HomeMy WebLinkAbout1.12 Stormwater MgmtChevron U.S.!\ Storll1\\,dtcr \1,1:1<lgcIllCllt Plan -April, 2009 . Storm Water Management Plan Chevron U.S.A. Inc. Skinner Ridge Field Permit Piceance Basin Natural Gas Development
Program Garfield County, Colorado September 2005 Revised JUlie, October 2006, August 200? Revised August 2008 Rel'ised .·jpril, 20{J9 Prepared by: Cordilleran, a division of Olsson Associates
826 21 Y2 Road Grand Junction, CO 81506 CO R DILLE IV\ N
Chevron U.S.A Stormwatcr \1zlI1agcmcnt Pbn -t\pl';i. ~~DY) Table of Contents Introduction ...................................................................................................
4 Stol'lnwater Runo!'!' Pcnnitting Requiremcnts ........................................... 4 1. Construction Site Description ............................................................
5 I.A Nature o{Constl'ltction Activity .... 1. B Sequence (!l Con.l'l rllct ion /lcl ivities ..... Developll1ent Stages ..... Production Stages .. Final Recallllation Stage.1 ........................
........... . I.C Eslimales o{Total Areal Acreage Disturbed ...... .. I.D Soil Data alld /:rosioll polential ................................ . I.E Vegetation Description and Eslima!e
..... ............ . I.F Polential Po/lution Sources and Locatiolls ......... . I.G Non-Sto{'((llvaler Discharges. i.N Receiving Waters. ..5 . .. 6 6 . ....... 12 .15 . ... 16 . .....
16 . ..... 18 ..19 . . ... 20 . ...... 20 2. Site IVlaps ............................................................................................ 21 2.A COllstruction Site BOllndaries
.. 2.B /!reas ojGround Slir/itce Distl'llbance. 2.C Areas ojeut & Fill ... 2. D Storgae Are((s(i)(' ,\lwerials. Equipment. Wast and Soil .... .......... . 2.£ Locatiun orA.lpltalt or
COllerel Batch Plallts 2.F Localion o/Stl'lfcfllrol 13MP.\' .. 2. G locatiun o(Noll-Slmct((ral BMPs 2.1-l Loca/ion (lL~·"jJril/,I!.s . • "";rI"CWlIs. fVetlwllls ami Other SUl./i.1CI!
TValu1"s .. .............. 21 . ..... 21 . 2 J . .......... 21 ......... 21 11 ) )
ChevronLJ,S,/\ StornlWd~Cr '.1'lJlagement PI<l.Il· April, 2009 : ... 3. Stonnwater Management Controls ................................................. 23 JA SlOrlll\V(/ler Adminislralor
.. ............ . .23 3.B Potelltial Pollution Sources. . .... 21 3. C BMPs for Storlllwater Pollution Prevention .. H •• 25-32 4.0 Final Stabilization and Long-tcrm Managclllcnt ....................
....... 33 5.0 Inspection & Maintenance Pl'Occdures ........................................... 34 Table I Table 2 Figure I Figure 2 Appendix A Appendix B Appendix C Appendix D Appendix
10 LIST OF TABLES Skinner Ridge Vegetation Descriptions ** ** Skinner Ridge Final Stabilization Seed Mixtures LIST OF FIGURES Skinner Ridge Field Location 1I'[a)1s ** ** BMP Selection
and Construction Phase Guidelines LIST OF APPENDICES SkilUler Ridge Common Plan of Development Storm Water Permit, CDPHF: Certification Ii **,"** List of Down-Hole Chemicals Typical
Storm Water BMP Details Storm Water Inspection Form Post Construction SWIvlP
ChCVl"nll lJ-S.,\ StCITll\\'Clter \lanagement Plan -April, 2009 : Introd Ilction This Stormwatcr Managemcntl'lan (SWJ:dl') is written to comply with the Colorado Department of Public
Health and Environment's (CDPEE) General Permit No. COR-030000 issued on July I, 2007 and expiring on June 30, 2012, and related U.S. Environmental Protection Agency (US EPA) National
Pollutant Discharge Elimination Svstem (NPDES) stormlVater regulations. Chevron's permit renewal approval is provided in Appendix A. Construction permits arc required for oil and gas
activities that disturb 1 or more acres during the life of the project or are part of a larger common plan of development. CDPHE added another option for permits in its Slumnmter Facl
Sheel-ConSll'llctioli at Oil and Gas Facilities (revised in July 2007): the Field Permit certillcation. In this document, CDPHE recommended that oil and gas developments be covered under
a field Permit certitication. Thc Field Permit covers all construction activities and discharges to all creeks listed in the permit for the entire project area. Chcvron has amended its
original pcrmit renewal application to be covered under a Ficld Permit rather than a common plan of development, as originally submitted. This Master SWMP providcs information, procedures,
and best management practices (I:lMPs) that will be used across the project area for construction activities associated with development of the natural gas resources in the Skinner Ridge
Field. This SWMP will be updated as necessary to address planned devclopments, new disturbances, and other changes neecled to manage stormwater and protect surface water quality. Site-specific
SWMP site maps, based on controls and procedures summarized in the Master SWMP, wiII be prepared for each facility/construction project and provided as appendices to this plan. Stormwater
Runoff PCl'Illitting Rcquircments The Federal Clean Water Act [Section 402(1')] requires that discharges of pollutants to watcrs or the United States li'om any point source be rcgulated
by Nl'DES permits. In November 1990 the USEPA published final regulations that established application requirements for storm water associated with cOllstruction activity for soil disturbances
of 5 acres or more be regulated as an industrial activity and co\cred by an NPDlC:S permit. In December 1999 the USEr A published final Phase II NPDES regulations that established application
requirements for storm water associated with construction activity for soil disturbances to be regulated as an industrial activit\' and covered by an NI'DES permit. These regulations
became eftective July 1,2002. On June 30, 2005, the State or Colorado stonnwalcr rCb'ulation went into effect to require Colorado Discharge Permit System (CDI'S) permits li'om the Water
Quality Control Di\'ision (the Division) for stonnwater discharges from construction activities associated with small construction activit)' for oil and gas sites (those that disturb
between one and fi\'c acres). Permitting for oil and gas construction disturbing liw or more acres during the Ide or the project. or are part of a larger COJlllllOn plan or dcvcloplllelli.
has been required since 1992.
Chevron USA Storlll1,.vJlcr f','1anagcllleill Plan -:\pril, 2009 Although federal permit eo,'erage for these discharges ",as conditionally exempted ii'om the Fedcral Clean Water Act
by the 2005 Federal Energy Bill. the Colorado Water Quality Control Commission has maintained the requirement within Colorado's regulations, and therefore permit coverage for these activities
remains in effect in Colorado. These requirements are in addition to the requirements of the Colorado Oil and Gas Conservation Commission (COGCC). 1. Construction Site Description Thc
following section describes site locations and provides a description of the construction areas. Storm water runoff characteristics of these areas are also described. LA Na ture of Construction
Activity The Skinner Ridge Field is located in Garfield County, Colorado within To\Vnships 5, 6, 7, 8 and 9 South, Ranges 97 and 98 West (Figure 1). The town of Debcquc, Colorado is
the nearest population center; it is approximately 14 miles south of the Skinner Ridge Field. Chevron is developing about 33,000 acres in the Piceance basin. The Program anticipates
drilling about 2,800 wells over a 14 year period. Design life of the field is projected at 30 years. Field gathering lines collect production fluids from the well pads and transport
the full well stream (FWS) to the Production Cluster Pads (PCP) for initial natural gas separation. Discharge lines ii'om the joint trunk lines flow to a Central Production Facility
(CPF) (mUltiple production facilities will be required for thc Program). At the production facilities, the natural gas and liquids arc further separated. The natural gas is compressed,
dehydrated and sent to a sales point through a recently constructed 30-inch expOli gas pipeline. Hydrocarbon condensate will be stabilized and stored in holding tanks for transport to
processing facilities via tanker truck Over the next two years, much of the produced water will be used for hydraulic fracturing operations or disposed of in an on-site permitted injection
well. In 20 lOa water treatment plant is expected to begin operating and remove salts and any remaining hydrocarbons. The treated water will be used for drilling operations and potentially
as a potable watcr supply. Brine and solids are anticipated waste streams Ii-om this process. Current plans are to use permitted disposal injection wells for the brine and to transport
the solids to a permitted waste disposal facility. The current drilling and development plan includes well pad construction, well drilling, completion and testing, access road improvement/constructio
n, support facility construction (production facilities, oftlces, water treatment facilities, etc.), utility installation, and pipeline construction. The are" of estimated disturbance,
including the natural gas well pads, the access roads, and gathering systcm pipc!ine, \ViII exceed 370 acres. Disturbance beyond live years will require re-evaluation. Figure 1 shows
some of the well pads and bcilities associated with the early phases of the Program.
Chevron U.S.A SlOl"ll1\Vater Management Plan -April, 2009 1.B Sequence of Construction & Development Activities As mentioned in Section 1.2 thc dcvelopmcnt oCthe Program will involve
multiple construction activities including well pad construction, well drilling, completion and testing, access road improvement/constmction, support lacility construction (production
facilities, offices, water treatment facilities, etc.), utility installation, and pipeline construction. The development of natural gas L~cilities is generally accomplished in three
distinct work phases. The first phase is Development (Construction/Drilling/Completion), the second phase is Production (Operation/Maintenance), and the third phase is Final Reclamation.
Development Stages W cll Pad Developmcnt The well pad develoJlment phme includes the following activities: pad construction, well drilling, well complction, gas line installation, and
pad area reclamation. Pad rcclamation is accomplished by backfilling the reserve pit, contouring disturbed soils to conform with the surrounding terrain, replacing the stockpiled top
soil, seeding of disturbed soil areas in order to re-establish a cover vegetation, and construction 0 f erosion and sediment control structures. The completion of the wells and resulting
beginning of gas production, generally triggers a one-year time period in which the reclamation phase of work should be completed. The final stabilization seed mixture for locations
above and below 7,000 feet is provided in are-vegetation specification provided in Table 2. During the initial stages of the well pad construction, heavy equipment will be used to shape
and contour the site and any access roaels. Design and construction techniques anel other practices are to be employed to minimize surface clistmballce and the associatcd effects of
pl'Oposed operations and maintain the reclamation potential of the site. A typical well pad will be approximately 200 feet by 400 feet, though dimensions may vary due to topography and
production. Because of the location of the project, steep slopes are expected to be encountered at many 0 f the projected well pad sites. Many of the sites will require vertical cuts
and steep fill slopes. Steps will be taken to avoid or mitigate construction in riparian areas and other areas deemed as areas subject to severe erosion. Thc well site will also be reviewed
to determine its effect on the location of the access road. Construction procedures will be implemented that minimize surface disturbance. All topsoil is to be removed from the entire
cut and till area and stored in a designated stockpile for reuse during interim and final reclamation. Topsoilillust bc segregated and stored separately from subsurface materials to
avoid rnixing during construction. storage, and interinl reclamation. Stockpiles \vill be properly located and protected so t11inillli7l~ \\·ind and water erosion and mnximi7.c .:l.vnilab\e
topsoil for reclamation.
