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HomeMy WebLinkAbout1.19 Storm water mgmt planStorm Water Management Plan for Skinner Ridge Field Permit Piceance Basin Natural Gas Development Program Garfield County, Colorado September 2005 Revised June , Darker 2000, August 2007 fie yard: tognsl 1000 Prepared for: Chevron U.S.A. Inc 760 Horizon Drive Grand Junction, CO 81506 Prepared $v: ./e° CORDILLERAN Cordilleras Compliance Services, Inc 826 21 /, Road Grand Junction, CO 81506 dugusi 2008 additions hv: Washington Group International Integrated Engionling, Gonswenon. and Manegetnent Solution. 7800 E. Union Ave., Suite 100 Denver, CO 80237 Slower RidgoiStormwater(SW Addinans RevisionsIAogess 2006 SWMIP Revisions Spinner Ridce Master SWMP Table of Contents Chevron U.S.A., Inc. 1.0 INTRODUCTION »» »...» ...» ...I 1.1 Storm Water Runoff Permitting Requirements 1 1.2 Project Description and Background 2 13 Project Owner and Operator 3 2.0 CONSTRUCTION SITE DESCRIPTION...». ..4 2.1 Site Location and Construction Area Description 4 2.2 Vegetative Communities 6 2.3 Regional Climate 6 24 Regional Surface Water Classification 717 3.0 Schedule of Construction Activities..... 8 3.1 Development (Construction/Drilling/Completion) . 8 3.1.1 Well Pad Development 8 3.1.2 Pipeline Development 9 3.1.3 Road Development 10 3.1.4 Facilities Development 13 3.2 Production (Operation/Maintenance)and Interim Reclamation 14 3.2.1 Wcll Pad Production Activities and Interim Reclamation 14 3.2.2 Pipeline Completion and Interim Reclamation 15 3.2.3 Road Completion and Interim Reclamation 16 3.2.4 Facilities Production Activities and Interim Reclamation 16 3.3 Final Reclamation 17 3.3.1 Well Pads Final Reclamation. 17 3.3.2 Pipeline Final Reclamation 17 3.3.3 Roads Final Reclamation.. 17 3,3.4 Facilities - Final Reclamation. 18 4.0 Potential Pollution Sources 5.0 Description of Control Measures 5.1 Soil Erosion and Sediment Controls 5.2 Storm Water Management Controls 5.3 Other Controls 5.4 Construction Site Housekeeping 19 .. ».... »........... 20 20 25 26 28 Skinner Ridge Master SWMP Chevron U.S.AInc. 6.0 INSPECTION AND MAINTENANCE PROCEDURES 29 7.0 NON - STORMWATER DISCHARGES 31 8.0 FINAL STABILIZATION 32 LIST OF TABLES Table 1 Table 2 Skinner Ridge Vegetation Descriptions Skinner Ridge Final Stabilization Seed Mixtures LIST OF FIGURES Figure 1 Figure 2 Skinner Ridge Location BMP Selection and Construction Phase Guidelines LIST OF APPENDICES Appendix A Skinner Ridge Common Plan of Development Storm Water Permit Appendix B List of Down -Hole Chemicals Appendix C Typical Storm Water BMP Details Appendix D Storm Water Inspection Form Appendix E Compliance Updates ii Skinner Ridge Master SWMP Chevron U.S.A., lne. 1.0 INTRODUCTION This Stormwater Management Plan (SWMP) is written to comply with the Colorado Department of Public Health and Environment's (CDPHE) General Permit No. COR- 03000 issued on July 1, 2007 and expiring on June 30, 2012, and related U.S. Environmental Protection Agency (USEPA) National Pollutant Discharge Elimination System (NPDES) stormwater regulations. Chevron's permit renewal approval is provided in Appendix A. Construction permits are 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 Stormwater Fact Sheet — Construction at 011 and Gas Facilities (revised in July 2007): the Field Permit certification. In this document, CDPHE recommended that oil and gas developments be covered under a Field Permit certification. The Field Permit covers all construction activities and discharges to all creeks listed in the permit for the entire project area. Chevron has amended its original permit renewal application to be covered under a Field Permit rather than a common plan of development, as originally submitted. This Master SWMP provides information, procedures, and best management practices (BMPs) 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 developments, new disturbances, and other changes needed to manage stormwater and protect surface water quality. Site - specific SWMP site maps, based on controls and procedures sununarized in the Master SWMP, will be prepared for each facility /construction project and provided as appendices to this plan. 1.1 Storm Water Runoff Permitting Requirements The Federal Clean Water Act [Section 402(p)] requires that discharges of pollutants to waters of the United States from any point source be regulated by NPDES permits. In November 1990 the USEPA published final regulations that established application requirements for storm water associated with construction activity for soil disturbances of 5 acres or more be regulated as an industrial activity and covered by an NPDES pcmtit. In December 1999 the USEPA published final Phase II NPDES regulations that established application requirements for stormwater associated with construction activity for soil disturbances to be regulated as an industrial activity and covered by an NPDES permit. These regulations became effective July I, 2002, On June 30, 2005, the State of Colorado stormwater regulation went into effect to require Colorado Discharge Permit System (CDPS) permits from the Water Quality Control Division (the Division) for stormwater discharges from construction activities associated with small construction activity for ail and gas sites (those that disturb between one and five acres). Permitting for oil and gas construction sites that disturb five or more acres 1 Skinner Ridge Master SWMP Chevron U.S.A., Inc. during the life of the project, or are part of a larger common plan of development, has been required since 1992. Although federal permit coverage for these discharges was conditionally exempted from the Federal 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). 1.2 Project Description and Background The Skinner Ridge Field is be located in Garfield County, Colorado within Townships 5, 6, 7, 8 and 9 South, Ranges 97 and 98 West (Figure 1). The town of Debeque, 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 from the joint trunk lines flow to a Central Production Facility (CPF) (multiple production facilities will be required for the Program). At the production facilities, the natural gas and liquids are further separated. The natural gas is compressed, dehydrated and sent to a sales point through a recently constructed 30 -inch export 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 2010 a 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 water supply. Brine and solids are anticipated waste streams from 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/construction, support facility construction (production facilities, offices, water treatment facilities, etc.), utility installation, and pipeline construction. The area of estimated disturbance, including the natural gas well pads, the access roads, and gathering system pipeline, will exceed 370 acres. Disturbance beyond five years will require re- evaluation. Figure 1 shows some of the well pads and facilities associated with the early phases of the Program. Skinner Ridge Master SWMP Chevron U.S.A., lee. 13 Project Owner and Operator 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: Michael DeBerry Manager, Piceance Basin Operations 760 Horizon Drive Grand Junction, CO 81506 Oftice: 970-257-6005. Cell: 307 - 679 -4050 SWMP Administrator(s): Richard Carroll Environmental Specialist, Piceance Basin Operations Chevron MCA Office: 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 work will be supervised by Chevron and all decisions will be made by Chevron. 3 Skinner Ridge Master SWMP Chevron tJS.A., ire 2.0 CONSTRUCTION SITE DESCRIPTION 2.1 Site Location and Construction Area Description According to the Natural Resource Conservation Service (MRCS) Soil Survey Map of the Douglas Plateau Area, Colorado, Paris of Garfield and Mesa Counties, the subject area is located within the Piceance Basin on the eastem fringe of the Colorado Plateau. It includes the Roan Plateau, Bookcliffs, and is adjacent to portions of the Grand Mesa and Grand Valley areas. It consists or deeply incised valleys, entrenched plateaus, and foothills. The broader portion of the valley is carved out by the Colorado River and its tributaries. The development site elevation ranges from a valley floor elevation of 5,800 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 Ridge property. The shallowest stratigraphic trait in the Piceance Basin is the Uinta Formation, which consists of discontinuous layers of silty sandstone, siltstone and marlstone deposits. The Uinta Formation overlies the Green River Formation, which contains vast deposits of oil shale. The Wasatch, Lower Fort Union and Mesaverde Formations underlie the Green River Formation, and consist of sandstones, mudstones, and coal. These formations represent the major gas producing formations of the Piceance Basin. The natural gas occurs as non - conventional gas at the Skinner Ridge development site. Surface and groundwater features are located within the upper reaches of the Clear and Roan Creeks, where the Program area lies. These features consist of ephemeral streams fed by seasonal rainfall and snowmclt. 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 confluence of Tom Creek and Clear Creek. 4 Skinner Ridge Master SWMP Most of the geological material underlying the Skinner Ridge property is impervious to water. Except for the alluvium within the major svcambeds, there is no known extensive aquifer. The alluvial aquifer consists of narrow and relatively thin sand and gravel deposits adjacent to and beneath Clear Creek. In the northern portion of the development site, the alluvial aquifer is underlain by the confining unit below the Lower Piceance Basin aquifer (Douglas Creek Member of the Green River Formation), which consists of fine - 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 Upper Ficeancc Basin aquifer (Uinta Formation), which consists of silty sandstone and fractured siltstonc. Chevron C.S..t -. Inc- Developed Spring at the Continence of Tom and Clear Creek% The hydraulic gradient in the bedrock aquifers underlying the Roan Plato. is predominately vertical and downward. However, along the margins of the plateau there are strong horisntal hydraulic gradients flowing toward the cliff faces and valley slopes. Because of these strong horizontal gradients. ground water is discharged from the bedrock aquifers as springs even though the bedrock aquifers dip away from valley slopes. Numerous seeps and springs are present along the valley slopes above Clear 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 Environmental, Social and Health Impart Assessment (ESHIA) (ERM, 2008). Three main groups of soils are present within the Program area: (1) soils along drainages, (2) soils along side slopes, and (3) soils atop plateaus (also referred to as mesas). The soils along the drainages occur on benches. terraces, alluvial fans. and tloodplains in the valleys of Roan Creek, Clear Creek, and their tributaries. These soils are deep, well to somewhat poorly drained, and nearly level to gently sloping, with water erosion hazard ranges from slight to severe. The soils found along the drainages include soils that are classified as prime farmland. The soils along the side slopes of Skinner Ridge, Puddin Ridge, and other slopes along the mesa and other mountain slopes, are dominated by shallow, poorly developed soils and rock outcrops. These soils have a severe erosion potential and some have very steep slopes that limit their potential for construction and re- vegetation. 5 Skinnier Ridge Master SWMP Chevron U.S.A., Inc. 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. Nearby drainages will be protected by appropriate measures. The road will be graded and sloped to drain into roadside ditches and to direct runoff from adjacent slopes away from the 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. 2.2 Vegetative Communities The eleven 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 forests, deciduous oak shrublands, Douglas fir forests, mesic upland shrub communities, and mountain sagebrush shrublands are common in the higher elevations of the Piceancc area Big sagebrush shrublands, riparian areas, and irrigated cropland are present in the deep valleys. Juniper woodland forests, grcasewood flats, and desert shrub communities are common on the exposed steep slopes, in dryer areas, and on shale plateaus. Vegetation communities have developed across the landscape in response to climate, disturbance, and other environmental factors. Vegetation Community Type Percent of Study Area Aspen forest 4.0 Big sagebrush 2.6 Desert shrub 12 Douglas fir forest land 62 Exposed rock 1.0 Forest - dominated riparian 1.1 Greasewond fans and flats 13 irrigated cropland 7.6 _ _ Juniper woodland forest land 5.2 Manic upland shrub 22.2 Mountain sagebrush 46.7 Additional information about vegetation communities associated with the various soil types is presented in Table 1. Identification of the vegetative community to be disturbed is very important, because some types are more sensitive to disturbance, while others are far more resilient. 2.3 Regional Climate Climate information was collected as part of the ESHIA study. The ESHIA report describes the general climate of the study arca as influenced by dry air, sunny days, clear nights, variable precipitation, with moderate evaporation and large diurnal temperature changes. These are generally due to changes in topography between the valleys and mesas. 