Appendix C2 Stormwater Pollution Prevention Plan Framework

Appendix C2 Stormwater Pollution Prevention Plan Framework

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TABLE OF CONTENTS C2.1 Introduction... C2-1 C2.2 Purpose... C2-2 C2.3 Notification Requirements and Implementation... C2-2 C2.4 Project Modifications... C2-4 C2.5 Mitigation Measures... C2-4 C2.6 Mitigation Maintenance, Inspection, Repair, and Monitoring... C2-8 C2.7 Training... C2-8 C2.8 Postconstruction Stormwater Management... C2-8 C2.9 Literature Cited... C2-9 Energy Gateway South Transmission Project C2-i Plan of Development

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LIST OF ACRONYMS BIA BLM BMP Company EPA MS NOI NPDES POD Project SWPPP SW UPDES USFS Bureau of Indian Affairs Bureau of Land Management Best Management Practice PacifiCorp U.S. Environmental Protection Agency Municipal Sewer Notice of Intent National Pollutant Discharge Elimination System Plan of Development Energy Gateway South Transmission Project Stormwater Pollution Prevention Plan Stormwater protection measure Utah Pollutant Discharge Elimination System U.S. Forest Service Energy Gateway South Transmission Project C2-iii Plan of Development

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APPENDIX C2 STORMWATER POLLUTION PREVENTION PLAN FRAMEWORK C2.1 Introduction In compliance with criteria in the Environmental Protection Agency s (EPA) Clean Water Act, all construction site operators engaged in clearing, grading, and excavating activities that disturb 1 acre or more must obtain a National Pollutant Discharge Elimination System (NPDES) general permit for stormwater discharges (Code of Federal Regulations, Title 40, Parts 122 and 123). NPDES permits are issued by the EPA or a similar authorized state entity. In accordance with this requirement, the states of Wyoming, Colorado, and Utah each have issued a General Construction Permit for their respective states as follows: Wyoming: Wyoming Pollutant Discharge Elimination System General Permit WYR10-0000 Colorado: Colorado Discharge Permit System General Permit COR900000 Utah: Utah Pollutant Discharge Elimination System (UPDES) General Permit for Discharges UTRC00000 On tribal lands, storm water permits must be acquired through EPA Region VIII (Region 8) (NPDES, Federal Construction General Permit [2012 GCGP]). The EPA delegates the authority under the NPDES program to the individual states (except tribal lands) and as such, the NPDES permit obtained in each state is issued by the respective state s department of environmental quality or water quality. The discharge elimination permit is issued only after submittal of a Notice of Intent (NOI) for construction activities and preparation of a Stormwater Pollution Prevention Plan (SWPPP) that describes how erosion and sediment transport will be minimized to adjacent waterbodies. Measures to ensure construction activities comply with state and EPA requirements for stormwater management to be incorporated into the SWPPP are outlined in this plan framework. PacifiCorp (Company)/Construction Contractor(s) will be responsible for developing a SWPPP and obtaining coverage under the Storm Water General Permit for Construction Activities for each respective state agency by filing a NOI and appropriate fee with the appropriate agency in accordance with the NOI instructions. C2.1.1 Plan Framework Updates This plan framework will support the draft Plan of Development (POD) sufficiently to complete and execute the Bureau of Land Management (BLM) and U.S. Forest Service (USFS) Records of Decision, the BLM right-of-way grant, USFS special-use authorization, and the Bureau of Indian Affairs (BIA) encroachment permit and grant of easement for the Project. This plan framework serves as a baseline document to guide development of the complete SWPPP developed with the POD before issuance of the Notice(s) to Proceed and commencement of construction. The complete SWPPP will be developed by the Construction Contractor(s) in consultation with the Company and the agencies as detailed engineering design of the Project is completed and will contain the detailed information necessary for site-specific guidance. This plan framework provides Project-specific guidance for development of the complete SWPPP by identifying treatments and measures required to avoid, minimize, and mitigate Project-related impacts; prevent unnecessary degradation of the environment; ensure stormwater pollution prevention activities comply with federal, state, or other agency requirements; and meet any stipulations of the Records of Decision, BLM right-of-way grant, USFS special-use authorization, and BIA encroachment Energy Gateway South Transmission Project C2-1 Plan of Development