Chevron U.S.A Storm water Management Plan -Apri!, 2009 : Excavation of the cut and till slopes is normally guided by information on the slope staKes. Fills should be compacted to minimize
the chance of slope failure. [1' exccss cut material exists after till areas have been brought to grade. the exccss material will be stockpiled at approwd locations. The area of the
\\'ell pad where the drilling rig substructure is located should be lewl and capable of supporting the rig. The area to be used for mud tanks, mud storage, drilling chemicals, and fuel
tanks should be at a slight slope, where possible, or a suitable alternative such as ditching should be used to provide drainage ii'om the work area to a reserve pit. To reduce erosion
and soil loss, it may be appropriate to divert storm water away 11-OIn well locations with ditches, berms, or waterbars above the cut slopes and to trap \\'ell location runoff and sediments
on or near the location through use of sediment controls. Sediment controls will dominate this carly phase of construction. Temporary BMPs such as silt fences, waddles, and other erosion/sediment
controls will be used in the initial stages to provide perimeter sediment runoff control. As the construction work progresses and the contour of the site are completed, more permanent
structural and non-structural BMPs will be implemented. The focus in these later changes will be on implementing effective erosion controls and attempting to re-vegetate disturbed areas
with native grass seed mix. A summary of the primary Program BMPs is provided in Appendix C. The attachment includes information on 13MPs, including where and when to use them, their
limitations, along with construction details and maintenance requirements. A site specific SW:VIP map will be developed for each well pad as part of the engineering design and provided
as an attachment to this plan. Pipeline Development Steep hillsides and water courses should be avoided when locating pipeline routes. When clearing, the width disturbed should be kept
to a minimum. During the excavation phase, designated topsoil stockpiles must be established to the side of the pipeline construction rolltes. Topsoil material must be segregated and
not be mixed or covered with subsurface material. Bladed materials lllUSt be placed back into the cleared route lIpon completion of construction and returned back to the original contour
before reapplying topsoil. Pipeline trenches should be compacted during backfilling. After con~truGtion, Gut-and-till slopes must be re-graded to conform to the adjacent terrain and
reclaimed. Pipeline right-of-wav must be maintained in oreler to correct baci,lill settling and prevent erosion. Appropriate B1v[P~ must be used in sensitive areas to ensure proper site
stabilization. Site specific S\V\IP maps for caeb pipeline corridor will be developed as part of the engineering design and provided as all attachment to this plan.
Chevron U.S./\ Storm water ;vlanagcment Plan -April, 2009 , Pipeline construction should not block, dam, or change the natural course of any drainage. Suspended pipelines should provide
ndequate clearance for high-now events. Pipelines buried across stream crossings should be buried below the scouring depth. Pipelines crossing streams or wetlands will require a U.S.
I\rm)' Corp of Engineers (USACE) :\ationwide or Individual (developed [or the entire Program) permit. This requirement may be avoided by boring under these areas. Road Development Roads
used to access oil and gas locations are rarely permanent and exist only as long as necessary to complete exploration and production operations. Things to consider when constructing
a road: • Road width, maximum grade, and crown design. • Location of turnouts. • Plans for soils, hydrology, and topography -dependant drainage, including ditches and locations and sizes
of culverts and bridges. • On and off-site erosion control. • Plans for re-vegetation of disturbed areas. • Fence cuts and cattle guards. • Major cuts and fill. • Source and storage
sites for topsoil. Plans for maintaining roads. All roads must be designed, constructed, and maintained in a safe and environmentally responsible manner. Roads have the potential to
Cause environmental harm through erosion, air pollution, stream degradation, habitat alteration, and increased public use. Careful attention to the proposed road location and design
can significantly minimize environmental impacts. When selecting a location for new roads, consider following topographic contours. Following natural contours preserves natural drainage
patterns and typically results in lower costs and less impact on the environment. I nitial steps in road location include: • Determine the intended usc ofthc road including seasonal
use, type of vehicles to be used, and amount of traffic, and safety. • Examine biological, physical, and cultural conditions ofthe area. • Consider geotechnical factors including soil
type, construction I reclamation limits, landslide areas, water prohlcm areas, etc. Basic Design Requirements: Design for pre-determined speed limit. • Typically width is 24 feet \\ith
turnouts in areas where wi,hh is less than 16 feel.
.-. --Chevron U.S.A Slortll\vJtcr .\li:H:olgclllent Plan -April, 2009 -;\ . • Road gradient has major impact on erosion and visual impact. Follow natural terrain as closely as possible.
If terrain allows, gradient should not exceed 8 percent except Illr short distances of 300 feet or less. • Drainage control must be ensured over thc cntire road through the use of drainage
dips, in sloping, natural rolling topography, ditch turnouts, ditchcs, or culverts, Ditches and culverts may be required in some situations depending on grades, soils, and local hydrology.
If culverts or drainage crossings are needed, they should be designed for a 25 year or greater storm frequency. • Gravel may be needed for "soft" road sections, steep grades, highly
erosive soils, and clay spoils. • Culverts should be designed for 25 year (one-hour duration) storm frequency with an allowable head that does not overlap the roadway. The minimum size
culvert diameter is 18 inches. Construction: • Excavation and fill construction will be performed to secure the greatest practicable degree ofroadbed compaction and stability. • Use
of excess excavation material, where practical, shall be practiced to improve the road grade or to flatten fill. • Roadbed materials shall be placed parallcl to thc axis of the roadway
in evcn, continuous horizontal layers. Surface and Drainage Structures: • The proper design and construction of structures for the surface drainage of water frol11 01' through the roadway
contributes the most to the long-term success of the road and structure, and minimizes maintenance and adverse environmental effects such as sediment erosion and sediment production.
It is vitally important to keep water off the road. Surface drainage provides for the interception. collection, and removal of "vuter from the surface of roads and sloped areas. The
design may need to allow for debris passage, mud flows, and water heavily laden with silt. sand, and gravel. • Thc need for drainage structurcs can bc minimizcd by proper road location.
Howevcr, properly designed drainage is essential for a stable road. Drainage system must include the best combination of various design clements, such as ditches, culvelis, drainage
dips, crown, in-slope or out-slope, lo\\' water crossings, subsurLlce drains, and bridges. Drainage Structures -Propel' location and design can providc economical and efficient drainage.
Structural measures are ollen required to ensure proper and adequate drainage. Some ofthc most common structures are drainage dips, ditches, road crowning, culverts, bridges, and low
water crossings. o Drainage Dips -The primary purpose of a drainage dip is to intercept and renw"e surface water from the roadway and shoulders beforc the combination before the combination
of water volume and velocity begins to erode the surface materials. Spacing of drainage dips depends upon loeal conditions such as soil material, grade, and topography.
Chevron U.S.A Stonnwatcr :'vli1n'U:ieml'll~ Plan -/\pril. 2009 ~;f'~ o Ditches -The design of ditches must consider the resource objectives for soil, water, maintenance capabilities
and associated costs. Ditch grades should be no less than 0.5 percent to allow for positive drainage and avoid sedimentation. o Road Crowning·-Crowning provides good drainage of water
li'om the surface of the road. Drainage or the inside ditch anel sielc hill runllffis essential irthe road is to be kcpt dry and passable during wet weather. o Culverts -Culverts are
used in two applications: (I) to allow the normal drainage ti'om streams and gullies to flow under the roadway and (2) to drain inside road ditches. All culverts should be laid on natural
ground or at the original elevation of any drainage crossed, except as noted below for ditch relief culverts. Culvert diameter design criteria should be a minimum of 18 inches. A hydrological!
hydraulic analysis should be performcd to determine the amount of water anticipatcd to flow through the culvert. Analytical factors that must be considered Include the delineation of
the drainage basin, soil types, drainage area slopes, and at a minimum a 25-year (one-hour duration) precipitation event. The outlet for all culverts should extend at least aile loot
beyond the toe of any slope. It may be necessary to install rip-rap or other energy dissipation devices at the outlct end of the culverts to prevent soi I erosion and trap sediment.
All culverts used in thc construction of access roads should be concrete or corrugated metal pipe (made of steel). Properly bedded and backfilled corrugated plastic pipe may be used
for secondary drainage but should not be used as part oj" any roadbed. Evacuation, bedding, and backlllling of culverts should be conducted according to Program specifications. Ditch
relief culverts are installed to periodically relieve the ditch line !low by piping water to the opposite side of the road where the flo\v can be dissipated away from the roadway. The
spacing of ditch relief culverts is dependent on the road gradient, soil types, and runoff characteristics. The dcpth of culveit burial must be sufftcient to ensure the culvert is protected
lor its design life. This requires anticipating the amount of material that may be lost due to road use and erosion. The culvcrt gradient should be greater than the approach stream or
ditch gradient. This improves the t10w hydraulics and reduces sedimentation and debris plugging at the culvert inlet. Additional factors to consider for construction activities involving
drainage channels: Bridges and 1vlajor Culyerts: • Construction of some stream crossings may require a USACE Nationwide (404) or Individual Permit. Where a road is open to public travel,
applications \\"ill be prepared and submitted with sufficient time allowed for any required public comment input periods and approval of the pcrmit by the surC1ce management agcncy.
Wetlands: • \Vetlands arc especially sensitive areas and should be avoided, if possible. Generally, these arcns require crossings that prevent unnatural Iluctuatiotls in waler leVel.
Under
Chevron U.S.A StoJ'lllwater Man<lgCll1Cllt Plan -April, 2009 wetland circulllstances, culverts should be designed with a nat grade so water can now either direction and maintain its
natural level on both sidcs. Spccial attcntion should bc gi yen to selection of culvert materials that will resi sl corrosion. Loll' Water Crossings: • Roads may cross small drainages
and intermittent streams wherc culverts and bridges are unnecessary. The crossing can be effectively accomplished by dipping the road down to the bed of the drainage, The construction
of gravel, rip-rap, or concrete bottoms may be required. In no case should the drainage be tilled so that water will be impounded. Low water crossings that are not surfaced should not
be used in wet conditions. Appropriate B)'IPs must be used in sensitive areas to ensure proper site stabilization, Site specific SWMP maps for all road construction or improvements will
bc developed as part of the engineering design and provided as an attachment to this plan, Facilities Dcvelopmcnt The category of Facilities is intended to capture all projects constructed
in a supporting role to the production facilities previously described. Program facilities will include offices, maintenance facilities, water storage and treatment facilities, compressor
stations, man camps, and communication towers, A site specitic SWMP lIlap for each facility will be developed as part of the engineering design and provided as an attachment to this
plan. As many of these facilities may be "one of a kind", more detailed inli.mnation may be provided to addrcss specific site conditions and construction activitics. During the initial
stages of construction, heavy equipment will be used to shape and contour the construction site and any access roads. Design and construction techniques and other practices are to be
employed to minimize surface disturbance: and the associated effects of proposed operations and maintain the reclamation potent in I of the site. Steps will be taken to avoid or mitigate
construction on stcep slopes, riparian arcas and other areas deemed as areas subject to severe erOSIOn. Construction procedures will seek to minimize surl11ee disturbance. All topsoil,
when practical, is to be removed from the entire cut and fill area and stored in a designated stockpile for reuse during interim and final reclamation. Topsoil must be segregated and
stored separately from subsurface materials to avoid mixing during construction, storage, and interim reclamation. Stockpiles should be properly located and protected so minimize wind
and water erosion and maximize available topsoil for reclamation. To reduce erosion and soil loss, it may be appropriate to divert stonnwater aIVay limn facility construction sites with
ditches, berms, or waterbars above the cut slopes and to trap well location runoff and sediments on or near the location through use of sediment controls, Sediment controls will dominate
this early phase of construction. Temporary 13:Y!Ps such as silt Cences. waddles, and erosion controls will be used in the jnitial stages to provide perinlctcr
Chevron U.S.A Stormwater ~v1at1agellle!lt PLm -April. 2009 sediment runoff control. As the construction work progresses and the contour of the site are completed, more permanent structural
and non-structural BMPs will be implemented. The focus in thcse later changes \\'ill be on implementing effective erosion controls and in attempting to rcvegetate disturbed areas \ ...