6 Skinner Ridge Master SWMP Chevron U.S.A., lee. Annual precipitation ranges from about 10 to 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 SOs 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 movements arc strongly influenced by topography including elevated mesas. steep slopes, narrow canyons and rough terrain in the Study Area. 2.4 Regional Surface Water Classifications 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, Regulation 37, Regulations for the Lower Colorado Basin, these are named Segments 14a and 14b of the Lower Colorado River Basin and Sub - basin. Segment 14a includes the main stem of Roan Crcck including all wetlands and tributaries. from the source to a point immediately above the confluence with Clear Creek (except for a listing in Segment 14b); Clear Creek, including all tributaries and wetlands, from the source to a point immediately below the confluence of Tom Creek. Segment 14b consists of Clear Creek. including all tributari es and wetlands, from a point immediately below the confluence with Tom Creek to the confluence with Roan Creek; Roan Creek, including all tributaries and wetlands, from a point immediately above the confluence with Clear Creek to a point immediately below the confluence with Kimball Creek. Segment 14a is designated as reviewable and its classified beneficial uses are: aquatic fife 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 standard tier I, 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 Management Practices (BMPs)]. Segment 14b has the same designation and classified use; however. it has a cold temperature standard tier Il, for the presence of rainbow and brown trout, mottled sculpin, mountain whitefish, longnose sucker, and Arctic grayling. Again these designations are indicative of a sensitive habitat warranting greater protection when considering disturbance proper selection of BMPs. 7 Skinner Ridge Master SWMP Chevron USA., Inc. 3.0 Schedule of Construction Activities As mentioned in Section 1.2 the development of the Program will involve multiple construction activities including well pad construction, well drilling, completion and testing, access road improvement/construction, support facility construction (production facilities, offices, water treatment facilities, etc.), utility installation, and pipeline construction. The development of natural gas facilities 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. 3.1 Development ( Construction /Drilling/Completion) 3.1.1 Well Pad Development The well pad development phase includes the following activities: pad construction, well drilling, well completion, gas line installation, and pad area reclamation. Pad reclamation 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 of 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 a re- 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 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 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 of 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. The 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 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 will be properly located and protected so minimize wind and water erosion and maximize available topsoil for reclamation. Skinner Ridge Master SWMP Chevron USA., Inc. Excavation of the cut and fill slopes is normally guided by information on the slope stakes. Fills should be compacted to minimize the chance of slope failure. if excess cut material exists after fill areas have been brought to grade, the excess material will be stockpiled at approved locations. The area of the well pad where the drilling rig substructure is located should be Level 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 from the work area to a reserve pit. To reduce erosion and soil loss, it may be appropriate to divert storm water away from well locations 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 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 in 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 BMPs, including where and when to use them, their limitations, along with construction details and maintenance requirements. A site specific SWMP map will be developed for each well pad as part of the engineering design and provided as an attachment to this plan. 3.1.2 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 routes. Topsoil material must be segregated and not be mixed or covered with subsurface material. Bladed materials must be placed back into the cleared route upon completion of construction and returned back to the original contour before reapplying topsoil. Pipeline trenches should be compacted during backfilling. After construction, cut -and- fill slopes must be re- graded to conform to the adjacent terrain and reclaimed. Pipeline right -of -way must be maintained in order to correct backfill settling and prevent erosion. Appropriate BMPs must be used in sensitive areas to ensure proper site stabilization. Site specific SWMP maps for each pipeline corridor will be developed as part of the engineering design and provided as an attachment to this plan. 9 Skinner Ridge Mnater SWMP Chevron U.S.A., Inc. Pipeline construction should not block, dam, or change the natural course of any drainage. Suspended pipelines should provide adequate clearance for high -flow events. Pipelines buried across stream crossings should be buried below the scouring depth. Pipelines crossing streams or wetlands will require a U.S. Army Corp of Engineers (USAGE) Nationwide or Individual (developed for the entire Program) permit. This requirement may be avoided by boring under these areas. 3.13 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 revegetation 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. Initial steps in road location include: • Determine the intended use of the road including seasonal use, type of vehicles to be used, and amount of traffic, and safety. Examine biological, physical, and cultural conditions of the area. • Consider geotechnical factors including soil type, construction / reclamation limits, landslide areas, water problem areas, etc. Basic Design Requirements: • Design for pre- determined speed limit. • Typically width is 24 feet with turnouts in areas where width is less than 16 feet. 10 Skinner Ridge Maaler SWMP Chevron US.A., Inc. • 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 for short distances of 300 feet or less. • Drainage control must be ensured over the entire road through the use of drainage dips, in sloping, natural rolling topography, ditch turnouts, ditches, 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 of roadbed 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 parallel to the axis of the roadway in even, continuous horizontal layers. Surface and Drainage Structures: • The proper design and construction of structures for the surface drainage of water from or 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 water 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. • The need for drainage structures can be minimized by proper road location. However, properly designed drainage is essential for a stable road. Drainage system must include the best combination of various design elements, such as ditches, culverts, drainage dips, crown, in -slope or out - slope, low water crossings, subsurface drains, and bridges. • Drainage Structures — Proper location and design can provide economical and efficient drainage. Structural measures are often required to ensure proper and adequate drainage. Some of the 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 remove surface water from the roadway and shoulders before the combination before the combination of water volume and velocity begins to erode the surface materials. Spacing of drainage dips depends upon local conditions such as soil material, grade, and topography. 11 Skinner Ridge Master SWMP Chevron U.S.A., Inc. 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 from the surface of the road. Drainage of the inside ditch and side hill runoff is essential if the road is to be kept dry and passable during wet weather. o Culverts— Culverts are used in two applications: (1) to allow the normal drainage from 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 performed to determine the amount of water anticipated 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 one foot beyond the toe of any slope. It may be necessary to install rip-rap or other energy dissipation devices at the outlet end of the culverts to prevent soil erosion and trap sediment. All culverts used in the 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 of any roadbed. Evacuation, bedding, and backfilling of culverts should be conducted according to Program specifications. Ditch relief culverts are installed to periodically relieve the ditch line flow by piping water to the opposite side of the road where the flow can be dissipated away from the roadway. The spacing of ditch relief culverts is dependant on the road gradient, soil types, and runoff characteristics. The depth of culvert burial must be sufficient to ensure the culvert is protected for its design life. This requires anticipating the amount of material that may be lost due to road use and erosion. The culvert gradient should be greater than the approach stream or ditch gradient. This improves the flow hydraulics and reduces sedimentation and debris plugging at the culvert inlet. Additional factors to consider for construction activities involving drainage channels: Bridges and Major Culverts: • Construction of some stream crossings may require a USACE Nationwide (404) or Individual Permit. Where a road is open to public travel, applications will be prepared and submitted with sufficient time allowed for any required public comment input periods and approval of the permit by the surface management agency. 12 Skinner Ridge Master SWMP Chevron U.S.A., Inc. Wetlands: Wetlands are especially sensitive areas and should be avoided, if possible. Generally, these areas require crossings that prevent unnatural fluctuations in water level. Under wetland circumstances, culverts should be designed with a flat grade so water can flow either direction and maintain its natural level on both sides. Special attention should be given to selection of culvert materials that will resist corrosion. Low Water Crossings: • Roads may cross small drainages and intermittent streams where 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 filled so that water will be impounded. Low water crossings that are not surfaced should not be used in wet conditions. Appropriate BMPs must be used in sensitive areas to ensure proper site stabilization. Site specific SWMP maps for all road construction or improvements will be developed as part of the engineering design and provided as an attachment to this plan. 3.1.4 Facilities Development 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 specific SWMP map 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 information may be provided to address specific site conditions and construction activities. 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 potential of the site. Steps will be taken to avoid or mitigate construction on steep slopes, riparian areas and other areas deemed as areas subject to severe erosion. Construction procedures will seek to minimize surface 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. 13 Skinner Ridge Master SWMP Chevron USA, lac. To reduce erosion and soil loss, it may be appropriate to divert stonnwater away from 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 BMPs such as silt fences, waddles, and erosion 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 in 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 BMPs, including where and when to use them, their limitations, along with construction details and maintenance requirements. 3.2 Production (Operation/Maintenance) and Interim Reclamation 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 separation unit, from one to several 400 - barrel capacity aboveground tanks for condensate, and 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 revegetated areas and maintenance of the erosion and sediment control structures. Natural gas wells in the Skinner Ridge area are projected to produce for approximately 20 to 30 years. 3.2.1 Well Pads Production Activities and Reclamation 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 pit(s) 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. Petroleum products also may be present at the well pads, including gasoline, diesel fuel, lubricant oils, hydraulic oils, used oils, and solvents. 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 off -site disposal. All storage of petroleum products will be in accordance with the Piceance Basin Field Spill Prevention Control and Countermeasures (SPCC) Plan. 14 Skinner Riders Master SWMP Chevron U.S.A., Inc. Housekeeping will be maintained in all chemical storage areas. All containers are to remain closed except when adding or removing materials. Where appropriate, materials will be stored in locations to prevent containers from being exposed to precipitation events. Inspection of chemical storage areas will be included as part of the SWMP inspection program. 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 of re- vegetated areas and maintenance of the erosion and sediment controls structures. Installation, inspection and maintenance of BMPs to control sediment runoff will continue as needed. New BMPs 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 reclamation is accomplished by backfilling 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 site 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 intermediate 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 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. 3.2.2 Pipeline Completion and Reclamation Pipeline route reclamation involves placing fill in trenches, compacting fill, re- grading cut and fill slopes to restore the original contours, replacing topsoil, installing temporary waterbars and silt fencing only where necessary to control erosion, and re- vegetation. Waterbars and other appropriate BMPs must be maintained and repaired as necessary. Following successful re- vegetation, remaining waterbars are to be flattened to blend with the slope. 15 Skinner Ridge Master SWMP Chevron U.S.A., Inc. 3.2.3 Road Completion and Reclamation Maintenance activities normally required include blading, surface replacement, dust control, spot repairs, slide removal, ditch cleaning, culvert cleaning, litter pickup, noxious weed control, maintenance of interim reclamation, and snow removal. Additional inspections and maintenance may be needed during periods of snowmelt or heavy, prolonged rainfall to look for drainage, erosion, or sedimentation problems. Re- vegetation of road ditches and cut and fill 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 protect habitat. To ensure successful growth of vegetation, topsoil must be stored in designated stockpiles (where available) during road construction and re- distributed on cut slopes, fill slopes, and borrow ditches prior to re- vegetation activities. 