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Home My WebLink About20123288.tiff STATE OF COLORADO Bill Owens,Governor Dennis E. Ellis, Executive Director .of Co Dedicated to protecting and improving the health and environment of the people of Colorado NY:. 4300 Cherry Creek Dr, S. Laboratory Services Division *.i. n Denver,Colorado 80246-1530 8100 Lowry Blvd. • r Phone(303)692-2000 Denver,Colorado 80230-6928 !ere TDD Line(303)691-7700 (303)692.3090 Colorado Department Located in Glendale,Colorado of Public Health http://www.ociphe.state.co.us and Environment 4/4/2006 Fred Clausen, Sr- Superintendent Drilling Kerr McGee Rocky Mountain LLC 3939 Carson Avenue Evans, CO 80620 970/330-0614 RE: Final Permit,Colorado Discharge Permit System—Stormwater Certification No: COR-039798, Adams County Area 2 Local Contact: Keith Kilcrease,Area Superintendent,970/330-0614 Anticipated Activity: 03/30/2006 through 12/31/2008 On >5 acres(>5 acres disturbed) Dear Sir or Madam: Enclosed please find a copy of the permit certification that was issued to you under the Colorado Water Quality Control Act. Your certification under the permit requires that specific actions be performed at designated times. You are legally obligated to comply with all terms and conditions of your certification. Note that the Stormwater permit for construction activities now covers construction sites disturbing down to one acre(the previous threshold was 5 acres). Effective July I, 2002,any construction activity that disturbs at least I acre of land(or is part of a larger common plan of development or sale that will disturb at least 1 acre) must apply for permit coverage. Please read the permit and certification. If you have any questions please visit our website at http://www.cdphe.state.co.us/wq/permitsunitiwqcdpmt.htrnl,or contact Matt Czahor at(303) 692-3575. Sincerely, C f^ (~ Kathryn Dolan Stormwater Program Coordinator Permits Unit WATER QUALITY CONTROL DIVISION Enclosure xc: Regional Council of Governments Adams County Health Department District Engineer, Technical Services, WQCD Permit File Fee File Permit No. COR-030000 Facility No. COR-039798 PAGE 1 of 17 CERTIFICATION CDPS GENERAL PERMIT STORMWATER DISCHARGES ASSOCIATED WITH CONSTRUCTION Construction Activity: Oil & Gas Field Development This permit specifically authorizes: Kerr McGee Rocky Mountain LLC to discharge stonnwater from the facility identified as Area 2 which is located at: map in file Denver, Boulder, Broomfield, Co latitude 40.081, longitude 104.717 in Adams County Boulder Creek to: South Platte River effective: 04/04/2006 Annual Fee: $270.00 (DO NOT PAY NOW. You will receive a prorated bill.) STATE OF COLORADO John W Hickenlooper,Governor �p coy. Christopher E. Urbina,MD. MPH aE \. Executive Director and Chief Medical Officer 4( Dedicated to protecting and improvirg the health and environment of the people of Colorado !.,. 4300 Crony Creek Dr S. Laboratory Services Division •\76 •%. Denver,Colorado 80246-1530 8100 Lowry Blvd Phone(303)692-2000 Denver.Colorado 80230-6928 Colorado Department Located in Glendale.Colorado (303) 692-3090 of Public Health http:i%www.cdphestate co us and Environment June ?1. '_01? RECEIVED Esc: Paul I) Schneider. Sr Staff EHS Rep Kerr McGee Oil & Gas Onshore LP 1099 18 St Ste 1800 Denver. CO 80202 RE: Renewal of Permit/Certification Administrative Continuation For: Area 2 Kerr Located at: See \-lap in File, Denver & Boulder & Broomfield, Adana County Permit No.: COR039798 Dear Mr. Schneider: The Division has received an application to renew the above permit certification. It has been determined that there is sufficient information to make this permitcertitication eligible for renewal. More information may be requested by the Division as progress is made in developing a new permit/certification for the above listed facility. This information must be made available to the Division when requested to complete the permit process. The Division is currently in the process of developing a new permit or master general permit and associated certification for the above permitted facility. The development and review procedures required by law have not yet been completed. When the discharge permit issued to you for your tacility expired on June 30, 2012 your permit is administratively continued and remains in effect under Section 104(7) of the Administrative Procedures Act. C.R.S. 1973, 24-4-101. et seq (1982 repl. vol. 10) until the new permit-certification is issued and effective. All effluent permit terms and conditions in your current permit will remain in effect until your new permit:certitication is issued and effective. PLEASE KEEP THIS LETTER WITH YOUR PERMIT AND SW)IP TO SHOW CONTINUATION OF PERMIT COVERAGE. Sincerely, Debbie Jessop Permits Section WATER QUALITY CONTROL DIVISION xc: Permit File FIELD WIDE STORMWATER MANAGEMENT PLAN FOR CONSTRUCTION ACTIVITIES AREA 2 WATTENBERG FIELD, COLORADO REVISED JANUARY 2009 Prepared for: KERR-MCGEE OIL & GAS ONSHORE LP 3939 Carson Avenue Evans, Colorado 80620 Prepared by: LT ENVIRONMENTAL, INC. 4600 West 60th Avenue Arvada, Colorado 80003 (303) 433-9788 TABLE OF CONTENTS 1.0 CERTIFICATION 1 2.0 INTRODUCTION 2 3.0 SWMP ADMINISTRATOR 2 4.0 SITE DESCRIPTION 3 4.1 Nature of Construction Activity 3 4.2 The Proposed Sequence of Major Activities 3 4.3 Area of Disturbance 5 4.4 Soil Description 5 4.5 Existing Vegetation 5 4.6 Location of Potential Pollution Sources 5 4.7 Non-Stormwater Discharges 5 4.8 Receiving Waters 5 5.0 SITE MAPS 6 6.0 STORMWATER MANAGEMENT CONTROLS 6 6.1 Identification of Potential Pollutant Sources 6 6.1.1 Disturbed and Stored Soils 7 6.1.2 Vehicle Tracking Controls 7 6.1.3 Management of Contaminated Soils 7 6.1.4 Loading and Unloading Operations 7 6.1.5 Outdoor Storage Activities 8 6.1.6 Vehicle and Equipment Maintenance and Fueling 8 6.1.7 Dust or Particulate Generating Processes or Activities 8 6.1.8 Routine Maintenance Activities 8 6.1.9 On-site Waste Management Practices 8 6.1.10 Concrete Truck Washing 8 6.1.11 Dedicated Concrete and Asphalt Batch Plants 8 6.1.12 Non-Industrial Waste Sources 9 6.1.13 Potential Spills 9 6.2 Best Management Practices (BMPs) 9 6.2.1 Structural Practices for Erosion and Sediment Control 10 6.2.2 Non-Structural Practices for Erosion and Sediment Control 12 6.2.3 Phased BMP Implementation 13 6.2.4 Material Handling and Spill Prevention 14 6.2.5 Dedicated Concrete or Asphalt Batch Plants 14 6.2.6 Vehicle Tracking Control 14 6.2.7 Waste Management and Disposal, Including Concrete Washout 14 6.2.8 Groundwater and Stormwater Dewatering 14 TABLE OF CONTENTS (CONTINUED) 7.0 FINAL STABILIZATION AND LONG-TERM STORMWATER MANAGEMENT 15 7.1 Reclamation 15 7.2 Post Construction Structural Measures 16 7.3 Finally Stabilized 16 8.0 INSPECTION AND MAINTENANCE PROCEDURES 16 8.1 Inspections 16 8.1.1 14-day Inspection/Active Stage 17 8.1.2 Monthly Inspection/Completed Stage 17 8.1.3 Final Stabilization Stage 18 8.1.4 Winter Conditions 18 8.1.5 Precipitation Event Inspections 18 8.2 Preventive Maintenance 18 8.2.1 Good Housekeeping 19 8.2.2 Material Storage 19 8.2.3 Waste Removal 20 9.0 EMPLOYEE TRAINING 20 10.0 RECORD KEEPING 21 11.0 SWMP REVIEW/CHANGES 21 FIGURES FIGURE 1 AREA 2 STORMWATER CONSTRUCTION PERMIT TABLES TABLE 1 CHEMICAL PRODUCT LIST TABLE 2 BMP SELECTION CRITERIA TABLE 3 STRUCTURAL AND NON-STRUCTURAL BMP CLASSIFICATION TABLE 4 SEED MIXES AND APPLICATION RATES APPENDICES APPENDIX A STORMWATER GENERAL PERMIT COR-03000 AND KERR- MCGEE OIL & GAS ONSHORE LP AREA 2 STORMWATER PERMIT COR-039798 APPENDIX B SITE-SPECIFIC INFORMATION APPENDIX C BMP MANUAL APPENDIX D TRAINING LOGS ii Sfra7 1.0 CERTIFICATION Kerr-McGee Oil & Gas Onshore LP (Kerr-McGee) has prepared this Field Wide Stormwater Management Plan (SWMP) for Construction Activities for Area 2 of the Wattenberg Field, Colorado. I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. 1 r X 4 Signature \ Date Z44—n e1 Name ` 51-44e—ti GII ✓l4 Zr �5 1 TiticS tQ t2Av ro&,.-,.1-k\ f i2-1 �c v AAA-11s1- 1 /t 2.0 INTRODUCTION LT Environmental, Inc. prepared this Stormwater Management Plan (SWMP) for Kerr-McGee to be used for Area 2 in the Wattenberg Field, Colorado. This SWMP was prepared in accordance with good engineering, hydrologic and pollution control practices to ensure the Best Management Practices (BMPs) are selected, installed, implemented and maintained to protect surface waters. Changes or additions may be required to address changes in conditions in the project area. As a condition of the Colorado Discharge Permit System (CDPS) permit, the provisions identified in the SWMP will be implemented as written and updated as needed from commencement of construction activity until final stabilization is complete. This document contains the required elements of a SWMP associated with Kerr-McGee's construction activities for Area 2, as defined in the CDPS General Permit for Stormwater Discharge Associated with Construction Activity, Authorization to Discharge under the Colorado Discharge Permit System (Permit No. COR-030000, effective July 1, 2007). A copy of the permit submitted to the Colorado Department of Public Health and Environment (CDPHE) for this project is provided in Appendix A. 3.0 SWMP ADMINISTRATOR The SWMP Administrator for Kerr-McGee is responsible for developing, implementing, maintaining, and revising the SWMP. The SWMP Administrator has the authority to dedicate the financial and human resources to implement the SWMP. The SWMP Administrator is: Mr. Paul Schneider— Staff Environmental and Regulatory Analyst, Denver, Colorado Office: (720) 929-6726 Mobile: (303) 868-6665 The SWMP Administrator will ensure that the SWMP is followed and delegates responsibility for coordination of the SMWP inspections and maintenance of stormwater records to the Operations Manager. The Operations Manager will provide support for the SWMP Administrator with the implementation of the SWMP. The Operations Manager is: Mr. Greg Hamilton—Senior Environmental and Regulatory Analyst, Evans, Colorado Office: (970) 506-5948 Mobile: (970) 590-6256 Both the SWMP Administrator and the Senior Environmental and Regulatory Analyst will manage the SWMP Team. Other foremen or designated personnel may also assist in stormwater inspections and maintenance of records. Overall, the SWMP Team is responsible for: Implementing spill/upset clean up procedures; Notification to local authorities and local residents of reportable releases; 2 41111: Coordinating various stages of BMPs implementation; Conducting inspections; Maintenance of all records; and Coordination of a preventive maintenance program and housekeeping measures. 4.0 SITE DESCRIPTION 4.1 Nature of Construction Activity Kerr-McGee currently owns or leases oil and natural gas mineral rights in the Wattenberg Field area which includes Adams, Boulder, Broomfield, Denver, Larimer and Weld Counties, Colorado. Kerr-McGee has split the field into three project areas for operations management purposes. Individual pad sites within the permitted area range from approximately 3/4 acres to three acres in size. The project area also includes field and site-specific access roads, pads, and pipelines. A map of the project area (Area 2 within the Wattenberg Field) is provided as Figure 1. The development of oil and natural gas wells is generally accomplished in three distinct work phases. The first phase is the Development (construction/drilling/completion), the second phase is the Production (operation/maintenance), and the third phase is the Abandonment with final reclamation. Each work phase is briefly discussed below. 4.2 The Proposed Sequence of Major Activities The overall development of oil and natural gas pad sites is generally accomplished in three distinct work phases: development, production, and abandonment. The work completed and sequences of events for each phase are briefly discussed below. Approximately ' acres to three acres of surface terrain are disturbed during the construction of a new pad site. The construction phase includes the following sequence of activities: pad construction, well drilling, well completion, gas flowline installation, equipment installation, access road building, and well pad reclamation. The production phase includes the operation and maintenance activities during oil and natural gas production. The typical equipment on a pad site during the production phase consists of a wellhead, a separation unit, and one or more 300-barrel (typical) capacity aboveground tanks for condensate (if needed). Gas wells in the field are projected to produce for approximately 20 to 30 years. When the oil and/or natural gas production of a well is exhausted it will be abandoned. Well abandonment includes plugging and capping the well and removal of all surface equipment. The pad area will be reclaimed by contouring disturbed soils to conform to the surrounding terrain. 3 �� Gas activity types requiring ground surface disturbance include: a new drill site, a facility site, a plugged and abandoned (P&A) site, and an excavation/other site as well as pipeline construction and access roads. Each of these types is described as follows: A new drill site includes pad construction, well drilling, well completion, gas flowline installation, access road building and well pad reclamation. Pad reclamation is accomplished by backfilling the reserve pit (if applicable), contouring disturbed soils to conform to the surrounding terrain, replacing the stockpiled top soil, seeding, and thatched/mulched of disturbed soil areas in order to reestablish coverage vegetation. A facility site includes pad construction, tank and sump installation (if applicable), gas flowline installation, access road building and pad reclamation. Pad reclamation is accomplished by contouring disturbed soils to conform to the surrounding terrain, replacing the stockpiled top soil, seeding, and thatch/mulched of disturbed soil areas in order to reestablish coverage vegetation. A P&A site includes well abandonment, flowline re-routing or abandonment, access road decommissioning, and removal of all oilfield operations from the pad site. Pad reclamation is accomplished by contouring disturbed soils to conform to the surrounding terrain and seeding and/or thatch/mulched of disturbed soil areas in order to reestablish coverage vegetation. An excavation/other site includes excavation for a variety of reasons. Excavation areas will be reclaimed by backfilling and contouring the disturbed area to conform to the surrounding terrain and seeding and/or thatch/mulched of disturbed soil areas in order to reestablish coverage vegetation. Access roads provide access to the drill sites, pad sites, pipeline connections, facility sites, excavation sites, and P&A sites listed above. Roadwork construction and maintenance are included in this SWMP for these access roads. Road reclamation is accomplished by contouring disturbed soils to conform to the surrounding terrain, replacing the stockpiled top soil, and seeding and/or thatch/mulched of disturbed soil areas in order to reestablish coverage vegetation. For stormwater regulation purposes, construction sites have been divided into the following stormwater stages: Active, Completed, and Final Stabilization. Details regarding the stormwater stages are provided later in Section 6.2.3 of this plan. Additionally, an Oil Polishing Facility is located approximately 0.3 miles west of the intersection of Weld County Road 49 and on the north side of Weld County Road 30. This construction project has been shared with Noble Energy Production, Inc. who operates on the northern portion of this facility. The Kerr McGee operating area consists of approximately 9.25 acres of rangeland where multiple tanks have been constructed. The overall drainage of the Kerr McGee facility leads to a detention pond in the southeast corner of the facility where sediments can drop out of surface water before leaving the site to a road ditch at the south end of the facility. 4 STD 4.3 Area of Disturbance The total field wide area of disturbance is 150 acres. The site-specific site boundaries, and areas of disturbance are identified on the site-specific database site maps; specific inspection forms; and history reports. (Appendix B). 4.4 Soil Description The Wattenberg Field is a large area covering Adams, Boulder, Broomfield, Denver, Larimer, and Weld counties. Kerr-McGee's Area 2 operation falls within Adams, Boulder, Broomfield, and Weld Counties. Topsoil varies within the area, and is classified as loam, sandy loam, clay loam, loamy sand, and sand according to the U.S. Natural Resources Conservation Service (http://websoilsurvey.nrcs.usda.qov/app/). Percentages of each type of topsoil vary widely throughout the area. 4.5 Existing Vegetation The well pads are primarily surrounded by low shrubs and brush rangeland, tall grass, short grass prairie land, sand dune complexes, and occasional crop land. Pre-disturbance ground cover varies from zero to 80%. Specific vegetation data at each pad site are entered on the site-specific inspection forms. 4.6 Location of Potential Pollution Sources The location and description of all potential pollution sources are provided in detail in Section 6.1 and summarized in Table 1. 4.7 Non-Stormwater Discharges The following is a summary list of non-stormwater discharges which are allowed under the stormwater permit: • Discharges from emergency fire-fighting activities or a fire hydrant; • Landscape irrigation or return flow; • Uncontaminated springs; and • Construction dewatering. Kerr-McGee does not anticipate any non-stotmwater discharges at the pad sites. 4.8 Receiving Waters The stormwater discharged may directly impact unnamed tributaries to, as well as Boulder Creek, Beebe Draw, Speer Canal, Box Elder Creek, Barr Lake, Milton Reservoir, and then will ultimately be received by the South Platte River. 5 �� The majority of Kerr-McGee's pads or access roads do not intrude or encroach on any wetland acreage. If a wetland is designated to be within a pad construction area, Kerr-McGee will consult with the Army Corp of Engineers, as applicable. 5.0 SITE MAPS The site maps are kept in Kerr-McGee's database. Kerr-McGee's database is intended to manage and track all site-specific stormwater records for Kerr-McGee. The database consists of current inspection forms with supporting visio map attachments. Maps are updated at every inspection interval and dated to show changes from one inspection to the next. For the purposes of this SWMP, the site-specific map information required to be included in the SWMP (Appendix B) will actually be comprised of the Kerr-McGee database. Construction site boundaries; ground surface disturbances; areas of cut and fill; storage areas for building materials, equipment, soil or waste; structural BMP locations; non-structural BMP locations (as applicable); locations of springs, streams, wetlands or other surface waters; wellhead locations; and other pertinent site-specifics are shown on maps attached to the site- specific SWMP Inspection Reports (Appendix B). 