·ith natiyc grass seed mix. A sUllunary of the prilnar~./Program 13l'vlPs is providcd in Appendix C. The attachment includes information on BMPs, itlcluding where and when to use them:
their limitations, along with construction details and maintenance requirements. Production Star;es The production phase follows the development phase and includes the operation and
maintenance activities that will be conducted during natural gas production. The typical equipment on a pad during the production phase consists of a wellhead, a separatioll unit, trom
one to several 400-barrd capacity aboveground tanks for condensate, atld an above ground tank for storing produced water. Gas pipelines are also installed during this phase of work.
Reclamation activities during this phase include maintenance of re-vegetated areas and maintenance of the erosion and sediment control structures. Natural gas wclls in thc Skinner Ridge
area are projected to produce for approximately 20 to 30 years. Well Pads Once the well pad site is constructed, drilling operations will begin. Depending on the number of wells to be
completed and the local conditions encountered, drilling operations at a specific well pad may take six to nine months to complete. Each pad will have reserve pitts) to handle and contain
drilling fluids and cuttings. As part of drilling operations, chemicals used in drilling operations will be stored onsite. A comprehensive list of chemicals that will be used at well
pads is provided as an attachment to this plan. PetroleuIll products also lllay be present at the well pads, including gasoline, diesel fuel, lubricant oils, hydraulic oils, used oils,
and solvcnts. Ditches will be placed around chemical storage areas to capture and direct any spills to a well cellar. Well pad drainage is designed to flow to the reserve pits in the
event of a large spill or release. Drip pans will be utilized if necessary. All wastes will be placed and stored in the proper receptacles prior to removal for ofl~site disposal. All
storage of petroleum products will be in accordance with the Piceance Basin Field Spill Prevention Control and Countermeasures (SPCC) Plan. Housekeeping will be maintained in all chemical
storage areas. All containers me to remain closed except when adding or removing materials. Where appropriate, materials will be storcd in locations to prevent containers from being
exposed to precipitation evcnts. Inspection of chemica! storage areas will be included as part of the SW'vlP inspection program.
Chevron U.S.A Stol"lllwater Management Plan, April, 2009 : .. The production phase includes the operation and maintenance activities associated with natural gas production. Typical well
pad equipment includes a wellhead, a separation unit and one or more 400 barrel capacity above ground storage tank(s) containing condensate and or produced water. Secondary containment
will be provided around chemical storage areas including condensate tanks and separators. Reclamation activities during this phase include maintenance ofre-vegetated areas and maintenance
orthe erosion and sediment controls structures. Installation, inspection and maintenance of 8MPs to control sediment runoff will continue as needed. New 8MPs will be installed and maintained
as required. Once drilling operations have been completed and prior to beginning production, parts of the well pad will be reclaimed. Initial pad rcclamation is accomplished by back
tilling the reserve pit, contouring the disturbed soils to conform to the surrounding terrain, replacing stockpiled top soil, seeding of disturbed soil areas in order to reestablish
a cover vegetation, and construction of erosion and sediment control structures. Oil and gas sites are considered stabilized once sitc preparation and interim reclamation are complete,
and the above final stabilization criteria have been met, even though the site will be disturbed again in the future for final reclamation. Interim reclamation consists of minimizing
the footprint of disturbance by reclaiming all portions of the well site not needed for production operations. The portions of the well site not needed for operations and safety purposes
will be re-graded to a final or intermediatc contour that blends with the surrounding topography as much as possible. Topsoil will be re-spread over areas not needed for all weather
purposes. "Final stabilization" means that all ground surface disturbing activities at the site have been completed, and all disturbed areas have becn cither built on, paved, or a uniform
vegetative cover has been established with an individual plant density of at least 70 percent of per-disturbance levels. Pipeline Completion and Reclamation Pipeline route reclamation
involves placing till in trenches, compacting fill, re-grading cut and till slopes to restore the original contours. replacing tOJlsoil, installing temporary waterbars and silt fencing
only whcrc necessary to control erosion. and re-vegctation. Waterbars and other appropriate 13MPs must be maintained and rcpaired as necessary. Following slleeesslill revegetation, remaining
water bars are to be flattened to blend with the slope. Road COlllpldion and Reclamation Maintenance activities normally required include blading. surface replacement, dust control,
spot repairs, slide rC1110vat ditch cleaning, culvert cleaning, litter pickup .. noxious weed con1roL maintenance of interim reclamation: and ~now removal. Additional inspections and
maintenance
Chevron U.S.A Storlllwatcr Management Plan . April, 2009 may be needed during periods or sno\\me!t or hem'y, prolonged rainfall to look for cirainage, erosion, or sedimentation problems.
Re-vegetation of road ditches and cut and 1111 slopes will help stabilize exposed soils and reduce sediment loss, reduce the growth of noxious weeds, reduce maintenance costs, maintain
scenic quality and forage, and protcct habitat. To ensure successful growth of vegetation, topsoil must be stored in designated stockpiles (where ""ailable) during road construction
and re-distributed On cut slopes, till slopes, and borrow ditches prior to re-vcgetation activities. Facilities Production Activities and Reclamation Many of the tacilities constructed
will be active for as long as the field is in production. As part of operations, materials and chemicals may be stored onsite. All product and any generated wastes will be placed and
stored in the proper receptacles prior to use or removal for off-site disposal. Where appropriate, secondary containment will be provided for storage of materials, chemicals and wastes.
All petroleum based materials will be stored in accordance with the Piceance Basin Field spec plan. Housekeeping will be maintained in all chemical storage areas. All containers are
to remain closed except when transferring materials in and out of the container. Where appropriate, materials will be stored to prevent their containers from being exposed to precipitation
events. Interim reclamation consists of minimizing the footprint of disturbance by reclaiming all portions of the site not needed for support of production operations. The portions of
the site not needed are to be re-graded to a tina 1 or intcrmediate contour that blends with the sUlTonnding topography as much as possible. Topsoil will be re-spread over areas not
needed for all weather purposes and the areas will be re-vegetated with native grasses. "Final stabilization" means that all ground surface disturbing activities at the site havc been
completed, and all disturbed areas have been either built on, paved, or a uniform vegetative cover has been established with an individual plant density of at least 70 percent of per-disturbance
levels. Documented inspections will be performed during this period to ensure proper site stabilization.
Fillal Reclalllatioll , Chevron U.SJ\ Storll1\\,<lLcr :\1allagcrnent Plan -April, 2009 !.:" .f,' r ollowing the development and production phases, all production facilities will be reclaimed
by contouring disturbed soils to conform to the surrounding terrain, by replacing the stockpiled top soil, by seeding of disturbed soil areas in order to reestablish cover vegetation,
and by construction of erosion and sediment control structures as needed. Once stabilization is achieved, defined as uniform vegetative cover established with a density of at least 70
percent of pre-disturbance levels, a construction project may be removed from the SWMP inspection program. EMPs will stay in eHeet as an ongoing company practice to ensure proper management
of storm water protection. If petroleum hydrocarbons or other chemicals impact stormwatcr as a result of industrial activities omitc, the impacted stonmvater will be addressed by following
the provisions contained in the Piceance Basin Field spec plan. Well Pads The site will be reclaimed after the end of its operational lite in accordance with local, state and federal
requirements. Following well plugging, rcclmnation activities will include removing all production equipment and re-grading the site to the original contours of the surrounding terrain.
All excavations and pits lUust bc closed by backfilling when they arc dry and li'ce of waste. Subsequent steps include replacement of topsoiL re-vegetation of the site with the appropriate
seed mix (see Table 2), and installation and maintenance of storm-water controls until final stabilization is achieved. Water breaks and terracing should only be installed when absolutely
necessary to prevent erosion of fill material ane! should be removed when the site is successfully re-vegetated and stabilized. Pipelines Final abandonment of pipelines and 110w lines
will involve l1ushing and properly disposing of any residual fluids remaining in the lines. All pipeline sections that have become exposed due to water or wind erosion, soil movement,
or anticipated subsequent use, must be removed. Deeply buried lines may remain in place unless otherwise directed by the authorizing agency. Roads Roads used to access oil and gas locations
are typically constructed for that primary purpose, are rarely permanent, and exist only as long as necessary to complete exploration and production operations. Final reclamation includes
re-grading the road back (0 the original contour, seeding, controlling noxious weeds, and ma)' include other techniques (0 improve reclamation success such as ripping, scarifying, replacing
topsoil, placing waterbars. pitting. and mulching. Seeds of native. perennial species will be used.
Chevron U.S.A Storlll\Vatcr MClll;'lgcmcnt Pbn -April, ~009 i '-!n. Facilities The site will be reclaimcd aftcr the end of its operational life in accordance with local, state and federal
requirements. Reclamation activities will includc removing all buildings and equipment and re-grading the site to the original contours of the surrounding terrain. Subsequent steps include
replacement of topsoil. re-vegetation of the sitc with the appropriate seed mix: and installation and maintenance of storm-water controls until tin,li stabilization is achicved. \Vater
breaks and terracing should only bc installed whcn absolutely necessary to prevent crosion of fill material and should be removed when the site is successfully re-vegetated and stabilized.
I.e Estimate of Total AI'ea of Site and Acres Disturbed The total arca of disturbance including the natural gas \\'ell pads, thc access roads and gathering system pipeline will be approximately
370 acrcs. l.D Soil Data and Erosion Potential According to the Natural Resource Conservation Service (NRCS) Soil Sur"ey Map of the Douglas Plaleall Area. Colorado, Paris of Gar/ield
and Mesa COlln/ies, the subject area is located within the Piceance Basin on the eastern Ii-inge of the Colorado Plateau. It includes the Roan Plateau, Bookcliffs, and is adj aeent to
portions of the Grand Mesa and Grand Valle), areas. It consists of deeply incised valleys, entrenched plateaus, and foothills. The broader portion of the valley is carved out by the
Colorado River and its tributaries. The developmcnt site clevation ranges from a valley floor elevation of ),800 feet to a height of 8,500 feet at the Roan Plateau. The Roan Plateau
extends north into Rio Blanco County. and surrounds the Skinner Ridgc property. The shallowest stratigraphic unit in the Piceance Basin is the Uinta Formation. which consists of discontinuous
laycrs of silty sandstone, siltstone and marlstone dcposits. The Uinta Formation o\'erlies the Green Ri\,('l" Formation: which contains \'<:1st deposits of oil shale.