3.2.4 Facilities Production Activities and Reclamation Many of the facilities 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 SPCC 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 final or intermediate contour that blends with the surrounding 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 have been completed, and all disturbed areas have been either built on, paved, or a uniform vegetative cover has been established with an individual plant density of at least 70 percent of per- disturbance levels. Documented inspections will be performed during this period to ensure proper site stabilization. 16 Skinner Ridge Muter SWMP Chevron U.S.A., Inc 3.3 Final Reclamation Following 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. BMPs will stay in effect as an ongoing company practice to ensure proper management of storm water protection. If petroleum hydrocarbons or other chemicals impact stormwater as a result of industrial activities onsite, the impacted stormwater will be addressed by following the provisions contained in the Piceance Basin Field SPCC plan. 3.3.1 Well Pads - Final Reclamation The site will be reclaimed after the end of its operational life in accordance with local, state and federal requirements. Following well plugging, reclamation activities will include removing ail 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 free 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 and should be removed when the site is successfully revegetated and stabilized. 33.2 Pipeline - Final Reclamation Final abandonment of pipelines and flowlines will involve flushing 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. 3.3.3 Roads - Final Reclamation 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. 17 Skinner Ridge Master SWMP Chevron U.S.A., Inc Final reclamation includes re- grading the road back to the original contour, seeding, controlling noxious weeds, and may include other techniques to improve reclamation success such as ripping, scarifying, replacing topsoil, placing waterbars, pitting, and mulching. Seeds of native, perennial species will be used. 3.3.4 Facilities - Final Reclamation The site will be reclaimed after the end of its operational life in accordance with local, state and federal 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. 18 Skinner Ridge Master SWMP Chevron U.S.A.. Inc. 4.0 POTENTIAL POLLUTION SOURCES Potential pollution sources associated with construction sites and natural gas development include: • Sediment resulting from erosion of soil stockpiles and other areas cleared of vegetation; • Leakage of fuels and lubricants from equipment and spills from fueling; • Trash and debris from 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 quality of a receiving stream. 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. These products are 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 water from above ground storage tanks are common and regular activities within the Skinner Ridge project area that may contribute to stormwater contamination. Debris from Iaydown areas, residue from equipment cleaning and maintenance, and solid waste generated from 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 certain events may require specialized training due to health and safety concerns. For a list of down -hole chemicals used during development activities please refer to Appendix B. Concrete trucks must be rinsed out prior to leaving the site and this water has the potential to contaminate stormwater 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. 19 Skinner Ridge Master SWMP Chevron USA., Inc. Skinner Ridge Muter SWMP Chevron U.S.A., Inc. 5.0 DESCRIPTION OF CONTROL MEASURES The objective of erosion and sediment controls is to minimize the release of sediments to storm water runoff. This can be accomplished through a combination of structural and/or nonstructural controls. The following sections provide a description of typical BMPs employed to prevent soil erosion, work practices and managerial controls used to prevent storm water impacts, and fuels, chemicals, and materials handling practices. 5.1 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. Berms A berm is a ridge of compacted soil Located at the top or base of a sloping disturbed area to contain or divert surface runoff. Where used, soil berms shall be constructed of soil with sufficient fines 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 filtration device and/or divert clean water away from disturbed areas. Check Dams Check darns are small, temporary dams constructed across a diversion or roadside ditch. Check dams can be constructed using gravel, rock, gravel bags, geo- ridges, 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 channel itself or from the contributing drainage area as storm water runoff flows through or over the structure. Culverts Culverts are typically used to move ditch water under the road or to direct stream flow under the access road. Culverts are typically constructed out of concrete, steel, aluminum, or plastic pipe. Where used, culverts should have inlet and outlet protection features to minimize erosion such as placing a non -woven textile material under rip rap at each end of the culvert. Diversion 20 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 flows from eroding slopes and to direct sediment Laden flows 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 matting. 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 upgradient surface runoff away from a well pad. Channels and berms must be designed to manage peak storm 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 (before 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 be 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 small tree branches, root mats, grass, leaves, stone or other debris or material naturally available or left over from the site clearing and grubbing. Rock filter berms use site gravel, stone, or rock. Both types of filter berms are placed along a level contour to slow, filter, and divert flow and act as an efficient form of sediment control. Georidne GeoRidge® is a permeable ditch berm designed for erosion and sediment control. The use of GeoRidge® reduces flow velocities and provides a smoother water flow resulting in less erosional energy, and thus minimizing the problem of downstream sediment. Gravel Surfacing Gravel surfacing may be used to cover soil in areas of high traffic source as roads, facility areas, and areas near the well heads. Gravel surfacing forms a layer that protects and minimizes soil erosion and vehicle soil tracking. 21 Skinner Ridge Master SWMP Chevron U.S.A., Cue. 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, pipelines, facilities and access roads and helps to control surface runoff, soil erosion, and sedimentation during and after construction in these areas. Grading also includes road crowning and sloping to properly route runoff off the access roads. Level Spreader A level spreader is a BMP used to prevent erosion and to improve infiltration by spreading concentrated storm water runoff evenly over the ground as shallow sheet flow instead of through channels. It usually involves a depression in the soil surface that disperses flow onto a flatter area across a slight slope and then releases the flow onto level vegetated areas. This reduces flow speed and increases infiltration 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. When mulching is used in combination with seeding, surface 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 space 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. Revegetation Revegetation involves planting seed to establish a vegetative cover on disturbed areas. Revegetation reduces erosion and sedimentation by stabilizing disturbed areas in a manner that is economical and adaptable to site conditions. It also reduces runoff 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. Riprap Riprap is a permanent, erosion - resistant layer made of stones, rock, or boulders. It is intended to stabilize areas subject to erosion and protect against scour of the soil caused by concentrated, high velocity flows. 22 Skinner Ridge Master SWMP Chevron U.S.A., Int. Roadside Ditches and Turnouts Roadside ditches are channels conducted parallel to roads. The ditches convey concentrated runoff of surface water from roads and surrounding areas to a stabilized outlet. Turnouts are used to effectively remove run-off water from the roadside ditch into well - stabilized areas before it reaches a waterway. Sediment Trap Sediment traps are intended to intercept, trap, and retain sediment from runoff while allowing detained runoff to slowly drain, infiltrate, or both. They are usually installed in a drainage way or other point of discharge from a disturbed area. This BMP is formed by excavating below grade and/or constructing an earthen embankment with a protected spillway to slow the release of runoff. Silt Fence Silt fences are used as temporary perimeter control structures that are designed to slow, temporary impound, and filter sediment laden water. Installation techniques and maintenance is critical to proper performance. Slope Drain Slope drains are used with earth dikes and drainage ditches to intercept and direct surface flow away from slope areas to protect cut or fill slopes. A slope drain is applicable for any construction site where concentrated surface runoff can accumulate and must be conveyed down a slope in order to prevent erosion. The slope drain may be a rigid pipe such as corrugated metal, flexible conduit or a lined terrace drain with the inlet placed at the top of the slope and the outlet at the bottom of the slope. Inlets must be securely anchored and outlets must be stabilized with riprap. Stabilized Construction Entrance A stabilized construction entrance is a pad of gravel laid over filter cloth where construction traffic will be entering or leaving a construction site to or from a public right -of -way, street 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 onto county roads or state highways. As a vehicle drives over the gravel, mud and sediment are removed from the vehicle's wheels and offsite transport of soil is reduced. This BMP reduces erosion, tire rutting and the filter fabric separates the gravel from the soil below by minimizing the migration gravel into subsurface soil from heavy vehicle loads. A stabilized construction entrance should be used at facility ingress and egress locations. 23 Skaeeer Ridge Mester SWMP Chevron U.S.A., lee. Straw Bale Barrier A straw bale barrier is a series of entrenched and staked straw bales placed on a level contour to intercept sheet flows. The barrier reduces runoff velocity and filters sediment laden runoff from small drainage areas of disturbed soil. This BMP may also be used to protect against erosion in small shallow drainage channels. Straw Wattles 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, sheet and rill erosion until permanent vegetation can be established. Straw rolls will last an average of one to two years. Surface Roughening Soil surface roughening is a temporary erosion control practice often used in conjunction with grading. Soil roughening involves increasing the relief of a bare soil surface with horizontal grooves (emanating) or tracks ( tracking) using construction equipment Slopes that are not fine graded and that are left in a roughened condition can reduce erosion, trap sediment, and prepare ground surfaces for seeding. Terracing Terraces are made of either earthen embankments or ridge and channel systems that are properly spaced along a fill slope. Terraces are constructed with an adequate grade to promote drainage to a stabilized outlet. They reduce damage from erosion by collecting and redistributing surface runoff to stable outlets at slower speeds and by decreasing the distance of overland runoff flow. They also surpass smooth slopes in holding moisture and help to minimize sediment Loading of surface runoff. Vegetative Buffer Vegetative buffers are areas of either natural or established vegetation that are maintained to protect the water quality of neighboring areas. Vegetative buffers reduce storm water runoff velocity, prevent soil erosion, promote infiltration and act as a filter to remove sediment. Water Bar A water bar is an earthen ridge, or ridge and charnel, 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. 24 Skinner Ridge Master SWMP Chevron US.A., lee. Additional BMP references: The structural and non - structural BMPs listed above are intended to include BMPs 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, and maintenance of BMPs. Additional information resources are listed below: • For oil and gas operations, the Bureau of Land Management and U.S. Forest Service have developed "Surface Operating Standards and Guidelines for Oil and Gas Exploration and Development,' "Gold Book." The most recent version (fourth edition) of this is available on the Internet at http:/ /www.blm.eov/bmp/Go]dBook Draft v12.pdf. • For construction BMPs the Urban Drainage and Flood Control District, a Colorado front range group of city and county agencies has developed a BMP manual that is available on the internet at http: / /wwv.udfcd.oru/usdem/vol3.htm • For construction BMPs and surface stabilization methods. the Alabama Soil and Water Conservation Committee have developed "Erosion Control. Sediment Control and Stormwater Management on Constmction Sites and Urban Areas, Volume 1 Developing Plans and Designing Best Management Practices." This information is available on the Internet at hurl /swcc.state.al.uv'pdf /ASWCC June 2003 Alabama Handbook _Construetio n t:$S Control.pdf • For access roads, the US Forest Service and Bureau of Land Management have developed "Low - Volume Roads Engineering, Best Management Practices Field Guide," which is available on the Internet at http ;//www.b1m.aav/bmn /field %20guidc.htm 5.2 Storm Water Management Controls Structural BMPs will be installed, inspected, and maintained as needed. Description of typical BMPs that may be used on individual construction sites are provided in Appendix C. This SWMP will be revised as needed to address new disturbances. Depending on the type and location of new facilities there may be a need for inclusion of new and different BMPs, in general, new development should be planned with consideration for storm water quality (e.g. minimize disturbed area and maximize distance from surface wafer drainages. as practicable). Other developments 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 25 Skinner Ridge Master SWMP Chevron U.S.A., Inc. addressed through construction activities, hut will likely need to be addressed through BMPs which will be added to the plan as needed. 