permit and grant of easement. The Company/Construction Contractor(s) will be responsible for preparing and implementing the complete SWPPP. C2.2 Purpose The purpose of a SWPPP for the Energy Gateway South Transmission Project (Project) is to identify and implement stormwater pollution prevention measures to reduce the quantity of impacted runoff and to deal with runoff in a manner minimizing environmental impacts during construction, operation, and maintenance of the Project. A SWPPP is needed to minimize the volume of contaminated runoff, including sediment runoff, and to implement mitigation measures in a manner minimizing environmental impacts. The SWPPP also will spell out design features of the Project for environmental protection specific to storing and handling fuel and oil, concrete, and all other hazardous materials (refer to Appendix C3 Spill Prevention Containment and Countermeasures Plan). Temporary stabilization methods are not guaranteed or fail-safe measures without regular maintenance and field inspection throughout construction activities. The SWPPP will outline the inspection schedule and inspection protocol for the Project. In addition to conventional methods of erosion control, there are numerous new and improved products, and the Construction Contractor(s) is encouraged to review these progressive or improved materials in the development and implementation of a SWPPP. Development, implementation, and maintenance of the SWPPP will provide the Construction Contractor(s) with the mechanisms for reducing soil erosion and minimizing pollutants in stormwater during construction. The proper implementation of mitigation measures associated with a SWPPP is imperative during all construction activities. These activities will be conducted in an environmentally sensitive and responsible manner so no discharge of sediment or contaminants may be conveyed as either direct or indirect discharge to wetlands or waters of the United States. C2.3 Notification Requirements and Implementation Before construction begins, the Company/Construction Contractor (s) will be responsible for developing a SWPPP and obtaining coverage under each state s respective Storm Water General Permit for Construction Activities by filing an NOI and appropriate fee with the appropriate state in accordance with NOI instructions. All SWPPPs must conform to the format set forth by the state. The Construction Contractor(s) will be responsible for implementing a SWPPP and will be required to perform routine inspections throughout the duration of construction activities. The primary intent of the erosion and sediment control measures is to control and minimize erosion at the source. For the Project, the main source of potential stormwater contamination will be erosion of soils from construction activities. It will be the responsibility of the Construction Contractor(s) to implement erosion control measures where necessary to minimize pollutants in stormwater and to keep the Project in compliance with state regulations. The SWPPP is meant to be a control document that identifies potential impacts and corrective actions through inspections and maintenance and also serves as a measure of final site stabilization as part of the requirements for contract termination once work has finished. A copy of the SWPPP shall remain at the multi-use construction yard(s), and be readily available while the Project is under construction, from the start of construction activities until completion of reclamation for the Project. Energy Gateway South Transmission Project C2-2 Plan of Development

The Construction Contractor(s) must retain a set of construction site maps for the duration of the Project and for 3 years after the Notice of Termination that delineate the following items: Areas of soil disturbance that have been stabilized Areas to be graded along with a time schedule Areas of potential soil erosion where control practices will be implemented Types of control practices and time schedule for implementation Locations of any postconstruction projects Copies of all inspections performed over the duration of the Project C2.3.1 Stormwater Pollution Prevention Plan Framework This SWPPP Framework serves as the baseline document for the development of a complete SWPPP to be developed by the Construction Contractor(s). The SWPPP should contain detailed information necessary for site-specific guidance. Following is the base format for the POD SWPPP Plan. 1. Contractor/management contact information. List all stakeholders and contact information. 2. Type of work and sequence of construction/schedule. Define the characteristics of the site and the type of construction that will be occurring. Address project components (pads, access roads, staging areas, etc.). 2.1 Clearing vegetation removal 2.2 Grading 2.3 Clean-up post construction 2.3.1 Installation of erosion control devices 2.3.2 Reclamation (see Appendix C1 Reclamation, Revegetation, and Monitoring Plan Framework) 3. Location of Disturbances 3.1 Disturbances. List total disturbance area with disturbance by state/agency (could be in table format). Include mapping for locations and any site-specific mapping. 3.2 Sensitive areas Discuss procedures in or around environmentally sensitive areas. Include residential areas. 3.3 Total new impervious surfaces/changes in run-off coefficient 4. Existing conditions 4.1 Topography 4.2 Vegetation 4.3 Regional drainage 4.3.1 Waterbodies. List rivers, lakes, watersheds, etc. Note if any watersheds have special restrictions. 4.3.1.1 Impaired Waters. Discuss any impaired waters within the project vicinity, including Total Maximum Daily Loads. 4.3.2 Wetlands 4.3.3 Municipal sewers (MS)/MS4. List any MS4s. 4.4 Soils 5. Best management practices (BMPs) 5.1 Erosion and sedimentation control measures. Describe the BMPs that will be implemented to control erosion and the release of pollutants in stormwater. Address each disturbance type. Energy Gateway South Transmission Project C2-3 Plan of Development

