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HomeMy WebLinkAboutEFC_SEPAChecklist_260611_v1SEPA Environmental checklist September 2023 Page 1 (WAC 197-11-960) SEPA 1 Environmental Checklist Purpose of checklist Governmental agencies use this checklist to help determine whether the environmental impacts of your proposal are significant. This information is also helpful to determine if available avoidance, minimization, or compensatory mitigation measures will address the probable significant impacts or if an environmental impact statement will be prepared to further analyze the proposal. Instructions for applicants This environmental checklist asks you to describe some basic information about your proposal. Please answer each question accurately and carefully, to the best of your knowledge. You may need to consult with an agency specialist or private consultant for some questions. You may use “not applicable” or “does not apply” only when you can explain why it does not apply and not when the answer is unknown. You may also attach or incorporate by reference additional studies reports. Complete and accurate answers to these questions often avoid delays with the SEPA process as well as later in the decision-making process. The checklist questions apply to all parts of your proposal, even if you plan to do them over a period of time or on different parcels of land. Attach any additional information that will help describe your proposal or its environmental effects. The agency to which you submit this checklist may ask you to explain your answers or provide additional information reasonably related to determining if there may be significant adverse impact. Instructions for lead agencies Please adjust the format of this template as needed. Additional information may be necessary to evaluate the existing environment, all interrelated aspects of the proposal and an analysis of adverse impacts. The checklist is considered the first but not necessarily the only source of information needed to make an adequate threshold determination. Once a threshold determination is made, the lead agency is responsible for the completeness and accuracy of the checklist and other supporting documents. Use of checklist for nonproject proposals For nonproject proposals (such as ordinances, regulations, plans and programs), complete the applicable parts of sections A and B, plus the Supplemental Sheet for Nonproject Actions (Part D). Please completely answer all questions that apply and note that the words "project," "applicant," and "property or site" should be read as "proposal," "proponent," and "affected geographic area," respectively. The lead agency may exclude (for non- projects) questions in “Part B: Environmental Elements” that do not contribute meaningfully to the analysis of the proposal. 1 https://ecology.wa.gov/Regulations-Permits/SEPA/Environmental-review/SEPA-guidance/Checklist-guidance SEPA Environmental checklist September 2023 Page 2 (WAC 197-11-960) A. Background Find help answering background questions2 1. Name of proposed project, if applicable: SWARR Station Security Perimeter Maintenance Project 2. Name of applicant: Puget Sound Energy, Inc. 3. Address and phone number of applicant and contact person: Kathryn Hodges Elaine Babby 206.549.7606 425.462.3805 4. Date checklist prepared: May 2026 5. Agency requesting checklist: City of Renton 6. Proposed timing of schedule (including phasing, if applicable): Design Q3 2025 through Q1 2026 Permitting Q2-Q3 2026 Construction Q3 2026 7. Do you have any plans for future additions, expansion, or further activity related to or connected with this proposal? If yes, explain. PSE has no plans for future additions or expansions at SWARR. As a regulated utility managing a dynamic energy system, PSE may propose additional maintenance and operational modifications as needed to keep this facility operating safely. PSE would coordinate any such efforts with the city of Renton. List any environmental information you know about that has been prepared, or will be prepared, directly related to this proposal. Arborist Report 2 https://ecology.wa.gov/Regulations-Permits/SEPA/Environmental-review/SEPA-guidance/SEPA-checklist-guidance/SEPA-Checklist-Section-A-Background SEPA Environmental checklist September 2023 Page 3 (WAC 197-11-960) Stream Assessment Geologically Hazardous Areas Report Targeted Drainage Report Do you know whether applications are pending for governmental approvals of other proposals directly affecting the property covered by your proposal? If yes, explain. No other applications are known to be pending for other proposals affecting the subject property. 8. List any government approvals or permits that will be needed for your proposal, if known. City of Renton Fence Variance, Building Permit, potential Construction Stormwater General Permit coverage from Department of Ecology. 