough and uneven soil surface and seedbed. This treatment will increase seed germination, and, will reduce the amount of surface runoff and soil erosion. Weed Control Non-native weed species have become established on many disturbed soils throughout the Roan Creek area. The disturbance of soil, particularly along riparian corridors, increases the chance of non-native weed invasion. The invasion of non-native weeds reduces the density of native vegetation and lessens the habitat values for native wildlife species. The continual control and removal of non-native weeds on the disturbed/rehabilitated sites of this project will help restore native vegetation that is valuable to wildlife. The Division of Wildlife notes that the Integrated Vegetation and Noxious Weed Management Plan sufficiently addresses these issues and includes recommendations for treatment and reduction of non- native weeds. The Division of Wildlife supports these recommendations, and would gladly provide any additional information needed on weed control. Roads Bears The Division of Wildlife notes and supports that minimal new roads are proposed with this new development. Minimizing the number of roads will benefit wildlife, as building of multiple roads in an area increases fragmentation of habitat, inhibits the natural movement of wildlife across the landscape, increases road -kill mortality, and broadens the opportunity for poaching. Minimizing roads and road use will also decrease fugitive dust, which can become severe during dry summer months. The Division of Wildlife recommends that Chevron strictly enforce speed limits on new and existing roads, and employ dust control measures as needed. The proposed CPF and the associated temporary storage area locations lie within year-round black bear habitat. Increased human use of the proposed development area may increase the potential for conflicts with black bears during the summer and early fall, particularly during years of drought. The potential for human/bear conflicts within this project area would be greatly reduced by placing and utilizing "bear proof" trash containers at work-site/camping locations. These trash containers should be emptied weekly at a minimum. The Division of Wildlife has information on the design and purchase of "bear proof" trash containers, and, will provide this information to anyone who is interested in preventing conflicts with bears. The Division of Wildlife recommends that employees be required to comply with "bear aware" policies regarding food, trash, BBQ grills, and birdfeeders; and educated on what to do if they encounter a bear. The Division of Wildlife would gladly offer specific on-site recommendations to minimize human -bear conflict, and provide bear education seminars for contractors and/or employees. Workers affiliated with this project should be advised not to feed bears, whether intentional or not, since this activity is detrimental to black bears, and is a violation of Colorado Wildlife Commission Regulation (WCR) #021(D). WCR #021(D) states, it is unlawful for any person to fail to take remedial action to avoid conflict with black bears after being notified by the Division of Wildlife that black bears are in the area. The Division of Wildlife recommends Chevron employees and subcontractors be advised of this regulation (WCR #021(D)). The Division also suggests workers affiliated with this project be notified that failure to comply with the regulation will result in the issuance of a citation by the Division of Wildlife. Cumulative Impacts Negative impacts to wildlife become significant when habitat disturbances caused by gas development are added over time and become cumulative. Negative impacts to wildlife are a result of noise from well heads and compressors; increased sedimentation; disturbance of fragile soils and steep slopes; loss of winter forage for wildlife; loss of migration corridors for wildlife; human disturbance to wintering populations of wildlife; animal harassment as a result of increased human activity; vegetation disturbance by road, pipeline and well pad construction; increased invasion of noxious weeds to disturbed sites; and increased access into roadless areas resulting in a loss of seclusion for wildlife and increased vulnerability to poachers. Furthermore, the rate in which disturbed sites are reclaimed is not equal to the rate of disturbances created by gas development. As a result, there is significant deficit to biologic systems created and compounded by the time it takes to restore lost habitat. Poaching Multiple species of wildlife that inhabit the area surrounding the proposed facility, including elk, mule deer, black bear, mountain lion, wild turkey and sage grouse, may be extremely vulnerable to illegal hunting during various times of the year. Wildlife species often concentrate near roads and riparian areas, particularly during the winter months when deep snow forces them to lower elevations. Wildlife along roadside habitats may become highly visible during certain times of the year and become easy targets for poaching. The Division of Wildlife acknowledges that DOW Law Enforcement presence is welcome at all times on Chevron property, and recommends that Chevron continue to internally enforce their rules regarding possession of firearms. Furthermore, the Division of Wildlife encourages Chevron and its employees to report any incidents of poaching immediately to the Division of Wildlife. If a poaching incident occurs, representatives of Chevron should immediately call the District Wildlife Manager (via the Colorado State Patrol at 970-249-4392, if after normal business hours) or Operation Game Thief (OGT) at 1-877-265-6648. Chevron should educate workers about poaching and encourage reporting of such incidents to Operation Game Thief. Thank you for the opportunity to comment on the Central Production Facility and Temporary Storage Area (Job # 29021-003) development proposal. The Division of Wildlife appreciates the opportunity to comment on new developments in Garfield County. Please feel free to contact District Wildlife Manager Albert Romero at 970- 255-6154 should you have any questions or require additional information. Sincerely, Dean Riggs Area Wildlife Manager cc: Ron Velarde, Northwest Regional Manager Brad Petch, Senior Wildlife Conservation Biologist Albert Romero, District Wildlife Manager Preliminary Noise Study Information From Paul Kiteck of Hoover & Keith EXHIBIT I have just completed a preliminary noise analysis of the Central Production Facility (CPF) for the Chevron Piceance Development Project based on the understood current design/layout of the CPF but do not have the results available in a document. Therefore, in this email, I will provide a summary of the findings that hopefully can support the permitting requirements prior to a more formal document with the results to be provided in the near future. Typical ambient sound levels for the area: 25 to 35 dBA (i.e., average ambient A -wt. sound levels of 30 dBA). Consequently, if the resulting/predicted sound level contribution due to the CPF during operation is equal to or less than the ambient sound level (e.g., 30 dBA), the noise of the facility will probably not be audible. 1) Estimated sound level contribution of the CPF (during full load operation) at a distance of 1 mile south of the facility (in the area of the canyon, along Clear Creek Road): 30 to 35 dBA Consequently, at the closest residences to the CPF (i.e., homes at intersection of Clear Creek Rd. & CR -204, in the area of the Cowboy Chapel, which are approx. 6 miles from CPF), the noise of the CPF during operation should not be audible. 2) Estimated sound contribution of CPF at the closest "non -Chevron" property of potential concern (i.e., Colorado Nature Ranch, approx. 4,500 feet to 1 mile west of CPF): 20 to 25 dBA Consequently, the noise of the CPF should not be audible at the Colorado Nature Ranch, noting that the Shiner Ridge, located between the CPF & Nature Ranch, will provide significant attenuation of the CPF noise). 3) Estimated sound contribution of CPF at 1/2 mile south of the facility (along Clear Creek Rd): 42 to 45 dBA 4) Estimated sound contribution of CPF at 350 feet from the site center (i.e., Compressor Building): 60 to 65 dBA Note that the noise requirements of the COGCC could require that the CPF achieve 50 dBA (nighttime) at 350 feet if there were occupied structures, such as residences, located near the facility that are not on Chevron property. Since there are no residences near the CPF, based on our interpretation of the COGCC regulations, the CPF is required to meet the "light industrial standard" (i.e., 65 dBA, nighttime) at the Chevron property line, for which the CPF should easily achieve. This is a summary of the preliminary noise analysis of the CPF, and it is anticipated that any other facilities associated with the project, such as Well Pads with booster compressors, will generate lower sound levels than the CPF during full load operation. MEMORANDUM To: David Pesnichak From: Steve Anthony Re: Followup Comments on the Chevron Piceance Production Facility and Special Use Permit Date: February 28, 2008 Sally Cuffin from URS contacted me this morning. Sally will provide a more detailed weed inventory of the project site to the County by June 1, 2008. She is looking into the tamarisk issue (mentioned in the earlier memo and referencing tamarisk treatment on the pipeline project) and will provide further information to our office. February 28, 2008 Mr. David Pesnichak Garfield County Planning 108 8`I' Street, Suite 401 Glenwood Springs, CO 81601 MOUNTAIN CROSS ENGINEERING, INC. CIVIL AND ENVIRONMENTAL CONSULTING AND DESIGN EXHIBIT RE: Review of Central Production Facility & Temporary Storage SUP for Chevron USA. Dear David: This office has performed a review of the documents provided for the Central Production Faci.lity and Temporary Storage Area of Chevron USA, Inc. -The submittal was found to be thorough and well organized. The following continents, questions, or concerns were generated: 1. Multiple permits are in various stages of completion: Grading, Special Use, Building, Flood Plain, etc. Copies of permits should be conditions of approval and provided to Garfield County as they are obtained. 