6.0 STORMWATER MANAGEMENT CONTROLS 6.1 Identification of Potential Pollutant Sources To identify, evaluate, and assess potential sources of stormwater runoff pollutants that may exist at a pad site, the following activities and pollutant sources were evaluated: Disturbed and stored soils; Vehicle tracking controls; Management of contaminated soils; Loading and unloading operations; Outdoor storage activities; Vehicle and equipment maintenance and fueling; Dust or particulate generating processes or activities; Routine maintenance activities; On-site waste management practices; Concrete truck washing; Dedicated concrete and asphalt batch plants; 6 4$' Non-industrial waste sources; and Potential spills. Refer to site specific maps found in Appendix B for the possibility of these potential pollutant sources existing onsite. 6.1.1 Disturbed and Stored Soils Disturbed soil and excavated materials will be stored on or next to the pad within the construction area. Topsoil and other soils will be stockpiled separately and seeded as needed. Excavation in sensitive areas may be conducted using special techniques as specified by the landowner/agency representative. Excavated materials will be utilized as backfill when practical. An exception may be excess rock generated by rock blasting excavation activities. In these areas, some select backfill materials may be required to protect the project area. Excess rock may be pushed into rock filter dikes, used in energy dissipation zones below culverts, constructed into rock check dams within grassed swales, or distributed over a portion of the project area. All cut slopes made in steep rolling terrain during construction will be re-graded and contoured to blend into the adjoining landscape and natural drainage patterns will be reestablished to as near pre-disturbance levels as possible. Temporary workspace areas will be restored to approximate pre-construction conditions. 6.1.2 Vehicle Tracking Controls Properly constructed and graveled roads provide the best off-site tracking control. Access road entrances adjacent to paved county roads are often graveled to prevent or minimize any off-site soil tracking from pad areas or access roads. In some instances, cattle guards are used to drop off caked mud before the vehicle exits the site area. If tracking is observed, the roads will be cleaned by any combination of road scraping/sweeping as necessary. 6.1.3 Management of Contaminated Soils If contaminated soils are excavated at a Kerr-McGee site, additional BMPs will be employed to ensure containment of any stormwater runoff. In addition, stockpiles of contaminated soil will be removed from the site and disposed or landfarmed as soon as possible. 6.1.4 Loading and Unloading Operations The majority of loading and unloading activities occur during well drilling and well completion activities. Well drilling and completion surfactants, friction reducers, dilute hydrochloric acid, potassium chloride solutions, drilling mud, condensate, and other fluids are transported or unloaded directly into the well from trucks, on site tanks, and/or the reserve pit. Dry drilling mud components are contained in paper bags and are stacked on pallets, which are unloaded using a forklift or by hand. In the event of a spill, the SWMP material handling and spill 7 417ro prevention procedures will be followed (see Section 6.2.4). Other activities include unloading of drill pipe, completion pipe (casing), and natural gas line pipe, which are not potential pollution sources. 6.1.5 Outdoor Storage Activities The most common substances that are stored on a pad area are: 1) fuel and lubricants used by vehicles and construction equipment; 2) frac fluids (surfactants, friction reducers, hydrochloric acid, and potassium chloride) used during well completion procedures; 3) production water from the well; and 4) produced crude oil and condensates. A list of chemical products typically used at a Kerr-McGee site is included as Table 1. 6.1.6 Vehicle and Equipment Maintenance and Fueling Kerr-McGee does not fuel or maintain construction-related vehicles or equipment located within the Kerr-McGee Area 2 Wattenberg Field, Colorado sites. 6.1.7 Dust or Particulate Generating Processes or Activities Dust and/or particulates generated from vehicle traffic on graveled access roads may produce fugitive emissions. Dust and particulate generation are highest during dry and hot times of the year. If dust from vehicle traffic on graveled access roads becomes significant, dust suppression procedures will be implemented that include road watering. 6.1.8 Routine Maintenance Activities Routine maintenance activities involving fertilizers, detergents, fuels, solvents and oils are not completed at the Kerr-McGee sites. Herbicides will be applied annually in some areas to control noxious weeds. Herbicide application will always be conducted by certified and trained individuals, and with consideration for runoff potential to nearby surface waters. 6.1.9 On-site Waste Management Practices All waste from materials imported to the construction site are placed in appropriate containment and then removed for disposal/recycling to an appropriate licensed disposal/recycling facility. No waste materials will be buried, dumped, or discharged to waters of the state. 6.1.10 Concrete Truck Washing Concrete truck/equipment washing, including the concrete truck chute and associated fixtures and equipment, is not conducted within the Kerr-McGee Area 2 Wattenberg Field, Colorado sites. 6.1.11 Dedicated Concrete and Asphalt Batch Plants No dedicated concrete or asphalt batch plants are located within the Ken-McGee Area 2 Wattenberg Field, Colorado sites. 8 (4:171 6.1.12 Non-Industrial Waste Sources Cleanup of trash and discarded materials will be conducted as noticed. Cleanup will consist of patrolling the roadway, access areas, and general work areas in order to pick up trash, debris, scrap, or other discarded materials. All waste from materials imported to the construction site are placed in appropriate containment and then removed for disposal/recycling to an appropriate licensed disposaUrecycling facility. This also includes sanitary sewage facilities (typically portable), which will be placed, anchored, and maintained with proper care. 6.1.13 Potential Spills Spills or leaks will be handled by Kerr-McGee personnel or contractors, according to the Kerr- McGee Wattenberg Field, Colorado Spill Prevention, Control and Countermeasure (SPCC) Plan. Kerr-McGee personnel conduct discharge prevention measures, including procedures for routine handling of products. Loading and transfer issues are discussed in monthly safety meetings. Preventive maintenance is scheduled by the SWMP Administrator. As part of the preventive maintenance program, Kerr-McGee personnel conduct monthly inspections for good housekeeping issues, operation and maintenance issues, and the condition of structural controls, specifically around tanks and containers. Operators are trained in the safe handling of materials and spill discovery, response, and cleanup procedures during safety meetings. Emergency numbers are posted at the Evans office, located at 3939 Carson Avenue, in Evans, Colorado. In general, small spills will be handled by Kerr-McGee personnel. The SWMP Administrator or his designee will handle spills and emergencies. In most cases, an absorbent material is used to pick up the spill. The spill response equipment is also located at the Evans office. In the situation of a larger spill, the SWMP Administrator or Senior Environmental and Regulatory Analyst would be notified and a contractor would be called to respond to the spill. For the protection of spill response personnel, all drums, tanks, and other containers are clearly labeled to identify contents, in the event of a spill. Materials handling is discussed in detail in Section 6.2.4 of this plan. 6.2 Best Management Practices (BMPs) BMPS for sediment and erosion control will be accomplished through a combination of construction techniques, vegetation and re-vegetation, administrative controls, and structural features. Typical configurations of structural controls discussed below and technical drawings with references are provided in a BMP Manual (Appendix C). BMP selection is guided by the criteria listed in Table 2 and Appendix B. Structural and non-structural BMPs are discussed in the following sections, and are summarized in Table 3. 6.2.1 Structural Practices for Erosion and Sediment Control Structural practices primarily include physical attributes of a pad site, access road or pipeline designed to reduce erosion and control stormwater or sediment movement. 6.2.1.1 Erosion Reduction and Control Construction of a pad requires the removal of vegetative cover and topsoil, thereby increasing peak flood flows, water velocity, and the volume of stormwater runoff. An increase in water runoff volume and velocity results in increased erosion. Erosion reduction and control will be accomplished by using all or combinations of various erosion control methods. These methods include, but are not limited to the following: Diversion and control of runon water; Diversion and control of runoff water; Vegetation establishment and maintenance; and Application and maintenance of mulches, blankets, tackifiers, tracking, and contouring. Runoff control procedures that will be used to mitigate and reduce the erosive transport forces of stormwater during and after construction of a pad will include but will not be limited to the following: Check Dams; Berms; Culverts; Culvert Protection; Diversions; Land Grading; Mulches, with or without a tackifier; and Erosion Control Blanket. Existing vegetation cover and topsoil are removed only where necessary for the operation of equipment and construction of the pad. Trees and large shrubs that are not cleared from the pad area will be protected from damage during construction by avoiding them with equipment. For example, the blade of a bulldozer will be in a raised position except for designated areas. Trees will be cut or trimmed only to facilitate clearing, grading, and safe installation of a pad. Trees outside the area of disturbance will not be cut, but may have overhanging limbs trimmed if 10 LTD necessary. Refer to Tables 2 and 3 for a list of all BMPs to be used throughout the Field Wide SWMP. Appendix C includes details on BMP installation and maintenance procedures. 6.2.1.2 Sediment Reduction and Control The reduction and control of sediment contained in stonnwater runoff will be accomplished by the use of sediment containment systems. Sediment containment systems are hydraulic controls that allow the detention of suspended particles via gravity, filtering or entrapment. Sediment controls that will be used to mitigate and control sediments generated from the erosive transport forces of stormwater during and after construction of a pad will include but will not be limited to the following: Silt Fence; Straw Bales; Wattles; and Vehicle Tracking Controls. Refer to Tables 2 and 3 for a list of all BMPs to be used throughout the Field Wide SWMP. Appendix C includes details on BMP installation and maintenance procedures. 6.2.1.3 Detailed Structural and Administrative Site Management Practices The following structural and administrative site management practices are expected to reduce, minimize, and control erosion and sediment transport: In order to minimize disturbances associated with installation of pads, level and gently sloping terrain outside the construction project area will not be graded, except where necessary. To prevent tracking of sediment mud and rocks onto public roads, portions of access roads may be graveled, as appropriate. Other means such as track pads/angular rock or cattle guards may be utilized if appropriate. Silt barriers (e.g. wattles, silt fence, straw bales) will be installed as needed on down-gradient portions of project areas. Side hill cuts (cut slopes) will be kept to a minimum to protect local resources while providing a safe and stable plane for the efficient and safe use of equipment. Where conditions warrant, erosion control structures such as berms, diversion or culverts may be constructed to divert water away from project areas. These control structures will also reduce soil erosion along and adjoining areas disturbed during construction. During construction near perennial streams, lakes or wetlands, the utilization of silt fence or straw bales may be considered in order to prevent suspended sediments from reaching down slope watercourses, streams, lakes or wetlands. Where appropriate, staked straw bales or silt fence may be constructed adjacent to crossings to reduce potential sedimentation in streams or wetlands. In areas that have steep slopes, water bars or runoff diversions may be installed. When used, water bars will generally begin and end in undisturbed ground at approximately a 2% slope. Culverts may be installed at a grade ranging from 2% to 5%. Inlet protection may include inlet aprons and rock armoring around the culvert perimeter while below grade inlet sumps may be installed to enhance sediment deposition. Outfall protection may include the use of a rock barrier to slow the discharge of runoff water. Culvert pipe or outfall protection will be extended to the toe of the slope on the discharge end. During the reclamation of a pad, all cut and fill slopes in steep terrain will be graded and contoured to blend into the adjoining landscape. Natural drainage patterns will also be recreated to as near pre-disturbance as possible. When possible, cut and fill slopes will be constructed so they are no steeper than a 1 to 3 ratio. Reclaimed pads may have a fence constructed around areas that have been seeded. These fences will be installed in order to keep livestock and vehicles off reseeded areas. 6.2.1.4 Implementation of Structural Practices The following structural practices (sediment controls) may be utilized at disturbed areas: silt fences, straw bales, earth berms, or equivalent sediment controls. These sediment control structures will be installed so as to protect down slope surface waters, wetlands, and roads from sediment flow due to runoff from a precipitation or snow melt event. All graded surfaces, walls, dams and structures, vegetation, erosion and sediment control measures, and other protective devices identified in the plan will be maintained, repaired, and restored as necessary. Table 3 contains a summary list of structural and non-structural BMPs. 6.2.2 Non-Structural Practices for Erosion and Sediment Control Erosion and sediment control can also be controlled via non-structural BMPs. Non-structural BMPs are BMPs that are not engineered as a stormwater barrier and are capable of limiting the amount of potential pollutants available to reach receiving water bodies. Non-structural BMPs can achieve the same effect as structural BMPs through erosion control, filtration trapping, and the settling of sediment load within a perimeter. Kerr-McGee has implemented non-structural practices for stormwater management into their pad site development, including Program Oversight, Construction Site Planning and Management, and Materials Management. Table 3 summarizes the details of such practices. Pad sites can include a slope to the reserve pit or a buffer zone of natural vegetation used as a non-structural BMP to inhibit sediment travel offsite and minimize the footprint of the pad. 12 Sr.? 6.2.3 Phased BMP Implementation The phases of construction or development and stormwater stages are linked to the implementation of structural and non-structural BMPs. For stormwater regulation purposes, construction sites have been divided into the following stormwater stages: Active, Completed, and Final Stabilization. Stormwater controls to be used for each phase are listed in Tables 2 and 3. Approximately 3/4 to three acres of surface terrain is disturbed during the construction of a new pad. The Development phase includes the following activities: pad construction, well drilling, well completion, gas flowline installation, access road building, 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 and/or thatch/mulched of disturbed soil areas in order to reestablish a cover vegetation. The completion of a well generally triggers a one-year time period in which the reclamation phase of work should be completed. During pre-construction, drilling, and other active construction, the focus will be primarily on containment type BMPs. An example would be a continuous berm to contain stormwater pollutants on site. During this phase, stormwater runoff is specifically controlled so as not to leave the pad site. The production phase includes the operation and maintenance activities 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 300-barrel capacity aboveground tanks for condensate, and a sump for storing produced water. Reclamation activities during this phase include maintenance of revegetated areas and maintenance of the erosion and sediment control structures. Wells in the field are projected to produce for approximately 20 to 30 years. When the oil and natural gas production of a well is exhausted it will be abandoned. Upon well abandonment each borehole will be plugged, capped, and all surface equipment will be removed. Subsurface pipelines will be removed to specified locations and plugged. The pad area will be reclaimed by contouring disturbed soils to conform to the surrounding terrain, by replacing the stockpiled top soil, by seeding and/or thatch/mulched of disturbed soil areas in order to reestablish cover vegetation, and by construction of erosion and sediment control structures as needed. For the purposes of this SWMP and the stormwater construction general permit, only active and completed sites will be monitored. Once a completed site is revegetated and stable, it will be removed from this stonnwater construction SWMP. Depending upon the type of site, the site terrain, and the phase of construction, different stormwater BMPs will be utilized. Various BMP options are listed in Table 2, and design specifications are shown in the BMP Manual (Appendix C). 