5.3 Other Controls Waste Management and Disposal Well pad construction and drilling will generate various other wastes during the course of construction. Other wastes may include the following: Sagebrush, shrubs and trees from clearing operations; • Trash and debris from construction materials and workers; • Drill cuttings, drilling fluids, frac sand, completion fluids; and Sanitary sewage. Each of these wastes will be managed so as to not contribute to storm water pollution. Construction trash and debris will be collected in containers and hauled 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. 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, diesel fuel, lubricant, hydraulic, and miscellaneous oils and solvents will be stored in portable storage tanks with secondary containment. Pollutants from petroleum 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 contacting the ground. Proposed maintenance and safe storage practices will reduce the chance of petroleum products contaminating the 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 identify leaks and initiate corrective actions, if needed. The Piceance SPCC plan and or Emergency Response Plan will be activated as appropriate to manage any petroleum product spill. The following guidelines for storing and managing petroleum products will be used: - All product containers will be clearly labeled. • Drains will be kept off the ground within secondary containment and stored under cover if needed. 26 Skinner Ridge Master SWMP Chevron USA., Inc. • Fuel tanks will be stored within secondary containment or in the case of an active drilling pad operation, provided with a collection system that would direct any release to the reserve pit. • Lids of drummed materials will be securely fastened. • Emergency spill response procedures will be available on -site. • Spill clean up and containment materials (absorbent, shovels, 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 meetings. All spills and releases of exploration and production waste or produced fluid exceeding 5 barrels (210 gallons) including those contained within unlined berms, shall be reported in writing on the COGCC Spill/Release Report Form 19 within 10 days of discovery of the spill. All spills/releases that exceed 20 barrels (840 gallons) of exploration and production liquids/waste shall be reported on the COGCC Spill Release Report, Form 19, and shall also be verbally reported to the COGCC at (303) 894 -2100 within 24 hours of discovery. Spills or releases of any size that impact or threaten to impact any waters of the state, residence or occupied structure, livestock or public byway, shall be reported in writing on the COGCC Spill/Release Report Form 19 and shall also be verbally reported to the COGCC immediately after discovery (COGCC Rule 906). If the spill impacts waters of the state (which includes surface water, ground water and dry gullies or storm sewers leading to surface water), it must also be reported immediately to the Colorado Department of Public Health and Environment (CDPHE) at 1 -877- 518 -5608 and the National Response Center at 1 -800- 424 -8802. Any size discharge (i.e. one that creates a sheen, emulsion, or sludge) that affects or threatens to affect navigable waters of petroleum crude oil products such as gasoline, diesel fuel, oil, or derivatives of mineral, animal or vegetable oil shall be reported to the National Response Center and the state of Colorado Division of Oil and Public Safety at (303) 318 -8547 within 24 hours. A hazardous substance release in any amount which enters or threatens to enter waters of the state shall be reported to Colorado Department of Public Health & Environment (CDPHE) and the National Response Center. Other Chemicals Products Management Additional materials will be used and stored on site for use in construction. These materials will be stored appropriately and managed to minimize spills and leaks. Storage 27 Skinner Ridge Master SWMP Chevron U.S.A., toe. areas will be regularly inspected and any minor spills or leaks will be cleaned up immediately. Materials Management The construction contractor will maintain a Iaydown 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. 5.4 Construction Site Housekeeping Housekeeping will consist of neat and orderly storage of materials and containerized fluids. Wastes will be temporarily stored in containers and regularly collected and disposed of at approved off -site facilities. If spills occur prompt cleanup is required to minimize any commingling of waste materials with storm water runoff. Routine maintenance will be limited to fueling and lubrication of equipment. Drip pans and/or absorbent material will be used during routine fueling and maintenance to contain spills or leaks. Any waste product from maintenance will be contained and transported off site for disposal or recycling. All attempts will be made to minimize major equipment overhauls conducted on site. Equipment will be transported off site for major overhauls if required. Cleanup of trash and discarded materials will be conducted during the course of each work day. Cleanup will consist of patrolling the road way, access areas, and other work areas to pickup trash, scrap debris, other discarded materials, and any contaminated soil. These materials will be disposed of in accordance with all applicable rules and regulations. 28 Skinner Ridge Master SWMP Chevron U.S.A., Inc. 6.0 INSPECTION AND MAINTENANCE PROCEDURES To meet requirements of the General Permit, inspection and maintenance of erosion and sediment controls must occur during the project. The inspection program 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 cover these areas: • Evidence of surface erosion for disturbed areas; • Material and chemical storage areas; • Best Management Practices (BMPs); • Surface water diversions and down gradient areas; • New access roads and ditches; and • Locations where vehicles enter or exit the site. 3. Routine Inspections will be performed at least once every 14 or 30 calendar days in accordance with State requirements and within 24 hours after a significant precipitation or snow melt event that causes erosion. If no construction activities occurs following a storm event, post -storm event inspections shall be conducted prior to re- commencing construction activities but no later than 72 hours following the storm event. 4. Permanently stabilized areas will be periodically inspected to monitor ongoing 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 office.. 6. Inspections are not required for disturbed areas when snow cover exists over the entire site for an extended period as long as melting conditions do not exist. 7. Water quality will be visually assessed for all receiving streams and discharge areas during each inspection if present. 8. Disturbed areas and material storage areas that are exposed to precipitation will be inspected for evidence of pollutants entering nearby drainages. 9. Check dams, wattles, and other BMPs will be inspected for evidence of deterioration, under - cutting, and build up of sediment. Sediment will be removed when it has built up one -third to one -half the height of the hay bales or wattles. 29 Skinner Ridge Master SWMP Chevron U.S.A. , tne. 10. Roads used for vehicle access will be inspected for evidence of oft -site sediment transport. 11. The SWMP will be modified as necessary whenever there is a change in design, construction or operation that changes the potential for pollutant discharge to waters of the state. 12. An inspection report summarizing the scope of the inspection, the name of the 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. 13. Actions taken to modify storm water control measures will be recorded with inspection reports and maps and maintained with the SWMP. Personnel performing facility inspections such as access roads, well pads or other operational facilities will record site conditions on the Storm Water Inspection Report form in Appendix D. Immediately when deficiencies are discovered, the Chevron local contact will be contacted and 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. 30 Skinner Ridge Munger SWMP Chevron U.S.A., Inc. 7.0 NON - STORMWATER DISCHARGES Non -storm water discharges anticipated from the project include permitted construction dewatering and pipeline hydro -test waters. In addition, the extraction of natural gas can produce large quantities of water that are trapped in the formation along with the gas. 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 2010 a 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 water source. Depending on the level of treatment achieved and volume of water treated, a permit may be pursued to discharge treated effluent either into surface water or ground water at the project location. Brine and solids are anticipated waste streams from 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. 31 Skinner Ridge Master SWMF' Chevron U.S.A. Inc. 8.0 FINAL STABILIZATION Areas which have been disturbed are considered to be stabilized when a uniform vegetative cover with a density of 70 percent of 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. Table 2 contains approved seed mixtures and application rates provided by the Natural Resources Conservation Services (MRCS) for the Skinner Ridge project area. Typical Pure Live Seed (PLS) application rates are recommended to be doubled if seeding is performed by hydro- seed or broadcasting. Areas not used for facilities, access roads, materials storage yards, or other work areas will . be stabilized with vegetation. Areas that are stabilized with vegetation will be considered to have achieved final stabilization when a uniform stand of vegetation with a density of at least 70 percent of the pre- disturbance has been established. Sprayed on mulches and other slope stabilization materials may be used in combination with seeding techniques in select areas to promote and establish surface vegetation cover. Other areas which may include facilities, access roads, materials storage yards, and other work areas will be stabilized with the use of permanent, physical erosion reduction methods which include, but are not limited to: 1, Surface hardening — covering of the soil surface with hardened products such as concrete or asphalt pavement. 2. Surface covering — covering of the surface soil with structure that inhibits contact of precipitation with the soil surface which is generally considered to be placement of a structure (building or tank) over the soil surface. 3. Gravel surfacing — gravel surfacing will be applied in areas such as access roads, materials storage yards, and other work surfaces. Some gravel may be lost due to erosion from intense precipitation events or due to vehicle traffic. Gravel surfaces will be periodically inspected to determine the need for gravel replacement. Gravel surfaces will be replaced or repaired (through grading) when inspection reveals that the gravel surface is no longer effectively covering the soil surface. 32 Table 2 020011 ,Sun 011113110 26010 012121250(1 920!11911126 10010 911 1.01101 lass) qeg L10001 smislunoA 8L xmdmo0 - a».s20L0A al.upwunl .x01S Pa0!0IP IPM P!d01 119 -114 9 m v . d mmu0010 4a9oA-sallgge9 SL m .0015011 0p10S91 0022 - 1140.126 490709 111 &mu° 10111 WA aw.1pm P.gmA IPM P1:4e11 06 -0't 5 ,gyw.aiun sz1e0g mmf. ^91 Laa11 1002.0.1;1 10 01.201mg9 000, 21111120111 / x011012009091 P0719 112M 089311 9.1 weal 2201/1109 020.111) 00 OM. 0.0A 11.01 0!0!050 1101 3001904 .' 9-IIa damn, 5 li !up 11026 P!dex 9C -01 Pmlpuomun AO-n:11!410012 69 01 .0010! Lpu2g 300N.1pss10uL 2u.21 011A 110010291 9.01,.P 19.45 P1611 09-00 01001 men! 029019 L1000911200L L9 9414019 ...... f... 21002 01am0pou0 0121!011222 ..w. A... .,, if 91101919 ......_.......... 10!120x0120200 mi 11391 99 0192100/5 IPM 3.1.31,wa 0110 P2m..1P IRx ,I 14975 5011 11501.05,91 .x015 121-1 •11.01 apes utm0lwN 10001 AK E9 20211.0209 2202ap0(1 F.0.911026 2!12111 65-40 urea1 1:02011. 1w1n1xrn 101111 9S .Suwo7 pun use/ .Slimy - in3ui,umoomd - 11102s ,Vas 010.050122 palgup IPA", P1 001, wan? 0212015 Ltiue04 x11!4.001 SS 012( 250522 0.01019115 mar 10.111!.1000(1 Il202 j -0n900J0d 149!1S x010 0121, 2019 502l221P 11292 10019 5-1 01001 9060911111909-3 021911024 511 10022 km 01200 I m 2.0019 9011 Pau tut) K01 m 01^!F1W 05-9 me l (e L1 113 3ued1e9,SrA0AS Ppy- .001202211x229 ES uearaoae - 30099 :10571 9a01.0P IPM POW 59-02 mom 090100 d00101029 domino 9F 39090144011 - 20099 1/01150122 9091815112A1 011.92(1 52-21 L2sp 4 1A 24015 Lumol 11121209 it - 00019 2101/50224 92901' 11126 02016 21 -E 1017 LP011 w093wdoo :144011 1'6 WAS 11 01a0.0150(9 Pa0?e1P P14011 09.00 ,4suus00I o9 111100112 nmun019 oango.p 21 maul Lela Outs 4991 948gS m,IS Pa•!•0P 0S200d 26015 E-0 .Slla0dm101n1-1 mow,/ .0018 01ua26e0n19, 90 120099 112020 922211115111/5 00250(1 5-5 "1001 Lei 100010112.111912920 12( 00300,91 55 11(895 0+015 P.,,,5 11a/5 ..010 E -9 uwol imp 001„ 121 .) 0011ap2us25 0a2012wn07 If 20099 P51.2 000115102 91101AP 01/5 P01 Oil faleuxua LuA maul 6691 00(4090(! 6Z 0 0110205001 909009 )00 ,x 12 maul 0010 M0,04014011 10115091 149!18 malu2poh' wyxaumc x9211 E -[ L9ws 1211a0.20� 110.x9111010012 0110.1 11 92 01 Pa0!.12 PAS 20120 xots 0111.05091 512011115 IPM 0015 9-1 0e010911.9 011201111!1191V 1310x90001 01 12001(2 3101150(1 50.001911026 211219 0(^02 001101011201{1 0044.1(11191003 12021110..110192191 L - 201018 11.12901,1 929019 IPM 0.01949 121•0 011101 u1001 3m1109 010(4 0 aunts 121A x010 LOA 9202001, 111/5 Rldu 12,A 69-01 p22aywP N, .000010 {w 02012354 W.IR11 Z 120129091 19996 121305619 1a099 1P116 20015 0 -0 11.0101015. 