2. Flood plains are delineated and have fill placement proposed. Garfield County flood plain perinits may be required. 3. The application proposes bottled water and portable toilets. The duration of the project does not seem to warrant what would generally be considered a temporary solution. 4: The potential duration of the project warrants. a more .permanent solution for water and wastewater such as wells and ISDS. These are discussed as future possibilities in the narrative section of the application. However there are setbacks, restricted uses, and design considerations that are. associated with wells and ISDS. At a minimum, these should. be considered at this time so that the proposed buildings and appurtenances do not conflict and preclude these for the future. 5. The water supply contracted by Down Valley Septic is purchased from the Town of Silt. In times of drought, municipalities often turn off water supplies to these outside contractors. An adequate and legal supply of water should be verified by the •applicant. 6. According to the applications, sounds studies and wildlife mitigation measures are in various stages of completion. These should be completed and submitted to the County. Feel free to call if any of the above .needs clarification or if you have any questions or comments. Sincerely, Mounta'j Cross Engi eer'ng, Inc. e Chris Hale, PE 82.6 1/2 Grand Avenue • Glenwood Springs, CO 81601 PH: 970.945.5544 • FAX: 970.945.5558 • www.mountaincross-eng.com David Pesnichak From: Cuffin, Sally [Sally.Cuffin@wgint.com] Sent: Friday, February 29, 2008 3:57 PM To: David Pesnichak Subject: RE: Chevron CPF - Change in Grading Plans Dave, Per your request... EXHIBIT 1/1 The total site disturbance for the Central Production Facility will include about 12 acres. This includes the actual facility location (3.3 acres), a temporary storage area (multi-purpose area - 1.6 acres), a topsoil stockpile (about 1.5 acres), and general construction activity disturbance (about 5.6 acres). The majority of the site will be reclaimed shortly after construction (8.7 acres), while the actual facility (3.3 acres) will remain in operation for the life of the gas field operations. Sally But I need to ask one more question... My understanding is that this facility will be operational for at least 30 years, unless the field depletes faster than anticipated. How does that affect the bond? From: David Pesnichak [mailto:dpesnichak@garfield-county.com] Sent: Fri 2/29/2008 3:17 PM To: Cuffin, Sally Subject: RE: Chevron CPF - Change in Grading Plans Thanks Sally, So if I understand this correctly, we are looking at 8.7 acres of disturbance to be secured for 1 year or less ($2500 per acre) and 3.3 acres to be secured under the 20 year timeframe ($4000 per acre)? Am I on the right track here? Also, is it possible for you to send me a simple email to this effect which I can attach as an exhibit to show that I did not just make these numbers up? Thanks, Dave David Pesnichak Senior Planner - Long -Range Garfield County 108 8th Street, Suite 401 Glenwood Springs, CO 81601 Tel: (970) 945-8212 Fax: (970)384-3470 Email: dpesnichak@garfield-county.com www.garfield-county.com 1 U m 1 00-L90-LL-ZI-SZO ---------- RECEIVED MAR 0 7 2008 r , BUiLOli'Ki & i LAidMNG O CC 3 2 2 2 W CC 1 6 S a pis i�u� �z+srrir�r�u� a Y r a a pr. ar. s 5 1 i a dg $g a a 1 6 M 1.0 o CO 2 ao a tl a UU1LL) ` D I N M I CO REC MAR 0 sHflC I i.e ... . i-'LAi NG IF _ RON NORTH AMERICA nap DEVELOPMENT -EP: :NTRAL FACILITIES ,MENT ARRANGEMENT .f. 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I • Revised Equipment List / Electrical Equipment Detail 1.3 Required Production Equipment / Storage Items The current CPF equipment list includes the following: MAR 0 7 2008 • Gas Separator (two phase) • Liquid Separator (three phase)^E{. • 3 Compressor Skids complete with: Add 1 Permanent and 1 12ental' Compressor•Skids — for a total of 4 Permanent and 1 Rental Unit o Compressor o Natural Gas Engine o Bottles o Scrubbers o Coolers o Interconnect Piping (ICP) o Programmable Logic Controller (PLC) o Lubrication system • Glycol Dehydration Tower — Add another tower for a total of 2 • 2 Glycol Regeneration Skids (called out as Glycol Reboilder / Surge • Volatile Organic Compound Recovery Skid for Glycol Dehydration Combuster Skid on drawing) • Water Surge Tank & Transfer Pumps (called out as Produced Water Pumps on Drawing) • Add Condensate Loading Skid • Condensate Settling Tank • Produced Water Tank • 6 Condensate Tanks • Flare Scrubber / Pump Skid • Flare Stack • 2 Gas Pipeline Scrapper (Pig) Receivers — Gathering Line Cleaner • 2 Liquid Pipeline Scrapper (Pig) Receiver — Gathering Line Cleaner • Chemical Injection Points • Add Sump Tank for Servicing Scrappers • Emergency Shutdown / Fire & Gas System (ESD / F&G) • Vapor Recovery Unit (VRU) Skid for Off -Gas Recovery • Instrument Air Compressor Skid • Power Generation / Distribution • Add Gas Filter Separator • Add Fuel Gas Skid • Add Start Air Receiver Skid • Electrical Building (8 ft x 40 ft) • Add Second Electrical Building (40 ft x 40 ft) • Electrical Substation Building (20 ft x 20 ft) • Control Building (8 ft x 40 ft) • Warehouse Building (8 ft x 40 ft) • Add Second Warehouse Building (40 ft x 40 ft) • Compressor Building (53 ft x 154.5 ft) • Instrument Air Building (20 ft x 20 ft) Skid on Drawing) System (called out as & Condensate • Add Telecommunications Building (10 ft x 12 ft) • - Replaced by second Electrical Building • 1 Gas Turbine System Transformers and Associated Electrical Equipment (Now shown connected to turbine generator) • Programmable Logic Controllers & Infield Ethernet Ring • Associate Piping and Control Cables 1.7.5 Major Electrical Equipment In order to power the CPF equipment until the field electrical distribution system is available (see Section 1.8), the following electrical generation and distribution equipment are proposed for the CPF location. All electrical equipment will be located away from the hydrocarbon -handling portions of the CPF (see Drawing 2033 -240 -20 -AP -0002-0002-01, Rev. b IC). Additional electrical generation system layout information is provided on Drawing PSBR 607A ELE GAR URS 00000 00001 00 Drawing 2033 -240 -20 -AP -0002-0002-01, Rev. 1 C. Major equipment items include: • Gas turbine -driven generator (rated at 2.5 MW) - provides power for continuous operation of the CPF (see Drawings 63771-149063, Rev. 01, Sheets 5, 7, 8, and 11); power to the electrical system if required; • Diesel engine -driven generator (rated at 750 kW) - provides backup power when the gas turbine -driven generator is not in service (also provides the power required to start the gas turbine -driven generator); • A future rental diesel engine -driven generator (rated at up to 500 750 kW) will be used until the gas turbine generator is available Otherwise this unit will be used on a temporary basis when the backup diesel engine -driven generator or gas turbine -driven generator(s) is not in service; • Power distribution center with switchgear and adjacent transformers for distributing power from the generators to the CPF equipment and nearby 25 kV distribution lines; and • Diesel fuel storage tank to provide a 3 -day fuel reserve for diesel engine -driven generators. The fuel gas skid to supply natural gas to the gas turbine -driven generator will be located away from the generators and near the fuel gas skid that supplies the engines for the CPF main gas compressors. 75 150 300 eet CPF AREA Tom Creek Natural Springow and Facility Layout Ivo '...,1-..........c..tb. t/....e:eu Ew.�..e..,,a..m,�..„ SU. MO SWAM RIME m' O ' d er. CO PROPERTYWIVw °{ � coax. tee.. n..e URS REvsaa w. n w..on nR o w EXHIBIT 5 CHEVRON PICEANCE BASIN NATURAL GAS DEVELOPMENT PROJECT (GARFIELD COUNTY, COLORADO) RESULTS OF A PRELIMINARY ACOUSTICAL ASSESSMENT OF THE PROJECT WHICH INCLUDES A CENTRAL PRODUCTION FACILITY AND SEVERAL NATURAL GAS WELL SITES H&K Report No. 2205 H&K Job No. 4004 Date of Report: March 6, 2008 Prepared for: Project Applicant: Submitted by: MAR 0 7 2008 BUILDING & Environmental Resources Management (ERM) 6455 S Yosemite St. Ste. 900 Greenwood Village, Colorado 80111-4954 Chevron North America Exploration and Production Paul D. Kiteck, P.E. (primary author) Hoover & Keith Inc. 11391 Meadowglen, Suite D Houston, Texas 77082 Hoover & Keith Inc. Consultants in Acoustics and Noise Control Engineering 11391 Meadowglen, Suite D, Houston, TX 77082 Phone: (281) 496-9876 ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project REPORT SUMMARY Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) This report includes the results of a preliminary acoustical assessment of the Chevron Piceance Basin Natural Gas Development Project to be located primarily in Garfield County, Colorado, which includes a Central Production Facility (i.e., a natural gas gathering/transmission compressor station) along with booster compressors and several well sites that will include well drilling activities. The primary purpose of the acoustical assessment is estimate the sound attributable to project facilities that could generate noise, such as the Central Production Facility (CPF), compare the results of the acoustical assessment to applicable sound criteria and assess the potential noise impact of the project facilities. In addition, a limited amount of ambient sound tests were conducted at the project site, and based on the measured ambient sound data, the ambient sound levels for the area surrounding the project are 25 dBA to 35 dBA (typical ambient A -wt. sound level of 30 dBA). At a distance of 1 mile south of the facility (in the area of the canyon, along Clear Creek Road), the estimated sound contribution of the CPF during operation is 35 dBA. Consequently, at the closest occupied residences to the CPF (i.e., homes at the intersection of Clear Creek Road & CR -204, approx. 