9. Give brief, complete description of your proposal, including the proposed uses and the size of the project and site. There are several questions later in this checklist that ask you to describe certain aspects of your proposal. You do not need to repeat those answers on this page. (Lead agencies may modify this form to include additional specific information on project description.) PSE proposes to perform maintenance and repair at the existing SWARR Station, a natural gas system 'peak shaving' facility that is designed to provide supplemental capacity to the natural gas system during periods of peak demand or system disruption. The developed area is limited to the central portion of the property, covering an area approximately 5 acres in size, with the remainder of the property to the north and south undeveloped. The developed portion of the site consists of a level area containing buried tanks and piping (covered with turf grass), outdoor processing equipment, a single-story building (approximately 5,000 square feet), access driveways and small parking area. With the exception of the south side of the parcel, which borders single family residential property, the entire parcel is bordered by South Puget Drive and Benson Drive South. The developed area is currently surrounded by an existing chain link perimeter fence with barbed wire. The fence is antiquated and damaged in places, and a number of security breaches have occurred in recent years. To protect the property and associated critical infrastructure against unauthorized access, theft, vandalism and other threats, PSE plans to perform maintenance on the physical security perimeter. Fencing, gates, security equipment and associated electrical and network equipment will be replaced. 10. Location of the proposal. Give sufficient information for a person to understand the precise location of your proposed project, including a street address, if any, and section, township, and range, if known. If a proposal would occur over a range of area, provide the range or boundaries of the site(s). Provide a legal description, site plan, vicinity map, and SEPA Environmental checklist September 2023 Page 4 (WAC 197-11-960) topographic map, if reasonably available. While you should submit any plans required by the agency, you are not required to duplicate maps or detailed plans submitted with any permit applications related to this checklist. The street address is 2100 Benson Drive South, Renton, WA 98055. The property is located in the SW Quarter of Section 20; Township 23; Range 5 E. W. M. See attached vicinity map for additional information. Abbreviated Legal Description: BEG AT SW COR OF SW 1/4 TH N 501.87 FT TH N 87-09-25 E 70.26 FT TO TPOB TH N 02-06- 30 E 1666.90 FT TH N 74-32-17 E 144.09 FT TO WLY MGN OF RDWY TH SLY ALG SD RDWY 1352.705 FT TH S 21-20-40 E 429.865 FT TH S 87-09-25 W 801.99 FT TO TPOB LESS ST HWY - - TCO 17-1232 B. Environmental Elements 1. Earth Find help answering earth questions3 a. General description of the site: The project site is situated in the southern portion of a 16.71 acre triangular parcel (tax lot 2023059071) bordered by Benson Drive South and South Puget Drive. The site is located in a northwest-southeast trending drainage of Rolling Hills Creek. The developed portion of the site is bounded by a gently sloping (slope gradients between 5 to 15 percent) forested area to the north, by steep slopes (slope gradients ranging between 40 to 65 percent) up to South Puget Drive and businesses to the east, by gentle slopes (slope gradients between 5 to 20 percent) down to single-family residential developments to the south, and to the west by steep slopes (slope gradients ranging between 40 to 70 percent) up to Benson Drive South, the PSE Seattle South Gate Station, tennis courts, single-family residential developments and forested areas. Slopes around the developed portion of the site are vegetated with evergreen and deciduous trees and shrubs, blackberries, ivy, grass and other understory vegetation. Existing facilities located near the center of the project site include a one-story metal sided building, natural gas piping and aboveground storage tanks situated on a gravel surface. Existing underground storage tanks are located on the north side of the developed area where the ground surface is turf grass. The south side of the project site contains the main driveway into the site, a parking area, underground natural gas pipelines (owned by Williams and PSE), forested habitat with little understory 3 https://ecology.wa.gov/regulations-permits/sepa/environmental-review/sepa-guidance/sepa-checklist-guidance/sepa-checklist-section-b-environmental-elements/environmental-elements-earth SEPA Environmental checklist September 2023 Page 5 (WAC 197-11-960) vegetation and maintained areas of turf grass. The northern portion of the parcel (outside of the fenced facility) is undeveloped and forested with shrub understory. The original construction of the SWARR Station facilities resulted in the relatively flat to gently sloping ground surface between approximately elevation 160 above mean sea level (MSL) to approximately 150 feet above MSL from south to north. The project area is approximately 10 to 30 feet lower in elevation than Benson Drive South on the west side of the site and between approximately 50 and 90 feet lower in elevation than South Puget Drive on the east. Circle or highlight