100009001)1 ely 1 1.1!1,17194 11111.210.1 1103 3.052.11 pus u.110a3 Aergestuam 111.9] 1.!1,111012 ri01g 11091,1 .01112112025 00µ101.m0,1 .010,26 anrms,a young 11!05 r..y leiltai023 009241105 120.4 faddy 1105 wes9uld 1'1901 Table 2 Final Stabilization Seed Mixtures *Elevations up to 7,000ft* Species Variety % in mix Drill Rate LS Species „tn nr.t nir_ : % in mix 25 - 2.8 5.6 Galleta Grass (floret Viva 25 2.8 5.6 Alkali Sacation Sandy Drvpseed ifsan. ) 25 0.4 0.8 Indian Rice_ Paloma 25 3.0 6.0 Native and Introduced Mixture/Variety Species Species Variety % in mix Drill Rate (PLS) Broadcast Rate (PLS) Crested Wheatgrass Ephraim 25 1.5 3.0 Galleta Grass (floret) Viva 10 1.1 2.2 Alkali Sacation Sandy Dropsced (ifsandy) 15 0.2 0.2 Indian Ricegrass Paloma 25 3.0 6.0 Russian Wildrye Bozoisky 25 2.5 5.0 *Elevations 7.000 to 9.000ft* Table 2 Final Stabilization Seed Mixtures *Elevations 7,000 to 9,000ft* HLPV44• a Species Variety Variety % in mix Drill Rate Broadcast Rate (PLS) ,.r,n1arr.%ary .zc Critana 25 2.5 5.0 Western WheatGrass 25 4.0 8.0 Green Necd1e s 25 2.5 5.0 Prairie Jun MIMI 15 5.0 0.4 R. ... ' . , .o , . Bandera 10 0.6 1.2 Fourwin_ Saltbrush Add on 10 2.0 Table 2 Final Stabilization Seed Mixtures *Elevations 7,000 to 9,000ft* 'PLS = Pure Live Seed HLPV44• a Species Variety % in mix Drill Rate (PLS) Broadcast Rate (PLS) Pubescent Wheatgrass Luna 25 2.5 5.0 Western Wheatgrass Arriba 25 4.0 8.0 Russian Wildrye Bozoisky 25 2.5 5.0 Alfalfa Ladak 15 0.2 0.4 Small Burnet Delay 10 0.6 1.2 Fourwing Saltbrush Add on 1.0 20 'PLS = Pure Live Seed Figure 1 Figure 2 BMP Selection Guidelines Clearing Stage Production Stage Reclamation Stage j Dada Pads Pads Filter Bcun Land Grading, Level Spreader Wattles Riprap Sediment Trap Silt Fence Straw Bale Barrier Surface Roughening Terracing Vegetative Buffer Water Bar Diversion Ditch Filter Bern. Land Grading Level Spreader Wattles Riprap Sediment Trap Silt Fence Straw Bale Ranier Surface Raughcnine Terracing Vegetative Buffer Water Bar Diversion Ditch Gravel Surfacing Barn Check Dams Drainage Dip Erosion Control Blanket Slope Drain Slope Stabilisation Filter Berm Land Grading Level Spreader Wattles Riprap Sediment Trap Silt Fence Slaw Bale Barrier Surface Roughening Terracing Vegetative Buller Water Bar Diversion Ditch Gravel Surfacing Bum Cheek Dams Drainage Dip Erasion Control Blanket Mulching Slope Stabilization Piielbles '-i _`.JslP.Iflellfi ift:Wl'i:;r'• ? Hoes __ -'... Fitter Berm Land Grading Level Spreader Wattles Riprap Sediment Trap Silt Fence Straw Bale Barrier Surface Roughening Terracing Vegetative Buffer Water Bar Diversion Ditch _ Filter Berm Land Grading Level Spreader Wattles Riprap Sediment Trap Silt Fence Straw Bala Barrier Surface Roughening Terracing Vegetative Buffer Water Bar Diversion Ditch Cheek Darns Culverts Culvert Protection Drainage Dip Rcvcgetation Slope Stabilization Filter Bens Land Grading Level Spreader Wattles Riprap Sediment Trap Silt Farce Straw Bale Barrier Surface Roughening Terracing Vegetative Buffer Water Bar Diversion Ditch Check Dams Culverts Culvert Protection Draiatade Dip Erosion Control Blanket Mulching Revegetation Slope Stabil imtinn Clearing Stage Production Stage Reclamation Stage Access: Roads Access Reads Areas Roads Filter Berm Land Grading Level Spreader Wattles Ripmp Sediment Trap Silt Fence Straw Bale Barrier Surface Roughening Terracing Vegetative Stiffer Water Bar Diversion Ditch Gravel Surfacing Roadside Ditches Tnmouta Stabilized Entrance Filar Benn Land Grading Level Spreader Wattles Riprap Sediment Trap Silt Fence Straw Bale Barrier Surface Roughening Terracing Vegetative Buffer Water Bar Diversion Ditch Gravel Surfacing Check Dams Berm Culverts Culvert protection Drainage Dip Erosion Canhvl Blanket Retaining Wall Geo-Ridges Revegetation Roadside Ditches Turnouts Slope Drain Stabilized Entrance Slope Stabilization Filter Berm Land Grading Level Spreader Wattles Riprap Sediment Trap Silt Fence Straw Bale Barrier Surface Roughening Terracing Vegetative Buffer Water Bar Diversion Ditch Gravel Surfacing Check Dams Benn Culverts Culvert protection Drainage Dip Erosion Control Blanket Mulching Revegetation Roadside Ditches Turnouts Stabilized Entrance Slope Stabilization Facilities' - ' yekilf+ .f,'3.,c...,„4,,,, .I. -e '— .. . edit .z.`.�' .• Filter Senn Land Grading Level Spreader Wattles Riprap Sediment Trap Silt Fence Straw Bale Barrier Surface Roughening Terracing Vegetative Buffer Water Bar Diversion Ditch Gravel Surfacing Fitter Berm Land Grading Level Spreader Wattles Riprap Sediment Trap Silt Fence Shaw Bale Barrier Surface Roughening Terracing Vegetative Buffer Water Bar Diversion Ditch Gravel Surfacing Berm Check Dams Drainage Dip Erosion Control Blanket Revegetation Slope Drain Slope Stabilization Filter Bran Land Grading Level Spreader Wattles Riprap Sediment Tmp Sih Fence Straw Bale Barrier Surface Roughening Terracing Vegetative Buffer Water Bar Diversion Ditch Gravel Surfacing Bend Cheek Dams Drainage Dip Erosion Control Blanket Mulching Revegetation Slope Stabilization STATE OF COLORADO Bill Bitter, Jr., Governor James B. Martin, Executive Director Dedicated to wowing and Improving the health and environment of the people of-Colorado 4300 Cherry Creek Dr. S. Denver. Colorado 80246-1530 Phone (303) 6922000 TDD Line (303) 891 -7700 L350100 in Glendale. Colorado httpdavwvmdpheatatam va June 20, 2007 Laboratory Services Division 8100 Lowry Blvd. Denver, Cddredo 80230-632B (903) 8823090 Michael De Berry, Piceance Ops Mgr Chevron USA Inc, Hector E. Cavazos 11111 S. Wilcrest P.O. Box 36366 Houston, TX 77099 970/257 -6005 RE: Final Permit, Colorado Discharge Permit System — Stormwater Certification No: COR- 037787 Skinner Ridge Natural Gas Wells Garfield County Local Contact: George Badovinatz, Ops Super 970/257 -6002 Dear Sir or Madam: Colorado Department of PublicHealtl 2nd Environment Y tci. Enclosed please find a copy of the new permit and certification which have been re- issued to you under the Colorado Water Quality Control Act Your old permit expires on Dune 30, 2007. This is a renewal to the permit, and replaces the old one. See page 2 of the Rationale (the pages in italics) for a summary of the changes to the permit Your Certification under the permit requires that specific actions be performed at designated times. You arc legally obligated to comply with all terms and conditions of the permit. Please read the permit and certification. If you have any questions please visit our website at : www.cdphc. state. co .uslwa /permitstmit/storonwate or contact Matt Czahor at (303) 692 -3517. Sincerely, rTh Kathryn Dolan Stornwater Program Coordinator Permits Unit WATER QUALITY CONTROL DIVISION xc: Regional Council of Governments Local County Health Department District Engineer, Technical Services, WQCD Permit File STATE OF COLORADO COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT WATER QUALITY CONTROL DIVISION TELEPHONE: (303) 692 3500 CERTIFICATION TO DISCHARGE UNDER CDPS GENERAL PERMIT COR -030000 STORMWATER DISCHARGES ASSOCIATED WITH CONSTRUCTION Certification Number COR037787 This Certification to Discharge specifically authorizes: Chevron USA Inc LEGAL CONTACT: Michael De Berry, Piceance Ops Mgr Chevron USA Inc 11111 S Wilcrest P.O. Box 36366 Houston, IX 77099 Phone # 970/257 -6005 LOCAL CONTACT: George Badovinatz Ops Super, Phone # 970/257 -6002 During the Construction Activity: Gas /Oil Field Exploration and/or Development to discharge stormwater from the facility identified as Skinner Ridge Natural Gas Wells which is located at: Tom Creek in Skinner Ridge area. Garfield County, Co Latitude 393877, Longitude 108.3418 In Garfield County to: Tom Creek Anticipated Activity begins 02/07/2005 continuing though 06/07/2006 On 3.4 acres (18.0 acres disturbed) Certification is effective: 07/01/2007 Certification Expires; 06/30/2012 Annual Fee: 5245.00 (DO NOT PAY NOW — A prorated bill will be sent shortly.) Page 1 of 22 Page 2 of 22 Permit No. COR -030000 CDPS GENERAL PERMIT STORMWATER DISCHARGES ASSOCIATED WITH CONSTRUCTION ACTIVITY AUTHORIZATION TO DISCHARGE UNDER THE COLORADO DISCHARGE PERMIT SYSTEM In compliance with the provisions of the Colorado Water Quality Control Act, (254 -101 at seq., CRS, 1973 as amended) and the Federal Water Pollution Control Act, as amended (33 U.S.C. 1251 et seq,; the "Act "), this permit authorizes the discharge of stormwater associated with construction activities (and specific allowable non- stormwater discharges in accordance with Part LD.3 of the permit) certified under this permit, from those locations specified throughout the State of Colorado to specified waters of the State. Such discharges shall be in accordance with the conditions of this permit. This permit specifically authorizes the facility listed on page I of this permit to discharge, as of this date, in accordance with permit requirements and conditions set forth in Parts I and 11 hereof. All discharges authorized herein shall be consistent with the terms and conditions of this permit. This permit and the authorization to discharge shall expire at midnight, June 30, 2012- Issued and Signed this 31" day of May, 2007 COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT Janet S. Rider Permits Section Manager Water Quality Control Division SIGNED AND ISSUED MAY 31, 2007 EFFECTIVE JULY 1, 2007 TABLE OF CONTENTS PART I A. COVERAGE UNDER THIS PERMIT 3 1, Authority to Discharge 3 a) Applicable Sections 3 b) Oil and Gs Construction 3 2. Defmitions 3 3. Permit Coverage Without Application- Qualifying Local Programs 3 a) Appliable Sections 3 b) Low Agency Authority 4 c) Permit Coverage Termination. 4 d) Compliance with Qualifying Local Program 4 e) Full Permit Applicability 4 4. Application, Due Dates 4 a) Application Due Dross 4 b) Summary of Application 4 5. Permit Certification Procedures 4 a) Request for Additional Information 4 0) Automatic Coverage. 5 c) individual Permit Required 5 d) General vs. Individual Permit Coverage 5 e) Local Agency Authority 5 6. Inactivation Notice 5 7. Transfer of Permit 5 8. Reassignment of Pamir 5 9. Sale ofResiderceto Homeowners 6 10. Permit Expiration Date_.._ 6 11. Individual Permit Criteria 6 B. STORMWATER MANAGEMENT PLAN - GENERAL REQUIREMENTS 6 C. STORMWATER MANAGEMENT PLAN - CONTENTS 7 L. Site Description 7 2. Site Map..._....._ 7 3. Starmwater Management Controls 8 a) SWMPAdminisratm 8 b) identification of Potential Pollutant Sources 8 e) Best Management Practices (BMPs) for Stmrmtater Pollution Prevention - 8 4. Final Stabilization and Long -term Stormwater Management 9 5. Inspection and Maintenance 10 D. TERMS AND CONDITIONS 10 1. General Limitations 10 2. BMP Implementation and Design Standards 10 3. Prohibition of Non- Stormwatcr Dtxburges..._ 11 4. Releases in Excess of Relwrmble.Quantitiea 11 5. SWMP Requirements 11 a) SWMP Preparation sled Implementation 11 0) SWMP Retention Requirements 11 e) SWMP Review /Changes 11 d) Responsive SWMP Changes. I2 6. Inspections 12 a) Minimum Inspection Schedule.._ 12 b) Inspection Requirements 13 e.) Required Actions Following Site Inspections 13 7. BMP Maintenance ..._ 13 8. Replacement and Failed BMPs 14 9. Reporting 14 -2a- TABLE OF CONTENTS (eons.) 10. SWMP Availability . 14 11. Total Maximum Daily Load (TMDL) 14 E. ADDITIONAL DEFINITIONS 15 F. GENERAL REQUIREMENTS 16 1. Signatory Requiremouts 16 2. Retention of Records 16 3. Monitoring 16 PART II A. MANAGEMENT REQUIREMENTS 17 1. Amending a Permit Certification 17 2. Spetial Notifications - DefmitionS 17 3. Nonrnmpliance Notification 17 4. Submission of Incorrect or Incomplete Information 18 5. Bypass 18 6. Upsets 18 7. Removed Substances l8 8. Minimization of Adverse Impact. 18 9. Reduction, Loss, or Failure of Siormwater Controls L9 10. Proper Operation and Maintenance 19 B, RRSPONSIBILiTIES 1. Inspections and Right to Entry.._ 2. Duty to Provide Information 3. Transfer of Ownership or Control 4. Modification, Suspension, or Revocation of Permit By Division 5- Permit Violations. 6. Legal Responsibilities 7. Severability 8. Renewal Application 9. Confidentiality 10. Fees 11. Requiring an Individual COPS Penoit 19 19 19 19 20 2I 21 21 21 2] 21 22 PART I A. COVERAGE UNDER THIS PERMIT 1. Autl__mjasgEmpagge PART 1 Permit - Page 3 Permit No. COR -030000 Under this permit, facilities are granted authorization to discharge sonmwata associated with construction activities into waters of the state of Colorado. This permit also authorizes the discharge of specific allowable orn- sormwater discharges, in accordance with Part 1i13 of the permit, which incNdca discharges the ground. This Inc/tides stormwater discharges from areas that are dedicated to producing earthen materials, such as soils, sand and gavel. for use at a single 00rrsmncti00 sire a.e., borrow or fill areas). This permit also nutharizes stormwn0 discharges from dedicated asphalt batch punts and dedicated concrete batch plants. (Coverage ander the construction site permit is not required for batch plants if they have alternate CDPS permit coverage.) This permit does not amhorizethe discharge amine water or process water from such a) Applicable Sections: In accordance with Part LA.3 of this permit, some pens of this permit do not apply to sites coveted under a Qualifying Local Program, as defined in LA2d- For sites not covered by a Qualifying Local Program, all pens of the permit apply except Part 1.A.3. The permitter will be responsible for dehrmiaing and them complying with the applicable sections. b) Oil and Gas Construction: Stmmwater discharges associated with construction activities directly related CO ot7 and gas exploration, production, processing, and treatment operations or transmission facilities are regulated under the Colorado Discharge Permit System Regulations (5CCR 1002 -61), and require coverage under this permit in accordance with thin regulation. However, refercaces in this permit to specific authority under the Federal Clean Water Act (CWA) do not apply to stormwater discharges associated with these oil and gas related construction activities, to the extent that the references are limited by the federal Energy Policy Act of 2105. 