13 �,/�� 6.2.4 Material Handling and Spill Prevention A SPCC is required for this Project site as it does meet the applicability criteria set forth in Section 112.1 of 40 CRF Part 112 and in the Colorado Storage Tank regulations. These regulations require a SPCC Plan for non-transportation related facilities that could reasonably expect to discharge oil into or upon a navigable body of water of the United States; and the facility has a total combine above ground storage tank capacity of greater than 1,320 gallons of oil. Both regulations further add that an SPCC Plan is required if any single aboveground oil storage tank's capacity exceeds 660 gallons. Hazardous materials and petroleum products used in construction of a pad include fuel and lubricants for construction equipment and vehicles; small quantities of paints and solvents; water or gel based frac fluids (surfactant, friction reducer, dilute hydrochloric acid, potassium chloride) used during well completion; produced water; and crude oil/condensate. Material Safety Data Sheets (MSDS) for materials to be used or that are produced, are maintained at Kerr-McGee's Evans, Colorado office. If a spill of pollutant(s) threatens stormwater or has the potential to discharge from the site, the Stormwater Administrator will be contacted immediately. 6.2.5 Dedicated Concrete or Asphalt Batch Plants Kerr-McGee does not have or subcontract any dedicated concrete or asphalt batch plants for its pad site development or construction in Area 2 Wattenberg Field, Colorado, nor will stormwater encounter concrete or asphalt batch plant activities. Dedicated concrete or asphalt batch plants are further discussed in Section 6.1.11 of this plan. 6.2.6 Vehicle Tracking Control Kerr-McGee will employ BMPs to minimize vehicle tracking. Further discussion on this topic is in Section 6.1.2 of this SWMP. 6.2.7 Waste Management and Disposal, Including Concrete Washout Waste disposal is further discussed in Sections 6.1.9 and 6.1.12 of this plan. Concrete washout does not occur at Kerr-McGee's sites, and therefore, will not be a potential pollutant to stormwater. 6.2.8 Groundwater and Stormwater Dewatering Construction dewatering may take place on a limited basis at Kerr-McGee sites. The permit allows for conditional discharge of construction dewatering to the ground (to infiltrate), however no groundwater from construction dewatering can be discharged as surface runoff or to surface waters. For large construction projects with planned dewatering activity, Kerr-McGee will apply for a separate dewatering permit from the state, as required. 14 4$? 7.0 FINAL STABILIZATION AND LONG-TERM STORMWATER MANAGEMENT 7.1 Reclamation Unless otherwise directed by the landowner or a jurisdictional authority, rocks, cut vegetation, and other surface material temporarily stockpiled during construction will be redistributed as backfill on the project area. During reclamation, sediment BMPs will remain in use. Disturbed areas will be seeded using seed mixes appropriate to the location as noted in Table 4, unless the landowner wishes to return the land to agricultural production. Local soil conservation authorities with the U.S. Natural Resources Conservation Service, surface owners and/or reclamation contractors familiar with the area may be consulted regarding the other seed mixes to be utilized. On terrain where drill seeding and/or thatch/mulched is appropriate, seed may be planted using a drill equipped with a depth regulator to ensure proper depth of planting. The seed mix will be evenly and uniformly planted over the disturbed area. Drilling will be used where topography and soil conditions allow operation of equipment to meet the seeding requirements of the species being planted. Broadcast seeding will occur on steep terrain and on areas where the cut vegetation and rocks were redistributed over a right-of-way. Hydraulic mulch consists of applying mixture of shredded wood fiber or a hydraulic matrix, and a stabilizing emulsion or tackifier with hydro-mulching equipment, which temporarily protects exposed soil from erosion by raindrop impact or wind. Hydraulic mulch is suitable for disturbed areas requiring temporary protection until permanent stabilization is established, and disturbed areas that will be re- disturbed following an extended period of inactivity. Seeding will be done when seasonal or weather conditions are most favorable according to schedules identified by the jurisdictional authority, reclamation contractor, or landowner. Whenever possible, seeding will be timed to take advantage of moisture, such as early spring or late fall, which will benefit from winter precipitation. Seed mixes will be planted in the amount specified in pounds (as noted in Table 4) of pure live seed per acre. No primary or secondary noxious weeds will be in the seed mix. The reestablishment of vegetative cover as well as watershed stabilization measures will be scheduled during the working season and before the succeeding winter. Re-vegetation will be accomplished as soon as practical following the reclamation of a pad, pipeline or road. Mulch will be laid down during re-vegetation as appropriate. The cut vegetation and rocks will act like mulch in the areas where they are applied. Where straw or hay mulch is applied, the mulch will be applied and crimped into the soil. The need for fertilizers will be determined in conjunction with the landowner. If fertilization is necessary, the rates of application will be based on site-specific requirements of the soil. A special condition exists for pad sites within crop lands. According to the CDPHE Stonnwater Fact Sheet dated July 2007: 15 Srs7 When portions of an oil and gas site are restored to crop land in accordance with the COGCC rules, and returned to the control of the farmer following interim reclamation, permit coverage is no longer required for those areas, and it is not necessary for the oil and gas site to either stabilize or reassign permit coverage for the area restored to crop land When this condition exists for a pad site, inspections will be discontinued and the site will be removed from the stormwater construction permit program. 7.2 Post Construction Structural Measures Permanent culverts, trench plugs and/or other permanent structural measures may be installed on steep slopes and at wetland and stream crossing boundaries. After restoration and reclamation work is complete, required repairs to vegetation and erosion and sediment control BMPs will be completed as required. 7.3 Finally Stabilized According to stormwater regulations, "finally stabilized 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 and a density of at least 70 percent of pre-disturbance levels, and the vegetation cover is capable of providing erosion control equivalent to pre-existing conditions, or equivalent permanent, physical erosion reduction methods have been employed." A special condition exists for oil and gas pad sites regarding pavement. According to the CDPHE Stormwater Fact Sheet dated July 2007: Areas developed as stabilized unpaved surfaces as needed for operation of the facility after interim reclamation also qualify as 'finally stabilized". The term "stabilized unpaved surfaces" includes dirt road surfaces and the portions of the well pad surfaces that cannot be revegetated due to operational necessity, but does not include slopes, ditches and other areas where revegetation is necessary. Stabilized unpaved surfaces must be prepared in such a way as to minimize erosion, such as preventing rill erosion on pad surfaces or roads. 8.0 INSPECTION AND MAINTENANCE PROCEDURES 8.1 Inspections Inspections will be conducted to document the status of erosion and sediment control structures and re-vegetation efforts. Inspection forms will document non-compliance conditions, including any uncontrolled releases of sediment or other contaminants, additional BMPs that are needed, or repair and maintenance issues. Required actions or modifications, as documented on the SWMP Inspection Report, will be implemented as soon as possible, immediately in most cases, to minimize the discharge of pollutants. Routine inspections may be conducted at pad areas and along access roads and pipelines during all phases of work and after a precipitation-related event. 16 /,/�� All inspection observations will be recorded on the SWMP Inspection Report. The SWMP Inspection Report provides a standardized format that will be completed during all inspections, and includes a signature line for the inspector to ensure compliance with the regulations. For stormwater regulation purposes, construction sites have been divided into stormwater inspection stages: Active, Completed, and Final Stabilization. Each of these stormwater inspection stages is discussed below. Once a Completed Site is revegetated and stable, it will be removed from this stormwater construction permit program and all site-specific structural BMPs will be removed. A special condition exists for pad sites within crop lands, which is detailed in Section 7.1 of this plan. When pad sites are being returned to a farmer for agricultural usage, the sites may be removed from the stormwater construction permit program. Personnel responsible for inspections will be trained to evaluate stormwater management concerns, erosion and sediment control BMPs, and to evaluate pad and surrounding area vegetation. 8.1.1 14-day Inspection/Active Stag The construction phase of work is classified as the Active phase, according to stormwater regulations. The inspection frequency is every 14 days during the Active phase and must be conducted within 24 hours after the end of any precipitation or snowmelt event that causes surface erosion. The construction perimeter, disturbed areas, and any stored materials that are exposed to precipitation will be inspected for evidence of, or the potential for pollutants to possibly enter the drainage system. Erosion and sediment control systems identified on the site-specific SWMP Inspection Report will be inspected to ensure they are in good condition and operating properly. 8.1.2 Monthly Inspection/Completed Stage For sites or portions of sites that meet the following criteria, but final stabilization is not achieved due to a vegetative cover that has not become established, a thorough inspection will be conducted at least once every month, and post-storm event inspections are not required. This reduced inspection schedule is only allowed if: All construction activities that will result in surface ground disturbance are completed; All activities required for final stabilization, in accordance with the SWMP, have been completed, with the exception of the application of seed that has not occurred due to seasonal conditions or the necessity for additional seed application to augment previous efforts; and The SWMP has been amended to indicate those areas that will be inspected in accordance with the reduced schedule. However, because slopes and other disturbed areas are not vegetated, erosion in these areas still occurs which requires maintenance activities such as regrading, erosion control blankets, and 17 SIC-77 seeding of problems areas. As such, inspections must continue in order to address these situations. The SWMP for the site must be amended to indicate those areas that will be inspected at this reduced frequency. 8.1.3 Final Stabilization Stage Final stabilization is reached when all ground surface disturbing activities at the site have been completed, and uniform vegetative cover has been established with an individual plant density of at least 70% of pre-disturbance levels, or equivalent permanent, physical erosion reduction methods have been employed. When the site has reached final stabilization, an Inactivation Notice will be filed with CDPHE to inactivate the stonnwater permit. All temporary site- specific BMPs no longer required will be removed. 8.1.4 Winter Conditions Inspections will not be required where construction activities are temporarily halted because snow cover exists over the entire site for an extended period as long as melting conditions do not exist. The following information must be documented in the inspection record for use of this exclusion: dates when snow cover occurred, date when construction activities ceased, and date melting conditions began. 8.1.5 Precipitation Event Inspections Active site inspections will be conducted within 24 hours after a precipitation or snowmelt event that causes surface erosion. Surface erosion generally occurs when precipitation or snowmelt results in surface water flow. If no construction activities will occur at a site following a storm event, post-storm event inspections will be conducted prior to re-commencing construction activities, but no later than 72 hours following the storm event. 8.2 Preventive Maintenance Preventing stormwater from passing through pad areas where contamination may occur is a key element of preventative maintenance. Another key element of preventative maintenance is the routine inspection and repair of erosion and sediments control structures. Regular cleaning of diversion ditches and other BMPs to keep them free of debris and sediment will be practiced. Spillways and culvert systems will also be routinely cleaned and inspected. These maintenance procedures will help to ensure that the stormwater does not leave disturbed areas via unintended channels. The following preventive maintenance procedures will be implemented to reduce or eliminate potential stormwater contamination sources that may exist on a pad: Storage containers, fuel tanks, and equipment used during construction activities should be visually inspected routinely for obvious leaks. These inspections should be conducted by site and contractor personnel as they perform their routine duties; Drums will be properly labeled so an enclosed substance can be quickly identified. OSHA- approved labeling and sign systems will be followed for all secondary containers; 18 sit) Erosion damage to the berms, outfalls, silt barriers, collection channel, containment ponds, and any other erosion and sediment controls will be repaired as soon as practical; Areas of stained soil will be inspected in order to identify the sources of the staining. Contaminated soil will be removed and properly disposed; Energy dissipating material, such as riprap, cobbles or gravel will be placed, or existing materials will be utilized at the stormwater outfalls to prevent erosion damage. Barrow ditches should be free from vegetation and debris which may cause impounding of stonnwater; and Stormwater management structures will be cleared of debris and repaired when necessary; and surface runoff controls such as culverts, and ditches will be used to control runoff. 8.2.1 Good Housekeeping In accordance with BMPs that provide procedures to eliminate contamination, and direct, divert, and contain stormwater, Kerr-McGee has implemented a number of housekeeping practices. These practices will help prevent soil sediment, trash, and toxic or hazardous substances from entering navigable waters. Housekeeping practices include regular cleaning, organization and maintenance of pad equipment and erosion and sediment control structures throughout the project. Areas where chemicals are stored and used at the project should be stored in buildings or containers where there is limited potential for stormwater contact. These areas include producing pads that typically consist of wellheads, separator units, dehydration units, and 300-barrel capacity aboveground tanks. The following items will be addressed in order to maintain a clean and orderly pad during the development, production, and abandonment phases of work: Inspect pad areas routinely; Correct deficiencies noted during inspections; Clean and maintain stonnwater management structures and components; Routine trash collection and proper disposal; Familiarize employees and contractors with spill clean-up equipment and storage locations; and Familiarize employees and contractors with good housekeeping procedures and pad pollution prevention procedures. 8.2.2 Material Storage The following good housekeeping practices will be followed at the material storage areas: Storage containers will be stored away from direct traffic to prevent accidents. They will also have proper labels; 19 Sra7 Dumpsters and trash receptacles will be enclosed in order to prevent the dissemination of refuse; Storage areas will be kept free of refuse; Chemical substances used at pads will be properly labeled and will have proper spill containment; and Chemical substance containers will be clearly labeled with an MSDS kept on file. 8.2.3 Waste Removal All waste from materials imported to the construction site will be removed for disposal/recycling to an appropriate licensed disposal/recycling facility, including sanitary sewage facilities (typically portable). No wastes of imported materials will be buried, dumped, or purposely discharged to waters of the state. There are no other pollutant sources from areas other than construction areas. 9.0 EMPLOYEE TRAINING Kerr-McGee will inform and train employees who are involved with SWMP activities. Training will cover information and procedures contained in the SWMP and will be conducted on an as- needed basis. Personnel work responsibilities will be used to identify the appropriate attendees. Safety and environmental elements of the SWMP will also be covered. A Training Log (Appendix D) will be kept and updated on an annual basis. The following topics may be presented and discussed during SWMP training: Introduction to CDPS Stonnwater Permit; Stormwater regulations; Purpose of stormwater permit; Requirements of stormwater permit; Components of the SWMP; Identification of potential pollutant sources; BMPs; Preventative maintenance; Good housekeeping; Inspections and maintenance; and Record keeping. 20 Sle 10.0 RECORD KEEPING The following record keeping procedures will be implemented in order to provide accurate and complete documentation of events associated with the stormwater management program. Routine inspections will include the 14-day, monthly, and post precipitation event inspections. Stonnwater related inspection records, site maps, and diagrams will be also kept on file or in the Kerr-McGee database. All stormwater related records will be filed and stored by Kerr-McGee for a minimum of three years after each individual site has achieved final stabilization 11.0 SWMP REVIEW/CHANGES Kerr-McGee will amend the SWMP whenever there is a significant change in design, construction, operation, or maintenance, which has a significant effect on the potential for the discharge of pollutants to water of the state, or if the SWMP proves to be ineffective in achieving the general objectives of controlling pollutants in stormwater discharges associated with pad activities. The SWMP is considered a "living document". 