5.1.1 Temporary BMPs (to be removed after construction) 5.1.2 Permanent BMPs (long term BMPs or installed postconstruction) 5.2 Mitigation measures. Describe construction and postconstruction mitigation measures. Include the final stabilization/termination design to minimize erosion and prevent stormwater impacts after construction is complete. 5.2.1 Construction mitigation measures 5.2.2 Postconstruction mitigation measures 5.2.2.1 Recontour 5.2.2.2 Revegetation (refer to Appendix B4 Vegetation Management Plan) 6. Waste storage and management 7. Inspections and maintenance 7.1 Construction. Regular inspection schedule during construction, including reporting procedures and corrections protocol. 7.2 Postconstruction. Inspection schedule after construction, including reporting procedures and corrections protocol. 8. Report finalization and close-out C2.4 Project Modifications The Construction Contractor is responsible for maintaining an up-to-date SWPPP and shall amend the SWPPP whenever there is a change in construction or operations that may affect the discharge of pollutants to surface waters or groundwater. The SWPPP shall also be amended if it is in violation of the Storm Water General Permit for Construction Activities or has not achieved the general objective of eliminating pollutants in stormwater discharges. The SWPPP shall be amended and implemented in a timely manner but in no case more than 14 days after it has been determined the SWPPP is inadequate. All amendments should be dated and directly attached to the SWPPP. The Company must approve the SWPPP and any amendments. Up-to-date copies of the SWPPP must be maintained by the Construction Contractor(s) and will be provided to the Applicant on a monthly basis. A final SWPPP will be provided after Project close-out. C2.5 Mitigation Measures This section describes practices intended to protect potential environmental resources through the Project SWPPP. The protection measures described below include design features of the Project for environmental protection (Section C2.5.1) and selective mitigation measures (Section C2.5.2). C2.5.1 Design Features of the Project for Environmental Protection Following are design features of the Project for environmental protection to reduce potential impacts resulting from pollution to stormwater associated with the construction and operation of the Project. Design features for environmental protection are to be applied to all affected Project areas to help reduce potential impacts on stormwater. Listed below are stormwater-related design features to be implemented by the Construction Contractor(s) during construction of the Project facilities: Design Feature 2. In construction areas where there is ground disturbance or where recontouring is required, surface reclamation will occur as required by the landowner or land-management agency. The method of reclamation normally will consist of, but is not limited to, returning Energy Gateway South Transmission Project C2-4 Plan of Development

disturbed areas to their natural contour, reseeding, installing cross drains for erosion control, placing water bars in the road, and filling ditches. All areas on lands administered by federal agencies disturbed as a part of the construction and/or maintenance of the Project will be seeded with a seed mixture appropriate for those areas. The federal land-management agency will approve a seed mixture that fits each range type. Seeding methods typically will include drill seeding, where practicable; however, the federal landmanagement agency may recommend broadcast seeding as an alternative method in some cases. A Reclamation, Revegetation, and Monitoring Plan Framework identifying reclamation stipulations will be developed and incorporated into the POD, which will be approved by the affected federal land-management agency prior to the issuance of a right-of-way grant (BLM), special-use authorization (USFS), encroachment permit and grant of easement (BIA), etc. Design Feature 9. Based on preconstruction surveys and results of Section 7 consultation, state and federally designated sensitive plants, habitat, wetlands, riparian areas, springs, wells, water courses, or rare/slow regenerating vegetation communities will be flagged and structures will be placed to allow spanning of these features, where feasible, within the limits of standard structure design. Design Feature 17. In disturbed temporary work areas, the topsoil will be salvaged/segregated and distributed and contoured evenly over the surface of the disturbed area after construction completion. The soil surface will be seeded with an agency-approved seed mix and left rough to help reduce the potential for weeds and erosion. Design Feature 18. Grading will be minimized by driving overland in areas approved in advance by the land-management agency in predesignated work areas whenever possible. Design Feature 30. Hazardous material will not be drained onto the ground or into streams or drainage areas. Totally enclosed containment will be provided for all trash. All construction waste will be removed to a disposal facility authorized to accept such materials within 1 week of Project completion. A Spill Pollution Prevention, Containment, and Countermeasures Plan Framework, will be developed as part of the POD. Refueling and storing potentially hazardous materials will not occur within a 328-foot (100- meter) radius of a body of water in Utah and Colorado (500-foot [153-meter] radius in Wyoming), a 200-foot radius of all identified private water wells, and a 400-foot radius of all identified municipal or community water wells. Spill prevention and containment measures will be incorporated as needed. Design Feature 33. Consistent with BLM Riparian Management Policy, surface-disturbing activities within 328 feet (100 meters) of riparian areas (defined as areas of land directly influenced by permanent surface or subsurface water having visible vegetation or physical characteristics reflective of permanent water influence, including wetlands, stream banks, and shores of ponds or lakes) in Utah and Colorado will be required to meet exception criteria defined by the BLM, such as acceptable measures to protect riparian resources and habitats by avoiding or minimizing stormwater runoff, sedimentation, and disturbance of riparian vegetation, habitats, and wildlife species. In Wyoming, surface-disturbing activities within 500 feet (153 meters) of all perennial waters and/or wetland and riparian areas and 100 feet (30 meters) of all ephemeral channels also will be required to meet exception criteria in association with the BLM Rawlins Field Office Resource Management Plan (BLM 2008). Mitigation measures will be developed on Energy Gateway South Transmission Project C2-5 Plan of Development