one: Flat, rolling, hilly, steep slopes, mountainous, other: The overall site topography slopes north, with the west edge of the property sloping down towards the east and the east edge of the property sloping down to the west. The developed portion of the site is situated on a developed flat pad; see site plan for more details. b. What is the steepest slope on the site (approximate percent slope)? The steepest slopes (slope gradients ranging between 40 to 70 percent) on the site are located to the west of the developed area and include the cut/fill slopes up to Benson Drive South. c. What general types of soils are found on the site (for example, clay, sand, gravel, peat, muck)? If you know the classification of agricultural soils, specify them, and note any agricultural land of long-term commercial significance and whether the proposal results in removing any of these soils. The NRCS Web Soil Survey (USDA-NRCS 2021a) shows two types of soil on site: Alderwood gravelly sandy loam, 15 to 30 percent slopes and Beausite gravelly sandy loam, 6 to 15 percent slopes. Based on previously soil explorations completed between .5 to 2.5 feet below grade, subsurface conditions consist of fill and glacial till. The fill is likely regraded glacial till and both the fill and glacial till consist of sand with variable silt and gravel content. d. Are there surface indications or history of unstable soils in the immediate vicinity? If so, describe. There are no indications or history of unstable soils in the immediate site vicinity. e. Describe the purpose, type, total area, and approximate quantities and total affected area of any filling, excavation, and grading proposed. Indicate source of fill. Earthwork will include the following construction activities: SEPA Environmental checklist September 2023 Page 6 (WAC 197-11-960) Activity Land Disturbance Area (sf) Fill/Cut (cy) Grade ground level 1,250 5/5 between gate posts Remove blackberry; 430 N/A replace with turf grass Conduit Trenching 760 38/40 Fence Post Holes 760 0/125 Totals 3,200 43/170 f. Could erosion occur because of clearing, construction, or use? If so, generally describe. There could be a temporary increase in erosion as soil is disturbed and stockpiled during construction. g. About what percent of the site will be covered with impervious surfaces after project construction (for example, asphalt or buildings)? No new impervious surface will be installed as part of site maintenance activities. h. Proposed measures to reduce or control erosion, or other impacts to the earth, if any. Temporary erosion and sedimentation control (TESC) best management practices (BMPs) appropriate for the site will be employed. Examples of potential BMPs include maintaining the existing paved and gravel driveway and parking areas, installing a stabilized construction entrance or staging area as needed, using mats to access vegetated areas as needed, installation of catch basin inlet protection, compost socks and straw wattles, plastic sheeting covering any soil stockpiles, placing temporary and permanent mulch and seed, implementing BMPs for asphalt sawcutting, concrete handling and washout areas, protecting existing vegetation and surface conditions, and minimizing vegetation trimming and tree cutting necessary to protect the facilities and for operation of the security system. SEPA Environmental checklist September 2023 Page 7 (WAC 197-11-960) 2. Air Find help answering air questions4 a. What types of emissions to the air would result from the proposal during construction, operation, and maintenance when the project is completed? If any, generally describe and give approximate quantities if known. During construction, minor temporary emissions would result from vehicles and equipment. During operations and maintenance once construction is complete, there will be no emissions associated with the replaced equipment and fencing. b. Are there any off-site sources of emissions or odor that may affect your proposal? If so, generally describe. Not applicable; the proposed maintenance work will not be affected by emissions or odor. c. Proposed measures to reduce or control emissions or other impacts to air, if any: Construction equipment and vehicles will meet required emission standards for their class. 3. Water 5Find help answering water questions6 a. Surface: Find help answering surface water questions7 Based on information available from the City of Renton (COR), the site is within the COR Flow Control Duration Standard (matching forested conditions) and within the Black River drainage basin. The project does not contain nor is it adjacent to an aquifer protection area. Land use in the area includes residential development zoned R-8. According to the COR Utility Geographic Information System (GIS) data, there are multiple stormwater discharge points that direct water towards the SWARR Station parcel. Surface water along Benson Drive South collects within curbside gutters and enters three catch basins located on the east side of Benson Drive South Road adjacent to the west side of the project parcel. Stormwater along this portion of Benson Drive South, as