21 r m O i • C z z C CST z A x v y r: z r \,7 TABLE I CHEMICAL PRODUCT LIST AREA 2 WATTENBERG FIELD, COLORADO KERR-MCGEE OIL & GAS ONSHORE LP MSDS Product Name Manufacturer's Product Use/Chemical Description Chemical Manufacturer Product Number DRILLING FLUID PRODUCTS Alcomer 110RD Flocculant 10299 Drilling Fluid Product M-1 Drilling Fluids Barite 10617 Drilling Fluid Product M-1 Drilling Fluids Bentonite(Gel) Drilling Fluid Product Black Hills Caustic Soda 10540 Drilling Fluid Product M-1 Drilling Fluids Cottonseed Hulls 10154 Drilling Fluid Product M-1 Drilling Fluids DEFOAM-A Defoamer 10167 Drilling Fluid Product M-I Drilling Fluids DESCO CF Thinner Drilling Fluid Product M-I Drilling Fluids DRISPAC Liquid Polymer 251230 Drilling Fluid Product Drilling Specialties DRISPAC Polymer 25950 Drilling Fluid Product Drilling Specialties Lignite Drilling Fluid Product Black Hills Lime 10546 Drilling Fluid Product M-I Drilling Fluids Soda Ash 10555 Drilling Fluid Product M-I Drilling Fluids FUELS& LUBRICANTS Acetylene Fuel BOC Gases 'hain Oil 00003 Lubricant Delta Rky. MM. Diesel Fuel Fuel Frontier Oil Co. Drive Chain Fluid 7684 Lubricant Chevron 80-90W Gear Oil 7234 Lubricant Chevron Grease 6790 Lubricant Chevron Hydraulic Oil 10910 Lubricant Chevron Motor Oil 6931 Lubricant Chevron Propane 03840 Fuel BP(Amoco) PAINTS Paints- Industrial Enamel Paint Sherwin-Williams Paints-Gloss White Paint Tnemec Co. Paints-Primer Primer Tnemec Co. Paints-Thinner Paint Thinner Tnemec Co. MISCELLANEOUS Antifreeze 10298 Various uses Texaco Methanol 001065 Various uses Airgas, Inc. Rig Wash Various uses Jet-Lube, Inc. Starting Fluid 81030 Various uses Lawson Products Thread Dope(Cal Bronze LF 302G Various uses Bestolife Corp. WD-40(Aerosol) Various uses WD-40 Company WD-40(Liquid) Various uses WD-40 Company Carbon Injectate Cleanup contaminated soil TABLE 2 BMP SELECTION CRITERIA AREA 2 WATTENBERG FIELD,COLORADO KERR-MCGEE OIL& CAS ONSHORE LP ACTIVE COMPLETED FINAI.STABILIZATION . s3.:-:T . = 'f it+ .-'S x mfil Berm Berm Berm Cattle Guard Cattle Guard Cattle Guard Check Dams Check Dams Culverts Culvert Protection Culvert Protection Diversion Ditch/Ditch&Berm Ditch&Berm Ditch&Berm Revegetation Erosion Control Blanket Erosion Control Blanket Mulches,with or without a tackifier Land Grading Land Grading Mulches,with or without a tackifier Mulches,with or without a tackitier Revegetation Revegetation Silt Fence Roadside Ditches Vehicle [racking Control Silt Fence Straw Bales Straw Bale Wind Erosion Control Wattles Wattles -1-ifiEr Berm Berm Berm Cattle Guard Cattle Guard Cattle Guard Check Dams Check Dams Culverts Culverts Culverts Culvert Protection Culvert Protection Culvert Protection Ditch&Berm Ditch&Berm Ditch&Bean Gravel Surfacing Erosion Control Blanket Erosion Control Blanket Rcvcgctation Land Grading Land Grading Mulches,with or without a tackifier Silt Fence Revegetation Straw Bale Silt Fence Vehicle Tracking Control Straw Bales Wind Erosion Control Wattles wg N. y }y {y { [ y i { X51 t. 2S x�. �:W 1�aY'+,'8 x"'M3. £+ 4#R .. .' �ti '.'�.Y'1 Yd . ..�•'.t �.xilatt....� '� 1 � '�Y u8 `fie. :- Notes: BMP=Best Management Practice ) {ox ad / ,„ -0 ) } ; / CI C 1- § - / t 2 ® C e : . r ) / 0 J ) > CC2uu2y 44t _ C. Co) / \ z \\ \/ /\\ \ § c & ; u ; a : : dc ( 2 ) ~ \ on j # � 0 0'a) ) co k2I5k ( } •\ 2 \\ 2 } « « � _ _ _ a ` ' & , 2 1— Z ` 23 m ! ciwi : az » S : yE ; ; : § ; CC f / \ ( $ ,\ : ) ; [ } < J - z / u - � } 2 do.2 " _ t. 2 � 2 ' © �) \ / \ \ \ § 7 7to w - _ ! { } ) \ \ j \ / � 3f\ ® eN - i--M a 4 §C .,J | --n,L aka , : ! 2 � ! = z § F = r { aa & , Ee = Ea u 3au � z , Ea &2 > , VIz (7:> § ( \ / ) � _ ) ©cl ) s , / ] ) ; f - 2 7 COtera 2 § ! ± f ! f E / f) ) 02 « 41 to 3 ! ! / ) & % tt0 ! 24 | 1- -.-> i 2 k \/ / j / I. u 3 ± ) 3 z TABLE 4 SEED MIXES AND APPLICATION RATES AREA 2 WATTENBERG FIELD, COLORADO KERR-MCGEE OIL & GAS ONSHORE LP SEED MIX APPLICATION RATE(lbs/acre) PBSI Dryland Aggressive Mix (20%)Green Needlegrass, Lodorm (20%)Slender Wheatgrass,Native (20%)Western Wheatgrass,Native 25 (20%)Pubescent Wheatgrass,Luna (20%) Intermediate Wheatgrass,Oahe/Rush PBSI Native Prairie Mix (25%)Blue Grama (10%)Buffalograss (20%)Green Needlegrass 15 (20%)Sideoats Grama (25%) Western Wheatgrass PBSI Native Sandyland Mix (20%)Yellow Indiangrass (10%)LittleBluestem (10%) Indian Rice Grass (10%)Sideoats Grama 15 (10%)Sand Lovegrass (10%)Prairie Sandreed (20%)Switchgrass PBSI Premium Irrig. Pasture Mix#1 (75%)Meadow Bromegrass, Paddock/Fleet 25 (25%)Orchardgrass, Elsie/Megabite/Paiute Notes: lbs/acre= pounds per acre %=percent tie STATE OF COLORADO Bill Owens,Governor - Dennis E. Ellis,Executive Director orco Dedicated to protecting and improving the health and environment of the people of Colorado N= 4300 Cherry Creek Dr. S. Laboratory Services Division ` * Denver,Colorado 80246-1530 8100 Lowry Blvd. . •herb s* Phone(303)692-2000 Denver,Colorado 80230-6928 TDD Line(303)691-7700 (303)692-3090 Colorado Department Located in Glendale,Colorado of Public Health http://www.cdphe.state.co.us and Environment 4/4/2006 Fred Clausen, Sr.Superintendent Drilling Kerr McGee Rocky Mountain LLC 3939 Carson Avenue Evans,CO 80620 970/330-0614 RE: Final Permit,Colorado Discharge Permit System—Stormwater Certification No: COR-039798,Adams County Area 2 Local Contact: Keith Kilcrease,Area Superintendent,970/330-0614 Anticipated Activity: 03/30/2006 through 12/31/2008 On>5 acres(>5 acres disturbed) Dear Sir or Madam Enclosed please find a copy of the permit certification that was issued to you under the Colorado Water Quality Control Act. Your certification under the permit requires that specific actions be performed at designated times. You are legally obligated to comply with all terms and conditions of your certification. Note that the stormwater permit for construction activities now covers construction sites disturbing down to one acre(the previous threshold was 5 acres). Effective July 1,2002, any construction activity that disturbs at least I acre of land(or is part of a larger common plan of development or sale that will disturb at least 1 acre) must apply for permit coverage. Please read the permit and certification. If you have any questions please visit our website at http://www.cdphe.state.co.us/wq/permitsunit/wgcdpmt.html,or contact Matt Czahor at(303) 692-3575. Sincerely, U)( --- Kathryn Dolan Stormwater Program Coordinator Permits Unit WATER QUALITY CONTROL DIVISION Enclosure xc: Regional Council of Governments Adams County Health Department District Engineer, Technical Services,WQCD Permit File Fee File Permit No. COR-030000 Facility No. COR-039798 PAGE 1 of 17 CERTIFICATION CDPS GENERAL PERMIT STORMWATER DISCHARGES ASSOCIATED WITH CONSTRUCTION Construction Activity: Oil & Gas Field Development This permit specifically authorizes: Kerr McGee Rocky Mountain LLC to discharge stormwater from the facility identified as Area 2 which is located at: map in file Denver, Boulder, Broomfield, Co latitude 40.081, longitude 104.717 in Adams County Boulder Creek to: South Platte River effective: 04/04/2006 Annual Fee: $270.00 (DO NOT PAY NOW. You will receive a prorated bill.) Best Management Practices (BMPs) Berm (B) Description 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. Berms may be constructed from either excavated topsoil or subsoil. The purpose of a berm is to control runoff velocity, divert onsite surface runoff to a sediment trapping device, divert clean water away from disturbed areas, and to provide a safe slope barrier for vehicle traffic. Applicability Berms are usually appropriate for drainage basins smaller than five acres, but with modifications they can be capable of servicing areas as large as ten acres. With regular maintenance, earthen berms have a useful life span of approximately 18 months. Berms are applicable for the following applications: • Along the outside shoulder of an insloped road to ensure that runoff from the roadway drains inward and to protect the fill slope from continual disturbance during road blading and maintaining. • Upslope of cut or fill slopes to divert flows away from disturbed areas. • Downslope of cut or fill slopes to divert onsite runoff to a stabilized outlet or sediment trapping device, although diversions are more commonly used for this application. • Along the outside shoulder of a road to provide vehicle safety. Limitations • Berms may erode if not properly compacted and stabilized with vegetation. Berms which are adjacent to concentrated flows will require erosion blanketing. • If a berm crosses a vehicle roadway or entrance, its effectiveness can be reduced. Wherever possible, berms should be designed to avoid crossing vehicle pathways. a Design Criteria ' .5 cr Q♦ EAR T— BERM 1 DIRECTION OF FLOW Drawing. URS 2008 .E Construction Specifications 1. Prior to berm construction, remove all trees, brush, stumps and other objects in the path of the berm and till the base of the berm before laying the fill. Fill may consist of topsoil or subsoil excavated during the construction of nearby roads or well pads. 2. For roadside berms, construct according to Figure B-1. 3. To remain effective, berms should be compacted with tracked equipment, if possible. 4. All berms shall have positive drainage to a stabilized outlet so that runoff does not collect in ponds on the upslope side of the berm, but instead flows along the berm until ti reaches a stabilized outlet. Field location should be adjusted as needed. Stabilized outlet may be a well- vegetated area, a well pad detention pond, or a sediment control such as a silt fence or sediment trap where sedment can settle out of the runoff before being discharged to surface water. 5. If the expected life span of the berm is greater than 15 days, it is strongly recommended that the berm be stabilized with vegetation or an erosion control blanket immediately after construction. Stabilization is required where concentrated flows are expected. 6. Berms should be constructed and fully stabilized prior to commencement of major upslope land disturbance. This will maximize the effectiveness of the structure as a storm water control device. Maintenance Considerations 2 The frequency of inspections should be in accordance with the Storm Water Management Plan (SWMP). Berms should be inspected for evidence of erosion or deterioration to ensure continued effectiveness. Berms should also be maintained at the original height. Any decrease in height due to settling or erosion, which impacts the effectiveness of the BMP, should be repaired imm Removal Berms should remain in place and in good condition until all upslope disturbed areas are permanently stabilized. There is no need to formally remove the berm on completion of stabilization until interim or final reclamation. References Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February, 2003. http://www.dec.state.ny.us/website/dow/toolbox/escstandards New York State Department of Environmental Conservation, New York Guidelines for Urban Erosion and Sediment Control. New York. Fourth Edition, 1997. http://www.dec.state.nv.us/website/dow/toolbox/escstandards Table B-1 Berm Stabilization Treatment Channel Grade Type (1) A (<5 Ac.) B (5-10 Ac.) 0.5-3.0% Hydro-seed and use Hydro-seed and use tackifier tackifier Seed and cover with 2 3.0-5.0% Hydro-seed and use erosion control tackifier blanket, or lined with 2-inch stone Seed and cover with Line with 4 to 8- 3 5.0-8.0% erosion control inch stone or rock blanket, or lined (2) with 2-inch stone Line with 4 to 8- 4 8.0-20.0% inch stone or rock Engineering Design (2) (I) In highly erodible soils, as defined by the local approving agency, refer to the next higher slope grade for type of stabilization. 3 (2) Site rock, if available, shall be broken into the required size. Check Dam (CD) • • Description Check dams are small, temporary dams constructed across a diversion or road side ditch. Check dams can be constructed using gravel, rock, sandbags, gravel bags, earth with erosion control blanketing, straw bales, or synthetic materials to slow the velocity of concentrated flow in a channel and thus reduce erosion. 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. Applicability Check dams are most often used in small, open channels with contributing drainage area of less than 10 acres, and side slopes of 2:1 or less. Check dams may be used in the following applications: • In diversion or roadside ditches where it is not practical to line the channel or implement other flow control and sediment control practices. • In diversions or roadside ditches where temporary seeding has been recently implemented but has not had time to take root and fully develop. • As a series of check dams, spaced at appropriate intervals, used in one of the above two applications. 4 • Rock ditch checks should be perpendicular to the flowline of the ditch. • Rock ditches must be designed so that water can flow over them, not around them. The ditch check should extend far enough so that the ground level at the ends of the check is higher than the low point on the crest of the check. The following table provides check spacing for a given ditch grade: Ditch Grade Check Spacing Check Spacing (Percent) (feet) (meters) 5 59 18 6 49 15 7 43 13 8 36 11 9 33 10 10 30 9 Limitations • Check dams should not be used in live, continuously flowing streams unless approved by an appropriate regulatory agency. • Check dams may require frequent removal of accumulated sediments. Dams should therefore be located in areas accessible to maintenance vehicles. • Leaves have been shown to be a significant problem by clogging check dams in the fall. Therefore, they might necessitate increased inspection and maintenance. • Straw bale check dams decompose over time, and may be consumed by livestock. 5 Design Criteria ROCK CHECK DAM 1 f me T. .... -17 pow ��a� ii�� i1 i•sti-`:"r@� L • The clamps etch that pointsLE-At �.,. .�.,.1. A and Bare of equal ervoWn A L B SPACING BETWEEN CHECK DAMS From:`dirgirta Soil and Water Conservation Commission.1585 6 ROCK SOCK ?" vrIT - SWALE ELEVATION I: V F itaka \ EVOECCEC ROCK SWALE SPACING MIA RSS ROCK SOCK IN SWALE 7 Construction Specifications • Install straw bale check dams, rock check dams and other check dams according to Figures and respectively. Other types of check dams shall have similar designs. • Check dams should be located in areas accessible to maintenance vehicles for the periodic removal of accumulated sediments. • Dams should be installed with careful placement of the construction material. Mere dumping of the dam material into a channel is not appropriate and will reduce overall effectiveness. • Check dams can be constructed from a number of different materials. Most commonly, they are made of straw bales or rock. When using rock, the material diameter should be 4 to 8 inches depending on the expected velocity and quantity of runoff within the channel. Wattles or sand/gravel bags may also be used,but only if straw bales or rock is unavailable or not feasible for the location. Earth collected during excavation of diversions or roadside ditches may also be placed as check darns if covered with erosion control blanketing. • All check dams should have a maximum height of three feet with sufficient space up slope from the barrier to allow ponding, and to provide room for sediment storage. The center of the dam should be at least six inches lower than the edges. This design creates a weir effect that helps to channel flows away from the banks and prevent further erosion. • Additional stability can be achieved by implanting the dam material approximately six inches into the sides and bottom of the channel. • In order to be most effective, dams used in a series should be spaced such that the base of the upstream dam is at the same elevation as the top of the next downstream dam. • When installing more than one check dam in a channel, outlet erosion stabilization measures should be installed below the final dam in the series. Because this area is likely to be vulnerable to further erosion, riprap, erosion control blanket lining, or some other stabilization measure is highly recommended. Maintenance Considerations The frequency of inspections should be in accordance with the Storm Water Management Plan (SWMP). During inspection, large debris, trash, and leaves should be removed. The center of a check dam should always be lower than its edges. If erosion or heavy flows cause the edges of a dam to fall to a height equal to or below the height of the center, and the effectiveness of the check dam is compromised, repairs should be made immediately. Accumulated sediment should be removed from the upstream side of a check dam when the sediment has reached a height of the dam (measured at the center). Close attention should be paid to the repair of damaged or 8 rotting straw bales, end runs and undercutting beneath bales. Replacement of bales should be accomplished promptly. Removal Removal of check dams is optional. Check dams within roadside ditches are usually used as temporary controls, where other check dams may be left in place to silt out. If removing a check dam, all accumulated sediment should be removed. Removal of a check dam should be completed only after the contributing drainage area has been completely stabilized. Permanent vegetation should replace areas from which rock or other material has been removed. References Colorado Department of Transportation (CDOT), Erosion Control and Stormwater Quality Guide. 2002. http://ww.dot.state.co.us/enviromental.envWaterOual/wgms4.asp Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February 2003. http://cfpud.epa.eov/npdes/stormwater/menufbmps/con site.cfin Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. North Dakota Department of Health Division of Water Quality, A Guide to Temporary Erosion- Control Measures for Contractors, Designers and Inspectors, June 2001 *Other materials may be used instead of straw. 9 Culvert (C) Description Culverts are typically concrete, steel, aluminum, or plastic pipe used to move ditch water under the road or to direct stream flow under the road or construction area. Applicability Culverts are ideal on road grates less than 15%. For grades over 15%, it is difficult to slow down the water or remove it from road surface rapidly. On such steep grades, it is best to use frequently spaced relief culverts and drainage crossings culverts, with armored ditches (see RIPRAP [R]). Culverts may be used in the following applications. • As drainage crossing culverts in streams and gullies to allow normal drainage to flow under the traveled way. • As ditch relief culverts to periodically relieve the inside ditch line flow by piping water to the opposite side of the road where the flow can be dispersed away from the roadway. Culverts placed in natural drainages may be utilized for ditch relief. Limitations • If undersized, culverts are susceptible to plugging and require cleaning. • Culverts will not filter sediment. • Culverts are easily crushed if not properly designed. Design Criteria Pipe size can be determined using general design criteria, such as in table C-1, but is ideally based upon site specific hydrologic analysis. Depth The depth of culvert burial must be sufficient to ensure protection of the culvert barrel for the design life of the culvert. This requires anticipating the amount of material that may be lost to road use and erosion. 