6 miles south of the CPF), the noise attributable to the CPF should be significantly lower than the typical ambient sound level (e.g., 30 dBA), and therefore, the noise of the CPF should not be audible at the closest residences to the CPF. The estimated sound contribution of the CPF during operation at the closest "non -Chevron" property of potential noise concern (Le., Colorado Nature Ranch; closest property line located approx. 4,000 feet west of the CPF) is 26 dBA, which is equal to or lower than the ambient sound level for this area. Consequently, the "potential noise increase" of the ambient noise level at the closest non - Chevron property (i.e., Colorado Nature Ranch) during full load operation of the CPF should be less than 3 dB. As a result, the noise of the CPF may be slightly perceivable/audible at areas of the Colorado Nature Ranch that are closest to the CPF but the noise of the CPF should have minimum noise impact. In regard to the Colorado 011 and Gas Conservation Committee (COGCC) Rules and Regulations, the results of the acoustical assessment indicates that the noise attributable to the project facilities (e.g., noise generated by the CPF and other noise -generating facilities) should be well below the maximum permissible levels specified in the COGCC Rules and Regulations for this type of facility. For reference, it is anticipated that any other facilities associated with the project, such as the operation of booster compressors in the project area and/or well drilling operations on well pads, will generate lower sound levels than the CPF during full load operation. -Page i- ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project TABLE OF CONTENTS Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) Page 1.0 INTRODUCTION 1 2.0 BRIEF DESCRIPTION OF THE SITE AND FACILITIES 1 3.0 SOUND CRITERIA, TYPICAL METRICS AND TERMINOLOGY 2 4.0 MEASUREMENT RESULTS, OBSERVATIONS AND METHODOLOGY 3 4.1 Measurement Equipment and Data Acquisition 3 4.2 Summary of the Measured Ambient Sound Levels and Observations 3 5.0 ACOUSTICAL ANALYSIS (CPF) 4 6.0 SUMMARY OF NOISE CONTROLS AND/OR EQUIPMENT NOISE LEVELS 6 6.1 Building Enclosing the Engines/Compressors 6 6.2 JW Cooler for Each Gas Compressor Unit 6 6.3 Turbine and Generator for Each Gen -Set 6 6.4 Exhaust of the Turbine for Each Gen -Set 6 6.5 Engine Exhaust and Engine Air Intake 6 7.0 SUMMARY AND FINAL COMMENT 7 APPENDIX: FIGURES, SOUND DATA, RESULTS OF ANALYSIS, DESCRIPTION OF ANALYSIS METHODOLOGY, SOURCE OF SOUND DATA, COGCC REGULATIONS, TERMINOLOGY 8-23 Figure 1: "Overview" of Project Area, Areas of Interest & Sound Measurement Positions 9 Figure 2: "Closer" View of Area around CPF and Sound Measurement Positions 10 Figure 3: Conceptual Layout of Buildings and Equipment for the CPF 11 Description of the Analysis Methodology and Source of Data 12-13 Table A: Est'd Sound Contribution of the CPF during Operation at 1/2 Mile 14 Table B: Est'd Sound Contribution of the CPF during Operation at 1 Mile 15 Table C: Est'd Sound Contribution of the CPF at the Colorado Nature Ranch 15 Table D: Est'd Sound Contribution of the CPF at 350 Feet from the CPF Site Center 16 COGCC Noise Requirements (800 Series of the Rules and Regulations) 17-19 Summary of Metrics for Regulating Environmental Noise and Acoustical Terminology 20-23 -Page ii- ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project 1.0 INTRODUCTION Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) In this report, we include the results of a preliminary acoustical assessment of the Chevron Piceance Basin Natural Gas Development Project to be located primarily in Garfield County, Colorado. In addition, a limited amount of ambient sound tests were conducted at the project site and a summary of the ambient sound tests are included. The primary purpose of the acoustical assessment is estimate the sound attributable to project facilities that could generate noise, compare the results of the acoustical assessment to applicable sound criteria and assess the potential noise impact of the project facilities. 2.0 BRIEF DESCRIPTION OF THE SITE AND FACILITES Figure 1 (Appendix, p. 9) shows an "overview" of the project area showing the general location of project facilities, location of the ambient sound measurement positions and other areas of interest. Figure 2 (Appendix, p. 10) shows a "closer view" of the primary project facilities (e.g., CPF and nearby well sites) and location of ambient sound measurement positions around the area of the CPF. The project is located primarily in Garfield County, Colorado, in the area of the Piceance Basin (CO), approximately 16 miles NNW of DeBeque (CO). The land around the project is mostly rough terrain/mountains with activities related to the gas exploration/transmission in the area, and property for the project/area that is owned by Chevron is relatively large. In summary, the project includes a Central Production Facility (CPF), which is a natural gas gathering/transmission compressor station, booster compressors and several well sites that will include well drilling activities. The closest residences and other potentially noise -sensitive areas (e.g., Cowboy Chapel) not located on Chevron property are approximately 6 miles south the CPF (i.e., near the intersection of Clear Creek Rd. with CR -204). There are also a couple houses on the Chevron property located along Clear Creek Road. The closest non -Chevron property of potential noise concern is the area of the Colorado Nature Ranch, for which its closest property line is approximately 4,000 feet west of the CPF. Figure 3 (Appendix, p. 11) shows the current preliminary layout of buildings/equipment for the CPF. A total of three (3) engine -driven compressor units will be initially employed at the CPF for natural gas gathering/transmission. Each compressor unit will consist of a Caterpillar (CAT) Model G3520 engine driving a "high-speed" reciprocating gas compressor. The engines and compressors for gas compressor units will be enclosed in an insulated metal building (Le., Compressor Building). The following describes auxiliary equipment and other notable equipment at the CPF: -Page 1- ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) > Outdoor engine jacket -water (JW) air-cooled heat exchanger (i.e., JW cooler) for each main gas compressor, each JW cooler is designed a vertical fan that are direct -driven by the engine (i.e., via belts/sheaves), and the JW cooler will also function as a gas aftercooler; > Exhaust engine system designed with an exhaust muffler system; > Engine air intakes, which include an air filter/cleaner system; > Aboveground gas piping and piping system components (e.g., inlet separators, fuel gas scrubber, intermediate separator) along with other miscellaneous equipment. > Three (3) Solar turbine -driven generator (i.e., 2 gen-sets typically operate and 1 gen-set considered a spare), and the turbine and generator for each gen-set to be installed inside a skid -mounted acoustical enclosure. > Turbine exhaust for each gen-set will include an exhaust muffler. There also will be a need to utilize booster compressor units (i.e., "smaller" engine -driven compressor units) at or near some of the planned well sites. We understand that these booster compressor units will each be designed with a skid -mounted acoustical enclosure covering the engine -compressor for each package, and each package will include an outdoor engine JW/utility cooler designed with a vertical fan that is direct -driven by the engine (i.e., via belts/sheaves). 3.0 SOUND CRITERIA. TYPICAL METRICS AND TERMINOLOGY The Colorado 00 and Gas Conservation Committee (COGCC) regulate the oil and gas drilling and production industry in the State of Colorado and the mission of the COGCC is to promote the responsible development of Colorado's oil and gas natural resources The COGCC has the responsibility for regulating noise from natural gas facilities in Colorado, and Series 800 (i.e., "Aesthetic and Noise Control Regulations"; Section 801 and Section 802) of the COGCC Rules and Regulations address noise requirements (i.e., maximum allowable noise levels) for natural gas facilities in the State of Colorado. The complete noise regulations given in the COGCC Rules and Regulations are provided toward the end of the report (Appendix, pp. 17-19). The following summarizes our interpretation of the noise requirements of the COGCC Rules and Regulations as it applies to this project and the noise generated during operation of the CPF and other project facilities (e.g., booster compressors or well drilling activities): > In remote locations, where there is no reasonably proximate occupied structure or designated outside activity area, similar to the area surrounding the site of the CPF or booster compressor(s) for this project, the light industrial standard may be applicable. Consequently, to comply with the COGCC noise regulations, it is assumed that the noise radiated at the Chevron property line should not exceed a nighttime level of 65 dBA (i.e., between 7:00 PM to the next 7:00 AM), and at the property line of any residential -zoned area (e.g., closest residences), the noise generated by the CPF or booster compressors should not exceed a nighttime sound level of 50 dBA (i.e., between 7:00 PM to the next 7:00 AM). -Page 2- ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) In addition, if the intruding noise (e.g., noise of CPF during operation) causes less than a 3 dB increase in the overall ambient noise at nearby NSAs (i.e., defined as "potential noise increase"), the noise should be barely audible/perceivable by the human ear and should have minimum noise impact on the acoustical environment. If the intruding noise causes an increase in the overall ambient noise of between 4 dB and 9 dB, the intruding noise may be audible by the human ear but should still have minimum noise impact on the acoustical environment. For the reader's information, a summary of applicable acoustical terminology in this report and typical metrics used to measure and regulate environmental noise is provided at the end of the report (Appendix, pp. 20 — 23). 