2. DNIniGoes a) stormwater: Steamwater is precipitation - induced surface runoff. b) Construction activity: Construction activity refers o gro nd sulfa. disturbing activities, which include. but are not limited to, clearing, grading, excavation, demolition, installation of new or improved haul roads and access roads, staging areas, stockpiling of 171 materials, and borrow areas. Coost-aation does not include routine maintenance to maintain original line and grade, hydraulic capacity. or original Purpose of the facility. c) Small construction activity: Stormwater discharge associated with small croshvction activity means the discharge of srormwoa from construction activities that result in land disturbance of equal to or greater than one acre and less than five acres. Small construction activity also includes the disturbance of less than oae acre of toted land area that is part of a lager cootrnon plan of development or sale, if the larger common plan will uthmately disturb equal to or greater thane one and less than five acres. d) Qnafdying Local Program: This permit includes conditions that incorporate qualifying local erosion and sedoment control program (Qualifying Local Program) raryiremralo by reference. A Qualifying Local Program is a mnoicipal stormwater program for stormwatcr discharges associated with small construction activity that has been formally approved by the Division• Other Definition: Definitions of additional terms can he found is Part I.E, of this permit 3. Permit Coverage Without Auplication— for small construction activities under a Qualifying Local Program oat If a small coostructioo site is within the jurisdiction of a Qualifying Local Program, the operator of the constructer activity is authorized to discharge stotmwater associated with small construction activity coda this general permit without the submittal of as application to the Division. a) Applicable Sections: For sites covered by a Qualifying Local Program, only Pmts 1.A.1, 1-A2, I A3, I.D.3, 133.4, ID.7, 1J7.0,1.D.1 L, LE and Pmt 11 of this permit, with the exception of Pans IIA.1, 148.3. 11.B.B, and 11.810, apply. PART 1 Permit - Page 4 Permit14o. COR- 030000 A. COVERAGE UNDER THIS PERMIT (cont.) b) Loral Agra eyAnthority-. This permit does not pre -empt or supersede tie authority of Meal agencies to prohibit, restrict, or control discharges of somtwarer so storm drain systems or other water courses within their jurisdiction. c) Permit Coverage Termination: When a site tinder a Qualifying Local Program has been finally stabilized. coverage under this permit is automatically terminated. d) Compliance with Qoalllyiag Local Program: A construction site operator that has authorization to discharge render this permit ceder Part L.A.3 shall comply with the requirements of the Qualifying Local Program with jurisdiction over the site. e) Fall Permit Applicability-. TheDivisim may require any operator within the jurisdiction of a Qualifying Local Program covered under this permit to apply for and obtain coverage under the full requirements of this permit The operator mast to notified in writing that an application for full coverage is required. When a permit certification sander this pctmit is issued to an operator that would otherwise be covered tinder Pat 1.4.3 of this permit, the Hill requirements of this permit replace tie requirements as per Part LA3 of this permit, upon the effective date of the permit certification. A site brought under the full requirements of this permit must still comply with local stormwater management rcqu'vemcnts, policies or guidelines as required by Pat LD.I.g of this permit 4. Aoalicat op. Due Dates a) Application Diu Dates At least ten calendar days prior to the commencement of contraction activities, the applicant shall submit an application form as provided by the Division, with a certification that the Stonawata Management Pim (SWMP) is complete. b) One original completed discharge permit application shall be submitted, by mail or band delivery, to: Colorado Department of Public Health and Envirroa recut Water Quality Control Division WQ(D- Permits -132 4300 Cherry Creek Drive South Denver, Colorado 50246-1530 Summary of Application: The application requires, at ambsmum, the following: 1) The applicant's company name; address; telephone amber; and email address (if available); whether the applicant is the owner, developer, or contractor, and local contact information; 2) Project name, address, county and location of the construction site, including the latitude and longitude to the nearest 15 seconds of the approximate tatter of the co^eT1ction activity; 3) Legal description or map of the construction site; 4) Estimates of. the out area of the site, the area of the sire that is expected to be dismtbed, and the total area of the larger common plan of development or saint° undergo disarhaoce; 5) The nature of the construction activity, 6) The anticipated start dale and final stabilization date for the project; 7) The name of the receiving water {s), or the mmticipal separate storm sewer system and the ultimate (i.e., named) receivingwaa(s); B) Certification that the SWNIP for the aonsauetion site is complete (sec Part LC. below); and 9) The signature of the applicant, signed in accordance with Pan LP.] of this permit 5. Permit Certification Yroodures If this general permit is appropriate for the applicant's operation, then a certification will be developed and the applicant will be authorised to discharge starnwater under this general permit a) Request for Additional Information: The Division shell have up to oat calendar days after receipt of the about information 50 request additional data and/or deny the authorization for any paticulardisohargc. Upon receipt of additional infoncation, the Division shall have an additional ten calendar days to issue or deny authottiamon for the particular discharge. (Notification of denial shall be by letter, in casts where coverage tinder an alternate genera] permit or an individual permit is required, instead of coverage under this permit.) x � Ill in S'4L: g' .e liT d d a s 01 q.1 fM v-..- all 1P s l a 1t1 r z qi B E d g Pi b ,- i 8 1r '44 g pi 1 5.11 I!I $! sST ^ ' ° 4 Ell pas i age a :; -E 1 :111 Erns h g � W 0,A1 14 t m P111 14.t `oh A E6 a i gull g 1 uugg . fi fihit a a 8 m 9 0,15:A 6 :p .. 11. d nin i Z.q o 5 u 5 go, 4 12E PI la 1 la 1 i Pi LI It V. 0ti J� 31�g 'IDI 1 hilL s' ;it r• 0 -t hi: `-it ,,,,,' al . . ° 4D AI! IN! t 114 RIfi PO. 18 04 2'1'1 II t4 mh PART 1 Permit -Page 7 Permit No. COR-030000 B. STORMWATER MANAGEMENT PLAN (SWMP)— GENERAL REQUIREMENTS (coot) 2. The SWMP shall: a) Identify all potential sowccs of pollution which may reasonably be expected to affect the quality of stormwater discharges associated with construction activity from the facility: b) Describe the practices to he used to reduce the pollutants in slormwnter discharges associated with constntetion activity at the facility; and ensure the practices are selected and described in accordance with good =sneering practices, including the installation, implementation and maintenance requirements; and c) Be properly prepared, and updated in accordance with Part I.D.5.c, to enso a compliance with the terms and conditions of this permit. 3. Facilities must implement the provisions of the SWMP as written and updated, from commencement of construction activity uric] final stabilirpoa is compete, as a condition of this permit The Divisive reserves the right to review the SWMP, and 10 require the permittee to develop and implement additional measures to prevent and control pollution as necdcd. 4, The SWMP may reflect requirements for Spill Prevention Canny'. and Countermeasure (SPCC) plans under section 311 of the CWA, or Best Management Practices (BMPs) Programs otherwise required by a separate CDPS permit, and may incorporate any part of such plans Trim the SWMP by reference, provided that the relevant sections of such plans ars available as part of the SWMP coasisteat with Part 5. For any sites with permit coverage before Ante 30, 2007, the permitbee's SMWP must meet the new SWMP requirements as summarized in Section B.1 of the rationale. Any needed changes must be made by October I, 2007. C. STORMWATER MANAGEMENT PLAN (SWMP) — CONTENTS The SWMP shall include the following items, ate minimum_ 1. Site DeseriWinn. The SWMP shall clearly describe the construction activity, to ncludm . a) b) c) d) D 8) Ii) The nature of the construction activity at the site. The proposed sequence for major activities. Estimates of the total area of the site, and the area end location expected to be disturbed by clearing, excavation, grading, or other eoastrnction activities. A summary of any milling data used in the development of the site construction plans or SWMP that describe the son or czistiig potential for ao0 erosion. A descriptiea of the existing vegetation at the site and an estimate of the percent vegetative ground cover. The location and dcscnptien oral] potential pollution sources, including ground surface disturbing activities (see Pan I.A.2.b), vehicle fueling, storage of fertilizers or ebcmiw{s, etc. The location and deseription of may anticipated allowable sources of nor- starmwater disrh gt at the site, e.g., uncoaaminated springs, landscape irrigation rerun flow, construction dewateriog, and concrete washout. The dmoc of the receiving watcr(s) and the size, type and Location of any outfal(s). If the stormwateo discharge is to a municipal separate son m sewer system, the name of that system, tae location of the storm sewer discharge, and the ultimate receiving water(s). 2. Site Man. The SWMP shall include a legible site map(s), showing the entire 540, identifying: a) b) c) d) e) 1) g) h) construction site boundaries; all areas of ground surface disturbance; areas of can sad flfl: arras used for storage of haildiog materials, equipment, soil or waste; locations of dedicated asphalt or concrete batch plants; locations of al structural BMPs; locations of nod - structural BMPS as applicable; and locations of springs, streams, wetlands and other surface waters. PART 1 Perna - Page 8 Permit Na COR- 030000 C. STORMWATER MANAGEMENT PLAN (SWMP) — CONTENTS (coat) 3. Stormweter Management Controls. The SWMP must include a description of all smrmwater management controls that will he implemented as part o £the ooashwction activity to control polltttants in mariners= discharges. The appropriateness and priorities of slwrnwater management controls in the SWMP shall reflect the potential pollutant sources identified at the facility. The description ofstomwater management controls shall address the following components, at a minimum: a) SWMP Admhrtstrator - The SWMP shall identify a specific individual(s), position or title who is responsible for developing, implementing, mehmairing, and revising the SWMP. The activities and responsibilities of the administ amr shall address all aspects of the facility's SWMP. b) Identification of Potential Pollutant Sources - All potential pollutant sources, including materials and activities, at a site must be evaluated for the potential to eontnbute pollutants to smrmwa[c discharges. The SWMP shall identify and describe those sources determined to have the potential to contribute pollutants to atormwater discharges, and the sources must be controlled through BMP selection sad implementation, as required in paragraph (c), below, At a m�imum, each of the following sources and activities shall be evaluated for the potential to cootrbute pollutants to etormwater discharges, and identified in the SWMP if found to have such potential: 1) all disturbed and stored soils; 2) vehicle tracking of sediments; 3) management of contaminated soils; 4) loading and unloading operasions; 5) outdoor storage activities (building materials, fertilizers, chemicals, etc.); 6) vehicle and equipment maintenance and fue ling; 7) significant dust or particulate generating processes; 8) routine maintenance activities involving fertilizers, pesticides, detergents, hale, solvenm, oils, arc; 9) - on-sue waste managemrnt practices (waste piles, liquid wastes, dumpaters, etc.); 10) concrete meek equipment washing, including the concrete truck chute and associated fixtures and equipment; 11) dedicated asphalt and concrete batch plants; 12) non- industrial waste sources such as worker trash and portable toilets; and 13) other areas or procedures where potential spills van occur. c) Best Management Practices (BMPo) for Stormwaber Ponutian Prevention- The SWMP shall identify and describe appropriate BMPe, including, but not limited to, those required by paragraphs I through g below, that will be implemented at the fanilityto reduce the potential ofthe sources identified in Part I.C3.b to contribute pollutants to storemelsr discharges. The SWMP shall clearly d&Scribe the installation and implementation specifications for each BMP identified in the SWMP m ens sic proper implementation, operation and twiveaumce of the amp. 1) The SWMP shall clearly describe and locate all sruchiral practices implemented at the site to matimize erasion and sediment transport Practices may include, but are not limited to: straw bales, wattles/sedimert control logs, silt fences, earth dikes, drainage swales, sediment traps, subsurface drains, pipe slope drains, inlet protection, outlet protection, gabions, and temporary or permanent sediment basins. 2) Non - Strumpet Practices for Erosion and Sediment Control. The SWMP shall clearly describe and locate, as applicable, all non - structural practices implemented at the site to minimize aesion and sediment transport. Description roust include interim and permanent stabilization practices, and site - specific scheduling for implementation of the practices The SWMP should include practices to ensure that existing vegetation is preserved whore possible. Nondbachral practices may Include, but are not limited to: temporary vegetation, permanent vegetation, nulching, geotext iles, sod stabilization, slope roughening, vegetative buffm strips, protection of Tees, and preservation of mmure vegetation. C. PART 1 Pettit - Page 9 Permit No. COR -030000 STORMWATER MANAGEMENT PLAN (SWMP)- CONTENTS (cont) 3) Phased BMP Smolementaaian. The SWMP shall clearly describe the relationship between the phases of construction, and the impletnentation and maintenance of both structural and non- struewal stormwater management controls. The SWMP must identify the statmwater management Controls to he implemented during the project phases, which can include, but are not limited to, Bearing and grubbing; road construction; utility and inftustrucnne hutallatioe; vertical construction; fmal grading; and foal stabilization. 