Chevron U.S.A StonllW<lter \~,lI1clgL'IllCl1l Plan -Apl"iL 2009 The Wasatch, Lowcr Fort Union and Mesaverde Formations underlie the Grcen River Formation, and consist of sandstones,
mudstones, and coal. These /(Jrlnations represent the Im~or gas producing formations of the Piceance Basin. The natural gas occurs as non-conventional gas at the Skinncr Ridge developmcnt
site. Surhce anc! groundwater features are located within the upper reaches of thc Clear and Roan Creeks. wllere the Program area lies. These features consist of ephemeral streams fed
by seasonal rainf111 and snowmelt. Springs and seeps are also observed throughout the area. One seep in particular, was harnessed with a cistern and used for habitation of a historical
site near the conl1uence of Tom Creek and Clear Creek. 'vIost of the geological material underlying the Skinner Ridge property is impervious to water. Except for the alluvium within
the major streambeds, there is no known extensive aquifer. The alluvial aquifer consists of narrow and relatively thin sand and gravel deposits adjacent to and bcneath Clear Creek. In
the northern portion of the developmcnt site, the alluvial aquifer is underlain by the confining unit below the Lower Piceance Basin aquifer (Douglas Creek Member of the Grcen River
Formation), which consists of tine-grained sandstone, limestone and shale. And, in the southern portion of the site, the alluvial aquifer is underlain by the Wasatch Formation, which
consists of sandstone and shale. The Roan Plateau is underlain by the Uppcr Piceance Developed Spring at the Confluence of Tom and Clear Creeks Basin aquifer (Uinta Formation), which
consists of silly sandstone and fractured siltstone. The hydraulic gradient in the bcdrock aquifers underlying the Roan Plateau is predominately vertical and downward. However, along
the margins of the plateau there arc strong horizontal hydraulic gradients !lowing toward the cliff faces and valley slopcs. Because of these strong horizontal gradients, ground water
is discharged Ii·om the bedrock aqui fers as springs even though the bedrock aquifers dip away from valley slopes. "lul11erous seeps and springs are present along the valley slopes above
Clcar Creek and a large seep is present on the valley slope above Tom Creek. Detailed soil information was collected as part of Chevron·s internal EII1"il"olllllel/lal, Social and Ifealrh
/III])O({ A.lSeSSllleI11 (ESHIA) (ERM, 2008). Three main groups of soils are present within the Program area: (I) soils along drainages, (2) soils alongside slopes. and (3) soils atop
plateaus (also referred 10 as mesas). The soils along the drainages occur on benches: terraces. alltlyial Ems. and l100dplains in the valleys or Roan Creek, Clear Creek, and their tributaries.
These soils are deep, well to somewhat
Chevron U.S.A Stormwatcr Management Plan -April, 2009 . poorly drained, and nearly !n'd to gently sloping, with water erosion hazard ranges li'OJll slight to sevcre. The soils round
along the drainages include soils that are classified as prime farmland. The soils along the side slopes or Skinner Ridge, ['uddin Ridge, and other slopes along the mesa and other mountain
slopes. arc dominated by shallow, poorly dcveloped soils and roek outcrops. These soils have a severe erosion potential and some have very steep slopes that limit their potential for
construction and re-vegetation. The soils on the plateaus and mesa tops are mostly well-drained, cool soils, with dark-colored, organic-rich surface layers. These soils have a slight
to severe erosion potential. In areas that are disturbed by construction, soil materials will be managed so that erosion and sediment transport are minimized. J'-:earby drainages will
be protected by appropriate measures. The road will be graded and sloped to drain into roadside ditches and to direct runol1 ii'om adjacent slopes away liOJn thc road surface. The development
consists of the construction of roads, pipelines, drilling pads and gas treatment facilities. The construction of the facilities in the development area will be done using conventional
cut and fill, trenching and earth moving techniques. I.E Vegetation Description and Estimate The cleven vegetation communities that were found in the Program area are listed below. The
vegetation communities in the Program area reflect the wide ranges of elevation, topography, aspect, and moisture. Aspen forcsts, deciduous oak scrublands, Douglas fir forests, mesic
upland shrub communities, and mountain sagebrush shrub lands are common in the higher elevations of the Piceance area. Big sagebrush shrub lands, riparian areas, Vegetation Community
Type Percent of Study I Area _ .-j and irrigated cropland are present in the decp valleys. Juniper woodland forests, greasewood flats, and desert Aspen forest Bio sagebnlsh Desert shrub
Douglas fir forest land I 4.0 2.6 1.2 -6.2 shrub communities are common on Exposed rock 1.0 .. _--the exposed steep slopes, in dryer Forest-dominated riparian lJ areas) and on shale
plateaus. Greasewood fans and Hats 1.3 l!liaated cropland 7.6 I .. ----------_. Juniper woodland forest land -5.2 .~I V cgetation eommmutics have developed across the landscape in response
to climate, disturbance. and other envirolUllental factors. _____J _ _-=-22c_..: 2 :_ _---c ___ .L.. __ ~6. 7 Additional information about vegetation communities associated with the
various soil types is presented in Table 1. Identitication of the vegetative community to be disturbed is very important. because some types are more sensitive to disturbance, while
others are far more resilient.
Chevron U.S.A Storillwater Management Plan· April, 2009; ;.J:. Climate information was collected as part of the ESHIA study, The ESHIA report describes the general climate of thc study
are" as innuenced by dry air, sunny clays, clear nights, variable precipitation, with moderate cvaporation ancl large diurnal tempcrature changes, These arc generally due to changes
in topography between the valleys and mesas, Annual precipitation ranges ii'olll about IOta 20 inches, Seasonal and daily temperatures vary with elevation and, to a lesser extent, local
microclimates, Daily temperatures. in degrees Fahrenheit, in the summer usually range from the upper 40s to the lower 80s in mountain terrains, and mid 90s in the western valleys, In
the winter, cold air commonly accumulates in the valleys. Prevailing winds in the upper levels of the atmosphere are mostly from the southwest, but local air mo\'emeIllS are strongly
innuenced by topography including elevated mesas, steep slopes, narrow canyons and rough terrain in the Study Area. l.F Potential Pollution Sources and Locations Potential pollution
sources associated with construction sites and natural gas development include: • Sediment resulting ii-om erosion of soil stockpiles and other areas cleared of vegetation: • Leakage
of fuels and lubricants from equipment and spills from fueling; • Trash and debris hom clearing activities, construction materials, and workers; • Leakage or spills from storage tanks
and process equipment associated with natural gas deVelopment; • Concrete washout water: • Vehicle tracking The most common source of pollution from pad and access road construction
is sediment, which can be carried away from the work site with storm water runoff and impact the water qual it)' of a recelvtllg strcam, Clearing, grading, and otherwise altering previously
undisturbed land can increase the rate of soil erosion over pre-disturbance rates. Refined Petroleum products can also be potential storm water pollutants. Thcsc products arc used in
construction activities to power or lubricate equipment and include: fuel, gear oil, hydraulic oil, brake fluid, and grease. Loading and unloading of condensate and produced watcr from
ahove ground storage tanks arc common and regular activities lI'ithin the Skinner Ridge project area that may contribute to stortnwatcr contamination. Debris hom lay down areas, residue
ti'Olll equipment cleaning and maintenance, ancl solid waste generated li'om land clearing operations and human activity (trees, brush, paper. trash, etc,) present other potential pollution
sources within the construction site, Spills or leaks li·om potential petroleulll bascd sources are described in the SPCC plan, Response to certain events may require specialized training
due to health and safety concerns. For (\ list or ,
Chevron USA Stonnwatcr ~fatlagcmcnt Plan· April, 2009 the most common down-hole chemicals used during development activities please reter to Appendix B. Concrete trucks must be rinsed
out prior to leaving the site and this water has the potential to contaminate stormll'ater if not properly handled. Typically concrete wash out waters will be diverted to reserve pits
or other earthen impoundments to capture and evaporate wash out water. l.G NOIl-Stormwater Discharges l\on-storm water discharges anticipated from the project inc.lude permitted construction
dewatering and pipeline hydro-test waters. In addition, the extraction of natural gas can producc large quanti tics of water that are trapped in the formation along with the gas. Over
the life of this project, much of the produced water will be used for hydraulic fracturing operations or disposed of in an on-site permitted injection well(s). In addition, transportation
to an approved ofl~site disposal will remain a viable option in the event additional disposal is needed. Any storage of produced water will be covered under provisions of the SPCC Plan
including secondary containment and inspection requirements. l.H Receiving Waters The initial Program area lies in the Roan Creek watershed, which includes Clear Creek and its tributaries,
with future development in the Parachute Creek watershed. Under the Colorado Water Quality Control Commission, Regll/lllion 37, Reglilaliol1s for lize Lower Colorado Basin, these are
named Segments l4a and l4b of the Lower Colorado River Basin and Sub-basin. Segment l4a includes the main stem of Roan Creek including all wetlands and tributaries, [rom the source to
a point immediately above the confluence with C!car Creek (except for a listing in Segment l4b); Clear Creek, including all tributmies and wetlands, li-Olll the source to a point immediately
below the contluenee of Tom Creek. Segment 14b consists of Clear Creek, including all tributaries and wetlands, from a point immediately below the eontluenee with Tom Creek to the eontluence
with Roan Creek: Roan Creek, including all tributaries and wetlands. li'Oll1 a point immediately above the contluence with Clear Creek to a point immediately below the confluence with
Kimball Creek. Segment 14a is designated as reviewable and its c1assitied benellcial uses are: aquat,e life class one cold, recreation P (primary contact), water supply, and agriculture
(irrigation and cattle grazing). At a recent rulemaking hearing (June 2008), the Division indicated that this segment warranted a cold temperature srandard tier L due to the presence
of brook and cutthroat trout. This is indicative of a sensitive habitat that should utilize greater protection when considering disturbance and proper selection of stabilization and
erosion controls [typically referred to as Best Ivlanagemcnt Practices (B:V1Ps)].
Chevron U.S.A Stol"Jllwatcr \],magctncnt Plan -April. 2009~. ·'·.i Scgment 14b has the same designation and classified use; however, it has a cold temperature standard lier II, 1<)r
lhe presence of rainbow and brown trout, mottled sculpin, mountain whitefish, longnose sucker, and Arctic grayling. Again thesc designations are indicative of a sensitive habitat warranting
greatcr protection whcn considering disturbance proper selection of B\I'IPs. 2. Site Maps Due to the expanse and total acreage of the permitted area, one master map of the entire arca
will be provided with the SWMP. On this same note, the area is too large to address all construction boundaries on one map. Please refer to the site specific maps/inspection forms to
accurately depict these items. 2.A Construction Site Boundaries Please refer to the site specific mapslinspcction forms form an accurate depiction of Construction sitc boundaries 2.B
Areas of Ground Disturbance Please refer to the sile specific mapslinspcclion forms form an accurate depiction of areas of ground disturbance. 2.C Areas of Cut and Fill Pleasc refer
to the site spccil1c maps/inspection forms form an accurate depiction of areas of cut and till. 2.0 Storage Areas for Materials, Equipment, Waste, and Soil Please refer to the site specitic
maps/inspection forms form an accurate depiction of storage areas Cor material, equipment. waste: <:md soil. 2.E Location of Dedicated Asphalt or Concrete Bntch Plnnts There will be
no dedicated asphalt or concrete balch plants lI·ithin tbe permitted area that are under the control oj' Berry Petroleum.
Chevron U.S.A Slormwatel' j',l;anag:cllll:l1l Plall -/\pril, 2009 2.F Locatioll of All Structural BlVlPs. Please refer to the site specifIc maps/inspection forms form all accurate depiction
of locations Gnd type of all structural BMPs. 2.G Locatioll of Non-Structural BMPs Please refer to the sile specific maps/inspection forms form an accurate depiction of locations and
type of all non-structural BMPs 2.R Location of Springs, Streams, Wetlands, and other Surface Waters Please refer to the site specific mapslinspection forms [orm an accurate depiction
of locations of all springs, streams, wetlands, and other surface waters.