4.0 MEASUREMENT RESULTS. OBSERVATIONS AND METHODOLOGY 4.1 Measurement Equipment and Data Acquisition A limited amount of ambient sound measurements at the project site were performed by Paul Kiteck of H&K during our site visit in the daytime January 29, 2008. At each sound measurement position, the equivalentA-wt. sound level (i.e., Leq) and unweighted octave -band (O.B.) sound pressure levels (i.e., SPLs) were measured at 5 feet above ground. Sound measurements attempted to exclude "extraneous sound" such as cars or trucks passing immediately by the sound measurement location or other intermittent sources not typical of the ambient noise environment. The sound measurement system consisted of a Larson -Davis (LD) Model 2900 Real Time Analyzer/Sound Level Meter (a Type I SLM per ANSI Standard S1.4 & S1.11) and a 1/2 -in. condenser microphone with windscreen (analyzer/SLM calibrated with a LD Model CA250- 0493 microphone calibrator that was calibrated within 1 year of the service date). 4.2 Summary of the Measured Ambient Sound Levels and Observations The following Table 1 summarizes the measured/reported ambient daytime A -wt. sound levels (i.e., Leq) and some the sound measurement positions were taken relatively close to existing well drilling activities. Note that the ambient daytime Leq (Le., also referred to as Ld) assumed to be similar to or equal to the ambient nighttime A -wt. sound levels (i.e., Ln). Meas. Pos. Description of Sound Measurement Location Range of Meas'd Daytime A -Wt. Sound Levels (i.e., Ld) Pos. 1 Area of a house on Chevron Property, located along Clear Creek Road. 26 to 35 dBA Pos. 2 Area near the location of the CPF, along Toms Creek Road 28 to 32 dBA Pos. 3 Along Clear Creek Rd, 600 feet east of well drilling operations at Well 598 -35 -AV 46 to 48 dBA * Pos. 4 Approximately 250 feet south of well drilling operations at Well 598 -26 -AV 60 to 61 dBA * Pos. 5 Approximately 300 feet south of well drilling operations at Wet 598 -35 -AV 58 to 59 dBA * Table 1: Summary of the Meas'd Daytime A -Wt. Sound Levels at Areas of Interest for the Project * Noise of the well drilling operations (i.e., drilling rig at the well site) was the dominate noise source. -Page 3- ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) During the site visit on Jan. 29 ('08), the meteorological conditions were as follows: Temperature of 23 — 27 deg. F., mostly clear sky and there was a light wind primarily from the north. During the daytime sound tests at the ambient sound measurement positions not located near well drilling activities (i.e., Pos. 1 & Pos. 2), the audible noise sources that contributed to the ambient noise included distant construction equipment, the sound of birds, the sound of wind blowing in the trees/grass and at times, the noise of distant aircraft. We believe that the measured ambient sound data at Meas. Pos. 1 and Meas. Pos. 2 represents the typically daytime and nighttime A - wt. sound levels for the area during times of relatively low wind conditions. At measurement positions located relatively close to well drilling activities (i.e., Pos. 3, Pos. 4 & Pos. 5), the noise of the well drilling operations (i.e., drilling rig) was the dominant noise source. In summary, based on the measured sound data at the site, the typical ambient sound levels for the area surrounding the project are 25 dBA to 35 dBA, with a typical ambient A -wt. sound level of 30 dBA. Consequently, if the resulting/predicted sound level contribution due to the operation of project facilities is equal to or less than the typical ambient level (e.g., 30 dBA); the noise of the CPF and other project facilities will probably not be audible. 5.0 ACOUSTICAL ANALYSIS (CPFt The noise associated with the CPF during full load operation is considered the primary facility for the project that could generate significant noise. In addition, the noise of booster compressors during operation and well drilling activities could generate noise, but it is anticipated that other project facilities, such as booster compressors and well drilling activities, will generate lower sound levels than the noise associated with the CPF during operation. The estimated sound contribution of the CPF assumes the operation of 3 gas compressor units and 2 gen-sets. The acoustical analysis of the CPF considers the noise produced by all continuous -operating equipment that typically would operate at the facility. The following stationary noise sources associated with the CPF were considered significant: D Noise generated by the engines/compressors that penetrates the Compressor Building; D Noise of the engine exhaust of each gas compressor unit; D Noise radiated from aboveground gas piping and associated components; D Noise of the outdoor JW cooler for each gas compressor unit; D Noise associated with the turbine exhaust of each gen-set (includes an exhaust muffler); D Noise of the turbine/generator that radiates from the generator skid -mounted enclosure for each operating gen-set. For this acoustical analysis, we estimated the sound contribution of the CPF at different distances (e.g., noise contribution at % mile and 1 mile south of the CPF, along the canyon, and at 350 feet from the site) and at the closest area to the CPF of potential noise concern (i.e., Colorado Nature Ranch). A detailed description of the methodology for the acoustical analysis and the source of sound data for the CPF acoustical assessment are provided in the Appendix (pp. 12-13). -Page 4- ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) Table A (Appendix, p. 14) shows the spreadsheet calculation of the estimated A -wt. sound level and unweighted O.B. SPLs at the a distance of approximately 14 mile south of the CPF (along the canyon) as contributed by the CPF noise sources based on standard day conditions (i.e., no wind, 60 deg. F., 70% R.H.) along with the estimated total noise of the CPF (i.e., noise of the CPF plus the typical ambient noise). The analysis includes the effect of anticipated noise control measures for the facility equipment. Table B (Appendix, p. 15) is the spreadsheet calculation of the estimated A -wt. sound level and unweighted O.B. SPLs generated by the CPF at the distance of approximately 1 mile south of the CPF (along the canyon) as extrapolated from the estimated sound contribution at % mile (i.e., results in Table A). Table C (Appendix, p. 15) is the spreadsheet calculation of the estimated A -wt. sound level and unweighted O.B. SPLs generated by the CPF at the closest property line of the Colorado Nature Ranch (i.e., approximately 4,000 feet west of the CPF) as extrapolated from the estimated sound contribution at '% mile (i.e., results in Table A), noting that the Colorado Nature Ranch is considered the closest non -Chevron area of potential noise concern. For reference, Table D (Appendix, p. 16) shows the spreadsheet calculation of the estimated A - wt. sound level and unweighted O.B. SPLs at the a distance of 350 feet from the site center of the CPF (i.e., area of the Compressor Building) as contributed by the CPF noise sources, noting that the Shiner Ridge (i.e., located between the CPF and Nature Ranch) will provide significant attenuation of the CPF noise. The following Table 2 summarizes the calculated/estimated A -wt. sound levels of the CPF assuming operation of 3 CAT engine -driven reciprocating compressor units and other continuous -operating equipment at the CPF. Facility Operating Condition and Description of the Location Est'd A -Wt. Sound Level Contribution of the CPF Est'd sound contribution of CPF during operation at % mile from site center (along canyon) 43 dBA Est'd sound contribution of the CPF during operation at 1 mile from site center (along canyon) 35 dBA Est'd sound contribution of CPF at CO Nature Ranch (closest property line 4,000' west of CPF) 26 dBA Est'd sound contribution of the CPF during operation at 350 feet from the site center 63 dBA Table 2: Est'd A -Wt. Sound Level of the CPF at Several Distances and at the Closest Area to the CPF of Potential Noise Concern (i.e., Colorado Nature Ranch). -Page 5- ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) 6.0 SUMMARY OF NOISE CONTROL AND/OR EQUIPMENT NOISE LEVELS FOR PROJECT The following section provides a summary of anticipated noise control measures and equipment noise levels associated with the CPF equipment along with other assumptions or recommendations that may affect the noise generated by the CPF during operation. 6.1 Building Enclosing the Engines/Compressors Noise control measures will be applied to the building (Compressor Building) enclosing the engines and compressors rather than to the equipment themselves. The following describes specific requirements and other items related to the building components. ➢ The walls/roof will be constructed with an exterior metal skin, and it is recommended as a minimum, employ 24—gauge metal. Building interior surfaces will be covered with insulation, and it is recommended as a minimum, 6 -inch thick "high-density" mineral wool (6.0-8.0 pcf uniform density), covered with a perforated liner. 6.2 JW Cooler for Each Gas Compressor Unit Based on sound tests by H&K of the JW cooler for the gas compressor unit, the A -wt. sound level is approximately 72-74 dBA at a distance of 50 feet. 6.3 Turbine and Generator for Each Gen -Set The turbine and generator, which is directly driven by the turbine, for each gen-set will be installed in a Solar acoustical skid -mounted enclosure, typically designed to achieve an A -wt. sound level of approximately 85 dBA at 3 feet from the enclosure during operation of the gen-set. 6.4 Exhaust of the Turbine for Each Gen -Set The muffler for the turbine exhaust of each gen-set will be a Solar Model AX -5530 dissipative - type muffler with an overall length of 228 inches (i.e., 19 feet, from ground to stack exhaust flange) and diameter of 72 inches (i.e., 6 feet). 