well as stormwater from the north side of Benson Drive South, South 21st Street and South 19th Street, flows into the stormwater drainage system and discharges 4 https://ecology.wa.gov/Regulations-Permits/SEPA/Environmental-review/SEPA-guidance/SEPA-checklist-guidance/SEPA-Checklist-Section-B-Environmental-elements/Environmental-elements-Air 6 https://ecology.wa.gov/Regulations-Permits/SEPA/Environmental-review/SEPA-guidance/SEPA-checklist- guidance/SEPA-Checklist-Section-B-Environmental-elements/Environmental-elements-3-Water 7 https://ecology.wa.gov/Regulations-Permits/SEPA/Environmental-review/SEPA-guidance/SEPA-checklist-guidance/SEPA-Checklist-Section-B-Environmental-elements/Environmental-elements-3-Water/Environmental-elements-Surface-water SEPA Environmental checklist September 2023 Page 8 (WAC 197-11-960) onto the PSE property at a point outside of the northwest corner of the proposed work area. Evidence of water sheet flow (fine sediments, organic matter accumulation) from the discharge point that flows northeast through the northwest corner of the existing fence line towards Rolling Hills Creek. This sheet flow either infiltrates or eventually flows into Rolling Hills Creek. Surface water along South Puget Drive adjacent to the site is collected within curbside gutters and enters two catch basins located on the east and west sides of South Puget Drive. Water flows into the east catch basins and flows directly to the west side of South Puget Drive which discharge stormwater onto the slopes on the east side of the project area. Plastic piping has been installed on the site slopes to capture the discharged water and transport it to the base of the slopes. The water then flows into the half-rounds that have been installed on the east side of the site access the road to convey the water along the toe of the slopes to the northeast corner of the site where the water flows into an existing catch basin and then discharges to Rolling Hills Creek on the north side of the developed site. Surface water near the intersection of South Puget Drive and Benson Road South enters a series of catch basins located near the intersection. This water then flows through the stormwater drain system and discharges to the slopes southeast of the project area into a tributary that directs flow westward towards Rolling Hills Creek. However, due to natural topography, water does not directly enter the stream and evidence of standing water is located just east of the south portion of the site where Rolling Hills Creek enters the culvert. 1. Is there any surface water body on or in the immediate vicinity of the site (including year-round and seasonal streams, saltwater, lakes, ponds, wetlands)? If yes, describe type and provide names. If appropriate, state what stream or river it flows into. Rolling Hills Creek flows north through the project area but is located within a culvert under the developed portion of the subject property. The stream is mapped as fish bearing and Washington Department of Natural Resources (DNR) maps show the creek flowing north and west into the Black River. City of Renton maps depict the creek as flowing north and west and discharging into Springbrook Creek. Springbrook Creek discharges into the Black River, which flows into the Green River, which becomes the Duwamish River and eventually discharges into the Puget Sound. 2. Will the project require any work over, in, or adjacent to (within 200 feet) the described waters? If yes, please describe and attach available plans. Yes, the project will require work adjacent to the Creek. The fence will be placed near the culvert entrance on the south portion of the project area and up-slope from the culvert outlet on the north portion of the project area. However, the fence will be placed over the culverted portions of the stream within the previously impacted portions of the site and will not affect the buffer. SEPA Environmental checklist September 2023 Page 9 (WAC 197-11-960) 3. Estimate the amount of fill and dredge material that would be placed in or removed from surface water or wetlands and indicate the area of the site that would be affected. Indicate the source of fill material. No fill or dredge materials will be placed in or removed from Rolling Hills Creek. 4. Will the proposal require surface water withdrawals or diversions? Give a general description, purpose, and approximate quantities if known. There are no plans for surface water withdrawals or diversions as part of this proposal. 5. Does the proposal lie within a 100-year floodplain? If so, note location on the site plan. The proposed project is not located within a 100-year floodplain. 