Chevron U.S,A S~orn1\\"(ltL'r \lJilJgemcnt Plan -April, 2009 3. Stormwuter Management Controls Structural 8MPs will be installed, inspected, and maintained as needcd. Description of
typical 13MPs that may be used on individual construction sites are provided in Appendix C. This SWMP will be revised as needed to address nell' disturbances. Depending on the type and
location of new facilities there may be a need for inclusion o[ new and different BMPs. In general, new development should be planned with considcration for storm water quality (e.g.
minimize disturbed area and maximize distance [rom surface water drainages, as practicable). Other devciopments on the property, primarily existing and/or improved roads, not currently
or specifically addressed in the SWMP will be periodically checked for erosion and drainage problems. This is especially important for access roads located within 100 feet of surface
drainages or creeks. If problems are noted, they should be reported to the Operations Supervisor and/or Chevron SWMP Administrator. Problem areas may be addressed through construction
activities, but will likely need to be addressed through BMPs which will be added to the plan as needed. 3.A Stormwater Administrator The property owner and operator is Chevron U.S.A.,
Inc. Their address is: Chevron U.S.A. Inc. 760 Horizon Drive Grand Junction, CO 81506 The Chevron contact person for the project is: SWMP Administrator(s): Richard Carroll lvlichael
DeBerry :vlanager, Piceance Basin Operations 760 Horizon Drive Grand .function, CO 81506 Otllce: 970-257-6005. Cell: 307-679-4050 Environmental Specialist. Piceance Basin Operations
ChevronlvlC A Ofllce: 970-257-6026 Chevron will be in charge of all aspects of this project. Contractor(s) will be employed for construction, drilling, and construction management, but
all \I,(lrk will be supervised by Chevron and all decisions will be made by Chevron.
Chevron U.S.A Slormwater l\'ianagel1lclll Plal~ -April, 2009 3.B Potential Pollution Sources Potential pollution sources associated with construction sites and natural gas development
include: • Sediment resulting li'om erosion of soil stockpiles anc! other areas cleared of vegetation: • Leakagc of fuels and lubricants from equipment and spills from fueling; • Trash
and debris from clearing activities, construction materials, and workers; • Leakage or spills hom storage tanks and process cquipment associated \I'ith natural gas development; • Concrete
washout water; • Vehicle tracking The most common source of pollution from pad and access road construction is sediment, which can be carried away Ii'om the work site with storm water
1l1llOff and impact the water quality of a receiving stream. Clearing, grading, and otherwise altering previously undisturbed land can increase the rate of soil erosion over pre-disturbance
rates. Retined Petroleum products can also be potential storm water pollutants. Thcse products arc uscd in construction activities to power or lubricate equipment and include: hIe!,
gear oil, hydraulic oil, brake fluid, and grease. Loading and unloading of condensate and produced water frOI11 above ground storage tanks are common and regular activities within the
Skinner Ridge project area that may contribute to storm water contamination. Debris li'Olll lay down areas, residue ii'OlIl equipment cleaning and maintenance, and solid waste gencrated
ii-Olll land clearing operations and human activity (trees, brush, paper, trash, etc.) present other potential pollution sources within the construction site. Spills or leaks from potential
petroleum based sources are described in the SPCC plan. Response to ccrtain events may require specialized training due to health and safety concerns. For a list of the most common down-hole
chemicals used during development activities please rder to Appendix B. Concrete trucks must be rinsed out prior to leaving the site and this water has the pOlential to contaminate storm
mIter if not properly handled. Typicall\' concrete wash out waters will be diverted to reserve pits or other earthen impoundments to capture and evaporate wash out water.
Chevron U.S.A Storrn\\,(ltt~r \1a.n'1gemcnt Plan· April, 2009 3.e BMPs for Stormwater Pollution Prevention The objective of erosion and sediment controls is to minimizc the release of
sediments to storm water rllnoiI. This can be accomplished through a combination of structural and/or nonstructural controls. The following sections provide a description of typical
I3MPs employed to prevent soil erosion, work practiccs and managerial controls used to prevent storm water impacts, and fuels, chemicals, and materials handling practices. 3.Cl BMPs
for Soil Erosion and Sediment Controls The objective of erosion and sediment controls is to minimize the release of sediments to storm water runoff. This can be accomplished through
the use of structural and/or nonstructural controls. This section describes physical erosion and sediment controls to be used at active construction sites to minimize possible sediment
impacts to storm water runoff. For BMP installation details and selection guidelines refer to Appendix C and Figure 2. i\ berm is a ridge of compacted soil located at the top or base
of a sloping disturbed area to contain or diveli surface runoff. Where used, soil berms shall be constructed of soil with sufficient tInes to minimize flow through the berm. The purpose
of a berm is to control runoff velocity, divert onsite surface runoff to a sediment trapping or iiltration device and/or divert clean water away from disturbed areas. Check Dams Check
dams are small, temporary dams constructed across a di,·crsion or roadside ditch. Check dams cun be constructed using gravel, rock, gravel bags, geo-ridgcs, earth with erosion control
blanketing, straw bales, or wattles and are used to slow the velocity of concentrated flow in a channel. As a secondary function, check dams can also be used to catch sediment from the
channcl itself or hom the contributing drainage area as storm water runoff 110ws through or over the structure. Culverts Culverts are typically used to move ditch watcr under the road
or to direct stream t10w under the access road. Culverts are typically constructed out of concrek. stceL aluminum, or plastic pipe. Where used, culverts should have inlet and outlet
protection features to minimize erosion such as placing a non-woven textile materialuncler rip rap at each end of the culvcrt.
Chl'\'roll U.S.I\ Storillwaler Management Plan -April, 2009 Diversion Permanent diversion berms and structureS control storm water runoff by using a channel and an earthen ridge to prevent
sediment laden storm runoff from leaving the construction site, well pad or other disturbed area, to prevent nows from eroding slopes and to direct sediment laden nows to a trapping
device. Diversions are most often constructed of earthen materials with vegetative cover and are best used with channel linings such as vegetation or malting. Diversions are typically
used wherever the direction and velocity of runoff from up slope areas need to be controlled. A good example would be diverting up gradient surface runoff away [rom a well pad. Chal1llels
and berms must be designed to manage peak stann flow and must be stabilized to prevent erosion of the channels. Drainage Dip Drainage dips intercept and remove surface water from the
access roads, pads, facilities, pipelines, and roadside ditches (bcfore the combination of water volume and velocity begin to erode.) Drainage dips are constructed diagonally across
the flow of the surface water and will pass slow traffic while dispersing surface water. Erosion Control Blanket Erosion control blankets, and turf reinforcement mats (TRM), are porous
fabrics and are manufactured by weaving or bonding fibers made from organic or synthetic materials. Erosion control blankets are installed on steep slopes, over berms, or in channels
to prevent erosion until final vegetation is established. The erosion control blankets can also bc used as separators or to aid in plant growth. Filter Berm A filter berm is temporary
ridge made up of' natural materials that already occur on the project site. Brush filter berms use smali trce branches, root mats, grass, leaves, stone or other debris 01' material naturally
available or left over from the site clearing and grubbing. Rock filter berms use site gravel, stone, or rock. Both types of [!Iter berms are placed along a level contour to slow, filter,
and divert now and act as an eflicicnt form of sediment control. Geo-ridge Geo-Ridge® is a permcable ditch berm designed for erosion and sediment control. The usc of Geo-Ridge® reduces
now velocities and provides a smoother water now resulting in less erosion energy, and thus minimizing the prohlem of downstream sediment. Gravel Surfacing Gravel surfacing may be used
to coyer soil in areas of high traffic source as roads, Elcility areas~ and areas ncar the wdJ heads. Gravel surfacing forms a layer that protects and minimizes soil erosion and vehicle
soi I tracking.
Chevron U.S.A SlOr!l1WdlCr \l<1!l.Jgcmcnt Plan· April, 2009 , Land Grading Grading involves reshaping the ground surface to planned grades as determined by an engineering survey, evaluation,
and layout. Grading provides more suitable topography for well pads, pipelincs, facilities and access roads and helps to control surface runoff; soil erosion, and scdilllcntation during
and after construction in these areas. Grading also includes road cro\vning and sloping to properly route runofI alI the access roads. Level Spreader A level spreader is a BMP used to
prevent erosion and to improve infiltration by spreading concentrated storm water runolf evenly over the ground as shallow sheet now instead of through channels. It usually involves
a depression in the soil surface that disperses now onto a natter area across a slight slope and then releases the now onto level vegetated areas. This reduces now speed and increases
infiltration and promotes evaporation. Mulching Mulching is a temporary erosion control practice in which materials such as grass, straw, hay, wood fibers or wood chips are placed on
exposed or recently planted soil surfaces. Mulching stabilizes soils by minimizing rainfall impact and reducing storm water runoff velocity. Whcn mulching is used in combination with
seeding, surfacc soils retain moisture, promote seed germination and help insulate roots from extremes temperatures. Retaining Wall Retaining walls are structures that are used to stabilize
and hold soil in place, gain spacc on roadways or well pads, or to keep soil contained within a site boundary. This BMP can be constructed with rock, boulders, and/or cement blocks.
Re-vegetation Re-vegetation involves planting secd to establish a vegetative cover on disturbed areas. Revegetation reduces erosion and sedimentation by stabilizing disturbed areas in
a manner that is economical and adaptable to site conditions. It also reduces rUlloff volumes by increasing water percolation into the soil, binds soil with roots, and protects soil
from wind erosion, The permanent seed mix, rate, and application method is provided on Table 2. R!prap Riprap is a permanent, erosion-resistant layer made of stones, rock, or boulders.
It is intended to stabilize areas subject to crosion and protect against scour of the soil caused by conccntrated, high velocity flows. Roadside Ditches and Turnouts Roadside ditches
are channels constructed parallel to mads. The ditches convey concentrated runoff of surface water from roads and surrounding areas to a stabilized outlet. Turnouts are llsed
Chevron U,S.A Sto!'!llwater MJnJf,:ement Plan -April, 2009 -"-,.'' to cfrcctively reillove run-oil water from the roadside ditch into well-stabilized areas before it reaches a \vaterway.
Seciiment Trap Sediment traps are intended to intercept. trap. and retain sediment 11'OIn runoff while allowing detained runoff to slowly drain, inilltrate. or both. They are usually
installed in a drainage way or other point of discharge II'om a disturbed area. This BMP is formed by excavating below graele and/or constructing an earthen embankment with a protected
spillway (0 slow the releasc of runoff. Sill Fence Silt fences are used as temporary pcrimeter control structures that are designed to slow, temporary impound, and liIter sediment laden
water. Installation techniques and maintenance is critical to proper performance. Slope Drain Siopc drains arc used with earth dikes and drainage ditches to intercept and direct surface
flo\\' away from slope areas to protect eut or fill slopcs. A slopc drain is applicable for any construction site where concentratcd surface rUlloff can accumulate and must be conveyed
down a slope in order to prevent erosion. The slope drain may be a rigid pipe sllch as corrugated metal, flexible conduit or a lined terrace drain with the inlet placcd at the top of
thc slope ancl the outlet at the bottom of the slope. Inlets must be securely anchored and outlets must be stabilizcd with riprap. Stabilized Construction Entrance A stabilized cOllstruction
entrance is a pad of gravel laid over filter cloth wherc construction trattlc will be entering or leaving a construction site to or from a public right-of-way, strect or highway. This
is also referred to as vehicle tracking controL The purpose of a stabilized entrance to a site is to minimize the amount of traced mud and dust that leaves the site and tracked on to
county roads or state highways. As a vehicle drivcs over thc gravel, mud and sediment arc removed from the vehicle's wheels and oi'lsite transport of soil is reduced. This BMP reduces
erosion, tire rutting and the fllter L1bric separates the gravel from the soil below by minimizing the migration gravel into subsurfacc soil from heavy vchicle loads. A stabilized construction
entrance should be used at facility ingrcss and egress locations. Straw Bale Barrier A straw bale barrier is a series of entrenched and staked straw bales placed on a level contour to
interccpt sheet flows. The barrier reduces runoff velocity and (liters sediment ladcn runoff ii·om small drainage areas of disturbed soil. This I3MP may also bc used to protect against
erosion in small shallow drainage channels.