6.5 Engine Air Intake and Engine Exhaust The engine exhaust for each gas compressor unit will include a "residential -grade" muffler, and the engine air intake(s) for each gas compressor unit with include a "standard" air filter. -Page 6- ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project 7.0 SUMMARY AND FINAL COMMENT Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) At a distance of 1 mile south of the facility (in the area of the canyon, along Clear Creek Road), the estimated sound contribution of the CPF during operation is 35 dBA. Consequently, at the closest occupied residences to the CPF (i.e., homes at the intersection of Clear Creek Road & CR -204, approx. 6 miles south of the CPF), the noise attributable to the CPF should be significantly lower than the typical ambient sound level (e.g., 30 dBA), and therefore, the noise of the CPF should not be audible at the closest residences. The estimated sound contribution of the CPF during operation at the closest "non -Chevron" property of potential noise concern (i.e., Colorado Nature Ranch; closest property line located approx. 4,000 feet west of the CPF) is 26 dBA, which is equal to or lower than the ambient sound level for this area. Consequently, the "potential noise increase" of the ambient noise level at the closest non -Chevron property (i.e., Colorado Nature Ranch) during operation of the CPF should be less than 3 dB. As a result, the noise of the CPF may be slightly perceivable at areas of the Colorado Nature Ranch that are closest to the CPF but the noise of the CPF should have minimum noise impact. For reference, it is anticipated that any other facilities associated with the project, such as the operation of booster compressors in the project area and/or well drilling operations on well pads, will generate lower sound levels than the CPF during full load operation. In regard to the COGCC Rules and Regulations, the results of the acoustical assessment indicates that the noise attributable to the project facilities (e.g., noise generated by the CPF and other noise -generating facilities) should be well below the maximum permissible levels specified in the COGCC Rules and Regulations for this type of facility. As a final comment, to insure that the project facilities generate minimum noise impact, H&K will provide review the noise -related equipment submittals and other design features (e.g., Compressor Building design) during the detailed design phase for the project. Flle: WroMWordERM,Chevron Piceen a ProjectRepo,t - Noise Assessment for Chevron F ceencce Development Projectdoo -Page 7- ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project APPENDIX Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) > FIGURE 1: OVERVIEW LAYOUT AROUND THE PROJECT SITE, AREAS OF INTEREST AND SOUND MEASUREMENT POSITIONS > FIGURE 2: CLOSER AREA LAYOUT AROUND THE PROJECT SITE/CPF AND AMBIENT SOUND MEASUREMENT POSITIONS > FIGURE 3: CONCEPTUAL LAYOUT OF BUILDINGS & EQUIPMENT FOR THE CPF > ANALYSIS METHODOLOGY (NOISE ATTRIBUTABLE TO THE CPF) AND THE SOURCE OF SOUND DATA > ACOUSTICAL ANALYSIS (CFP) > COLORADO OIL & GAS CONSERVATION COMMISSION (COGCC) NOISE REGULATIONS (800 SERIES OF THE RULES AND REGULATIONS) > SUMMARY OF TYPICAL METRICS FOR REGULATING ENVIRONMENT NOISE AND ACOUSTICAL TERMINOLOGY -Page 8- ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project WELL SITE WELL SITE 598-26 WITH 598 -25 - BOOSTER -/AREA OF ;COMPRESSOR - BOOSTER PARCEL COMPRESSOR POS. 3 ° �,, I- BOUNDARY I° WELL SITE CLEAR 598 -25 -BV _ CREEK RD. WELL SITE WELL SITE �l (CR -211) --596-25-CV 1598-35 WITH TOM CREEK RD. BOOSTER I COMPRESSORP05.2 \ / CENTRAL PRODUCTION BOUNDARY WITH l/FACILITY (CPF) COLORADO NATURE RANCH L WELL SITE COLORADO NATURE / '; 36-1 RANCH BOUNDARY APPROX. 4.000' FROM CPF LEGEND - NON-RESIDENTIAL BUILDING - HOUSE OR MOBILE HOME NSA- NOISE SENSITIVE AREA * - MEASUREMENT POSITION * - WELL SITE APPROXIMATE SCALE IN FEET 0 2700 5400 10800 SHINER RIDGE __ SHINER RIDGE HOUSE ON CHEVRON PROPERTY CLEAR CREEK RO. (CR -211) Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) HINER GATE (TEMPORARY OFFICE) CLEAR CREEK SHINER RIDGE -->- OTHER HOMES HOUSE ON CHEVRON PROPERTY SHINER RIDGE CLEAR CREEK CLEAR ROAN - -F CREEK RD. CREEK RD. /r (CR -211) (CR -204) ROAN M \A' 'ROAN CREEK Y - CREEK RD. (CR -204) CLOSEST RESIDENCES NOT ON CHEVRON PROPERTY CLEAR CREEK -TREES Figure 1: Chevron Piceance Development Project: "Overview" Layout Showing the Project Facilities, Other Areas of Interest and Ambient Sound Measurement Positions. -Page 9- ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project WELL SITE 598-26 WITH BOOSTER COMPRESSOR PARCEL I BOUNDARY POS. 4 (250' FROM\ I WELL DRILLING RIG - DURING OPERATION) N, CLEAR (CR -211 I WELL WIT I� / �_ _ CREEK)RD. TH 598-35 BOOSTER COMPRESSOR p05.3 POS. 5 (300' FROM WELL DRILLING RIG DURING OPERATION) Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) WELL SITE 598 -25 -AV AREA OF BOOSTER r� COMPRESSOR WELL SITE __ 593 -25 -BV WELL SITE 599 -25 -CV TOM CREEK RD. / CENTRAL PRODUCTION FACILITY (CPF) BOUNDARY WITH COLORADO NATURE RANCH COLORADO NATURE RANCH BOUNDARY APPROX. 4,000' FROM CPF LEGEND - NON-RESIDENTIAL BUILDING — - HOUSE OR MOBILE HOME NSA- NOISE SENSITIVE AREA - MEASUREMENT POSITION - WELL SITE APPROXIMATE SCALE IN FEET 1100 2200 4400 WELL SITE z 361 SHINER RIDGE Figure 2: Chevron Piceance Development Project: "Closer' Area View of Project Facilities and Area(s) of Interest and Sound Measurement Positions in the Area of the CPF. -Page 10- ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project TOM CREEK RD. ji i_ COMMUNICATIONS ELECTRICAL 1 1 TOWER SUSTATION -,�J I 1 ELECTRICAL 1 I BUILDING I 1 CONTROL BUILDING ' � - 1I }} I U VRU Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) TURBINE -DRIVEN GEN -SET (TYP.) / ,—y PUMPS OHO i O O o DIKE LIQUID SEPARATOR 1-12I CLEAR CREEK RD. (CR -211) GAS SEPARATOR r1 GLYCOL TOWER 1 ' GAS FUEL GAS FILTER SKID I #1 #2 CENTRAL PRODUCTION FACILITY (CPF) PIPE RACK COMPRESSOR BUILDING WITH ENGINE DRIVEN COMPRESSOR UNITS PIPE RACK GLYCOL REBOILER / SURGE SKID FENCELINE APPROXIMATE SCALE IN FEET 0 35 70 140 Figure 3: Chevron Piceance Development Project: Conceptual Layout of the Buildings and Equipment at the Central Production Facility (CPF). -Page 11- ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project ANALYSIS METHODOLOGY (NOISE ATTRIBUTABLE TO CPF) Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) In general, the predicted sound level contributed by the CPF equipment was calculated as a function of frequency from estimated unweighted octave -band (O.B.) sound power levels (PWLs) for each significant sound source. The following summarizes the acoustical analysis procedure for the Station: ➢ Initially, unweighted O.B. PWL values of the significant noise sources were determined from equipment manufacturer's sound data and/or actual sound level measurements performed by H&K at similar type of equipment/components expected for this gas compressor facility. > Then, expected noise reduction (NR) or attenuation in dB per O.B. frequency due to any noise control measures, hemispherical sound propagation (discussed in more detail below*) and atmospheric sound absorption (discussed in more detail below**) were subtracted from the unweighted octave - band PWLs to obtain the unweighted O.B. SPLs of each noise source. Since sound shielding by buildings can influence the sound level contributed at the NSAs, we also included the sound shielding due to buildings, if appropriate. The sound attenuation effect due to foliage or land contour was not considered in the analysis although there probably will be some attenuation due to foliage/trees. ➢ Finally, the resulting estimated unweighted O.B. SPLs for all noise sources associated with the Station (with noise control and other sound attenuation effects) were logarithmically summed, and the total O.B. SPLs for all noise sources were corrected for A -weighting to provide the estimated overall A -wt. sound level contributed by the Station at the closest NSA. The predicted sound contribution of the Station at the closest NSA was utilized to estimate the Station noise contribution at the other nearby NSAs that are more distant that the closest NSA. *Attenuation due to hemispherical sound propagation: Sound propagates outwards in all directions (i.e., length, width, height) from a point source, and the sound energy of a noise source decreases with increasing distance from the source. In the case of hemispherical sound propagation, the source is located on a flat continuous plane/surface (e.g., ground), and the sound radiates hemispherically (i.e., outward, over and above the surface) from the sound source. The following equation is the theoretical decrease of sound energy when determining the resulting SPL values of a noise source at a specific distance ("r") of a receiver from the estimated PWL values: Decrease in SPL ("hemispherical propagation") from a noise source = 20*log(r) — 2.3 dB where "r" is distance of the receiver from the noise source. **Attenuation due to air absorption: Air absorbs sound energy, and the amount of absorption ("attenuation") is dependent on the temperature and relative humidity (R.H.) of air and frequency of sound. For example, the attenuation due to air absorption for 1000 Hz O.B. SPL is approximately 1.5 dB per 1,000 feet for standard day conditions (i.e., no wind, 60 deg. F. and 70% R.H.). -Page 12- ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project SOURCE OF SOUND DATA (CPFI Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) The following describes the source of sound data used for estimating the source sound levels and/or the source PWLs for the CPF (e.g., engines/compressors and other equipment/components associated with the compressor installation). (1) Estimated PWL values of equipment inside the building (i.e., engines, compressors and other equipment inside the building) was calculated from sound data measured by H&K on a similar type of compressor installation. (2) Exhaust PWL values were calculated from