10 Headwalls Use headwalls on culvert pipes as often as possible (see RETAINING WALL [RW]). The advantages of headwalls include: preventing large pipes from floating out of the ground when they plug; reducing the length of the pipe capacity; helping to funnel debris through the pipe; retaining the backfill material; and reducing the chances of culvert failure if it is overtopped. Construction Specifications Drainage crossing culverts • Make road crossings of natural drainages perpendicular to the drainage to minimize pipe length and area of disturbance (Figure C-1). • Use single large pipes versus multiple smaller diameter pipes to minimize plugging potential in most channels (unless roadway elevation is critical). In very broad channels, multiple pipes are desirable to maintain the natural flow spread across the channel. All culverts should be concrete corrugated metal pipe made of steel or aluminum, or properly bedded and backfilled corrugated plastic pipe. • Align culverts in the bottom and middle of the natural channel flowline so that installation causes no change in the stream alignment or stream bottom elevation. Culverts should not cause damming or pooling or increase stream velocities significantly. • Extend the outlet of the culvert at least one foot beyond the toe of the slope to prevent erosion of the fill material. Alternatively, use retaining walls (headwalls) to hold back the fill slope. • It may be necessary to install rip-rap, erosion control blanketing, a combination of both, or other energy dissipater device at the outlet end of the culvert to reduce soil erosion or to trap sediment(see CULVERT PROTECTION [CP]). • It may be desirable to construct pulloffs/turnouts for vehicle on one or both sides of narrow culvert crossings. This will help avoid culvert crushing as well as disturbance to roadside ditches and berms. Ditch relief culverts • See figure C-2 for installation details. 11 • Ditch relief culverts can provide better flow when skewed 0 to 30 degrees perpendicular to the road. • The culvert gradient should be at least 2% greater than the approach ditch gradient. This improves the flow hydraulics and reduces siltation and debris from plugging the culvert inlet. • Discharge culvert at natural ground level where possible ( see figure C-3,type A), on firm, non-erosive soil or in rocky or bushy areas. If discharge on the fill slopes, armor outlets with riprap or logging slash (see figure C-3, type B), or use down-drain structures (see figure C- 3, type C and SLOPE DRAIN [SD]). • Extend the inlet of the culvert at least one foot beyond the flowline of the roadside ditch. Extend the outlet of the culvert at least one foot beyond the toe slopes to prevent erosion of the fill material. • It may be necessary to install riprap or other energy dissipater devices at the outlet end of the culvert to prevent soil erosion or to trap sediment (see CULVERT PROTECTION [CP]). • Spacing of culverts is dependent on the road gradient, soil types, and runoff characteristics according to the following table: Road Grade Soil Type 2-4% 2-4% 2-4% Highly corrosive 240' 180' 140' granitic or sandy Intermediate erosive 310' 260' 200' clay or load Low erosive shale 400' 325' 250' or gravel • It may be desirable to construct pulloffsiturnouts for vehicle on one or both sides of narrow culvert crossings. This will help avoid culvert crushing as well as disturbance to roadside ditches and berms. 12 Backfill and Compaction See figure C-4. • Firmly compact well-graded fill material (soil or road base) around culverts, particularly around the bottom half, using placement in layers to achieve a uniform density. Use slightly plastic sandy gravel with fines. Avoid the use of fine sand and silt rich soils for bedding material because of their susceptibility to piping. Pay particular attention to culvert bedding and compaction around the haunches of the pipe. Do not allow the compaction to move or raise the pipe. In large fills, allow for settlement. • Cover the top of the metal and plastic culvert pipes with fill to a depth of at least 1 foot to prevent crushing by heavy trucks. Use a minimum cover of 2 feet of fill over concrete pipe. For maximum allowable fill height, follow manufacturer's recommendations. • Mound fill over the top of culvert pipes so that the road is slightly raised at culvert locations to help prevent erosion and water from ponding over culvert crossings. This practice, as well as placing large boulders around the culvert outlets, will also help to prevent culverts from crushing. Maintenance Considerations The frequency of inspections should be in accordance with the Storm Water Management Plan (SWMP). If any damage to culvert or inlet/outlet protection is noted or if there is any evidence of scour, repairs should be made immediately. Any debris that may be blocking the culvert inlet or outlet should be removed. References Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. Keller, Gordon and James Sherar, Low-Volume Roads Engineering, Best Management Practices Field Guide. United States Department of Agriculture (USDA), Forest Service, US Agency od International Development (USAID), 2005. http://www.blm.gov/bmq/field%20iuide.htm United States Department of the Interior and United States Department of Agriculture. Surface Operating Standards and Guidelines for Oil and Gas Exploration and Development "Gold Book". BLM/WO/ST-06/021+3071. Bureau of Land Management (BLM). Denver, Colorado. Fourth Edition, 2006. 13 Size of Drainage Structure (diameter and area) Drainage Area (acres) Steep Slopes (Light Vegetation) Gentle Slopes (Heavy Vegetation) C=0.7 C=0.2 Round Pipe (In) Area (sq.ft) Round Pipe (In) Area (sq.ft) 0-10 30" 4.9 18" 1.8 10-20 42" 9.6 24" 3.1 20-35 48" 12.6 30" 4.9 35-75 72" 28.3 42" 9.6 75-125 84" 38.5 48" 12.6 125-200 96" 50.3 60" 19.6 * Due to site specific conditions this table may not be used. 14 Drainage Crossing Culvert Alignment & Overflow Dip Ditch Relief Culvert Installation • flS flotatr.rwpe Koala,Sit .APrOtti raw. r•a talniM1n '5061K�ND.1W Eatrc CJrwt Mon l'ft/reel Isobar Mime*, thy halm Ettlr•LISSIJO SIP es_ c, -. ,, K t•ogorcnsa?IWpr .1 411 n.su Hi*['pin IOUS PIN Ww w-�yrao alma mei wraa 40110&111 15 Culvert Installation Options TYPE A TYPE B I.s.ragmvd wide Rut* 4H[W .. IMAMS 3-4n. ..caacW �.�Y�u96t •.em.��:la :,1 I b 4MP;new I AsiAbn +o-` O..A*r:1•4+ wewwm.. rm rvu vw rh wn iynp Jrv, TYPE C womW (yiy.ry Myra mnnralaa an - ',r /Sluau: �„ Orl1 �,, nw:oludne Mart TT.SCALE Culvert Backfill and Compaction ,0 A WaA of a ca`r fc•SY Imp tines tie oe .,... &I�:rn�ux went,. I m'Oabp pIMn _..- _... hcrR�w ' . CJal i� Temp eralwrsIr l MIN(-meta Ina .M•Sal um anal Liana - - LAS Al I slum Sus LW an!ry on caaMIL dm oA.nrt (ware IN PM IMAM Sun 3' %CT TO SCALE 16 Culvert Protection (CP) • .1V-f • , ' t, r - - Description Culvert protection may be required at the inlet of the culvert (upstream side) and/or the outlet side of the culvert (downstream side). Culvert inlet protection could involve placing boulders, riprap, gabions, rock retaining walls, slash, and/or any other protection at the inlet pipes. Riprap, or other energy-dissipating devices, will reduce the velocity of storm water flows and thereby prevent erosion and help protect the inlet structure. Culvert outlet protection involves placing structurally lined aprons or other appropriate energy- dissipating devices, such as large boulders or plunge pools, at the outlets of the pipes to reduce the velocity of storm water flows and thereby prevent scouring at storm water outlets, protect the outlet structure, and minimize potential for erosion downstream. Applicability Riprap inlet protection should be used where velocities and energies at the inlets of culvert are sufficient to erode around the inlet structure. Riprap may also be used to help channel the storm water to the inlet of the culvert. Culvert outlet protection should be used where discharge velocities and energies at the outlets of the culverts or channels are sufficient to erode the next downstream reach. Limitations Rock aprons at the culvert outlets should not be placed on slopes steeper than 10 percent. Runoff from pipe outlets at the top of cut/fills or on slopes steeper than 10 percent should be routed via slope drains or riprap chutes to a rock apron at the toe of the slope. Otherwise will re-concentrate and gain velocity as the flow leaves the apron. 17 Design Criteria Culvert inlet protection: Riprap, gabions, or rock retaining walls at culvert inlets shall be designed according to RIPRAP (R) or RETAINING WALL (RW). Culvert Outlet Protection: Gabions or rock retaining walls at culvert outlets shall be designed according to RETAINING WALL (RW). No formal design is required for plunge pools at outlets. Riprap aprons at culvert outlets shall be designed as follows. Tail-water depth: The depth of tail-water immediately below the pipe outlet must be determined for design capacity of the pipe. If the tail-water depth is less than half the diameter of the outlet pipe, and the receiving stream is wide enough to accept divergence of the flow, it shall be classified as a minimum tail-water condition. If the tail-water depth is greater than half the pipe diameter and the receiving stream will continue to confine the flow, it shall be classified as a maximum tail-water condition. Pipes that outlet onto flat areas with no defined channel may be assumed to have a minimum tail-water condition. Riprap Apron Size & D50: The apron length (LA) and the D50 of the riprap shall be determined from table CP-1 according to the design flow and weather there is a minimum or maximum tail- water condition. The apron width (W) shall then be determined as (W=d+0.4LA) where d is the diameter of the culvert. If the pipe discharges directly into a well defines channel, the apron shall extend across the channel bottom and up the channel banks to an elevation one foot above the maximum tail-water depth or to the top of the bank, whichever is less. The upstream end of the apron, adjacent to the pipe, shall have a width of two (2) times the diameter of the outlet pipe, or confirmed to pipe and section if used. Riprap Materials: The outlet protection may be done using rock riprap or grouted riprap. Riprap shall be composed of a well-graded mixture of stone size so that 50 percent of the pieces, by weight, shall be larger than the D50 size determined from table CP-1. A well-graded mixture, as used herein, is defined as a mixture composed primarily of larger stone sizes, but with a sufficient mixture of other sizes to fill the smaller voids between the stones. The diameter of the largest stone size in such a mixture shall be 1.5 times the D50 size. All grout for grouted riprap must be one part Portland cement for every three parts sand, mixed thoroughly with water. Filter: If a filter cloth or gravel is used, it should be designed according to RIPRAP (R). Apron Thickness: The minimum thickness of the riprap layer shall be 1.5 times the maximum stone diameter for D50 of 15 inches or less; and 1.2 times the maximum stone size for D50 greater than 15 inches. Riprap Stone Quality: Stone for riprap shall consist of field stone or rough un-hewn quarry stone. The stone shall be hard and angular and of quality that will not disintegrate in exposure to water or weathering. The specific gravity of the individual stone shall be at least 2.5. Site rock or site boulders may be used provided it has a density of at least 150 pounds per cubic foot, and does not have any exposed steel or reinforcing bars. 18 Construction Specifications Culvert Inlet Protection: 1. Riprap, gabions, or rock retaining walls at culvert inlets shall be constructed in accordance to RIPRAP (R) or RETAINING WALL (RW). 2. After installation of a culvert, examine the stream channel for the amount of debris, logs, and brushy vegetation present. In channels with large amounts of debris, consider using oversized pipes. 3. Boulder should be dry-stacked around the culvert inlet and up the slope to the edge of the road. Culvert outlet protection: Gabions or rock retaining walls at culvert outlets shall be designed according to RETAINING WALL (RW). Riprap aprons at culvert outlets shall be constructed according to CP-2 and as follows. 1. Prepare the sub-grade for the riprap to the required lines and grades. Any fill required in the sub-grade shall be compacted to a density of approximately that of the surrounding undisturbed material. 2. If a pipe discharges into a well-defined channel, the channel's side slopes may not be steeper than 2:1. 3. Construct apron to the design length and width with no slope. The invert elevations must be equal at the receiving channel and the apron's downstream end. No over-fall at the end of the apron of the apron is allowed. The elevation of the downstream and of the apron shall be equal to the elevation of the receiving channel or adjacent ground. The outlet protection apron shall be located so that there are no bends in the horizontal alignment. 4. If a culvert outlets at the top of cut/fills or on slopes steeper than 10 percent one of the following option is suggested: 5. Line slope below culvert outlet with a riprap channel to convey storm water to the bottom of the slope where a riprap apron, as designed above, shall prevent erosion at the bottom of the slope. The riprap channel shall be designed according to the table in the RIPRAP (R) construction specification that is based on depth of flow and slope. The riprap channel shall dip into the slope so that all water is contained within the channel, flows to the riprap outlet apron at the base of the slope, and does not spill over the sides onto unprotected soil. 19 Maintenance Considerations The frequency of inspection should be in accordance with the Storm Water Management Plan (SWMP). Inspect for debris at the entrance to culverts and within culverts. Inspect riprap at culvert inlets for damage and dislodged stones. The maintenance needs are usually very low for properly installed riprap aprons at culvert outlets. However, inspect for evidence of scour beneath riprap at outlets aprons or for dislodged stones. Anything that is found to reduce the effectiveness of the culvert or culvert outlet protection should be repaired immediately. References Keller, Gordon and James Sherar, Low-Volume Roads Engineering, Best Management Practices Field Guide. United States Department of Agriculture (USDA), Forest Service, US Agency od International Development(USAID), 2005. http://www.blm.gov/bmp/field%20guide.htm New York State Department of Environmental Conservation, New York Guidelinesfor Urban Erosion and Sediment Control. New York. Forth Edition, 1997.http://www.dec.state.nv.us/website/dow/tool box/escstandards 20 Riprap Aprons for Low Tailwater (downstream flow depth < 0.5 x pipe diameter) Culvert Lowest Value Intermediate values to inter Violate from Highest Value Diameter Q L^ D50 Q ALA, Ds0 Q LA D50 Q , LA Ds, Q LA D50 Cfs Ft In Cfs Ft In Cfs Ft In Cis Ft In Cfs Ft In 12" 4 7 2.5 6 10 3.5 9 131 6 12 16 7 14 17 8.5 15" 6.5 8 3 10 12 5 15 16 7 20 18 10 25 20 12 18" 10 9 3.5 15 14 5.5 20 17 7 30 22- 11 40 25 14 21" 15 11 4 25 18 7 35 22 10 45 26 13 60 29 18 24" 21 13 5 35 20 8.5 50 26 12 65 30 16 80 33 19 27" 27 14 5.5 50 24 9.5 70 29 14 90 34 18 110 37 22 30" 36 16 6 , 60 25 9.5 90 33 15.5 120 38 , 20 140 41 24 36" 56 20 7 100 32 13 140 40 18 180 45 23 220 50 28 42" 82 22 8.5 120 32 12 160 39 17 200 45 20 260 52 26 48" 120 26 10 170 37 14 220 46 19 270 54 23 320 64 37 Riprap Aprons for High Tailwater (downstream flow depth > 0.5 x pipe diameter) Lowest Value Intermediate values to inter jolatefrom Highest Value Culvert LA D50 Q LA Dst Q LA D5° Diameter Q LA D50 Q LA Ds. Q Cfs Ft In Cfs Ft Iu Cfs Ft In Cfs Ft In Cfs Ft In 12" 4 8 2 6 18 2.5 9 28 4.5 12 36 7 14 40 8 15" 7 8 2 10 20 2.5 15 34 5 20 42 7.5 25 50 10 18" 10 8 2 15 22 3 20 34 5 30 50 9 40 60 11 21" 15 8 2 25 32 4.5 35 48 7 45 58 11 60 72 14 24" 20 8 2 35 36 5 50 55 8.5 65 68 12 80 80 15 27" 27 10 2 50 41 6 70 58 10 90 70 14 110 82 17 30" 36 11 2 60 42 6 90 64 11 120 80 15 140 90 18 36" 56 13 2.5 100 60 7 140 85 13 180+ 104_ 18 220 120 23 42" 82 15 2.5 120 50 6 160 75 10 200 96 14 260 120 19 48" 120 20 2.5 170 58 7 220 85 12 270 105 16 320 120 20 21 Typical Inlet Protection .min. & w We the,Mari • Typical Outlet Protection A rawsu - a 5'.4 , �s '*( .{ t '/ 4 0- �' i--,E PAWS Pmn. �I - ",. ppy y fo.dllaP. .. _ s n o t o 4 , .t % Near lydM Ya Cp r tj • J F. Jelin twrien venom Mm c in=d,ln I _ ,� I Le 4yla:'° �'. `• 1 I C.‘" I -/ NCT TO Sr-ALE 22 Diversion Ditch Embankment Bases or Midslopes (DD) • • DIVERSION DITCH SECTION UNLINED CHANNEL DD DIVERSION DITCH FOR EMBANKMENT BASES OR MIDSLOPES Diversion Ditch Installation Notes • See the Plan view for the location(s) of the diversion ditches. • A plastic liner, riprap, or erosion control blanket may be necessary to protect the diversion ditch. • All material excavated from the ditch shall be used to construct the berm on the downhill side of the ditch. • The diversion ditch shall be a minimum of 18" deep with 3:1 side slopes. The adjacent berm shall be a minimum of 18" in height with 3:1 side slopes. All embankments shall be firmly compacted. • The discharge from the diversion ditch shall be directed towards an appropriately sized and constructed slope drain, or sediment pond. 23 • In locations where construction traffic must cross a diversion ditch, the erosion control supervisor shall install a temporary culvert with a minimum diameter of 12". Diversion Ditch Inspection and Maintenance Notes • The erosion control supervisor shall inspect the diversion ditch at the following intervals: • Immediately following initial installation. • Every 14 days while the site is under construction. • Immediately following any storm event that causes soil erosion. • Once a month following the end of construction, until vegetative cover has reached a consistent density of at least 70% of full vegetative cover. • Accumulated sediment shall be removed once the sediment has reached a depth equal to ' the crest height. • Diversion ditches shall be re-graded immediately following any signs of soil erosion. • Diversion ditches are to remain in place and properly maintained until vegetative cover has reached a consistent density of at least 70%of full vegetative cover and erosion and sedimentation is no longer a possibility as determined by the County inspector. In some instances, the diversion ditches may remain in place permanently. • When diversion ditches are removed, excavation shall be filled with suitable compacted topsoil. The berm portion of the diversion ditch shall be graded out and any disturbed areas associated with the installation, maintenance, and/or removal of the diversion ditches shall be roughened, seeded, mulched, and crimped. An erosion control blanket may be used in lieu of straw mulch. 