Straw wattles or rolls are intended to capture and keep sediment on slopes or in small shallow drainage channels. Straw rolls can be used to temporarily stabilize slopes by reducing
soil creep, shcct and rill erosion until permanent vegetation can be established. Straw rolls will last an average of one to two years. Surfacc Roughening Soil surface roughening is
a temporary erosion control practice oiicn uscd in conjunction with grading. Soil roughening involves increasing the relief of a bare soil surface with horizontal grooves (corrugating)
or tracks (tracking) using construction equipment. Slopes that are not fine graded and that arc left in a roughened condition can reduce erosion, trap sediment, and prepare ground surfaces
for seeding. Terracin!2 Terraces are made of either earthen embankments or ridge and channel systcms that are properly spaced along a fill slope. Terraces are constructed with an adequate
grade to promote drainage to a stabilized outlct. They reduce damage from erosion by collecting and redistributing surface rtmotf to stable outlets at slowcr spccds and by decreasing
the distance of overland runoff flow. They also surpass smooth slopes in holding moisture and help to minimize sediment loading of surLlce runot1. V egetati ve B uiTer Vegetative buffers
are areas of either natural or establishcd vegetation that arc maintained to protect the water quality of neighboring areas. Vegetativc bullers reduce storm water runoff velocity, prevent
soil erosion, promote in1iltration and act as a liltcr to rcmove sediment. A watcr bar is an earthen ridge, or ridge and channel, constructed diagonally across a slope road, trail, or
disturbed area. Water bars are normally used for drainage and erosion protection of closed, blocked. or infrequently used roads to divert storm water runoff and minimize erosion. AdditionalllMP
references: The structural and non-structural BMPs listed above arc intended to include 8MPs that may be used for gas gathering projects. However, there may be situations where a BMP
is needed but not included above or project personnel may need additional information on the use, specification, andmaintcnancc of BMPs. Additional infi1r111alion resources are listed
below:
Chevl'on U,S.A Storll1watcr :vlanagclllenL Plan, April, 2009 • For oil and gas operations, thc Bureau of Land Ivlanagement and U.S. Forest Service have developed "Suri'acc Operating
Standards and Guidelines for Oil ancl Gas Exploration and Development," "Gold Book." The most recent version (fourth edition) of this is available on the internet at http://w\v\\..blm.gov/bmp/Goldl3o
okJ)raftvll.pdf. • For construction BM!'s the Urban Drainage and Flood Control District, a Colorado hont range group of city and county agencies has developed a 13M!' manual that is
available on the internet at http://www.udfcd.org/usdcm/voI3.htm • For construction BMPs and surface stabilization methods, the Alabama Soil and Water Conservation Committee have developed
"Erosion Control, Sediment Control and Storm water Managemcnt on Construction Sites and Urban Areas, Volume I Developing Plans and Designing Best Management Practices," This information
is available on the internet http://swcc,state,al.us/pdti'ASWCC June 2003 Alabama Handbook Control.pdf at Construction E&S • For access roads, the US Forest Service and Bureau of Land
Management have developed "Low-Volume Roads Engineering, Best ::-'1anagement Practices Field Guide," which is available on the internet at !illp:/iwww.blnu2ov/bmpltleld%20guide.htm 3.C.2
Phased 8MI' Implementation Phasing for BMP implementation is described along with schedule of Development and Construction activities in Section 1,B 3,C.3 Materials Handling and Spill
Prevention Fuels and Materials Management Petroleum products which may be present at the construction site include: gasoline, diesel fuel, lubricant oils, hydraulic oils, used oils,
and solvents, Gasoline and diesel fuel will be stored in portable storage tanks with sccondary containment, Lubricant, hydraulic, and miscellaneous oils and solvents will be stored in
55-gallon 01' smaller containers, Pollutants fr0111 petroleu111 products used during construction activities adhere easily to soil particles and other surfaces, In case of a spill or
leak, soils contaminated with petroleum products will be contained and removed to a proper disposal site, Proposed soil erosion and sediment control practices will aid in retention of
spills or leaks, Use of secondary containment and drip pans will reduce the likelihood of spills or leaks contaetin~ the ground, Proposed maintenance and safe storage practices will
reduce the chance of petroleum products contaminating thc road site. Oily wastes such as crankcase oil, cans, rags, and paper containing oils will be placed in proper receptacles and
disposed of or recycled, An additional source of petroleum contamination is leaks from equipment and vehicles, Routine daily inspections will be conducted to identi1\' leaks and initiate
corrective actions. if ne\;?ded. The l<-)l\owing guidelines tor storil1g and managing pdrokulil products will be used:
Chevron U.S.A Storlnwatcr l\la!lagl'lllCll~ Piac -April, 2009 . All product containers will be clearly labeled. Drums \I'ill be kept off the ground within secondary containment and stored
undcr cover if necdcd. Fuel tanks will be stored within secondary containment. Lids of dru III III ccl materials will be securely lilstened. Emergency spill response procedures will
be available on-site. Persons trained in handling spills will be on call at all times. Spill cleanup and containment materials (absorbent, sho\'cls, etc.) will be easily accessible.
Spills will be immediately cleaned up and contaminated materials will be properly stored on site until they can be disposed of in accordance with applicable regulations. Storage areas
and containers will be regularly monitored for leaks and repaired or replaced as necessary. Contractors and subcontractors should be reminded about proper storage, handling and transferring
of petroleum products or other hazardous materials during safety Ineetings. All spills and releases shall be reported to the appropriate Federal, State and local agencies in accordance
with the procedures outlined in the Chevron Spill/Release Notification Procedures. Contained in this document is guidance on identifying chemicals and thresholds that are subject to
reporting and notification requirements established by various government agencies including EPA, COGCC, and thc CDP]-IE. Other Chemicals Products ;vlanagement Additional materials will
be used and stored on site lor use in construction. These materials will be stored appropriately and managed to minimize spills and leaks. Storage arcas will be regularly inspected and
an)' minor spills or leaks will be cleaned up immediately. Materials ManaQement The construction contractor will maintain a lay down or staging area for equipment and materials storage
on site. These areas will be maintained with good housekeeping and will be inspected on a regular basis for spills, leaks, and potential of materials commingling with storm water runoff
3.C.4 Dedicated Asphalt or Concrete Batch Plants There \\'ill be no dedicated asphalt or concrete batch plants within the permitted area. 3.C.S Vchicle Tracking Control The access roads
and pads used within the permitted area are unimpro\'ed and do not require the usc of tracking pads. Dust suppression is used to minimize airborne based sediment discharges. This is
done by spraying water or a mixture of water and magnesium chloride or another polymer as needed.
Cht";vrotl USA Stol"!11water \1anagelllellt Plan -April, 2009 3.C.G Waste Management and Disposal, Concrcte Washout \Vastc Management and Disposal \Vdl pad construction and drilling
will generate various other wastes during the course of construction. Other wastes may include the (ollowing: Sagebrush, shrubs and trees from clearing operations; Trash and debris from
construction materials and workers; Drill cuttings, drilling fluids: and Sanitary sewage. Each of these wastes will be managed so as to not contribute to stonnwater pollution. Construction
trash and debris will be collected in containers and hallied off-site for disposal in suitable landfills. Sanitary waste will be containerized in portable toilets or other storage tanks
with waste materials regularly pumped and transported off-site for disposal at approved facilities. There will be no need for a concrete washollt within the permitted area. Construction
Site Housekeeping HOllsekecping will consist of neat and orderly storage of materials and containerized l1uids. Wastes will be temporarily stored in containers and regularly collected
and disposed of at approved on~site facilities. If spills occur prompt cleanup is required to minimize any commingling or waste materials with storm water runoff. Routine maintenance
will be limited to fueling ancl lubrication of equipment. Drip pans ancllor absorbent material will be used during routine fueling and maintenance to contain spills or leaks. Any waste
product from maintenance \vill bc contained and transported 011' site for disposal or recycling. All attempts will be made to minimize major equipment overhauls conducted on site. Equipment
\\'ill be transported off site tor major overhauls if required. Cleanup of trash and discarded materials will be conducted during the course of each \\'ork day. Cleanup \\'ill consist
of patrolling the road way, access areas, and other work areas to piCK lip trash, scrap debris. other discarded materials, and any contaminated soil. These materials will be disposed
of in accordance with all applicable rules and regulations. 3.C.7 Ground Water and StOl'lllwater Dewatering No groundwater dewatering is anticipated at this time. If groundwater is encountered.
the dewatering orthe site will be regulated lw a dewatering permit issued through CDPI-IE. All stormwatcr will be diverted by diversion berms to avoid contact with the groundwater.
ChC\TOll U.S.A Stormwatcr Management Plall -April, 2009 4.0 Final Stabilization anel Long-tcl'Ill Stormwater Managemcnt Areas which have been disturbed are considered to be stabilized
when a uniform vegetative covcr with a density or 70 percent () r the pre-disturbance levels has been established or when an equivalent permanent, physical erosion reduction method is
in-place. The disturbed areas will be seeded and mulched for final stabilization. Tablc 2 contains approved seed mixtures and application rates provided by the Natural Rcsources Conservation
Services (NRCS) for the Skinner Ridge project area. Typical Pure Live Seed (PLS) application rates are recommended to be doubled if seeding is performed bl' hydro-seed or broadcasting.
Following the development and production phases, all production facilities will be reclaimcd by contouring disturbed soils to conform to the sUl1'0unding terrain, by replacing the stockpiled
top soil, by seeding of disturbed soil areas in order to reestablish cover vegetation, and by construction of erosion and sedimcnt control structurcs as needed. Once stabilization is
achieved, defined as uniform vegetative cover established with a density of at least 70 percent of pre-disturbance levels, a construction project may be removed Ii"om the SWMP inspection
program. BMPs will stay in effect as an ongoing company practice to ensure proper managcment of storm water protection. If petroleum hydrocarbons or other chemicals impact storm\\'ater
as a resull of industrial activities onsite, the impacted stonnwater will be addressed by f()llowing the provisions contained in the Piceance Basin Field SPCC plan and the COGCC Rule
1002.[" -Stormwater management that become effective on April I, 2009 (scc Appendix E). Wclll'acls The site will be rcclaimed after thc cne! of its operational life in accordancc with
local, state ane! federal requirements. Following well plugging, reclamation activities will include removing all production equipment and re-grading the site to the original contours
of the surrounding terrain. All excavations and pits must be closed by backfilling when they are dry and li'ec of waste. Subsequent steps include replacement of topsoil, re-vegetation
of the site with the appropriate seed mix (scc Table 2), and installation and maintenance of stor111-\\"atcr controls until final stabilization is achieved. Water breaks and terracing
should only be installed when absolutely necessary to prevent erosion of fill material and should be removed when the site is sllccessfully re-vegetated and stabilized. Pipclines Final
abandonment of pipelines and no\\' lines will involve Hushing and properly disposing of any residual Iluids remaining in the lines. All pipeline sections that have become eXJlosed due
to water or wind erosion, soilmovemenl, or anticipated snbsequent use, mllst be removed. Deeply buried lines may remain in place unless otherwise directed by the authorizing agcncy.