6. Does the proposal involve any discharges of waste materials to surface waters? If so, describe the type of waste and anticipated volume of discharge. No discharge of waste material will occur to surface waters as a result of the project. b. Ground: Find help answering ground water questions8 Ten monitoring wells were installed at the site between 2003 and 2007 as part of a previous study at the site. The most recent groundwater levels were measured in the wells during monitoring events in September 2010 and March 2011. Depths to groundwater measured in the vicinity of the storage and pumping ranged from approximately 2.7 to 11.4 feet below the ground surface (bgs) in September 2010 and March 2011. Depths to groundwater measured in the upgradient well located on the south side of the site entrance driveway ranged from approximately 7.8 to 17.8 feet bgs. Depths to groundwater measured in the downgradient well in the northeast corner of the developed site ranged from approximately 14.3 to 22.4 feet bgs. Seasonal fluctuation of groundwater levels (higher levels in the spring) is common throughout western Washington. Based on the depths to groundwater and groundwater elevations in the wells, the shallow groundwater flow direction at the site was to the northeast during the September 2010 and March 2011 monitoring events. This flow direction is 8 https://ecology.wa.gov/Regulations-Permits/SEPA/Environmental-review/SEPA-guidance/SEPA-checklist-guidance/SEPA-Checklist-Section-B-Environmental-elements/Environmental-elements-3-Water/Environmental-elements-Groundwater SEPA Environmental checklist September 2023 Page 10 (WAC 197-11-960) consistent with previous monitoring events evaluated since 2005 and reflects the topographic slope at the site. Based on our review of information from the COR, the project site is not located within a Wellhead Protection Area mapped by the COR. 1. Will groundwater be withdrawn from a well for drinking water or other purposes? If so, give a general description of the well, proposed uses and approximate quantities withdrawn from the well. Will water be discharged to groundwater? Give a general description, purpose, and approximate quantities if known. No groundwater will be withdrawn from any wells. 2. Describe waste material that will be discharged into the ground from septic tanks or other sources, if any (domestic sewage; industrial, containing the following chemicals…; agricultural; etc.). Describe the general size of the system, the number of such systems, the number of houses to be served (if applicable), or the number of animals or humans the system(s) are expected to serve. No waste material will be discharged into the ground. c. Water Runoff (including stormwater): 1. Describe the source of runoff (including storm water) and method of collection and disposal, if any (include quantities, if known). Where will this water flow? Will this water flow into other waters? If so, describe. Source of runoff may include stormwater runoff from precipitation during construction. It is unlikely that stormwater runoff will need to be collected and disposed of during construction because stormwater readily infiltrates into the permeable site soil. Stormwater collected after construction will be released to current stormwater facilities. Dewatering is not anticipated as part of the project at this time. However, dewatering may be required if unseasonably heavy precipitation occurs during construction, or if groundwater is encountered within the excavations. If needed, water will be removed from excavations using submersible pumps. Dewatering water will be discharged through sediment bags to a dry, stable, vegetated area for infiltration. Straw wattles, compost socks or gravel or sand bag berms will be used to slow discharged water flow for infiltration. Water may also be removed using vacuum trucks and discharged off site at an approved disposal facility. Appropriate pumping methods are to be determined by the Contractor depending on site conditions and needs. Extra pumps will be on-site to control stormwater runoff in the event of primary pump failure. 2. Could waste materials enter ground or surface waters? If so, generally describe. SEPA Environmental checklist September 2023 Page 11 (WAC 197-11-960) No, waste materials will not enter ground or surface waters. BMPs will be implemented for asphalt pavement sawcut activities and for concrete handling and washout areas. Concrete will be used for fence post foundations. 3. Does the proposal alter or otherwise affect drainage patterns in the vicinity of the site? If so, describe. Minor changes to drainage patterns on the site could result, however in-kind surface restoration will take place per city requirements. Minor change to existing grade will occur in a limited area near the site entrance to accommodate a new gate. d. Proposed measures to reduce or control surface, ground, and runoff water, and drainage pattern impacts, if any: During construction, compost socks and straw wattles will be used to prevent runoff from entering the stream. Stormwater runoff discharge for the completed project will be self-mitigated through use of the existing stormwater facilities. 