a site-specific basis, in consultation with the affected federal land-management agency, and incorporated into the POD. If any disturbance is anticipated within 20 feet of the edge of a riparian area or other wetland habitat, a silt fence or certified weed-free wattle will be installed along the travel route on the wetland side unless the wetland is up-gradient. Design Feature 36. Crossings of dry washes will be made during dry conditions, when possible. Repeated crossings will be limited to the extent possible but made at the same locations, if possible. Design Feature 37. If a riparian crossing were required during wet periods with saturated soil conditions, vehicles will not be allowed to travel when soils are moist enough for deep rutting (4 or more inches deep or a more stringent requirement as identified in individual resource management plans) to occur unless prefabricated equipment pads were installed over the saturated areas or other measures were implemented to prevent rutting. Equipment with lowground-pressure tires, wide tracks, or balloon tires will be used when possible. C2.5.2 Selective Mitigation Measures Recommended selective mitigation measures to be applied on a site-specific basis to prevention pollution to stormwater include the following to be implemented by the Construction Contractor(s): Selective Mitigation Measure 1 (Minimize/Avoid Disturbance to Sensitive Soils and Vegetation). In areas where soils and vegetation are particularly sensitive to disturbance, existing roads/two-tracks to be used for construction and maintenance will not be widened or otherwise upgraded, to the extent practicable. To allow construction equipment access to work areas where the equipment will extend beyond the width of the existing roads, the construction equipment will straddle the road traveling on the road s shoulder only where terrain and soil conditions will allow for safe operation/transport of the equipment (cranes, cement trucks, etc.). Landmanagement agencies will work with the Company to determine the extent these existing roads can be modified versus fully upgraded to ensure the roads/two-tracks are passable and safe for the equipment and construction and maintenance personnel. Selective Mitigation Measure 3 (Minimize Slope Cut and Fill). The alignment of any new access roads or cross-country routes in designated areas will follow the landform contours where practicable to minimize ground disturbance and/or reduce scarring (visual contrast) of the landscape, providing that such alignment does not impact other resource values. In addition to reducing ground disturbance associated with the construction of new access roads, modification to the size and/or configuration of the structure work areas facilitated by minor structure design adjustments will allow cut and fill slopes to be minimized and contoured to blend with existing topography to the extent practicable. Selective Mitigation Measure 5 (Minimize New or Improved Accessibility). To limit new or improved access into the Project area, as well as earthwork associated with the construction of tower pads in extremely steep terrain, all new or improved and structure work areas not required for maintenance will be closed or rehabilitated using the most effective and least environmentally damaging methods appropriate to that area and developed through consultation with the landowner or land-management agency. Methods for road closure or management include installing and locking gates, obstructing the path, revegetating and mulching the surface of the roadbed to make it less apparent, restoring the road to its natural contour and vegetation, or Energy Gateway South Transmission Project C2-6 Plan of Development