Chevron U.S.A StOl'llHvCltcr il'IClllagclllC'lll Plzln -April, 2009 Roads Roads used to access oil and gas locations are typically constructed for that primary purpose, are rarely pcrmancnt,
and exist only as long as necessary to completc exploration and production operations. Final reclamation includes re-grading the road back to thc original contour, seeding, controlling
noxious weeds, and may include other techniques to improve reclamation success such as ripping, scarifying, replacing topsoil, placing watcrbars, pitting, and mulching. Seeds of native,
perennial species will be used. Facilities The site will be reclaimed after the cnd of its operationallifc in accordance with local, state and fecleral requirements. Reclamation activities
will include removing all buildings and equipment and re-grading the site to the original contours of the surrounding terrain. Subsequent steps include replacement of topsoil, re-vegetation
of the site with the appropriate seed mix, and installation and maintenance of storm-water controls until final stabilization is achieved. Water breaks and terracing should only be installed
when absolutely necessary to prevent erosion of fill material and should be removed when the site is successfully re-vegetated and stabilized. 5.0 Inspection and Maintenance Procedures
To llleet requirements of the General Permit, inspection and maintenance of erosion and sediment controls must oeeur during the project. The inspection pl'Ogram will include the following:
1. A trained and qualified person familiar with the SWMP and storm water controls will conduct facility inspections and complete the Storm Water Field Inspection Report form in Appendix
D. 2. Inspections will eovcr these areas: Evidence of surface erosion for disturbed areas; Material and chemical storage arcas: Best Management Practices (m,,!!'s); Surface \-vater diversions
and do,,"n gradient areas; New access roads and ditches: and Locations where vehicles enter c1J' e:-;it the site. 3. Routine Inspections will be performed at least once every 14 or 30
calendar days in accordance with State requircments and within 24 hours after a significant precipitation or snow melt event that callses erosion. If no construction activities occur
following a
Chl2\TOtl U,S.i-\ Stonm,'(1tl2t' Management Plan· April, 2009 storm event, post-storm event inspcctions shall be conducted prior to re-commenemg construction activities but no later
than 72 hours follo"'ing the storm evcnt. 4. Permanently stabilized areas \Yill be periodically inspected to monitor ongomg conditions. 5. A log of inspections will be completed and
maintained for a minimum of three years. A copy of the inspections will be kept at the Hiner Gate Field Office along with electronic copies in the Grand Junction oHicc. 6. Inspections
are not required for disturbed areas "'hen snow cover exists over the entire site for an extended period as long as melting conditions do not exist. 7. Water quality will bc visually
assessed for all receiving streams and discharge areas during each inspection if prescnt. 8. Disturbed areas and material storage areas that are exposed to precipitation will be inspected
for evidencc of pollutants entering nearby drainages. 9. Check dams, wattles, and other BivIl's will be inspected for evidence of deterioration, under-cutting, and buildup of sediment.
Sediment will be removed when it has built up one-third to one-half the height ofthe hay bales or wattles. 10. Roads used for vehicle access will be inspectcd for evidence of on~sitc
sediment transport. 11. The SWMP will bc modified as necessary whenever there is a change in design, construction or opcration that changes the potential for pollutant dischargc to waters
of the state. 12. An inspection report sUlllmarizing the scope of the inspection, the name of ~he person conducting the inspection, date of inspection, and observations relating to the
implementation will be prepared. An example inspection report is provided in Appendix D. [3. Actions taken to modify storm water control measures will be recorded with inspection repolis
and maps and maintained with the SWMl'. Personnel performing facility inspcctions such as access roads, well pads or other operational facilities will record site conditions on the Storm
Water Inspection Report form in Appendix D. lnunediately when deficiencies are discovered, the Chen-on local contact will be contacted and will direct designated subcontractors to perform
BM], maintenance or replacement. Maintenance will include prompt adjustmcnts and repairs to crosion and sediment control structures that are found to be performing inadequately or deteriorating.
Signs of rill or gully surface erosion shall be immediately repaired. The Chevron local COIHact has the authority and will coordinate subcontractors to install nc" and or additional
storm water control 8MPs as needed.
Table 1
Soil "bp Lni1 7 12 2S 29 31 32 J6 ·12 44 :1:; ,I() "::>' ,).1 ~~ ~(, fl,; (1(, 67 (,() 70 71 75 7)l S(dl Sene:; .'\~a Ibdbnd 11,10. 1~led;;aw-SlInlip l~unkwa1cr Cumulic I faploh\)rolh
DeBeque Domingucz f)omin:;tlcz Fluvaqtlcnts Grohllllc Haprlc llappk 1I:I]lpk-R"ck outer(l)! aSS(lCI{I\I()I; Norlhwil\cr-.'\J<.:I complex l'anitc.:i1cl1 1)(!r~lehllle-IJii!\l1 ,','mpl,'"
!>;lr<lch\lll·-lrI~'.ll!-1\11"I1c.; ,1S~(lL:J;'II\lJl \Ii;h l(l;~m i-'>lTH>nilcllb warl1l~Rock outcrop complex I (\sea cllannery 'j'ravc;;sdlil-Rock outcrop complex Lfrcns litso-Rnck
outcrop complex WrayhaRabhil1.!X-Vea\cli complex YOlingslon Ecological Art'a Descriptioll Rivcrbotltllll Ridr,<:t'lpS alld c,lnY(>!l sidcs RlJllin;; lu;ull F()othill Juniper 1\lkalin...:
s!()Pc~ FOOlhili Swak Dcep loam Sc:midcsert Clay Loam Semitlcsert Clay Loam River noltom Muuntain Pinyon Rolling loam I "l:tTl1Y Slupc_, Ruck Outcrop SprucdSllbalptlH': Fir 1'()(11hill
SW:lk :-'I(lllil\,\in I,am :\1ld i.llam\ S;(lpC~ Ilflis!n 1,<1;\111 ;111(\ 1_, :llll\ \li)pc~ ;Vl<lI:l1I,li,l S,\-:d~' l'illyon/.lullljlcr Hrushy l.(l'llll Foothill Ju!\ipc[ Salt Flats
Rocky Maintain D()ugia:; Fir Moull1ain IJinY()J1 Loamy Salt desert Table 1 Prog.!:~ Soil Types Soil Texture --~~'i-,~ndy loam v"ic,llhncd bcdnlck Loam (,r<1vell), loam.'> Sandy 10:1111
Gravelly sandy clay loam V cry chanllcry loam Clay loam Clay loam Loam to gr:lVdly sandy clay loam Very ~h(lnncry loam V cry ell.1l1nc.:ry sandy loam Very channcry 1(1,1111 :;andy .Sandy
iO:Ul1 Clay loam L,)(l]1l [.,>:1111 I,Ll.11ll 1"l<1111 \In\\'~alllercd bedrock I.o<lm Sandy loam lO unwcmhcn.:d bedrock Loam Very channcl)' loam to llIlWe4lthcred bedrock Loam 10 Sandy
loam Loam Slope 0-3 I ()-6:' 3-12 10-40 I-X 1-3 5-20 1-3 3-8 0-3 30 -<i0 3-12 I ~-7.5 2:"-6:' :'i-50 1-6 )-30 2:i-:'i{1 1-12 35-'JCJ 25-80 10-35 1-8 40 -90 45 -65 1-6 Ruuoff Potential
Slow VCJY r:lpld Medium Rapid Slow Sinw Rapid Slow Medium Slow Rapid Slow \kditllll Rapid I'vkdiulll to rapid Slow i\:\cdlum to rapid Rapid .'ih)\\ Vcr) rapid Rapid Rapid Medium Rapid
Medium 10 rapid Slow Draillllgl' Class Well draiJl...:d Wcll draillcd Well drru'ncd \Vcll draincd Well drained Well drained to somewh,l! poorly drained Well drained Well drained Well
drained Poorly draincd \V d I drained \Vell drained \Vcil drained \-Vell drained Wdl Jr:lintd \Vdl drained \VcI! dr:U;lcd Wdl drametl .\-j(ldcr:lICI) well c!r:lI11cd Wcli drain.::u w
S')Ill<:Wilal cxcessivdy dnlincd Well draitlcd Well drained Well drained Wdl draincd Well dr3.lIled Well drained P(~rnH'llhllity Mlldcr:llC Very SlllW Mlldcrmc Mlltlcr:l\<.:: Moderal"::
~l(lw Moderate to llloderalt: slow Moderat~ rapid Slow Slow Slow Mod<.:r<1tc M\)deralc Moder,llc M(\(kr:lk 1I.,1()(kra1":: .'vtodCnltcly slO\\ ;v!lld..::r;ll(" .\'Iu(kmlc.: l\'l'Jdcr,lk'
IV!c\Uc.:r;llc 10 ll10dcrmcly rapid Modcf<ltC Moderate rapid Modcratt:ly slow Moderate Slow to In{)dcrate Moderately slow \V:ltcr Compa{·tioll Erosioll lUHI Rutting P{)f('njjli! ----l'-{)h'r-lt-j-:l-
1-Sli!.'ht Ml)d,:r<H~' Vc.:r) s~'vc~":: Sevcn.: Seven: Sever..:: Slil.ih1 Severe Slight Severe Slight Sc.:verc SCV!;[C Scycrc Sev<.:rc Scverc t(l y~'ry' ~c\'<.:rl: Slij!,hl M(){krat<.:
In \'''::1 \' ,~'\'~'I,' Vc.:ry sn'CJc.: .'ill ~,h[ 10 \,,'1'\' ~~',cJt' Vny sCl'ere Very severc Vcr; severc Vc.:ry $evc:re Very .severe Very severc Slight 10 Mnd"::l:llL: lli;.:"h __________________
________________ ~2: sev=-______ ~ __ _
Table 2
Table 2 Final Stabilization Seed Mixtures 'Elevations up to 7,000ft* ,----------------------~~------------------------I, Native MixtureiVariety ! Species I Variety % in mix i Drill Rate
! Broadcast (PLS) Rate (PLS) 'C" S~t..,r;::-ea..,n..,lt~)a~l",lk'''-\-''\:-,;'b;::e::cat'S;g-"ra==s,:>s--,-1 = _________ 2=-'5:--____ . ____ ]~.8 _____ +1-----=5::.:,.~6----_1 I Galleta
Grass (t1oret) i Viva 25: 2.8 i. __ -=5::.:,.6"--_--1 • Alkali Sacation ! Sandy 25 :------O.4---T 0.8 • Dropseed I I Indian Ricegrass ,I I Species i Crested Wheatgrass I Galleta Grass
(!loret) Alkali Sacation Indian Ricerrrass I Russian Wildrye I Species I Thickspike Wheatarass Western WbeatGrass Green '-:eedlegrass Prame Junegrass Rocky c.'jtn. Penstemon Fourwing
Saltbrush I (if sandy) I Paloma 25 3.0 I Nativeand Introduced Mixture/Variety i Variety 0/0 in mix Drill Rate i I , (PLS) i I Ephraim 25 I 1.5 , , i Viva 10 I 1.1 I .-~ .. I Sandy 15
0.2 I Dropseed ! ; : (if sandy) I I Paloma 25 3.0 I I Bozoisky 25 i 2.5 I "Elevations 7,000 to 9,OOOft* . Native MixturelVariety , Variety , I I Critana i i An-iba r ! i Bandera % in
mix Drill Rate -. _ fPLS) 7-2.5 , -) . -------~.--.---.--. 25 4.0 --------_ .. _---_. 75 2.5 -0.2 10 Add on _'--0.'"-6_---'. 1.0 6.0 Broadcast Rate (PLS) 3.0 2.2 0.2 6.0 5.0 Broadcast
Rate (PLS) 5.0 8.0 5.0 0.4 1.2 2.0
Table 2 Final Stabilization Seed Mixtul'es "Elevations 7,000 to 9,000ft* Native 'llld IntroduCed IVlIxtureNanety .. 1 ,I I .. Variety! % in mix Drill Rate I Broadcast ! f-c:--:-----:cc:;----__