4. Plants Find help answering plants questions a. Check the types of vegetation found on the site: ☒ deciduous tree: alder, maple, aspen, other ☒ evergreen tree: fir, cedar, pine, other ☒ shrubs ☒ grass ☐ pasture ☐ crop or grain ☐ orchards, vineyards, or other permanent crops. ☐ wet soil plants: cattail, buttercup, bullrush, skunk cabbage, other ☐ water plants: water lily, eelgrass, milfoil, other ☐ other types of vegetation b. What kind and amount of vegetation will be removed or altered? A total of fifty-nine (59) trees will be removed from the site. As described in the Arborist Report prepared for the project, this includes 42 trees recommended for removal due to safety concerns (dead or in poor/very poor condition) and 17 trees that must be removed to accommodate new fence construction. The species being removed include Douglas fir (Pseudotsuga menziesii), bigleaf maple (Acer macrophyllum), shore pine SEPA Environmental checklist September 2023 Page 12 (WAC 197-11-960) (Pinus contorta), wild cherry (Prunus avium), black cottonwood (Populus trichocarpa), western red cedar (Thuja plicata), willow (Salix spp.), red alder (Alnus rubra), Scots pine (Pinus sylvestris), bitter cherry (Prunus emarginata), western hemlock (Tsuga heterophylla), Oregon ash (Fraxinus latifolia), apple (Malus spp.), and grand fir (Abies grandis). Vegetation alterations will include minor crown raise pruning on retained trees to ensure proper clearance from the new fence, with no more than 10% of the overall canopies being removed. English ivy (Hedera helix) will be removed from numerous trees by girdling the ivy stems at the base to improve tree health. A minor extent of native understory plants near retained trees may need to be trimmed and/or temporarily covered with construction mats during construction activities. c. List threatened and endangered species known to be on or near the site. Based on a review of the Washington Department of Fish and Wildlife Priority Habitats and Species (PHS) map and the Washington State Department of Natural Resources Rare Plant and Ecosystem GIS database, there are no known threatened or endangered species documented on or in the immediate vicinity of the project site. d. Proposed landscaping, use of native plants, or other measures to preserve or enhance vegetation on the site, if any. Comprehensive tree protection measures will be implemented including use of air spade and/or hydrovac systems for excavation within Critical Root Zones, application of 3-inch layer of coarse arborist wood chips and/or construction mats to reduce soil compaction, and active supervision by an ISA Certified Arborist as needed during construction activities. English ivy (Hedera helix) may be removed from retained trees and Himalayan blackberry (Rubus armeniacus) may be managed as part of ongoing site maintenance. Native understory plants near retained trees will be protected during construction, with only minor trimming or temporary covering with construction mats as needed. A two- year seasonal care plan is proposed for all preserved trees, including continued monitoring to ensure their long-term health and viability following construction completion. These measures will maintain the site's natural screening function while preserving the forested character of the property. e. List all noxious weeds and invasive species known to be on or near the site. Himalayan blackberry (Rubus armeniacus) and English ivy (Hedera helix). SEPA Environmental checklist September 2023 Page 13 (WAC 197-11-960) 5. Animals Find help answering animal questions9 a. List any birds and other animals that have been observed on or near the site or are known to be on or near the site. Examples include: • Birds: hawk, heron, eagle, songbirds, other: • Mammals: deer, bear, elk, beaver, other: • Fish: bass, salmon, trout, herring, shellfish, other: b. List any threatened and endangered species known to be on or near the site. Per WDFW PHS mapper no threatened or endangered species are known to be on or near the site. c. Is the site part of a migration route? If so, explain. Washington State is within The Pacific Flyway, a known avian migration route. Waterfowl concentrations are mapped in the project vicinity. d. Proposed measures to preserve or enhance wildlife, if any. The proposed fence could alter existing wildlife access across the site, as any openings in the existing antiquated fence will be eliminated. However, there is a sizeable forested buffer around the fenced developed area that will remain unaltered. It is anticipated that wildlife will adjust access routes to those areas. No measures are proposed for preservation or enhancement. e. List any invasive animal species known to be on or near the site. None known. 9 https://ecology.wa.gov/Regulations-Permits/SEPA/Environmental-review/SEPA-guidance/SEPA-checklist-guidance/SEPA-Checklist-Section-B-Environmental-elements/Environmental-elements-5-Animals SEPA Environmental checklist September 2023 Page 14 (WAC 197-11-960) 6. Energy and natural resources Find help answering energy and natural resource questions10 a. What kinds of energy (electric, natural gas, oil, wood stove, solar) will be used to meet the completed project's energy needs? Describe whether it will be used for heating, manufacturing, etc. Electrical and communication requirements for the security system and automated gates are planned to be integrated into the new fence. Electrical and communication junctions along the fence will be strategically located to minimize the length of conduit routes that will tie-back to the existing Controls Building. b. Would your project affect the potential use of solar energy by adjacent properties? If so, generally describe. No, the project will not affect the potential use of solar energy by adjacent properties. c. What kinds of energy conservation features are included in the plans of this proposal? List other proposed measures to reduce or control energy impacts, if any. No energy conservation features are included in the proposed maintenance activities. The purpose of the project is to protect a critical energy system facility, which indirectly supports system reliability. 