constructing waterbars to ensure proper drainage. Tower pads will be contoured to blend with existing grade and revegetated to the extent practicable to reduce their visual dominance in steep terrain. Selective Mitigation Measure 10 (Helicopter-assisted Construction). Helicopter-assisted placement of towers during construction and helicopter patrol and maintenance may be used where practicable to reduce surface impacts in environmental constraint areas or steep terrain locations. Selective Mitigation Measure 11 (Minimize Right-of-way Clearing). Clearing of the right-ofway will be minimized to avoid environmental resources and reduce visual contrast. In select areas, the width of vegetation clearing in the right-of-way may be modified (within the limits of Appendix B4 Vegetation Management Plan and standard tower design), and/or current land uses will be allowed to continue unabated, provided the use meets applicable standards. Selective Mitigation Measure 13 (Overland Access). The Construction Contractor will use overland access to the greatest extent possible in areas where no grading will be needed to access work areas. Overland access will consist of drive-and-crush and/or clear-and-cut travel (removal of all vegetation while leaving the root crown intact to improve or provide suitable access for equipment). Prior to commencement of work activities, overland access routes will be staked to a minimum width of 14 feet. Routes will be specified in the POD. Use of overland access routes will be restricted based on dry or frozen soil conditions, seasonal weather conditions, and relatively flat terrain. C2.5.3 Other Specific Stipulations and Methods Stormwater protection measures (SW) used to ensure construction activities comply with NPDES and state requirements for stormwater management to be incorporated into the SWPPP include: SW-1 SW-2 SW-3 SW-4 SW-5 SW-6 SW-7 The SWPPP will identify areas with critical erosion conditions that may require special construction activities or additional industry standards to minimize soil erosion. Migration of construction-related sediment to all adjacent surface waterbodies will be prevented. Stormwater industry standards will be maintained on all disturbed lands during construction activities as described in the SWPPP. Approved sediment and erosion control industry standards will be installed and maintained until disturbed areas meet final stabilization criteria as defined in the POD. Temporary industry standards will be used to control erosion and sediment at multi-use construction yards (equipment storage yards, fly yards, multi-use construction areas) and substations. The construction schedule may be modified to minimize construction activities in rainsoaked or muddy conditions. Existing roads and trails will be used for travel to the maximum extent feasible unless otherwise authorized. During wet road conditions, any ruts deeper than 4 inches remaining on the roads from the Project will be repaired at the respective federal land-management agencies Authorized Officer s (or their designated representative s) discretion. Upon completion of construction, 70 percent of the disturbed area of the Project will be revegetated with approved vegetation (refer to Appendix C1 Reclamation, Revegetation, Energy Gateway South Transmission Project C2-7 Plan of Development

SW-8 and Monitoring Plan Framework) as required by the UPDES Storm Water General Permit for Construction Activities and in accordance with the SWPPP. The specific areas to be revegetated will be coordinated with and approved by the federal land-management agencies. In areas of drought susceptible soils, the soil surfaces will be mulched and stabilized to minimize wind erosion and to conserve soil moisture. C2.6 Mitigation Maintenance, Inspection, Repair, and Monitoring The Construction Contractor(s) will be required to conduct routine maintenance and emergency repairs on any structural controls, including the maintenance of erosion and sediment control measures and any required subsequent reporting. As part of the SWPPP, the Construction Contractor(s) will be required to develop an inspection schedule and conduct routine inspections to identify conditions that could lead to discharges of chemicals or contact of stormwater with storm drainages or surface waters. Schedules will be established for regular inspections of equipment and areas. Inspections of the construction site shall occur within 24 hours following any rainfall event of 0.5 inch or greater to identify areas contributing to a stormwater discharge and to evaluate whether industry standards are in place and functioning properly. For storm events with extended durations, observations shall be performed every 24 hours. During inspections, the Construction Contractor(s) also will determine if the industry standards identified in the SWPPP are adequate and whether additional control practices are needed. All monitoring and inspection records that have been produced in association with this SWPPP will be retained for a period of at least three years. C2.7 Training The Construction Contractor(s) will be responsible for the SWPPP implementation, amendments, and revisions. Onsite construction personnel will be responsible for installation and maintenance of onsite mitigation measures. Properly trained personnel are more capable of preventing spills, responding safely and effectively to accidents, and recognizing situations that could lead to stormwater contamination. The Construction Contractor(s) will be responsible for familiarizing their personnel with the information contained within the SWPPP. Training meetings will need to be held for new personnel who join the Project after the initial training has been provided. The purpose of these meetings will be to review the proper installation methods and maintenance of all erosion control measures to be used for the Project. The monitoring/inspection program and all required maintenance and repair will be conducted by trained personnel. C2.8 Postconstruction Stormwater Management Mitigation measures used to reduce pollutants in stormwater discharges after all construction phases have been completed at the sites should take into account local postconstruction stormwater management requirements, policies, and guidelines, as well as site-specific and seasonal conditions. Postconstruction mitigation measures will be assessed during future line maintenance. During Project maintenance, any areas disturbed by the line installation observed to be eroding sediment into drainages will be assessed for the appropriate permanent mitigation measure to control sediment movement off the disturbed area. Disturbed areas also will be reclaimed per Appendix C1 Reclamation, Revegetation, and Monitoring Plan Framework. Energy Gateway South Transmission Project C2-8 Plan of Development

C2.9 Literature Cited Bureau of Land Management. 2008. Record of Decision and Approved Rawlins Resource Management Plan. Rawlins Field Office, Wyoming. Energy Gateway South Transmission Project C2-9 Plan of Development

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