4) Matcriats llaadlina and Spill Prevention. The SWMP shall clearly describe and locate all practices implemented at the site to minimize impacts from procedures or sigtifiwat materials (see definitious at Part L.£.) that could contribute pollutants to runoff. Such procedures or significant materials could include: exposed storage of building materials; paints end solvents: fcutilircrs or chemicals; waste material; and equipment maintenance or fueling procedures. Areas orprocedures where potential spills can occur must have spill prevention and response procedures identified in the SWMP. 5) Dtdit*lc l Concede or Asphalt Batch P1rmts. The SWMP shall dearly describe and locate all practices implemented at rinc site to control stomtw .tc rpolla ion from dedicated concrete batch plants or dedicated asphalt batch plants covered by this certification. 6) Vehicle Tracking Cord, The SWMP Shall clearly describe and locate all practices implemented at the site m control potential sediment discharges from vehicle tracking. Practices must he implemented for all arras of potential vehicle tracking, and can include: minimizing site access; street sweeping or scraping; tracking per; gaveled parking areas, requiring that vehicles stay on paved areas on -site; wash racks; contractor education; and/or sediment control BMPs, etc. 7) Waste Management and DisoosaL including Concrete Washout. 1) The SWMP shall clearly describe and locate the prances implemented at the site to control stotmvater pollution from all construction site wastes (liquid and solid), including concrete washout activities. ii) The practices used for concrete washout must ensure that these activities do not result in the contribution of pollutants associated with the washing activity to stamwater runoff. iii) Part ID.3.c of the permit authorizes the conditional discharge of concrete wasdsout water m the ground. The SWMP shall ekarly describe and Isaac the practices to be used that will ensure that no washout ware from roacrete washout activities is discharged from the site as surface runoff or to surface waters. ' 8) Groundwater and Sterrawater Dewatetirsg. i) The SWMP shah clearly describe and locate the practices implemented at the site to control stormwater pollution from the dewatering of groundwater or stormwater from excavations, wells, etc. ii) Pat LD.3d of the permit authorizes the conditional discharge of construction dewatering to the ground. For any construction dewatering of groundwater not authorized under a separate CDPS discharge permit, the SWMP shall clearly describe and locate the practices to be used that will tatsure that no groundwater from coustruc0eu dewateting is disc-forged from the site as surface nntoff or to surface waters. 4. final Stabilization and Lene•term Stormwshr Management a) The SWMP shalt clearly describe rite practices used to achieve fund stabilization of all disturbed areas at the sire, and any ptazmed practices to control pollutants in stormwatcr discharges that will puce alter construction operations have been completed at the site. Is) Final stabilization practices for obtaining a vegetative rover should include, as appropriate: seed mix selection and application methods; sol preparation and amendments; soil stabilization practices (cg., aeictpccd straw, hydro mulch or rolled erosion conic products); and appropriate sediment control BMP5 as needed until Seal stabilization is achieved: etc. PART 1 Permit - Page 10 Permit No. COR -030000 C. STORMWATER. MANAGEMENT PLAN (SWMP) - CONTENTS (cent) a) Final stabilization is reached when all ground surface disttabmg activities at the site have been completed, and uniform vegetative cover has been estabbshed with asp individual plant density of at least 70 percent of pre- disturbance levels, or equivalent permanent, physical erosion reduction methods have beep employed The Division may, after consultation with the permittee and upon good cause, amend the final stabilization erneria in this section for specific operations. 5. inspection and Maintenance Part 1.D.6 of the permit includes requirements for site inspections. Part ID.7 of the permit includes requirements for BMP maintenance. The SWMP shall dearly describe the inspection and maintenance procedures implemented at the site to maintain all eon= and sediment control practices and other protective practices identified in the SWMP, m good and effective operating condition. D. TERMS AND CONDITIONS 1. General Limitations The following limitations shall apply to all discharges covered by this permit a) SLormwarer discharges from construction activities shall am cause, have Me reasonable potential to cause, or measurably contribute to an exceedaace of any water quality standard, including narrative standstills for water quality'• h} Concrete washout water shall not be discharged to state surface waters erne storm sewer systems. On -site permanent disposal of concrete washout waste is OSt authorized by this permit Discharge to the ground of concrete washout waste that will subaequendy be disposed of of -site is authorized by this permit See Part ID.3.c of the permit. c) Bulk storage saucwres for petroleum products and any other chemicals shall have secondary containment or equivalent adequate protection so as to contain all spills and prevent any spilled material from entering State waters. d) No chemicals are m he added to the discharge unless permission for the use of a specific chemical is granted by the Division. In granting the use of such cheminals, special conditions and monitoring may be addressed by separate correspondence. c1 The Division reserves the right to require sampling and testing, on a case-by-case bass, m the went that there is reason to suspect thin compliance with the SWMP is a problem, or to measure the effectiveness of the BMPs is removing pollutants in due effluent. Such monitoring may include Whole Effluent Toxicity testing. f) All site wastes must be properly managed to prevent potential pollution of State waters. Ibis permit does not authorize on-site waste disposal. g) All dischargers must comply with the lawful requirements of federal agencies, municipalities, cormties, drainage districts end other local agencies regarding any discharges of stotmwaterto storm drain systems or other Water opuses under their jurisdiction, including applicable requirements in municipal slormwater management programs developed to comply with COPS permits Dischargers must comply with local stormwater management requirements, policies or guidelines including erasion sad =limit control. 2. BMP Implementation and Destmr Standards Facilities mast select, install, implement, and maintain appropriate BMPs. following good engineering, hydrologic and pollution coatol practices. BMPs implemental at the site must be adequately designed to provide control for all potential pollutant sources associated with construction activity to prevent pollution or degradation of State waters. ?ART Permit - Page 11 Permit No. COR-030000 D. TERMS AND CONDITIONS (court) 3. prohibition of Non -Storm cater Discharges a) Except as provided is paragraaphs b, c, and d below. all discharges covered by this permit thnII be compeeed entirely of dtormwater associated with eonstructioa activity. Discharges of material other than atormwater must be addressed M a separate CDPS permit issued for that discharge. b) Discharges from the following soUnies diet are combined with shnmwater discharges associated with construction activity may he authorized by this permit, provided that the non- stormwater component oldie discharge is identified in the SWMP (see Pan1.C.1.g of this permit); • emergency fire fighting activities - uncontaminated springs - landscape irrigation return flow c) Discharges to the ground of concrete washout water from washing of tools and concrete mixer chutes may be authorized by this permit, provided that 1) the source is identified in the SWMP; 2) BMPs are included in the SWMP in accordance with Pan I.C.3(c)(7) and to prevent pollution of groundwater in violation of Part LOW l.te and 3) these discharges do not leave the site as surface runoff or to surface wows d) Discharges to the grand of water from conswction dewatering activities may be authorized by this permit, provided than 1) the Marco is grmmdwater and/or groundwater combined with oormwater that does not contain poliumne in concentrations cxceediag the State groundwater standards in Regalationa 5 CCR 100241 and 42; 2) the source is identified in the SWMP; 3) BMPs are included in the SWMP, as required by Pan I.C.3(cXg); and 4) those discharges do not leave the site as surface rural' or to surface waters Discharges to the ground from constriction dewatering activities that do not mart the above criteria must be covered under a separate CDPS discharge permit. Contaminated groundwater requiring coverage under a separate CDPS discharge permit may include grotmdwazer contaminant with pollutants from a landfill, mining ectrvtty, industrial pollutant plume, underground storage teak, or other source. 4. Releases in Excess of Reportable Oaantities This permit does not relieve the paretittee of the reporting requirements of 40 CFR 110, 40 CFR 117 or 40 CFR 302. Any discharge of hazardous material must be handled in accordance with the Divisions Noncompliance Notifltation Requirement (see Part IIA3 dam permit). 5. SWMP Requirements a) SWMP Preparation and Implementation. The SWMP shall be prepared prior to applying for coverage under the general permit, and certification of ins completion submitted with the application. The SWMP shall be implemented prior to commencement of ooastttetioe activities. The plan shall be updated as appropriate (see paragraph c, below), below). SWMP provisions shall be implemented until expiration or inactivation of permit coverage. h) SWMP Retention Requirements: A copy of the SWMP must be retailed on site unless another location, specified by the ppmittcc, is approved by the Division. c) SWMP Re Iew #Changes: The permitter shall ametM the SWMP: 1) when there is achange in design, construction. operation, or maintenance of the site, which would require the implementation of new or revised BMPs; or 2) if the SWMP proves to be ineffective in achieving the geu0'al objectives of eonnolfmg pollutants in stormwater discharges associated with constru.ction activity; or PART Permit • Page 12 Permit No. COR- 030000 D. TERMS AND CONDITIONS (cont.) 3) when BMPs are no longer necessary and are removed. SWMP changes shall be made prior to changes in the site conditions, except 0e allowed for im paragraph d below. SWMP revisions may include, but are not limited to; potential pollutant source identification; selection of appropriate BMPs for site conditions; BMP maintenance procedure;: and interim and final stabilization practices. The SWMP changes may include a schedule for further BMP design and implementation, provided that, if any interim BMPs are needed to comply with the permit, they are also included in the SWMP and implemented during the interim period d) Responsive SWMP Changes'. SWMP changes addressing Bbfi' installation sod/or implementation are often required to be made in response to changing conditions, or when current BMPs art determined ineffective. The majority of SWMP revisions to address these changes canoe made immediately with quick in-the-field revisions to the SWMP. la the less common scenario where more oomplex development ofmaterieiam modify the SWMP is necessary, SWMP revisions shall be made in accordance with the following requirements: 1) the SWMP shall be revised as soda as practicable bat in ate rase more than 72 boars after the change(s) in BMP installation teulio' implementation occur at the Site, and 2) a notation must be included in the SWMP prior to the site change(s) that includes the time and date of the chooge(s) in the field, an identification of the BMP(s) removed or added, and the location(s) of those BMP(s). 6. Site inspections must be conducted in accordance with the foIowmg requirements and minimum schedules. The required minimum inspe room schedules do not reduce or eliminate the permidee's responsibility to Implement and maittam BMPs in good and effective operational condition, and in accordance with the SWMP, which could require more frequent inspections. a) Nfmimum Inspection Schedule: The pennittee shall, at a minimum, make a thorough inspection, m accordance with the requirements in 1.D.6.b below, at least once every 14 calendar days. Also, post -storm event inspections must be conducted within 24 hours after the end of any precipitation or seowmelt event that causes surface erosion Provided the timing is appropriate, the post -storm inspections may be used to fulfill the 14-day routine inspection requirement. A more frequent inspection schedule than the minimum inspections described may be necessary, m ensure that BMPs continue to operate as needed to comply with the permit The following conditional modifications to this Minimum lospection Schedule are allowed' 1) Post-Storm Event Inspections at Temporarily Idle Sites — If no coastnsctioa activities will acct¢ following a storm event, post -storm meat inspections shall be conducted prior to re- commencing coaswction activities, but no later than 72 hours following the storm event. The occurrence of any such delayed inspection must be documented is the Inspection record Routine iospecdons still mustise conducted at least every 14 calendar days 2) Inspections at Completed Sites/Areas — For sites or portions of sites that meet the following criteria, but final stabilization has not been achieved due to a vegetative cover that has pot become established, the permittee shall make a thorough inspection of tbcir stortmvater management system at least once every month, and post- storm event inspections are not required, This reduced inspection schedule is only allowed if. i) all construction activities that will result is surface ground disturbance are completed; 0) all activities required for final stabilization, ice accordant with the SWMP, have been completed, with the exception of the application of seed that has apt occurred due to seasonal conditions or necessity for additional seed application to augment previous efforts; and di) the SWMP has been amended to indicate those areas that will be inspected in accordance with the reduced schedule allowed for in this paragraph. u n 6 �3 9 Eh I jil iiiI• g 6 k �g, R k ' 1 • 41 1 •o • g « e • li E 1aa .0 .l c1 a 3 . � 8 9 c .