~_ (PLS) __ --.J---.B~teJPLS)_~ S]lecies Pubescent Wheatgrass i Luna I 25 2.5 I 5.0 : Western Wheatgrass I Arriba I ---:2:-:5=-----J-----:4-:.0,----.. T: --"'8-:.0----;; Russian Wildrye
I Bozoisky i __ _=2.::,5 _ --1-_---:2"' . .::,5_.....J 5.0 Alfalfa i Ladak 15 I 0.2 i 0.4 ~S~m~al~I-=B~ll~n~le~t~~-----LiD ~el-=a~~ __-~ -, ___ ~10~ _+I--~0~.6~---+:--~1~.2~--+ FOUl'wing
Saltbrllsh i_C Add on. 1.0 ! 2.0 ~~=-_L-_~~ __ ~ __ ~ __ ~ 'PLS = Pure Live Seed
i, \ --
'.///<,.J I ,r J( ---. , --~-) ". .\ .. ; ":·~L_ . .i~C' ~. ",",-' .. ; /d :·1
Figure 2
IV",ela!iive Buffer Filter Berm Land Grading Level Spreader \Vattles Riprap I Oed1l11en! Trap \' C£Clilll'iC Buffer \Vater Bar Diversion Ditcb .. ..: Figure 2 BMP Selection Guidelines
I SllTlilCe Roughening IVegetati,'e Buffer Dams iD"lina:ge Dip '''""oi,,,, Conh"ol Blanket Berm Grading Level Spreader Wattles Riprap Sediment Trap Bale Barrier Roughening IV,:getati',e
Buffer Culvert Protection iDrtlina:sc Dip stope Stabilization Straw Bale Barrier Surface Roughening Terracing Vegetative Buffer Water Bar Diversion Ditch Surfacing Beml Check Dams Drainage
Dip Erosion Control Blanket Mulching Culvert Protection ,uralllRee Dip Erosion Control Blanket \1ulching Re\'eg(:tatioll I
Post Construction Storm Water Management Plan Chevron U.S.A. Inc. Skinner Ridge FieIci Permit Piceance Basin Natural Gas Development Pt'ogt'alll Garfield County, ColonlClo Apri! 2009
Prepared by: Cordilleran, a division of Olsson Assneia!es 826 21 y, Road Grand J lInetion, CO 81506 CORDILLERAN OLSSON
Chevron Post-Constl'uction Stormwater Management Plan 11 order to compiy WltI, the requirements of tile Colorado Oii and Gas Conservation Commission, rule 1002,1, final amendments from
Oecemoer, 2008, a Post Construction StormWater' Management plan has been implemented for Chevron's Skinner Ridge operations located witllin the Piceance Basin in Garfield County. Chevron
currently operates under a stormwater field permit issued by the COPHE. This PostConstruction SWMP will apply to those locations that have dropped out of the COOP HE stolmwater inspection
provisions and are considered stabilized as defined by obtaining 70% pre,disturbance levels. This plan will become effective on April 1 ", 2009. Inspections of the facilities covered
under this plan will take place semi-annually. Inspections will occur once in the fall prior to the onset of winter weather, and once in the spring during or after spring runoff or as
conditions allow. Additional inspections will be performed as needed in the event of extreme weather conditions. A trained and qualified person familiar with the SWMP and storm water
controls will conduct facility inspections and complete the Storm Water Field Inspection Report. Inspections will cover these areas: Evidence of surface erosion for disturbed areas:
Material and chemical storage areas; Best Management Practices (BMPs) inspected for proper functionality; Surface water diversions and down gradient areas; Water quality will be visually
assessed for all receiving streams and discharge areas during each inspection if present. Roads used for vehicle access will be inspected for eVidence of off-site sediment transport.
Good housekeeping with no debris or waste pcesent
l :.~ (J(){) Copies of these inspections are to be kept at the Grand Junction Office for a period of three years. Actions taken to modify storm water control measures will be recoraed
with inspection reports and maps and maintained with the SWMP. Immediately when deficiencies are discovered, Chevron will direct designated subcontractors to perform BMP maintenance
or replacement. Maintenance will include prompt adjustments and repairs to erosion and sediment control structures that are found to be performing inadequately or deteriorating. Signs
of rill or gully surface erosion shall be immediately repaired. The Chevron local contact has the authority and will coordinate subcontractors to install new and or additional storm
water control BMPs as needed. A. BMPs for Pollutants 1) Transport of chemicals and materials, including loading and unloading procedures is referenced in section 3.C in existing CDPHE
SWMP. This is also addressed under the Chevron Piceance Basin spec Plan. 2) Vehicle/equipment fueling is referenced in section 3.e of existing CDPHE SWMP. This also covered under the
Chevron Piceance Basin spce Plan. 3) Outdoor storage activities including chemicals and additives is referenced in section 3.C of existing CDPHE SWMP 4) Produced water and drilling fluids
storage is addressed section 1.G, 3.B and 3.C of existing eDPHE SWMP and Chevron Piceance Basin SPCC pian 5) Outdoor processing activities and machinery will be limited in scope. No
outdoor processing will take place. Machinery will be limited to maintenance of the existing roads and vehicular traffic for pumpers and routine unloading operations of produced fluids
6) Significant dust or particulate generation is not anticipated during the post construction phase of these facilities. 7) Erosion and vehicle tracking from well pads, road suriaces,
and pipelines will be min,mized due to the lack disturbed ground. Re-vegetation of the sites will be completed prior to the post construction phase. Tile access roads will be maintained
according to the existing CDPHE SWMP. Please reference section 3 C of the existing SWMP for control measures. 8) Waste disposal will be handled in accordance WI til the provisions outlined
in the ehevronPicence Waste Management Plan. 9) Leaks and spills will be covered under the Chevron Piceance Bas;n spec Plan for these sites Please reference section 3.C of tile exrsting
SWrvlP.
W) G!·ocmd dlsturb!ng mainte:18lCce activities will be limi[ed III scope On,) period.c maliltenance of :he roaels will be necessary and wil: be addressed 0'1 an as needed basis B. Development
SL:pervlsion, and Maintenance of Post Constl·uction SWI'I1P Tile post Construction SWIvlP will be administered by SIJIIIvlP Adm inistrator(s) Richard Carroll Environmental Specialist,
Piceance Basin Operations Chevron MCA Office: 970-257-6026 C. Maps for these facilities will be contained in the existing SIJIIMP. Installation specifications and implementation criteria
are contained in the existing SWMP under section 5. These clearly state implementation and maintenance criteria of the BMPs. Chevron is enacting these efforts in good faith to comply
with the requirements of COGCC. The sites covered under this post construction stormwater management plan are no longer included in the CDPHE field permit for stormwater management during
construction. The selection of BMPs will address potential pollution sources that could reasonably affect the quality of discharges from the sites during the ongoing extraction of natural
gas resources from existing wells.
Appendix D
Chnr<ln Storm Watcr Inspectiun Checklist Project :\allll' I nspection Date InSpl'CI()r Chen'on _____ Representa thT_ Pcrmit .'\al11c COR-1137787 i Permit Date ; 7!j!)()() i i .---, _
----------Field i\ame ----c-c-------------Work Completed Since Priority Last Inspection ----------------------------_._-------Comments Distance to 1 "iamc of Receiving Type ReceiYing
Water Water _____ -! __ _ ----------------_.-Best ~Ianagcl1ll'Ilt Practil'c? T)'Pe i i\laintcnanec i Date I COlllment I Required ' \laintcnancc ' ------------.----~ ------1 Estimated
Rl;;~;t:f-' i Coefficient --j ._----, ___ ~i _______ _ _,_. _________ _ _____________ ---"C-"o"-n.l~l'p~lc~t~c"d __ . __________________ .. __ --r--! ---._----._---.-----_.. ..-----_~~·~~~,_l's~ing}~
D~iV_~~~~I!!__ _ __________ _ Ii of I # of Freeboanl in Storm \YairI' Tanks: Separators: Sc('ondary -------i--------,--C'ulltailllHcnt Other Equipment in S('condar~ Cun ta inllle n t
-______ ' Co III lllt'n t
----------------~ ---------------------~------~ 1';1'e 21' E'llliJllllent 'Colllllle~_ -----~----------"--------J:I.o.t~,ekeeping/Site Trash --,'-'aferials Handling -----------~----------------------
--,-::pi1!s._or Leaks , ~ -----------..! -V-c-o"c'~t-a;t-i-oc-l:l-:-=--::--------,--=-::---------~ ---Seed Mix, Date 70°;', Comlllent -------------------, __-+I--,l~)I ,,,a-:cll. tc.,
,,d_ __--,--:R..-.:cng e ta ted I '-~----~ Files ~~--------..:.rype of File Locatio-ll---------------------------------------~--~ ---------c~ite Complies With Storm 'later Stan<l",,-tls.J~0or
:"01.
Storm Water Pollution Prevention Plan Drilling/Construction Activity FieldiProjecl: ______________ _ Yes No~ 08:8, __ _ Is this a rea~:irec CI-Vieekiy or monthly inspection? Is this
inspec::or 2 reSU!l of a precipitation event (0.5" or greater? Old you do a vlsuallnspectiol1 of access roads and constructior, areas? Culverts in gooe repair? Wing ditches in good condition?
Roadside dilclles in good condition? Rowand ditch lines in good condition? Are there any signs of major erosion? Are erosion control structures (hay bales, silt fences, etc.) in good
condition and functioning as designed? Final inspection -70% stabilization achieved Recommend Not'ce of Termination (NOT) be submitted Comments on deficiencies, needs, or required repairs,
final stabilizatior. -Signature of Inspector: ______________ _ Printed Name Of Inspector ____________ _ Yes ~ Yes Yes ~ Yes ~ Yes Yes Yes Yes ~ Yes Yes ~ No Date ~ No ~ "o~ No No ~ No
~ No No ~ No ~ No ~ Oate __ _ I certify under per'lalty of law that this document and all attach~l~ents were pr"epared u:lc'er nly dil-ec~icr or s~,pervisior; i!~ accordance with a system
designed to aSSLr8 that qU8ii~ied personnel properly gathered and evaluated the information submitted, Based on fllV inquiry of tIle person or per-sars ':.,rho manage U:e system, or
those persons directly respons!ble fOI-gathering tile inb~lllation, tl~e inforillation is subnlitted, to the best of knowledge a·ld belief. trUE. accurate. and C.o'~lp!ete_ I arl a\,rvare
that there are significant penalties fo~ submitting false inforrr:ation. i':c!uding the poss:biiity of fine and imprisonment or knowing vio!ations Signature: Oate,_~_