24 Erosion Control Blanket (ECB) Description Erosion control blankets, also called 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. However, blankets can also be used as separators or to aid in plant growth by holding seeds, fertilizers and topsoil in place. Applicability Erosion control blankets may be used in the following applications: • To control erosion on steep slopes and to promote the establishment of vegetation. • To stabilize channels against erosion from concentrated flows. • To protect berms and diversions prior to the establishment of vegetation. • To protect exposed soils immediately and temporary, such as when active piles of soil are left overnight. • As a separator between riprap and soil to prevent soil from being eroded from beneath the riprap and to maintain the riprap's base. • May be used on slopes as steep as 1:1. Limitations • Blankets used on slopes should be biodegradable, or photodegradable, non-toxic to vegetation or germination of seed, and non-toxic or injurious to humans. • Should not be used on slopes where vegetation is already established. • Some blankets might promote increased runoff and might blow away if not firmly anchored. • If the fabric is not properly selected, designed, or installed, the effectiveness may be reduced drastically. Manufacturer's specification should be followed. 25 Design Criteria There are many types of erosion control blankets available. Therefore, the selected fabric should match its purpose. Effective netting and matting require firm, continuous contact between the material and the soil. If there is no contact, the material will not hold the soil and erosion will occur underneath the material. Table ECB-I indicates some recommended criteria for the selection of erosion control blankets. Construction Specifications • Smooth soil prior to installation and apply seed prior to fabric installation for stabilization of construction sites. • Select the appropriate fabric type using the guidelines from table ECB-1. • Installation of the blankets shall be in accordance with the manufacturer's recommendations and according to figure ECB-1. For blankets being placed in channels, the fabric should be rolled out parallel to the channel if the width is sufficient to cover the entire width of the channel. The fabric needs to be in continuous contact with the exposed soil. • Pins or staples shall be made of wire 0.1621" or larger in diameter. "U" shaped staples shall have legs 8" long, and a 1" crown. The bar of the "T" shall be at least 4" long. Triangular survey stakes can also be used. Maintenance Considerations The frequency of inspections should be in accordance with the Storm Water Management Plan (SWMP). Inspections should determine if cracks, tears, or breaches have formed in the fabric. If the effectiveness of the erosion control blanket has been reduced, the fabric should be repaired or replaced immediately. Re-anchor loosened matting and replace missing matting and staple as required. It is necessary to maintain contact between the ground and the blanket at all times. Trapped sediment should be removed after each storm event. References Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February 2003. http://cfpud.epa.gov/npdes/stonnwater/menufbmns/con site.cfm Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. 26 Keller, Gordon and James Sherar, Low-Volume Roads Engineering, Best Management Practices Field Guide. United States Department of Agriculture (USDA), Forest Service, US Agency od International Development (USAID), 2005. http://www.blm.gov/bmo/field%20guide.htm North American Green, 2004.<http://www.nagreen.com Table ECB-1 Suggested Blanket Types Max Flow Description Longevity Applications Velocity Iteet/sec _.r .. Flow Channels , t i I opes 5 I Rapid Degrading Nets 4F :- I 2 1 Sic rc-c r. i Jc.:aI- l lei. a',reI Double Net Blanket ! 24 month. I Clr 2 1 i;gro H '0% SV aw1304U Coconut Mee,,.nr Flom(.han, It. Double Net Blanket 36 months I 1 F path• ne-s tp 1009f, Coconut nig� F.,-.vi Cn. .anna Double Net Blanket 1 t Slopes PolyproFYtenc I-,bii Extended Flow Areas "1-.1 High Flow Channels Glcriic Net 17 months I 4'1 3 1 Sopes c. Low Flow Channels Jr pan<. sets I?months 3 I . 2 1 Slopes l _ Modetale Flow Channels 't ..:•m he i 1 I I Slopes fl ! - medium F lr..v Channels mo�'I I 1 8 Greater Slopes t" High Flow Channel. 27 Additional Drawings: - Staple detail Detail 4 . : • • Detail Detail sSr /• 7� _- -- Row • Detail 1 Column - Erosion Control Blanket Persective View 4 in (102 mm) ; 3 in(76 nxm) minimum _ 6-12 in(152-305 mm) �}` minimum • • r-- Staple— Tamp soil fimdy ' Staple Terminal Fold- Terminal Fold- jute mesh only excelsior blanket DETAIL 1 erosion control paper 12in(305mm) — 12in(305mm) 6 in (152 mini) Staples - StaplesJunction Slot- Junction Slot- jute mesh erosion DFTAII 2 excelsior blanket control paper Erosion Control Blanket; Detail 1 and Detail 2 Section View 28 Additional Drawings: • 12 in (305 mm) Tamp soil firmlyTamp soil firmly • • 6-12in (152-305mm) -., . minimum depth ,0— • Staple Staples Anchor Slot- Check Slot- jute mesh erosion control paper excelsior blanket erosion control paper j)FTAII "{ DETAIL 4 4in (102mm) minimum - 1 in (25 mm) minimum 6 -12 in (152-305 mm) 4• minimum 11 '\ Staple Lap Joint- jute mesh STAPLE DETAIL excelsior blanket erosion control paper shall be butted togther DETAIL 5 Erosion Control Blanket; Detail 3, Detail 4, Detail 5, and Staple Detail Section View 29 Hydraulic Mulch at . . 1 Description and Purpose Hydraulic mulch consists of applying mixture of shredded wood fiber or a hydraulic matrix, and a stabilizing emulsion or tackifier with hydro-mulching equipment, which temporarily protects exposed soil from erosion by raindrop impact or wind. Applicability Hydraulic mulch is suitable for soil disturbed areas requiring temporary protection until permanent stabilization is established, and disturbed areas that will be re-disturbed following an extended period of inactivity. Limitations Wood fiber hydraulic mulches are generally short lived and need 24 hours to dry before rainfall occurs to be effective. May require a second application in order to remain effective for an entire rainy season. Construction Specifications • Prior to application, roughen embankment and fill areas by rolling with a crimping or punching type roller or by track walking. Track walking shall only be used where other methods are impractical. 30 • To be effective, hydraulic matrices require 24 hours to dry before rainfall occurs. • Avoid mulch over spray onto roads, sidewalks, drainage channels, existing vegetation, etc. • Paper based hydraulic mulches alone shall not be used for erosion control. Hydraulic Mulches Wood fiber mulch can be applied alone or as a component of hydraulic matrices. Wood fiber applied alone is typically applied at the rate of 2.000 to 4.000 lb/acre. Wood fiber mulch is manufactured from wood or wood waste from lumber mills or from urban sources. Hydraulic Matrices Hydraulic matrices include a mixture of wood fiber and acrylic polymer or other tackifier as binder. Apply as a liquid slum-using a hydraulic application machine(i.e.,hydro seeder) at the following minimum rates.or as specified by the manufacturer to achieve complete coverage of the target area: 2.000 to 4.000 lb/acre wood fiber mulch. and 5 to ro°o (by weight) of tackifier (acrylic copolymer,guar.psyllium. etc.) Bonded Fiber Matrix Bonded fiber matrix(BFDM)is a hydraulically applied system of fibers and adhesives that upon drying forms an erosion resistant blanket that promotes vegetation,and prevents soil erosion. BFMs are typically applied at rates from 3.000 lb acre to 4.0001b/acre based on the manufacturer's recommendation. A biodegradable BEd is composed of materials that are loo°o biodegradable. The binder in the BFN1 should also be biodegradable and should not dissolve or disperse upon re-wetting. Typically,biodegradable BEMs should not be applied immediately before,during or immediately after rainfall if the soil is saturated. Depending on the product. BFDis typically require 1210 ^_-1 hours to dry and become effective. 31 Land Grading (LG) Description Grading involves reshaping the ground surface to planned grades. Grading provides more suitable topography for well pads and pipelines and helps to control runoff, soil erosion, and sediment during and after construction in these areas. This BMP shall include the following: • Proper cut and fill techniques to ensure roads and well pads remain stable over time. • Road crowning or sloping to properly route runoff off the roadway. • Surfacing of roads or well pads with gravel to avoid mud, rutting, and large quantities of sediment that will wash away during storms. Applicability • This BMP is applicable to the construction and maintenance of any road or well pad, but particularly those located on steep topography or easily erodible soils. • Surface gravel is applicable to all areas with "soft" soils sections, steep grades, highly erosive soils, or where all weather access is needed. Gravel may be used as "fill" material in ruts or as a full structural section over the entire road or well pad. Limitations • Improper cut and fill slopes that disrupt natural storm water patterns might lead to poor drainage, high runoff velocities, and increased peak flows during storm events. • Rutting and wash boarding may develop if surface gravel is not designed properly or if road or well pad is not sloped. • Flat-blading to maintain the roadway must be done properly to avoid changes in gravel thickness, road slope, and road grade. Design Criteria Practices must be developed for erosion control, slope stabilization, and safe disposal of runoff water and drainage, such as ditches and culverts, grade stabilization structures, retaining walls, and surface drains. Land grading should be based upon well pad and pipeline layouts that fit and utilize existing topography and desirable natural surroundings to avoid extreme grade modifications. Clearing and grading should only occur at those areas necessary for well pad activity and equipment traffic. Maintaining undisturbed temporary or permanent buffer zones in 32 the grading operation provides a low cost sediment control measure that will help reduce runoff and offsite sedimentation. Slope Failures Landslides and failed cuts and fills can be a major source of sediment. They can close the roads or require major repairs, and they can greatly increase maintenance costs. Slope failures, or landslides typically occur where a slope is over-steep, where fill material is not compacted, or where cuts in natural soils encounter groundwater or zones of weak material. Good road location can often avoid landslide areas and reduce slope failures. When failure does occur, the slide area should be stabilized by removing the slide material, flattening the slope, adding drainage, or using structures as discussed below. Designs are typically site specific and may require input from geotechnical engineers and engineering geologist. Failures that occur typically impact operations and can be costly to repair. Failures near streams and channel crossings have an added risk of impact to water quality. Road Slope See figure LG-1. All roads should be designed with one of the following three slope types: • Out-sloped roads minimize the concentration of water and minimize road width by avoiding the need for an inside ditch, but nay require roadway surface and fill slope stabilization. Out-sloped roads with clay rich, slippery road surface materials often require surface stabilization with gravel or limited use during rainy periods to assure traffic safety. On road grades over 10 to 12 percent and on steep hill slope areas, out-sloped roads are difficult to drain and can feel unsafe. • In-sloped roads are the best method to control surface water. However, in-sloped roads also concentrate water and require a system of ditches and turnouts or cross draining culverts. • Crowned roads are appropriate for higher standard, two lane roads on gentle grades. They may or may not require roadside ditches, turnouts, and/or cross drains. It is difficult to create and maintain a crown on a narrow road, so generally in-sloped or out-sloped road drainage is more effective. Construction Specifications Cut and fill Slopes • All areas to be disturbed (both cut and fill) shall be cleared, grubbed, and stripped of topsoil to remove trees, vegetation, roots, or other objectionable material. 33 • Fill material shall be free of brush, logs, stumps, roots, or other objectionable material that would interfere with, or prevent construction or satisfactory fills. This material can be set aside and later used at the toe of fill slopes as filter berms. • Table LG-1 presents a range of commonly used cut and fill slope ratios appropriate for the soil and rock types described. Figures LG-2 and LG-3 present typical cut and fill slope design options for varying slope and site conditions. Vertical cut slopes should not be used unless the cut is in rock or very well cemented soil. Ideally, both cut and fill slopes should be constructed with a 2:1 or flatter slope to promote growth of vegetation, but cut slopes in dense, sterile soils or rocky material are often difficult to vegetate. • All fills shall be compacted as requires to reduce erosion, slippage, settlement, subsidence, or other related problems. • Topsoil required for the establishment of vegetation shall be stockpiled in the amount necessary to complete finished grading of all exposed areas. Areas that are to be top-soiled shall be scarified to a minimum depth of four inches prior to placement of topsoil. Road Slope • See figure LG-1. Compact soil or road base material to direct runoff. • If crowning a road, runoff is directed to both sides of the road requiring two roadside ditches, unless runoff will drain directly to well stabilized areas. • If using an in-slope design, runoff will be directed toward the hillside and requires a roadside ditch with periodic turnouts or cross drain culvert installation. • If using an outslope design, ensure a moderate road slope with dense vegetative cover • Surface Gravel • Ideally, aggregate surfacing material is (1) hard, durable, and crushed or screened to a minus 2 inch size; (2) well graded to achieve maximum density; (3) contains 5-15% clayey binder to prevent raveling; and (4) had a plasticity index of 2 to 10. • Gravel should be placed to a thickness of at least twice the diameter of the largest stone with a minimum thickness of four inches. Over very weak soils gravel thickness can be reduced with the use of geotextile or geogrid subgrade reinforcement. Also, geotextile layers are useful over soft soils to separate the gravel from the soil, keep it uncontaminated, and extend the useful life of the gravel. 34 • Compact the aggregate during construction and maintenance to achieve a dense, smooth surface and thus reduce the amount of water that can soak into the road or well pad. • "Spot" stabilize local wet areas and soft areas with four to six inches of coarse rocky material, add more as needed. • Blend coarse aggregate and fine clay-rich soil (when available) to produce a desirable composite roadway material that is coarse yet well graded with 5-15% fines for binder. Maintenance Considerations The frequency of inspections should be in accordance with the Storm Water Management Plan (SWMP). Inspect cut and fill slopes for rills or other indications of erosion. Maintain all crowns, out-slopes, in-slopes, and surface gravel. References Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control Washington, D.C., February 2003. http://cfpud.epa.gov/npdes/stonnwater/menufbmps/con site.cfm Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. Keller, Gordon and James Sherar, Low-Volume Roads Engineering, Best Management Practices Field Guide. United States Department of Agriculture (USDA), Forest Service, US Agency od International Development (USAID), 2005. http://www.blm.gov/bmp/field%20guide.htm New York State Department of Environmental Conservation, New York Guidelinesfbr Urban Erosion and Sediment Control. New York. Forth Edition, 1997. http://www.dec.state.ny.us/website/dow/toolbox/escstandards LG-1 Stable Slope Ratios for Various Conditions Slope Ratio Soil/Rock Condition (Hor:Vert) Most rock 1/4:1 to 1/2:1 Very well cemented soils 1/4:1 to 1/2:1 Most n-place soils 3/4:1 to1:1 Very fractured rock 1:1 to 1 1/2:1 35 Loose coarse granular soils 1 1/2:1 Heavy clay soils 2:1 to 3:1 Soft clay rich zones or wet seepage areas 2:1 to 3:1 Fills of most soils 1 1/2:1 to 2:1 Fills of hard, angular rock 1 1/3:1 Low cuts and fills 2:1 or flatter (<10 ft high) (for revegetaton) Figure LG-1 Typical Road Surface Drainage Options C`uwn Section Jr. Outsiope Sn'aion ary Insiope::itn Ditch SectionRoADsivi N( I 'a$C; 36 Paved & Graveled Vehicle Tracking Control (PGVTC) Description: CONCRETE STRUCTURE WITH GRAVEL AND CATTLE GUARD A stabilized construction entrance (tracking pad) is a pad of gravel or cattle guard where construction traffic leaves a site. The purpose of a paved and graveled entrance to a site is to minimize the amount of tracked mud and dust that leaves a site. As a vehicle drives over the pavement and gravel, mud and sediment are removed from the vehicle's wheels when crossing the cattle guards and offsite transport of soil is reduced. The paved and graveled pad also reduces erosion and rutting in the soil beneath the stabilized structure. Applicability Stabilized construction entrances are installed at locations where construction traffic leaves or enters an existing paved road. Limitations • Although stabilizing a construction entrance is a good way to help reduce the amount of sediment leaving a site, some soil may still be deposited from vehicle tires onto paved surfaces. To further reduce the chance of these sediments polluting storm water runoff, sweeping of the paved area adjacent to the stabilized site entrance is recommended. Maintenance Considerations The frequency of inspections should be in accordance with the Storm Water Management Plan (SW MP). Visual evidence of deterioration should be repaired immediately. Gravelled/Paved Vehicle Tracking Pad — Aerial View 24' Cattle Guard#1 lute••••••••••• ••••••••••••r •N••N••N•q•OgwO•0••gp••NM•H•O 5"Dia.Crushed ••••••N•••N•••••••:••gq►lp•••l•••• 30' Concrete iii•••••••••••••••••••••an* i••••••••••• •••••••NN••A•o��•oN••NNN�N•HN i i I{ Cattle Guard#2 "" 7' . , , , 14 144" 144" 13T 144" 190" 195" 144" 137" 144" 224" 245" 156" 137" 44"43" 40" 263" 295" 74" 187" 162" 1r' 136" 70" 35" 314" 290" 190" 166" ' 138" 154" 178" 87" 354" 290" 93" NOT TO SCALE Gravelled/Paved Vehicle Tracking Pad — Cattle Guard #1 Aerial View � 1 i Side View 0000000000000 O O Frontal View I O O CJ O O O 00 O Gravelled/Paved Vehicle Tracking Pad — Cattle Guard #2 Aerial View 1 1 I I i I 1 1 I I I I Side View 000000000000000 O O Frontal View i0 O O C) C) C) O O� Paved Vehicle Tracking Control (PVTC) Description CONCRETE STRUCTURE WITH CATTLE GUARD A stabilized construction entrance (tracking pad) is a pad of gravel or cattle guard where construction traffic leave a site. The purpose of a paved entrance to a site is to minimize the amount of tracked mud and dust that leaves a site. As a vehicle drives over the pavement, mud and sediment are removed from the vehicle's wheels when crossing the cattle guards and offsite transport of soil is reduced. The paved pad also reduces erosion and rutting in the soil beneath the stabilized structure. Sub-surface concrete boxes exist below each cattle guard crossing to trap sediment released from vehicle tires. Applicability Typically, stabilized construction entrances are installed at locations where construction traffic leaves or enters an existing paved road. However, the applicability of site entrance stabilization should be extended to any roadway or entrance where vehicles will access or leave the site. Limitations • Although stabilizing a construction entrance is a good way to help reduce the amount of sediment leaving a site, some soil may still be deposited from vehicle tires onto paved surfaces. To further reduce the chance of these sediments polluting storm water runoff, sweeping of the paved area adjacent to the stabilized site entrance is recommended. • Site traps or other secondary sediment controls are needed to capture that sediment that accumulates at the pad and may run off during storm events. Maintenance Considerations The frequency of inspections should be in accordance with the Storm Water Management Plan (SWMP). Sub-surface concrete boxes should be inspected for evidence of sediment deposition and cleanout should be recommended at appropriate times. Visual evidence of deterioration should be repaired immediately. 