�, ,� i3, I .io ,g P9 1 '� � li a lh ,1 4 1 111 1 e dttt1 44 as c - s4 a !< • 4 t i p �S 1'41 a g si ; a. s ili 1! .fi e dI T T - �a14 F At 1 41 s 1' '�. i ' im 1611 idM a 1 e All 1 .1i$ ..i.. ..1 Al yi ii `a • .4b « 114°4 iGt1 I. 1 tg IN 11 Pli b� x,89 A H hillA h IH HHh F°, - al `1N . i 6 tl g... rA A pij a i vi �' ?d0 2 °0 .%; 111.4'; i Vii431 e 7.14 th Iiilt II! • ";j hi� C W$ $gs a1 7t ^ Ar 1 IDel A MIEN g g4 bik"Iii 11112" .1 libl If A 1 QA18ft% 13.1 PVID11111 14414 -tis .E. 4181-14.ipli pig iufltiIilt / I i iIIH s T ph PART I Permit - Page 15 Permit No. COR -030000 E. ADDITIONAL DEFINITIONS For the purposes of this petmi1 1. Best Management Praetices (BAPS): schedules of actwiacs, prohibitions of practices, maintenance procedures, and other management practices to prevent or reduce the pollution of waters of the State. BMPs also include treatment requirements, operating procedures, pollution prevention, and practices to control site rusoff, spillage or leaks, waste disposal, or drainage from material storage. 2. Dedicated asphalt plants and concrete plants: portable asphalt plains and concrete plants that arc located on or adjacent to a construction site and that provide materials only to that specific construction site. 3. Final stabilization: when all grotmd surface disturbing activities at the site have been completed, and uniform vegetative cover has been established with an indlviduel plant density of at least 70 percent of p¢a- dtatorbance levels, or equivalent permanent physical erosion reduction methods have ban employed. Far pmpoaes of this permit, establishment of a vegetative cover capable of providing erosion control equivalent to pre-es ti-sting conditions at the site will be considered final stabilization 4. Municipal aeparate storm Bever system: a conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man -made charnels, w storm drains), owned or operated by a State, city, town. county, district. or other public body (created by stale law), having jurisdiction over disposal of sewage, industrial waste, storrmvater, or other wastes: designed or used for collecting or conveying stortnwater. 5. Operator. the entity thar has day-to -day supervision and control of activities occurring at the construction site. This can be the owner, the developer, the general conmactar or the agent of one of these parties, in some circumstances. It is anticipated that at diffetsst phases of aconstruction project, different types of parties may satisfy the definition of 'operator' and that the permit may be transferred as the roles clump. 6. Outfadl: a point soured at the point where sromtwater leaves the construction site and discharges to a recaving water or a stormwater collection system. 7. Part of a larger common plan of development or sale: a contiguous area where multiple separate and distinct eonsu coon activities may be taking ply at differenttimes oa ddfererx schedules. 0. Point soarer any discermblc, confined and discrete conveyance from which pollutant are or may be discharged Point source discharges of stmmwater malt from structures which increase the imperviousness of the ground which acts to collect nmoff, with nmoff being conveyed along the resulting drainage nr grading pattern. 9. Pollutant dredged spoil, dirt, slurry, solid waste, incinerator residue. sewage, sewage sludge, garbage, trash, chemical waste, biological nutrient biological material, radioactive material, heat. wrecked or discarded equipment, rock. sand, or may industrial. municipal or agricukural waste. 10. Process water any water which, during manufacturing or processing, comes into contact with or results from the pmdneaon of any mw material, intermediate product, finished product by product or waste product This definition includes mine drainage. I ]. Receiving Water any classified stream segment ( including ributaries) in the State of Colorado into which starmwater related 10 constrncbnn activities dischmges. This definition includes all water eoruees, even if they are usually dry, such as borrow ditches, arroyos, and other trammed waterways. 12. Significant Materials include, but are not limited to: raw materials; fuels; materials such as solvents, detergents, and plastic pellets; finished materials such as metallic prodoctc raw materials used in food Processing or production; hazardous substances designated under section 101(14) of CERCLA; any chemical the facility is required to repot pursuant to steno. 313 of tide 111 of SARA: fertilizers; pesticides; and waste produces such as ashes, slag and sludge that have the potential to be released with smrmwater discharge. 13. Stormwater: precipitation - induced surface runoff. PART I Permit -Page 16 Permit No. CoR- 030000 F. GENERAL REQUIREMENTS I. Signatory ReuidrementS a) All reports required for submittal shall be signed and certified for accuracy by the petmittec in accordance with the following criteria: 1) In the case of corporations, by a principal executive officer of a least the level of vice- president or his or her duly authorized representative, if such representative is responsible for the overat1 operation oldie facility from which the discharge described in the form originates: 2) In the case of a partnership, by a general partner, 3) In the case of a sole proprietorship, by the proprietor: 4) In the case of a municipal. stale, or other public facility, by either a principal executive officer, ranking elected official, or other duly authorized employee, if such representative is responsible for the overall operation of the facility from which the discharge described in the form originates. b) Changes to authorization. Ha) authorization under paragraph a) of this section is no longer acensaee because a differed individual or position has responsibility for the overall operation of the facility, a new authorization satisfying the requirements of paragraph a) of this section moot be submitted to the Division, prier to or together with any ripe, s, information, or applications to be signed by mm authorized representatve. c) Certification. Any person signing a doelment under paragraph a) of this section shall make the following certification: ^I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, 00 those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. 1 am aware that there are significant penalties for submitting false in formation, including the possibility of fine and imprisonment for Imowing violations.' 2. Retention of Retards a) The peratittee shall retain copies of the SWMP and all reports required by this "omit aad records of all data used to complete the application to be covered by tins permit, for three years after expiration or inactivation of permit coverage. b) The permeate shall retain a copy of the SUMP required by this permit 01 the construction site from the date of project initiation to the date of expiration or inactivation of permit coverage, unless another location, specified by the permitted is approved by the Division. 3. Muaitorine The Division reserves the right to require sampling =dusting, on a case -by -case basis (see Part 1.D.l.e), for exampie to implement the provisions of a TMDL (see Part 113.11 of the permit). Reporting procedures for any monitoring data collected will be included is the notifica loo by the Division of monitoring requirements. If monitoring is required, the following deflations apply: a) The thirty (30) day average shall be determined by the arithmetic mean of all samples collected during a thirty (30) coruautive -day period. A grab sample, far mvnitoriog requirements, is a single "dip and take" sample. b) PART 1I A. MANAGEMENT REQUIREMENTS I. Amendinea Permit certification The permittee shall inf the Division (Permits Section) in writing of changes to the information provided in the permit application, including the legal concoct, the project legal description or map originally submitted with the application, or the planned total disturbed acreage. The permittee shall furnish the Division with any plans and specifications which the Division deems reasonably necessary to evaluate the effect on the discharge and receiving stream. If applicable, this notification may be accomplished through submittal of CO application for a CDPS process water permit authorizing the discharge. The SWMP shall be updated and implemented prior 12 the changes (See Pan Any discharge to lice waters of the State from a point source other than specifically authorized by this permit or a different CDPS permit is prohibited. 2. Special Notifications -Definitions a) Spill: An tminteulional release of solid or liquid material which may cacao pollution of state waters. b) Upset An exceptional incident in which there is unintentional and temporary noncompliance with permit discharge limitations because of factors beyond the reasonable control of the permittee. An upset does not include noncompliance to the axle& caused by operational error, improperly designed treatment facilities, inadequate treatment facilities, lack of preventative maintenance. or careless or improper operation. 3. Noncomoliancn Natifeatior a) The permittee shall report the following i Shelves of noncompliance: 1) Any noncompliance which may endanger health or the environment 2) Any spill or discharge of hazardous substances or oil which may cause pollution of the warns of the stele. 3) Any discharge of stormwater which may cause an exceedance of a water quality standard. b) For all instances of noncompliance based on environmental hazards and chemical spills and release, all needed information must be prvvided orally to the Colorado Ow. c ,nt of Public Health and Environment spll3 reporting line (24 -hour number for environmental hazards mod chemical spills and release 1.877.515 -5608) widtia 24 hours from the time the permitter becomes aware of the circumstances. For 211 other instance of noncompliance as defined in this section, all needed information must be provided orally to the Water Quality Control Division within 24 hours from the time the permittee becomes aware of the circumstances. For all instances of noncompliance identified here, a 'minim submission shall also be provided within 5 calendar days of the time the prrmittee becomes aware of the circumstances. The written submission shall contain a description of 1) The noncompliance and its cause; 2) The period of noncompliance, including exact data and times, and if the noncompliance has not been corrected, the anticipated time it is expected to continue; 3) Steps takes or plumed to redact, eliminate, and prevent reoccurrence of the noncompliance. A. MANAGEMENT REQUIREMENTS (cont.) 4. Sobmisslgflof Irt.orr or In=mpIORClnformatlan Where the pennittee failed to submit any relevant facts m a permit application, or submitted incorrect information in a permit application or report o the Division, or relevant new information becomes available. the pnmtttee shall promptly submit the relevant application information which was not submitted err any additional information needed to correct any erroneous information previously submitted. 5. Byoass a) A bypass, which =Uses effluent limitations (Le., requirements to implement BMPs in accordance with Parrs I.13.3 and I.D2 of the permit) to be exceeded is prohibited, and the Division may take mforc=eot action against a permittee for such a bypass, mdess: I) Bypass was unavoidable to prevent loss of life, personal injury, or severe property damage; 2) There were no feasible alternatives to the bypass, such as the use of auxiliary treatment facilities (c.g. alternative BNIPs), retention of untreated wastes, or naamtenance during normal periods of equipment downtime. This condition is not satisfied if the permitrx could have installed adequate backup equipment (e.g., implemented additumal BMPs) to prevent a bypass which occurred during normal periods of equipment dawatime or preventative maintenance; and 3) The penmttee submitted notices as required in "Non- Compliadce Notification," Part A.A.3. 6. Uosets a) Ef( t of an Upset An upset constitutes as affirmative defense to an action brought for noncompliance with permit limitations and requirements if the requirements of paragraph b of this section me met. (No determination made during administrative review of claims that noncompliance was mused by upset, and before an action for noncompliance, is final administrative action subject to judicial review) b) Conditions Necessary for a Demonstration of Upset: A permittee who wishes to establish the affirmative defense of upset shall demonstrate through properly signed contemporaneous operating logs, or other relevant evidence that 1) An upset occurred and that the permittee can identify the specific cause(s) of the upset 2) The peraitted facility was at the time bang properly I 3) The pempittee Submitted notice of the apses as required in Part 11A3. of this permit (24 -boor notice); and 4) The pe:miltee complied with any remedial measures required under 40 CFR Section 122.41(d) of the federal regulations or Section 61.8(3)(h) of the Colorado Discharge Permit System Regulations. c3 Burden of Proof: In any enforcement proceeding the permit-tee seeking to establish the occurrence of an upset has the burden of proof. 7. Removed Substances Sobda, sludges, or other pollutants removed in the cease of treatment or control of discharges shall be properly disposed of in a manner such as o prevent any pollutant from such materials from =Whig waters of the State. J llhlmh atfon ofAdverse Dsma,q 8. The pumites shall rake all reasonable steps to minimize any adverse impact to waters of the State resulting from noncompliance with any terms and conditions specified in this permit, including such accelerated or additional monitoring as necessary to determine the name and impact of the noncomplying discharge.