field sound data measured by H&K on a similar type of engines to be utilized at this facility. The DIL values for the exhaust muffler are generally lower than the recommended values in order that the analysis incorporates a "margin of safety." (3) Noise radiated from aboveground piping is primarily a result the noise generated by the gas compressors. Consequently, measurement of both near field and far field sound data on gas piping is presumed to be an accurate method of quantifying the noise associated with the piping, and estimated PWL values for piping in the analysis were determined from near field and far field sound data by H&K on a similar type of compressor to that of the proposed compressor unit. (4) The estimated PWL values for coolers (e.g., JW/aux cooler and gas cooler) were designated to meet the design noise goal and the estimated PWL values for the cooler utilized in the acoustical analysis assumes some noise associated with piping associated with the coolers. The noise level for the cooler used in the acoustical analysis is generally higher than the sound level requirement in order that the noise design analysis incorporates an acoustical "margin of safety." In addition, there can be other noise associated with the cooler that is not directly related to the operation of the cooler fans. (5) The estimated PWL values for the engine air intake were calculated from measured sound data in the field tests by H&K on similar engine that will be employed. -Page 13- ERM - Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) Source No. & Dist (Ft) Noise Sources and Other Conditions/Factors associated with Acoustical Analysis PWL or SPL in dB Per Octave -Band Center Frequency (Hz) A -Wt. 31.5 63 125 250 500 1000 2000 4000 8000 Level 1) PWL of Engines/Compressors inside Bldg. (3 Units) 112 115 120 118 118 116 118 118 115 124 Attenuation of the Building -6 -10 -16 -20 -22 -25 -30 -32 -32 NR of any Additional Noise Mitigation Measures 0 0 0 0 0 0 0 0 0 Misc. Atten. (e.g., Shielding or Land Contour) 0 0 0 0 0 0 0 0 0 2600 Hemispherical Radiation -66 -86 -66 -86 -66 -66 -66-66 -66 260D Atm. Absorption (70% R.H., 60 deg F) 0 0 -1 -1 -2 -4 -8 -20 -36 2600 Source Sound Level Contribution - 40 39 37 31 28 - 21 14 0 0 29 2) PWL of Unsilenced Engine Exhaust (1 Unit) 120 125 132 126 124 128 126 114 100 131 PWL of Unsilenced Exhaust for 3 Units (+5 dB) 125 130 137 131 129 131 131 119 105 136 Atten. of Noise Control (Exhaust Muffler) -16 -22 -30 -35 -38 -38 -35 —25 -20 NR of any Additional Noise Mitigation Measures 0 0 0 0 0 0 0 0 0 Misc. Atten. (e.g., Shielding or Land Contour) 0 0 0 0 0 — 0 . 0 0 0 2800 Hemispherical Radiation -66 -66 -66 -66 -66 -66 -86 -66 -66 2600 Atm. Absorption (70% R.H., 80 deg 9 0 0 -1 -1 -2 -4 -8 -20 -36 2600 Source Sound. Level Contribution 43 42 40 29 23 23 22 8 0 30 3) PWL of JN9Utility Cooler for 1 Unit 110 112 108 105 102 98 95 92 88 104 PWL of All 3JW/Utility Coolers (+5 dB) 115 117 113 110 107 103 100 97 93 109 Atten. of Noise Control 0 0 0 IO G 0 O % M 0 0 0 0 0 NR of any Additional Noise Mitigation Measures 0 0 0 0 0 0 0 0 Misc. Atten. (e.g., Shielding or Land Contour) 0 0 0 0 0 0 0 0 2600 Hemispherical Radiation -66 -66 -66 -86 -66 -66 -68 -66 2600 Atm. Absorption (70% R.H., 60 deg 9 0 0 -1 -2 -4 -8 -20 -36 2800 Source Sound Level Contribution 49 - 51 48 39 33 26 11 0 40 4) PWL of Unsilenced Turbine Exhaust of Gen Set (1 Um 120 123 120 123 127 119 112 104 98 126 PWL of Unsilenced Exhaust for 2 Units (+3 dB) 123 126 123 126 130 122 115 107 99 129 Atten. of Noise Control (Exhaust Muffler) -2 -5 -12 -22 -30 -30 -28 -25 -20 Misc. Atten. (e.g., Shielding or Land Contour) 0 0 0 0 0 — 0 0 0 0 2600 Hemispherical Radiation -66 -66 -66 -66 -66 -68 -66 -68 -66 2600 Atm. Absorption (70% R.H. 60 deg 9 0 0 -1 °.-2 -2 -4 -8 -20 -36 2600 Source Sound Level Contribution f 55 55 44 36 32 22 13 0 0 35 5) PWL of Outdoor Gas Piping for All Compressor Units 105 104 102 100 98 95 92 90 88 101 NR of Noise Control 0 0 0 "` 0 0 0 0 0 0 Misc. Atten. (e.g., Shielding by Compr. Bldg.) 0 0 0 0 0 0 0 0 0 2800 Hemispherical Radiation -66 -66 -66 -66 -66 - -86 -66 -66 -66 2800 Atm. Absorption (70% R.H., 60 deg 9 0 0 -1 -1 -2 -4 -8 -20 -36 2800 Source Sound Level Contribution 39 38 35 33 30 25 18 4 0 31 6) PWL of Turbine -Driven Gen Set(1 Unit) 104 97 98 97 100 96 96 92 85 102 PWL of 2 Gen Sets (+3 dB) 107 100 101 100 103 99 99 95 88 105 NR of any Additional Noise Mitigation Measures 0 0 0 0 0 0 0 100 0000) 0 Misc. Atten. (e.g., Shielding by Compr. Bldg.) 0 0 0 0 0 — 0 0 0 2600 Hemispherical Radiation -66 -66 -66 -66 -66 -66 -66 -86 2600 Atm. Absorption (70% R.H., 60 deg 9 0 - 0 -1 -1 -2 -4 -8 -36 2600 Source Sound Level Contribution 41 34 34 33 35 29 25 0 35 7) PWL of Pumps, VRUs, Coolers, Glycol Regen. Skid 105 102 98 95 92 80 88 88 85 96 NR of any Additional Noise Mitigation Measures 0 0 0 0 0 0 0 0 0 Misc. Atten. (e.g., Shielding or Land Contour) 0 0 0 0 0 0 0 0 0 2800 Hemispherical Radiation -66 -66 -66 -66 -66 "-68 -66 -66 -66 2600 Atm. Absorption (70% R.H., 60 deg 9 0 0 -1 - -1 -2 -4 -8 -20 -36 2600 Source Sound Level Contribution 39 36 31 28 24. 20 14 0 - 0 26 Est'd Total Sound Contribution of CPF at 1t2 mile south of Site 66 57 50 45 42 36 30 15 0 4&1 Typical Ambient Sound Level at this Location 30.0 Est'd Sound Level of CPF plus Ambient Level (dBA) 43.3 IEst'd Potential Increase (dB) 13.3 Table A: Chevron Piceance Central Production Facility(CPF): Est'd Sound Contribution of the CPF at App tux. 112 Mile south of the Site (In the Area of Canyon) assuming Operation of Three (3) Compressor Units (i.e., CAT Model G3520 Engine -Driven Compressor Units) and Two (2) Solar Gen Sets. NOTE: DIL NR & PWL values on this spreadsheet analysis should riot be used as the specified values. Refer to the "Noise Control & Sound Requirements" in the report or other company specifications. -Page 14- ERM - Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) Source No. & Dist (Ft) Noise Sources and Other Conditions/Factors associated with Acoustical Analysis SPL In dB Per Octave -Band Center Frequency (Hz) A -Wt. Level 31.5 63 125 250 500 1000 2000 4000 8000 5280 5280 Estd SPLs of Station at 2600 Ft. (RE: Table A) Hemisph Radiation [209og(52802600) = 6dB] Atm. Absorption (70% R.H., 60 deg F) 56 -6.0 0 57 -6.0 0 50 -6.0 -1 45 -8.0 -1 42 -6.0 -2 36 -8.0 -4 30 -6.0 -8-20 15 -6.0 0 -6.0 -37 43.1 Est'd Total Sound Contribution of CPF at 1 mile south of Site 50 50 43 38 34 26 16 0 0 35.1 Typical Ambient Sound Level at this Locaton 30.0 Est'd Sound Level of CPF plus Ambient Level (d BA) 36.3 IEst'd Potential Increase (dB) 6.3 Table 8: Chevron Piceance Central Production Facility (CPF): Est'd Sound Contribution of the CPF at Approx. 1 Mile south of the Site (in the Area of Canyon) assuming Operation of Three (3) Compressor Units (I.e., CAT Model G3520 Engine -Driven Compressor Units) and Two (2) Solar Gen Sets. Source No. & Dist (Ft) Noise Sources and Other Conditions/Factors associated with Acoustical Analysis SPL in dB Per Octave -Band Center Freque cy (H ) A -Wt. Level 31.5 63 125 250 500 1000 2000 4000 8000 4000 4000 Estd SPLs of Station at 2600 Ft. (RE: Table A) Attenuation due to Shiner Ridge Hemisph Radiation (201og(45002600) = 3.7 dB] Atm. Absorption (70% R.H., 60 deg F) 56 -6 -3.7 0 57 -8 -3.7 0 50 -10 -3.7 0 45 -12. -3.7 42 -14 -3.7 -1 36 -15 -3.7 -2 30 -18 -3.7 -4 15 '.-20 -37 -11 0 -20 -3.7 -19 43.1 Est'd Total Sound Contribution of the Station at NSA 93 47 45 36 29 23 15 4 0 0 26.1 Typical Ambient So nd Level at this Locaton 30.0 Est'd Sound Level of Station plus Ambient Ln (dBA) 31.5 IEst'd Potential Increase (dB) 1.5 Table C: Chevron Piceance Central Production Facility (CPF): Est'd Sound Contribution of the CPF at Approx. 4,000 Ft West of Site (CO Nature Ranch, West of Shiner Ridge) assuming Operation of Three (3) Comp r. Units (i.e., CAT Model G3520 Engine -Driven Compressor Units) and Two (2) Solar Gen Sets. -Page 15- ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) Source No. & Dist (Ft) Noise Sources and Other Conditions/Factors associated with Acoustical Analysis PWL or SPL in dB Per Octave -Band Center Fr quency (Hz) A -Wt 31.5 83 125 250 500 1000 2000 4000 8000 Level 1) PWL of Engines/Compressors inside Bldg. (3 Units) 112 115 120 ..118 118 118 118 118 115 124 Attenuation of the Building -6 -10 -16 -20 -22 -25 -30 -32 -32 NR of Additional Mitigation Measures 0 0 0 : 0 0 0 0 0 0 Misc. Atten. (Shielding or Ground Effect) 0 0 0 0 0 0 0 0 0 350 Hemispherical Radiation -49 -49 -49 - -49 -49 49 -49 -49 -49 350 Atm. Absorption (70% R.H., 60 deg F) 0 - 0 0 0 0 -1 -1 -3 -5 350 Source Sound Level Contribution 57 56 55 49 47 42 38 35 30 49 2) PWL of Unsilenced Engine Exhaust (1 Unit) 120 125 132 126 124 126 126 114 100 131 PWL of Unsilenced Exhaust for 3 Units (+5 dB) 125 130 137 131 129 131 131 119 105 136 Atten. of Noise Control (Exhaust Muffler) -16 -.-22 -30 -35 -38 -38 -35 -25 -20 NR of Additional Mitigation Measures 0 '- 0 0 0 0 0 0 0 0 Misc. Atten. (Shielding or Ground Effect) 0 0 0 0 0 0 0 0 0 350 Hemispherical Radiation -49 -49 -49 -49 -49 49 -49 -49 -49 350 Atm. Absorption (70% R.H., 60 deg F) 0 0 0 0 0 -1 -1 -3 -5 350 Source Sound Level Contribution ` 60 59 58 47 42 44 46 43 32 51 3) PWL of JWUtlity Cooler for 1 Unit 110 112 108 105 102 98 95 92 88 104 PWL of All 3 JW/Utility Coolers (+5 dB) 115 117 113 110 107 103 100 97 93 109 Atten. of Noise Control 0 0 0 0 0 0 0 0 0 NR of Additional Mitigation Measures 0 0 0 0 0 0 0 0 0 Misc. Atten. (Shielding or Ground Effect) 0 0 0 0 0 0 0 0 0 350 Hemispherical Radiation -49 ' -49 -49 -49 -49 49 -49 -49 -49 350 Atm. Absorption (70%R.H., 60 deg F) 0 ` 0 0 -: 0 0 -1 -1 - -3 -5 350 Source Sound Level Contribution 66 88 64 61 58 54 50 46 40 60 4) PWL of Unsilenced Turbine Exhaust of Gen Set (1 Unr 120 123 120 123 127 119 112 104 96 126 PWL of Unsilenced Exhaust for 2 Units (+3 dB) 123 126. 123 126 130 122 115 107 99 129 Atten. of Noise Control (Exhaust Muffler) -2 -5 -12 -22 -30 -30 -28 -25 -20 Misc. Atten. (Shielding or Ground Effect) 0 0 0 0 0 0 0 0 0 350 Hemispherical Radiation 49 -49 -49 -49 -49 49 -49 -49 -49 350 Atm. Absorption (70% R.H., 60 deg F) 0 0 0 -2 0 -1 -1 -3 -5 350 Source Sound Level Contribution - 72 72 62 ''. 