37 Paved Vehicle Tracking Control Segment 8' 9" 19' 5" 18,6" 9' 6 'W- 10' 6" 10' 13, 6„ 14,8" 18'6" 17'7" 13'2" 17'6" 16'4" 12' 1" 16' 3" 15' 3" 12' 15' 1" 14' 3" 12' 13' 11" 13'2" 8'6" 12' 8" 12'4" 42" 10' 8" 13,4" 13' 13' 10' 8" 10' 12'4" 12 6" NOT TO SCALE LiF 38 Paved Vehicle Tracking Control Cattle Guard Weld Points IA" I Beam Metal 24' Weld Points 4 10' B" NOT TO SCALE c fff 39 Paved Vehicle Tracking Control Sub-Surface Concrete Box 24' 8„ 18.. 4/ 4„ 3'4" 23'4" 4" - - 4.. _10" 4" NOT TO SCALE AL LW 40 Revegetation (RV) Description Revegetation involves planting seed to establish a vegetative cover in disturbed areas. Revegetation reduces erosion and sediment by stabilizing disturbed areas in a manner that is economical, adaptable to site conditions, and allows selection of the most appropriate plant material. Revegatation also: • Absorbs the impact of raindrops. • Reduces the velocity of runoff • Reduces runoff volumes by increasing water percolation into the soil. • Binds soil with roots. • Protects soil form wind. • Improves wildlife habitat. • Enhances natural beauty. Applicability Revegetation is most effective on slopes no steeper than 2:1. Revegetation may be used as a permanent control or a temporary control in areas where exposed soil surfaces are not to be regarded for periods longer than 30 days. Such areas include denuded areas, soil stockpiles, berms, temporary road banks, etc. Limitations The effectiveness of revegetation can be due to the following: • High erosion potential during establishment. 41 • The need for stable soil temperature and soil moisture content during germination and early growth. • The need to reseed areas that fail to establish. • Limited seeding times depending on the season. • Proper seedbed preparation and the use of quality seed are important in this practice. Failure to carefully follow sound agronomic recommendations will often result in an inadequate stand of vegetation that provides little or no erosion control. • Seeding does not immediately stabilize soils. Prior to seeding, install necessary erosion and sediment control practices such as diversions, straw bales, and basins until vegetation is established. Design Criteria Successful plant establishment can be maximized with proper planning; consideration of soil characteristics; selection of plant materials that are suitable for the site; adequate seedbed preparation, liming, and fertilization; timely planting; and regular maintenance. When to seed Areas to be stabilized with vegetation must be seeded or planted one to four months after grading is completed unless temporary stabilization measures are in place. Possible dates for seeding are as follows: Seed Mix Climate, soils, and topography are major factors that dictate the suitability of plants for a particular site. Vegetation that is adapted to the site, has strong roots, and provides good ground cover should be used. Although a native need mix is best some grasses, such as Vetiver, have been used extensively worldwide because of their strong, deep roots, adaptability, and non- invasive properties. Construction Specifications 1. Seeding does not immediately stabilize soils. Temporary erosion and sediment control measures should be in place o prevent off-site transport of sediments from disturbed areas until vegetation is established. 2. Vegetation should not be established on slopes that are unsuitable due to inappropriate soil texture, poor internal structure or internal drainage, volume of overland flow, or excessive steepness,until measures haven taken to correct these problems. 42 3. If the area has been recently loosened or disturbed, no further roughening is required. When the area is compacted, crusted, or hardened,the soil surface shall be loosened by disking, raking, harrowing, or other acceptable means to ensure good water infiltration and root penetration(see SURFACE ROUGHENING [SR]). 4. The soil on a disturbed site may need to be modified to provide an optimum environment for seed germination and seedling growth. To maintain a good stand of vegetation, the soil must meet certain minimum requirements as a growth medium. If any of the below criteria cannot be met then topsoil shall be applied. The existing soil must have these characteristics: • Enough fine-grained material to maintain adequate moisture and nutrient supply. • Sufficient depth of soil to provide an adequate root zone. The depth to rock or impermeable layers such as hardpans shall be 12 inches or more, except on slopes steeper than 2:1 where the addition of soil is not feasible. • A favorable pH range for plant growth. If the soil is so acidic that a pH range of 6.0-7.0 cannot be attained by addition of ph-modifying materials, then the soil is considered an unsuitable environment for plant roots and further soil modification would be required. • Freedom from toxic amounts of materials harmful to plant growth. • Freedom from excessive quantities of roots, branches, large stones, large clods, earth,or trash of any kind. Clods and stones may be left on slopes steeper than 3:1 if they do not significantly impede good seed soil contact. 5. Add fertilizer and/or lime, if necessary. Lime and fertilizer may be incorporated into the top two to four inches of the soil if possible. The addition of lime is equally as important as applying fertilizer. Lime will modify the pH and supply calcium and magnesium. Its effect on pH makes other nutrients more available to the plant. 6. The appropriate seed shall be evenly applied with a broadcast seeder, drill, cultipacker seeder or hydrosceder. Seeding depth should be 1/4 to 'A inch. 7. If necessary,apply mulch according to MULCHING (M). the mulch will hold moisture and modify temperature extremes, and prevent erosion while seedlings are growing. Maintenance Considerations 43 The frequency of inspections should be in accordance with the Storm Water Management Plan (SWMP). Vegetation is considered established when a density of at least 70 percent of pre- disturbance levels has been reached. Seeded areas should be inspected for failure and any necessary repairs and re-seedings should be made within the same season if possible. References Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff ControL Washington, D.C., February 2003. http://cfpud.epa.gov/npdes/stormwater/menufbmps/con site.cfm Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. Keller, Gordon and James Sherar, Low-Volume Roads Engineering, Best Management Practices Field Guide. United States Department of Agriculture (USDA), Forest Service, US Agency od International Development (USAID), 2005. httv://www.blm.gov/bmv/field%20guide.htm 44 Roadside Ditches (RSD) and Turnouts (TO) Description Roadside ditches are channels constructed parallel to roads. The ditches convey concentrated runoff of surface water from roads and surrounding areas to a stabilized outlet. Turnouts (also called wing ditches) are extensions of road side ditches. Turnouts effectively remove run- off water from the roadside ditch into well-stabilized areas before it reaches a waterway. Applicability • Roadside ditches should be used for all roads built on sloping topography and with either an inslope or a crowned design. • Ditch turnouts should be used as much as possible but their best use may be on slopes longer than 150ft or greater than 5%, as conditions allow. • Turnouts are applicable where fairly flat naturally vegetative areas exist at intervals by the roadside. Limitations • If these structures are not installed correctly they may become a source of erosion. • Road-side ditches do not necessarily filter sediment from runoff. • Turnouts should be on gradual slopes only. • Turnouts require vegetative cover or other filter at the discharge point. • Turnouts only work well if small volumes of runoff drain into the turnout. Turnouts should only receive runoff from the road and ditch surface, not from large, uphill watersheds. Design Criteria No formal design required. Construction Specifications 45 Roadside ditches 1. Roadside ditches should be constructed with no projections of roots, stumps, rocks, or similar debris. 2. Excavate ditches along roadside to a width and depth that can handle expected flow according to figure RAD-1. 3. All ditches shall have uninterrupted positive grade to an outlet. Slope ditch so that water velocities do not cause excessive erosion, but no less than 0.5%. If steep slopes and high velocities exist, use check dams to slow runoff and catch sediment. 4. To control erosion and collect sediment, construct aggregate check dams according to figure CD-1 of CHECK DAM (CD). 5. All ditches shall convey runoff to a sediment trapping device such as a SEDIMENT TRAP (ST) or an undisturbed, well vegetated and stabilized area at non-erosive velocity. 6. If necessary, stabilize ditches with RIPRAP (R) or EROSION CONTROL BLANKET (ECB). Turnouts 1. Use turnouts wherever possible and on undisturbed soil. 2. Turnouts should be on gradual slopes only and should slope gradually down from the bottom of the road-side ditch. 3. Angle turnout at approximately 30 degrees to the road-side ditch 4. Discharge turnout into well-vegetated area or install a secondary control such as a wattle, sediment trap, or silt fence. As a good rule of thumb, the vegetated outlet area should be a minimum of one half the size of the total drainage area draining into it. If well-vegetated outlets areas are not available, use culverts or other controls to direct runoff to a stabilized area. 5. Space turnouts according to slope as indicated on figure TO-1. 6. Turnouts only work well if small volumes of runoff drain into the turnout. Turnouts should only receive runoff from the road and ditch surface, not from large, uphill watersheds. 46 Maintenance Considerations The frequency of inspections should be in accordance with the Storm Water Management Plan (SWMP). Road ditches and turnouts should be inspected for any signs of channelization, and repaired as necessary. Structures will fail if water exists in channelized flow. Also inspect for sediment buildup at the outlet and at aggregate check dams and remove if necessary. References Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. Keller, Gordon and James Sherar, Low-Volume Roads Engineering, Best Management Practices Field Guide. United States Department of Agriculture (USDA), Forest Service, US Agency od International Development (USAID), 2005. http://www.blm.gov/bmp/field%20guide.htm United States Department of the Interior and United States Department of Agriculture. Surface Operating Standards and Guidelines for Oil and Gas Exploration and Development "Gold Book". BLM/WO/ST-06/021+3071. Bureau of Land Management (BLM). Denver, Colorado. Fourth Edition, 2006. Figure RSD-1 Roadside Ditch Installation LLrt SIfl • clew ` FCEr'H9� .. -.5 liea.. a3lnn;mis rhsd:erns zoo • •iJislr U, (101O1 t:SrYch rfrwAsiA;f• • • f 02. 20'4 la alab'ved able! NOT T.sc::.ea E 47 Figure TO-1 Turnout Layout 48 Silt Fence (SF) 50 X 50 WOOD SAKE -OE OR SLOPE — FABRIC SECTION B ;t 46 FABRIC STAKE B SLOPE TI .371om ' 750 � S-AKE A• I l ^i 45C =ABRIC SECTION A Ia- SILT FENCE JOINING ROLL TO ROLL SILT FENCE INSTALLATION AT SLOPE BASE DETAIL (PLAN VIEW) GREEN SILT FENCE FABRIC SC X 50 WOOD STAKE 5C X 50 WOOD STAKE FABRIC END STAKE DETAIL (PLAN VIEW) INSTALLATION TRENCH DETAIL (PLAN VIEW) Description Silt fences are used as temporary perimeter control around sites where there will be soil disturbance due to construction activities. They consist of a length of filter fabric stretched between anchoring post at regular intervals along the site perimeter. Applicability Silt fences are generally applicable to construction sites with relatively small drainage areas. They are appropriate in areas where runoff will be occurring as low-level shallow flow, not 49 exceeding 0.5cfs. The drainage area for silt fences generally should not exceed 0.25 acre per 100-foot fence length. Slope length above the fence should not exceed 100 feet. Limitations • Silt fence should not be installed along areas where rocks or other hard surfaces will prevent uniform anchoring of fence posts and entrenching of the filter fabric. This will greatly reduce the effectiveness of silt fencing and can create runoff channels leading offsite. • Silt fences are not suitable for areas where large amounts of concentrated runoff are likely. • Open areas where wind velocity is high may present a maintenance challenge, as high winds may accelerate deterioration of the filter fabric. • Silt fences should not be installed across streams, ditches, or waterways. • When the pores of the fence fabric become clogged with sediment, pools of water are likely to form on the uphill side of the fence. Location and design of the silt fence should account for this and care should be taken to avoid un-necessary diversion of storm water from these pools that might cause further erosion damage. Design Criteria The fence should be designed to withstand the runoff from a 10-year storm event. Construction Specifications 1. Erect silt fence according to figure SF-1. 2. If standard strength fabric is used in combination with wire mesh, the support posts should be spaced no more than 10 feet apart. If extra-strength fabric is used without wire mesh reinforcement, the support posts should be spaced no more than 6 feet apart. 3. Stakes used to anchor the filter fabric should either be wooden or metal. Wooden stakes should be at least three feet tall and have a minimum diameter of two inches if a hardwood such as oak is used. Softer woods such as pine should be at least four inches in diameter. When using metal post in place of wooden stakes, they should have a minimum weight of 1 to 1.331b/linear foot. If metals post are used, attachment points are needed for fastening the filter fabric using wire ties. The height of the fence post should be between 16 and 34 inches above the original ground surface. 50 4. Material for silt fences should be a pervious sheet of synthetic fiber such as polypropylene,nylon, polyester, or polyethylene yarn, chosen based on minimum synthetic fabric requirements, as shown in the following table: ' Physical Property _ Roqulrom¢nts Fillennc Efficiency „-8.5A (minmIDm).eighty i_e�een f Tensile Strength_at 209£ Stantland:c stony; local conditions ratr 30 lbs./linear inch (maximum)Elongation I (menimum) Extra Strength-50 Ms/linear inch _ mirnm amt Ultravioiet Radiation 90% (minimums __ ____ Slurry Flow Rate =.3 gal/ft`lmin tminirrusi i _j 5. Use a continuous roll of fabric to eliminate unwanted gaps in the fence. If a continuous roll of fabric is not available, the fabric should overlap from both directions only at the stakes or posts with a minimum overlap of six inches. 6, Extend silt fence across grade and upslope for a short distance. 7. Compact backfill at base of fabric. 8. Plow in or entrench the bottom of the fabric fence at least 6 inches below the ground surface. This will help prevent gaps from forming near the ground surface that would render the fencing useless as a sediment bather. Maintenance Considerations The frequency of inspections should be in accordance with the Storm Water Management Plan (SWMP). Inspect silt fences to ensure that they are intact and that there are no gaps at the fence- ground interface or tears along the length of the fence. If gaps or tears which impact the effectiveness of the silt fence are discovered, they should be repaired or the fabric should be replaced immediately. Accumulated sediments should be removed from the fence base when the sediment reaches 1/3 to 1/2 the height of the fence. Sediment removal should occur more frequently if accumulated sediment is creating noticeable strain on the fabric and there is the possibility of the fence failing from a sudden storm event. Removal Remove silt fences and all accumulated sediment after uphill drainage areas are stabilized by vegetation or other means. References 51 Colorado Department of Transportation (CDOT), Erosion Control and Stormwater Quality Guide. 2002. http://ww.dot.state.co.us/enviromental.envWaterQual/wgms4.asp Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February 2003. Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. Keller, Gordon and James Sherar, Low-Volume Roads Engineering, Best Management Practices Field Guide. United States Department of Agriculture (USDA), Forest Service, US Agency od International Development (USAID), 2005. http://www.bhn.eov/bmp/field%20euide.htm 52 Straw Bale (SB) — Straw Bale Placement in Swale (SBS) TRENCH EXCAVATION •I 7 Ilf�`r�� ;I IIi il�ll�� l�Jl` Arar' STRAW BALE INSTALLATION /- \ )Hil1 v I. it I,IdJI. MrFL p- NN SECTION I_;1:=- IIR 11 SB STRAW BALE 53 3'I=:,r'r G•'L3 L IA__ ',:_I _L l�__ II. STRAW BALE IN SWALES SECTION 4 b:. l .• '.III `F; 5'.L � '.L L::.LL'-_ `. • • 4 ' 4 w 4 STRAW BALE DOWNSTREAM SPACING STRAW BALE IN SWALES SECTION I i Irff-" SBS STRAW BALE PLACEMENT IN SWALE 54 Straw Bale Installation Notes I .. .. . •• •'._L I I. .. •::I iNA, : N F . ...A1A [AC N. It I A "HI -I IL .:._CI -P•_L L. .LI!A "!J NIC A1 C., WEED `.ND MILES RABLL 'LAN JS- 'CM .