53 51 43 37 31 26 53 5) PWL of Outdoor Gas Piping for All Compressor Units 105 104 102 100 98 95 92 90 88 101 NR of Noise Control 0 0 0 0 0 0 0 0 0 Misc. Atten. (Shielding or Ground Effect) 0 0 0 0 0 - 0 0 0 0 350 Hemispherical Radiation -49 -49 -49 -49 -49 49 -49 -49 -49 350 Atm. Absorption (70% R.H., 60 deg F) 0 0 0 0 0 -1 -1 r -3 -5 350 Source Sound Level Contribution 56 55 53 51 49 ` 46 42 39 35 51 6) PWL of Turbine -Driven Gen Set (1 Unit) 104 97 98 97 100 96 96 92 85 102 PWL oft Gen Sets (+3 dB) 107 100 101 100 103 99 99 95 88 105 NR of Additional Mitigation Measures 0 -. 0 0 0 0 0 0 0 0 Misc. Atten. (Shielding or Ground Effect) 0 0 0 0 0 '.. 0 0 0 0 350 Hemispherical Radiation -49 -49 -49 .49 -49 49 -49 -49 -49 350 Atm. Absorption (70% R.H., 60 deg F) 0 0 0 0 0 -1 -1 -3 -5 350 Source Sound Level Contribution 58 51 52 51 54 50 49 44 35 56-'. 7) PWL of Pumps, VRUs, Coolers, Glycol Regen. Skid 105 102 98 95 92 90. 88 86 85 96 NR of Additional Mitigation Measures 0 0 0 - 0 0 "0 0 0 0 Misc. Atten. (Shielding or Ground Effect) 0 0 0 0 0 0 0 0 0 350 Hemispherical Radiation -49 -49 -49 -49 -49 -40 -49 ' -49 -49 350 Atm. Absorption (70% R.H., 60 deg F) 0 -.. 0 0 - 0 0 -1 -1 -3 -5 350 Source Sound Level Contribution 56 53 49 46 43 41 38 35 32 46 Est'd Total Sound Contribution at 350 Ft. from the Compr. Bldg. 74 74 68 63 61 57 54 50 43 63.0 Table D: Chevron Piceance Central Production Facility (CPF): Estd Sound Contribution of the CPF at Approx. 350 Ft. from the Site Center (I.e., Com pr. Bldg.) assuming Operation of Three (3 Compressor Units (i.e., CAT Model G3520 Engine -Driven Compressor Units) and Two (2) Solar Gen Sets. NOTE: Muffler DIL & Equipment PWL values on this spreadsheet should not be used as the specified values. Refer to "Noise Control Measures" section In report or other company specifications for actual specified values. -Page 16- ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) COLORADO OIL & GAS CONSERVATION COMMISSION (COGCC) NOISE REQUIREMENTS (800 SERIES OF THE RULES AND REGULATIONS} The COGCC regulates the oil and gas drilling and production industry in the State of Colorado and the mission of the COGCC is to promote the responsible development of Colorado's oil and gas natural resources. This "responsible development" balances efficient exploration and production of oil and gas with the prevention of waste, protection of mineral owner's rights, and protection of public health, safety and welfare and the environment. In Colorado, the COGCC has the responsibility for regulating noise from oil and gas facilities. AESTHETIC AND NOISE CONTROL REGULATIONS (Rules related to Noise Regulations and Noise Abatement as of November 30, 2006) 801. INTRODUCTION The rules and regulations in this section are promulgated to control aesthetics and noise impacts during the drilling, completion and operation of oil and gas wells and production facilities. Any Colorado county, home rule or statutory city, town, territorial charter city or city and county may, by application to the Commission, seek a determination that the rules and regulations in this section, or any individual rule or regulation, shall not apply to oil and gas activities occurring within the boundaries, or any part thereof, of any Colorado county, home rule or statutory city, town, territorial charter city or city and county, such determination to be based upon a showing by any Colorado county, home rule or statutory city, town, territorial charter city or city and county that, because of conditions existing therein, the enforcement of these rules and regulations is not necessary within the boundaries of any Colorado county, home rule or statutory city, town, territorial charter city or city and county for the protection of public health, safety and welfare. 802. NOISE ABATEMENT a. The goal of this rule is to identify noise sources related to oil and gas operations that impact surrounding landowners and to implement cost-effective and technically -feasible mitigation measures to bring oil and gas facilities into compliance with the allowable noise levels identified in subsection c. Operators should be aware that noise control is most effectively addressed at the siting and design phase, especially with respect to centralized compression and other downstream "gas facilities" (see definition in the 100 Series of these rules). b. Oil and gas operations at any well site, production facility or gas facility, shall comply with the following maximum permissible noise levels. Operations involving pipeline or gas facility installation or maintenance, the use of a drilling rig, completion rig, workover rig, or stimulation is subject to the maximum permissible noise levels for industrial zones. The type of land use of the surrounding area shall be determined by the Commission in consultation with the local governmental designee taking into consideration any applicable zoning or other local land use designation. c. In the hours between 7:00 a.m. and the next 7:00 p.m. the noise levels permitted below may be increased ten (10) db(A) for a period not to exceed fifteen (15) minutes in any one (1) hour period. The allowable noise level for periodic, impulsive or shrill noises is reduced by five (5) db(A) from the levels shown. -Page 17- ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) ZONE 7:00 am to next 7:00 om 7:00 pm to next 7:00 am (Daytime) (Nighttime) Residential/Agricultural/Rural 55 db(A) 50 db(A) Commercial 60 db(A) 55 db(A) Light industrial 70 db(A) 65 db(A) Industrial 80 db(A) 75 db(A) In remote locations, where there is no reasonably proximate occupied structure or designated outside activity area, the light industrial standard may be applicable. Pursuant to Commission inspection or upon receiving a complaint from a nearby property owner or local governmental designee regarding noise related to oil and gas operations, the Commission shall conduct an onsite investigation and take sound measurements as prescribed herein. The following provide guidance for the measurement of sound levels and assignment of points of compliance for oil and gas operations: (1) Sound levels shall be measured at a distance of three hundred and fifty (350) feet from the noise source. At the request of the complainant, the sound level shall also be measured at a point beyond three hundred fifty (350) feet that the complainant believes is more representative of the noise impact. If an oil and gas well site, production facility or gas facility is installed closer than three hundred fifty (350) feet from an existing occupied structure, sound levels shall be measured at a point twenty-five (25) feet from the structure towards the noise source. Noise levels from oil and gas facilities located on surface property owned, leased or otherwise controlled by the operator shall be measured at three hundred and fifty (350) feet or at the property line, whichever is greater. In situations where measurement of noise levels at three hundred and fifty (350) feet is impractical or unrepresentative due to topography, the measurement may be taken at a lesser distance and extrapolated to a 350 -foot equivalent using the following formula: db(A)@DISTANCE 2 = db(A)@DISTANCE 1 —20 x Iog10(distance 2/distance 1) (2) Sound level meters shall be equipped with wind screens, and readings taken when the wind velocity at the time and place of measurement is not more than five (5) miles per hour. (3) Sound level measurements shall be taken four (4) feet above ground level. (4) Sound levels shall be determined by averaging minute -by -minute measurements made over a minimum fifteen (15) minute sample duration if practicable. The sample shall be taken under conditions that are representative of the noise experienced by the complainant (e.g., at night, morning, evening, or during special weather conditions). (5) In all sound level measurements, the existing ambient noise level from all other sources in the encompassing environment at the time and place of such sound level measurement shall be considered to determine the contribution to the sound level by the oil and gas operation(s). -Page 18- ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) d. In situations where the complaint or Commission onsite inspection indicates that low frequency noise is a component of the problem, the Commission shall obtain a sound level measurement twenty-five (25) feet from the exterior wall of the residence or occupied structure nearest to the noise source, using a noise meter calibrated to the db(C) scale. If this reading exceeds 65 db(C), the Commission shall require the operator to obtain a low frequency noise impact analysis by a qualified sound expert, including identification of any reasonable control measures available to mitigate such low frequency noise impact. Such study shall be provided to the Commission for consideration and possible action. e. Exhaust from all engines, motors, coolers and other mechanized equipment shall be vented in a direction away from all occupied buildings. f. All facilities within four hundred (400) feet of occupied buildings with engines or motors which are not electrically operated shall be equipped with quiet design mufflers or equivalent. All mufflers shall be properly installed and maintained in proper working order. > For reference the following is a summary of the COGCC noise requirements as it applies to the CPF, per H&K interpretation: In remote locations, where there is no reasonably proximate occupied structure or designated outside activity area, similar to the area surrounding the site of the CPF or booster compressor(s) for this project, the light industrial standard may be applicable. Consequently, to comply with the COGCC noise regulations, it is assumed that the noise radiated at the Chevron property line should not exceed a nighttime level of 65 dBA (i.e., between 7:00 PM to the next 7:00 AM), and at the property line of any