`..I '-iADC. WYnMINC, !AC\TANA. j-A H -- •� 1U:.t;9 a"4)-- D.= .. \C ONI CI-A I •.\. OA': '1 - "IF.f I -A F MU, A:i HA, ; . .. . - , II Y ', ',III I '. -4 A`. - ' HI ,-'F CA-E T -AT ,OAS I . ,,) ".. 1 AN `, R. S' .. 8'',!L : `. I :`,. 1 „I 11:1 _ ..-'IC: -1 C: 4 1. `• da -p:'�. .I.?..VA; V r-, .}1^„11.1 r C SC .I �,ND \0 1NI c I �,:.ANN \ I-.' .1 ,I�: •.il B%, . ' 1 X;:AVAT 'Al -t V (CA -III I ..,.11 2Aw I' A•., CJ64FP. L6. :'• F. 1 ..F'....-:=f =P.-: - =f.• �: . ,--BLS.. 55 Straw Bale Installation & Maintenance Notes I _ • ;-VcR✓ 1t )Atom., :hF 'I ': 'JN '.F1 '. N. • AI Lr2 f :':LI uvuN "IIAI F..II :'JL L ''.52`I ',SP'ECTOR. RA .'.A_"r ., AI<L LVLJ. CFJY 1 _."J'2JtLL) _*j A 'LC W I I IL <.I AT ... . a. 'ENAN F. _ ,I VA. C- T-FF �'A BA_F3 3-'.I .: ., ..`=1•JF:J.. 56 Straw Mulch (SM) o Description and Purpose Straw mulch consists of placing a uniform layer of straw and incorporating it into the soil with a studded roller or anchoring it with a tacldfier stabilizing emulsion. Straw mulch protects the soil surface from the impact of rain drops. preventing soil particles from becoming dislodged. Suitable Applications Straw mulch is suitable for soil disturbed areas requiring temporary protection until permanent stabilization is established. Straw mulch is typically used for erosion control on disturbed areas until soils can be prepared for permanent vegetation. Straw mulch is also used in combination with temporary and/or permanent seeding strategies to enhance plant establishment. 57 Limitations • Availability of straw and straw blowing equipment may be limited just prior to the rainy season and prior to storms due to high demand. • There is a potential for introduction of weed seed and unwanted plant material. ■ When straw blowers are used to apply straw mulch, the treatment areas must be within 150 ft of a road or surface capable of supporting trucks. • Straw mulch applied by hand is more time intensive and potentially costly. ■ Wind may limit application of straw and blow straw into undesired locations. • May have to be removed prior to permanent seeding or prior to further earthwork. ■ "Punching"of straw does not work in sandy soils.necessitating the use of taclafiers. Implementation • Straw shall be derived from wheat,rice, or barley. Where required by the plans. specifications.permits, or environmental documents. native grass straw shall be used. is A tackifier is the preferred method for anchoring straw mulch to the soil on slopes. • Crimping. punch roller-type rollers.or track walking may also be used to incorporate straw mulch into the soil on slopes. Track walking shall only be used where other methods are impractical. • Avoid placing straw onto roads. sidewalks,drainage channels.sound walls,existing vegetation. etc. ■ Straw mulch with tackifier shall not be applied during or immediately before rainfall. • In San Diego.use of straw near wood framed home construction has been frowned on by the Fire Marshall. 58 Application Procedures • Apply straw at a minimum rate of 4.0cm lb/acre.either by machine or by hand distribution. • Roughen embankments and fill rills before placing the straw mulch by rolling with a crimping or punching type roller or by track walking. • Evenly distribute straw mulch on the soil surface. • Anchor straw mulch to the soil surface by"punching" it into the soil mechanically (incorporating). Alternatively,use a tackifier to adhere straw fibers. • Methods for holding the straw mulch in place depend upon the slope steepness.accessibility. soil conditions.and longevity. - On small areas, a spade or shovel can be used to punch in straw mulch. - On slopes with soils that are stable enough and of sufficient gradient to safely support construction equipment without contributing to compaction and instability problems, straw can be"punched"into the ground using a knife blade roller or a straight bladed coulter.lunown commercially as a "crimper". - On small areas and/or steep slopes, straw am also be held in place using plastic netting or jute. The netting shall be held in place using 11 gauge wire staples.geotextile pins or wooden stakes as described in EC-7.Geotextiles and Mats. - A tackifier acts to glue the straw fibers together and to the soil surface. The tackifier shall be selected based on longevity and ability to hold the fibers in place. A tackifier is 59 typically applied at a rate of 125 lb"acre. In windy conditions,the rates are typically iSo lb/acre. Costs Average annual cost for installation and maintenance (3-4 months useful life)is 52.500 per acre. Application by hand is more time intensive and potentially costly. Inspection and Maintenance • Inspect BMPs prior to forecast rain.daily during extended rain events,after rain events. weekly during the rainy season. and at two-week intervals during the non-rain-season. ■ Areas where erosion is evident should be repaired and BMPs re-applied as soon as possible. Care should be exercised to minimize the damage to protected areas while making repairs.as any area damaged will require re-application of BMPs. • The key consideration in inspection and maintenance is that the straw needs to last long enough to achieve erosion control objectives. • Maintain an unbroken.temporary mulched ground cover while disturbed soil areas are inactive. Repair any damaged ground cover and re-mulch exposed areas. ■ Reapplication of straw mulch and tackifier may be required to maintain effective soil stabilization over disturbed areas and slopes. References Controlling Erosion of Construction Sites.Agricultural Information Bulletin 4347. C.S. Department of Agriculture(USDA).Natural Resources Conservation Service(NRCS)(formerly Soil Conservation Service —SOS). Guides for Erosion and Sediment Control in California.USDA Soils Conservation Service. January 1991. Manual of Standards of Erosion and Sediment Control Measures.Association of Bay Area Governments.May 1995. Soil Erosion by Water.Agricultural Information Bulletin t513. U.S. Department of Agriculture. Soil Conservation Service. Stonnwater Quality Handbooks Construction Site Best Management Practices(BMPs)Manual. State of California Department of Transportation(Caltrans),November 2000. Stormwater Management of the Puget Sound Basin.Technical Manual.Publication =91-75. Washington State Department of Ecology.February 1992. Water Quality Management Plan for the Lake Tahoe Region.Volume II. Handbook of Management Practices.Tahoe Regional Planning Agency.November 1988. 60 Vehicle Tracking Control (VTC) Description CATTLE GUARD A stabilized construction entrance (tracking pad) is a pad of gravel or cattle guard where construction traffic leave a site. The purpose of a stabilized entrance to a site is to minimize the amount of tracked mud and dust that leaves a site. As a vehicle drives over the gravel pad, mud and sediment are removed from the vehicle's wheels and offsite transport of soil is reduced. The gravel pad also reduces erosion and rutting in the soil beneath the stabilized structure. The filter fabric separates the gravel from the soil below, preventing the gravel from being ground into the soil. The fabric also reduces the amount of rutting caused by vehicle tires by spreading the vehicle's weight over a larger soil area than just the width of the tire. Applicability Typically, stabilizing a construction entrances are installed at locations where construction traffic leaves or enters an existing paved road. However, the applicability of site entrance stabilization should be extended to any roadway or entrance where vehicles will access or leave the site. Limitations • Although stabilizing a construction entrance is a good way to help reduce the amount of sediment leaving a site, some soil may still be deposited from vehicle tires onto paved surfaces. To further reduce the chance of these sediments polluting storm water runoff, sweeping of the paved area adjacent to the stabilized site entrance is recommended. • Site traps or other secondary sediment controls are needed to capture that sediment that accumulates at the pad and may run off during storm events. 61 Design Criteria RDA:. wt:TH REGI IRE E "NV WITH CR:S F4'LL is :TH „=Y:. F ; 7,I: TH, IV Exr•Et. F I I r.A7i;I iE -iITlat WHERE RE::r..IRE .Ir 6" LIFT CRUSHED ROCK FILTER IN . SE IN EC:ES,_ Construction Specifications See figure SCE-1 for installation details. • If the pad in constructed on a crowned road, a road side ditch with check dams or sediment traps be located on both sides of the road to collect runoff from the pad. If the road slopes to only one side of the road then only one roadside ditch with sediment controls will be needed. • Place a matrix of 2 to 4 inch washed stone, reclaimed or recycled concrete equivalent to a minimum of 12 feet wide and 20 feet in length. • All surface water flowing or diverted toward construction entrance shall be piped across the entrance. If piping is impractical, a mountable berm with 5:1 slopes will be permitted. 62 .r ./r -- - _ r. }• ir16 i4ZSF '.'L`I'Z={. .;{a Ir�:lNi. GG , A i.: �. a.F_...., j r ` ^„ �\`>. m,. j/� s x \ice• e...i, der r.: .ate r i w o t �_ ..a _ -.Mal »na T. ',.......„......I ^ i.N:Y' i'n. v.a a �1 It. rl.LL .‘l ...mt.- .I. v re -� 'I »yam ₹ * 1 :x.•E�..� Via. JIIL r r ,../.,..1.u.. t T utrr"MC mitc_yl •-II-,.,_ s.,-- ,-,1- _fir Yi .r u r of Y b .." .� 1 :Yla ... ! i s p .: . r. r . ,1 .__ a d.,,,,,.,d.,,d.,,,,,.,AA .» .. • . i • F a °r .. alla Maas 1,- ,. ' = Al - y J.I eras US FY" Afl-1 'v.', �. I.;; .LI - frail.. WI....ir]aa I`J-�,.• _ •vr. Y. w 1. N. W _ 1 • r'.! 1 • 1.r' r l : ' /' n ,.. _. a..:,i, we cis r Sj -r. P 1 63 Maintenance Considerations The frequency of inspections should be in accordance with the Storm Water Management Plan (SWMP). Stabilization of site entrances should be maintained until the remainder of the construction site has been fully stabilized. Stone and grave; might need to be periodically added to each stabilized construction site entrance to keep the entrance effective. Soil that is tracked offsite should be swept op immediately for proper disposal. References Colorado Department of Transportation (CDOT), Erosion Control and Stormwater Quality Guide. 2002. http://ww.dot.state.co.us/enviromental.envWaterQual/wgms4.asp Environmental Protection Agency (EPA), National Pollutant Discharge Elimination System (NPDES). Construction Site Storm Water Runoff Control. Washington, D.C., February 2003. http://cfpud.epa.gov/npdeslstonnwater/menufbmps/con site.cfm Horizon Environmental Services, Inc, Guidance Document Reasonable and Prudent Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites. April 2004. 64 Wattles (W) Description A wattle, (consist of straw, rock, flax, or other similar materials bound into a tight tubular roll. When wattles are placed at the toe and on the face of slopes, they intercept runoff, reduce its flow velocity, release the runoff as sheet flow, and provide removal of sediment from the runoff. By interrupting the length of a slope, fiber rolls can also reduce erosion. Applicability Wattles may be suitable: • Along the top, face, and at the grade breaks of exposed and erodible slopes to shorten slope length and spread runoff as sheet flow. • At the end of a downward slope where it transitions to a steeper slope. • Along the perimeter of a project. • At the overflow locations of s sediment traps. • As check dams in unlined ditches. • Around temporary stockpiles. Limitations • Wattles are not effective unless trenched. • Wattles at the toe of the slope greater than 5:1 (H:V) should be a minimum of 20 inch diameter or installations achieving the same protection (i.e., stacked smaller diameter wattles, etc.). • Difficult to move once saturated. • If not properly staked and trenched in, wattles could be transported in high flows. • Wattles have a very limited sediment capture zone. • Wattles should not be used on sloped subject to creep, slumping, or landslide. 65 • Wattles should not be used where periodic road or surface maintenance activities are expected. Design Criteria I ;:' n. . �1 s'il...`a- i.as... 11® ---. J�;I O ti • �N! \ *yd Yw UJ.t3inner ��'^� ` . . ...a...a .a..-, -.. :v . I. Construction Specifications Wattles should be either prefabricated rolls or rolled tubes of erosion control blankets. If using erosion control blankets, roll the length of erosion control blanket, roll the length of the blanket into a tube of minimum 8" diameter and bind roll at each end and every 4 feet along length of roll with jute type twine. See figure W-1 for wattles used to control erosion along slopes. 1. Locate wattles on level contours spaced as follows: a. Slope inclination of 4:1 or flatter: Fiber rolls should be placed at a maximum interval of 20 feet. b. Slope inclination between 4:1 and 2:1: Fiber rolls should be placed at a maximum of 15 feet. 66 c. Slope inclination 2:1 or greater: Fiber rolls should be placed at a maximum interval of 10 feet. 2. Turn the ends of the wattles up slope to prevent runoff from going around the roll. 3. Stake wattles into a 2 to 4 inch deep trench with a width equal to the diameter of the wattle. Drive stakes at the end of each wattle and spaced 4 feet maximum on center. 4. If more than one wattle is placed in a row, the rolls should be overlapped, not abutted. Maintenance Considerations The frequency of inspections should be in accordance with the Storm Water Management Plan (SWMP). Repair or replace split, torn, unraveling, or slumping rolls. If the wattle is used as a sediment capture device, or as an erosion control device to maintain sheet flows, sediment that accumulates must be periodically removed in order to maintain wattle effectiveness. Sediment should be removed when sediment accumulation reaches half the distance between the top of the wattle and the adjacent ground surface. Removal Wattles are typically left in place. If wattles are removed, collect and disposed of sediment accumulation, and fill and compact holes, trenches, depressions, or any other gorund disturbance to blend with adjacent ground. References California Stormwater Quality Association, Stormwater Best Management Practices(BMP) handbook-Construction. January, 2003. <http://www.cabmphandbooks.com/Construction.asp> 67 Wind Erosion Control (WEC) eiewn • Description and Purpose Wind erosion or dust control consists of applying water or other dust palliatives as necessary to prevent or alleviate dust nuisance generated by construction activities. Covering small stockpiles or areas is an alternative to applying water or other dust palliatives. Suitable Applications Wind erosion controls BMPs are suitable during the following construction activities: • Construction vehicle traffic on unpaved roads • Drilling and blasting activities • Sediment tracking onto paved roads • Soils and debris storage piles • Batch drop from front-end loaders • Areas with unstabilized soil 68 • Final grading/site stabilization Limitations • Watering prevents dust only for a short period and should be applied daily (or more often) to be effective. • Over watering may cause erosion. • Oil or oil-treated sub grade should not be used for dust control because the oil may migrate into drainageways and/or seep into the soil. • Effectiveness depends on soil, temperature, humidity, and wind velocity. • Chemically treated sub grades may make the soil water repellant, interfering with long- term infiltration and the vegetation/re-vegetation on the site. Some chemical dust suppressants may be subject to freezing and may contain solvents and should be handled properly. • Asphalt, as a mulch tack or chemical mulch, requires a 24-hour curing time to avoid adherence to equipment, worker shoes, etc. Application should be limited because asphalt surfacing may eventually migrate into the drainage system. • In compacted areas, watering and other liquid dust control measures may wash sediment or other constituents into the drainage system. Implementation General Recently, the State Air Resources Control Board has, under the authority of the Clean Air Act, started to address air quality in relation to inhalable particulate matter less than 10 microns (PM- 10). Approximately 90 percent of these small particles are considered to be dust. Existing dust control regulations by local agencies, municipal departments, public works department, and public health departments are in place in some regions within California. Many local agencies require dust control in order to comply with local nuisance laws, opacity laws (visibility impairment) and the requirements of the Clean Air Act. The following are measures that local agencies may have already implemented as requirements for dust control from contractors: • Construction and Grading Permits: Require provision for dust control plants. • Opacity Emission Limits: Enforce compliance with Colorado air pollution control laws. 69 • Increase Overall Enforcement Activities: Priority given to cases involving citizen complaints. • Maintain Field Application Records: Require records of dust control measures from contractor; • Stormwater Management Plan (SWMP): Integrate dust control measures into SWMP. Dust Control Practices Dust control BMPs generally stabilize exposed surfaces and minimize activities that suspend or track dust particles. For heavily traveled and disturbed areas, wet suppression (watering), chemical dust suppression, gravel asphalt surfacing, temporary gravel construction entrances, equipment wash-out areas, and haul truck covers can be employed as dust control applications. Permanent or temporary vegetation and mulching can be employed for areas of occasional or no construction traffic. Preventive measures would include minimizing surface areas to be disturbed, limiting onsite vehicle traffic to 15 mph, and controlling the number and activity of vehicles on a site at any given time. For chemical stabilization, there are many products available for chemically stabilizing gravel roadways and stockpiles. If chemical stabilization is used, the chemicals should not create any adverse effects on stormwater, plant life, or groundwater. Costs Installation costs for water and chemical dust suppression are low, but annual costs may be quite high since these measures are effective for only a few hours to a few days. Inspection and Maintenance • Inspect and verify that activity-based BMPs are in place prior to the commencement of associated activities. While activities associated with the BMP are under way, inspect weekly during the rainy season and at two-week intervals in the non-rainy season to verify continued BMP implementation. • Check areas protected to ensure coverage. • Most dust control measures require frequent, often daily, or multiple times per day attention. 70 an O bA •—I .- Cl 6 m b 5 O O S. U o-4th E G CI) © 0 CJ U d ai E Hello