residential -zoned area (e.g., closest residences) the noise generated by the CPF or booster compressors should not exceed a nighttime sound level of 50 dBA (i.e., between 7:00 PM to the next 7:00 AM). -Page 19- ERM - Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) SUMMARY OF TYPICAL METRICS FOR REGULATING ENVIRONMENTAL NOISE AND ACOUSTICAL TERMINOLOGY RELATED TO THE REPORT (1) Decibel (dB): A unit for expressing the relative power level difference between acoustical or electrical signals. It is ten times the common logarithm of the ratio of two related quantities that are proportional to power. When adding dB or dBA values, the values must be added logarithmically. For example, the logarithmic addition of 35 dB plus 35 dB is 38 dB. (2) A -Weighted Sound Level (dBA): The A -wt. sound level is a single -figure sound rating, expressed in decibels (Re 20 µPa), which correlates to the human perception of the loudness of sound. The dBA level is commonly used to measure industrial and environmental noise since it is easy to measure and provides a reasonable indication of the human annoyance value of the noise. The dBA measurement is not a good descriptor of a noise consisting of strong low -frequency components or for a noise with tonal components. The A -weighted curve approximates the response of the average ear at sound levels of 20 to 50 decibels. The following are the relative response of A -weighted filter per octave band frequency, and a graph/curve is provided below that shows a graphical representation of the A -wt. filter response per frequency (in Hz). 31.5 Hz 63 Hz 125 Hz 250 Hz 500 Hz 1,000 Hz 2,000 Hz 4,000 Hz 8,000 Hz 16,000 Hz -39.4 dB -26.2 dB -16.1 dB -8.6 dB -3.2 dB 0 dB +1.2 dB +1.0 dB -1.1 dB -6.6 dB RELATIVE RESPONSE, I dB 10 0 -10 -20 -30 -40 50 16 31.5 63 125 250 500 1000 2000 4000 8000 16,000 FREQUENCY, Hz -Page 20- —� B,C N'N B A 16 31.5 63 125 250 500 1000 2000 4000 8000 16,000 FREQUENCY, Hz -Page 20- ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project (3) Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) C-Weiehted Sound Level (dBC): The C -wt, sound level is a single -figure sound rating, expressed in decibels (Re 20 µPa), which correlates to the human perception of the loudness of sound in excess of 85 decibels. The dBC level is commonly used to measure industrial and environmental noise since it is easy to measure and provides a reasonable indication of the overall sound. The difference between C and A -weighted sound levels provides and indication of the amount of lower frequency sound energy. The following are the relative response of C -weighted filter per octave band frequency, and a graph/curve is provided that shows a graphical representation of the C -wt. filter response per frequency (in Hz), and the graph/curve above in Definition (2) shows a graphical representation of the C -wt. filter response per frequency (in Hz). 31.5 Hz 63 Hz 125 Hz 250 Hz 500 Hz 1,000 Hz 2,000 Hz 4,000 Hz 8,000 Hz 16,000 Hz -3.2 dB -1.0 dB -0.2 dB 0 dB 0 dB 0 dB -0.2 dB -0.8 dB -3.0 dB -8.5 dB (4) Background or Ambient Noise: The total noise produced by all other sources of a given environment in the vicinity of a specific source of interest, and includes any Residual Noise. (5) Human Perception of Change in Sound Level • A 3 dB change of sound level is barely perceivable by the human ear ➢ A 5 or 6 dB change of sound level is noticeable ➢ If sound level increases by 10 dB, it appears as if the sound intensity has doubled. (6) Sound Pressure Level (Lp or SPL): Ten times the common logarithm to the base 10 of the ratio of the mean square sound pressure to the square of a reference pressure. Therefore, the sound pressure level is equal to 20 times the common logarithm of the ratio of the sound pressure to a reference pressure (20 micropascals or 0.0002 microbar). (7) (8) Octave Band Sound Pressure Level (SPL): Sound is typically measured in frequency ranges (e.g., high-pitched sound, low-pitched sound, etc.) that provides more meaningful sound data regarding the sound character of the noise. When measuring two noise sources for comparison, it is better to measure the spectrum of each noise, such as in octave band SPL frequency ranges. Then, the relative loudness of two sounds can be compared frequency range by frequency range. As an illustration, 2 noise sources can have the same dBA rating and yet sound completely different. For example, a high-pitched sound at a frequency of 2000 Hz could have the same dBA rating as a much louder low -frequency sound at 50 Hz. Daytime Sound Level (Ld) & Nighttime Sound Level (Ln): Ld is the equivalent A -weighted sound level, in decibels, for a 15 hour time period, between 07:00 to 22:00 Hours (7:00 a.m. to 10:00 p.m.). L„ is the equivalent A -weighted sound level, in decibels, for a 9 hour time period, between 22:00 to 07:00 Hours (10:00 p.m. to 7:00 a.m.). -Page 21- ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project (9) Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) Equivalent Sound Level (Log): The equivalent sound level (Leq) can be considered an average sound level measured during a period of time, including any fluctuating sound levels during that period. In this report, the Leq is equal to the level of a steady (in time) A -weighted sound level that would be equivalent to the sampled A -weighted sound level on an energy basis for a specified measurement interval. The concept of the measuring Leq has been used broadly to relate individual and community reaction to aircraft and other environmental noises. (10) Day -Night Average Sound Level (Ldn): The Ldn is an energy average of the measured daytime Leq (Ld) and the measured nighttime Leq (Ln) plus 10 dB. The 10 -dB adjustment to the Ln is intended to compensate for nighttime sensitivity. As such, the Ldn is not a true measure of the sound level but represents a skewed average that correlates generally with past sound surveys which attempted to relate environmental sound levels with physiological reaction and physiological effects. For a steady sound source that operates continuously over a 24-hour period and controls the environmental sound level, a Ldn is approximately 6.4 dB above the measured Leq. Consequently, a Ldn of 55 dBA corresponds to an Leq of 48.6 dBA. If both the Ld and Ln are measured, then n the Ldn is calculated using the following formula: Ldn =101ogml 15104,no + 2410(k.m)no24 (11) L -Percent Sound Levels: The L percent levels (e.g., L50, L90 & L10) refer to the A -weighted sound levels that are exceeded for 90, 50 and 10 percent of the time, respectively, during a sound measurement period. For example, the 50 -percentile exceeded sound level is designated to as L50 and is sometimes described as the median sound level. The range between the Lwand L90 values usually provides a good indication of the variability of the sound levels during the period of measurement. (12) Sound Level Meter (SLM): An instrument used to measure sound pressure level, sound level, octave -band SPL, or peak sound pressure level, separately or in any combinations thereof. The measured weighted SPL (i.e., A -Wt. Sound Level or dBA) is obtained by the use of a SLM having a standard frequency -filter for attenuating part of the sound spectrum. (13) Sound Power Level (Lw or PWL): Ten times the common logarithm of the ratio of the total acoustic power radiated by a sound source to a reference power. A reference power of a picowatt or 10'12 watt is conventionally used. (14) Tone: A tone is a sound sensation -having pitch, which is a listener's perception of the frequency (for example, the higher the frequency, the higher the pitch). For a measured sound spectrum, a tone is represented as a "peak" in the spectrum curve. Noise that contains significant tones is considered a tonal type of noise. -Page 22- ERM — Chevron Piceance Basin Natural Gas Development Project Results of a Preliminary Acoustical Assessment for the Project Hoover & Keith Inc. H&K Job No. 4004 H&K Report No. 2205 (03/06/08) (15) Relevant Standards, associated Standards Institute(s) and References American National Standards Institute (ANSI): ANSI is the national coordinator of voluntary standards development and the clearinghouse in the U.S.A. for information on national and international standards. American National Standards Institute (ANSI) 51.4: Specification for SLM: Type 1 SLM: Sound level meters (SLM) that meet this specification have a tolerance of +/- 0.5 dB from 22.4 to 11,200 Hz. Type 11 SLM: Sound level meters that meet this specification have a tolerance of +/- 0.5 dB from 63 to 2,000 Hz and +/- 1.0 dB from 22.4 to 11,200 Hz. ANSI S1.11-1971 (R-1976): Specifications for Octave, Half -Octave and Third -Octave Filter Sets. Includes a method to convert SPLs in the "old octave bands" to SPLs in the "new octave bands'. ASTM Standard E1014-84: Standard Guide for the Measurement of Outdoor A -Weighted Sound Level. This guide covers the measurement of A -weighted sound levels outdoors at specified locations or along particular site boundaries, using a general-purpose sound level meter. End of Report -Page 23- MidContinent / Alaska SBU Chevron North America Exploration and Production ISSUED FOR INFORMATION URS PICEANCE BASIN DEVELOPMENT Washington Division 10550 Richmond Avenue Houston, Texas 77042 (281) 529-3100 Date: FEB. 28, 2008 WATER MANAGEMENT POND AREA Drawing: PBSR-59836DVF-CIV-LAY-URS-00000-00004 EXHIBIT v4 CO / / / J// '- .7///� / / / /� /-/ — 1'////////�%//�/// l// �J// l///r - /// // �/i // / l i / /� / '��%/moi/�j�/ii�jj�/i'��(�i�/ /i��//moi z -,----=---;-----.--.-/-/-,V / � //// j/// /tom / ////i i/7- /,- //7.7„7,,;•„...,—,,,, � \ ...--/-7.------ ,-- --- /2:// 7 / 'ice/ �/ lr'�5%// )1/,,_---4///-L;// j/j j // llfr �// /,r///// )111 1!1Oil / �) Jl /////1 S (( / '1 1�) 1 /// I1)1 /1/ / //i� S i rl l ,,��i/ / r ` V/ 3 �\ I // 1 1s 'f / / I 1) (J ) / / 1 r / /, 1 f r/ / J / ‚'/7 /4 i 1. CONSTRUCTION PRELIMINARY NOT F - x0034 . 13 77012 - 10311 570-3100 8 / ar //� f�1 iv, '~. 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