7. Environmental health Health Find help with answering environmental health questions11 a. Are there any environmental health hazards, including exposure to toxic chemicals, risk of fire and explosion, spill, or hazardous waste, that could occur because of this proposal? If so, describe. The maintenance activities, including the replacement of fencing, gates, associated utilities and security system features, will involve soil disturbance. In 2003, PSE identified releases of ethylene glycol, lubricating oil and paint chips to the ground surface in portions of the compressor cooling system facility. An independent remedial action was completed to remove impacted soil from the site under MTCA (Remedial Investigation/Feasibility Study, SWARR Station, October 14, 2025 – GeoEngineers). However, the proposed project does not plan excavation in that immediate area. The existing utilities at the plant will be located prior to construction and have been added to the site plan to minimize the potential for conflict. Plant personnel familiar 10 https://ecology.wa.gov/Regulations-Permits/SEPA/Environmental-review/SEPA-guidance/SEPA-checklist-guidance/SEPA-Checklist-Section-B-Environmental-elements/Environmental-elements-6-Energy-natural-resou 11 https://ecology.wa.gov/Regulations-Permits/SEPA/Environmental-review/SEPA-guidance/SEPA-checklist-guidance/SEPA-Checklist-Section-B-Environmental-elements/Environmental-elements-7-Environmental-health SEPA Environmental checklist September 2023 Page 15 (WAC 197-11-960) with on-site facilities will be available during construction to consult on the location of equipment carrying flammable substances. 1. Describe any known or possible contamination at the site from present or past uses. In addition to the above and unrelated to PSE’s activities at the site, Arsenic concentrations in localized groundwater exceed MTCA Method A CUL (September 2009 & March 2010 Groundwater Monitoring, SWARR Station, May 12, 2010 – GeoEngineers). 2. Describe existing hazardous chemicals/conditions that might affect project development and design. This includes underground hazardous liquid and gas transmission pipelines located within the project area and in the vicinity. Natural gas transmission pipelines (owned by others) are located within the site, been identified on the site plans and the design has been coordinated with the owner. Underground storage of propane also occurs at this location, however no excavation is planned near the tanks. 3. Describe any toxic or hazardous chemicals that might be stored, used, or produced during the project's development or construction, or at any time during the operating life of the project. Ethelyne glycol, hydraulic and lubricating oils. Construction equipment will require diesel for operation. Once construction is complete, no toxic or hazardous chemicals will result from the completed security maintenance project. 4. Describe special emergency services that might be required. Spill response and first responders in the event of fire or other emergency may be required. 5. Proposed measures to reduce or control environmental health hazards, if any. Development of a site-specific Health and Safety Plan (HASP) and soil/groundwater management plan for site workers during construction as needed. Contractor will use the Call Before You Dig service to identify utility lines prior to construction. b. Noise 1. What types of noise exist in the area which may affect your project (for example: traffic, equipment, operation, other)? SEPA Environmental checklist September 2023 Page 16 (WAC 197-11-960) There are no noises that exist in the area that are expected to affect the project. 2. What types and levels of noise would be created by or associated with the project on a short-term or a long-term basis (for example: traffic, construction, operation, other)? Indicate what hours noise would come from the site)? There will be short term noise generated by construction vehicles and equipment. Once the project is complete, no noise will be generated. Construction noise would be generated during the work hours authorized in the city permits. 3. Proposed measures to reduce or control noise impacts, if any: Construction will be limited to permitted daytime hours only. Construction equipment will have muffled exhaust systems. 8. Land and shoreline use Find help answering land and shoreline use questions12 a. What is the current use of the site and adjacent properties? Will the proposal affect current land uses on nearby or adjacent properties? If so, describe. Current Use: Peak Shaving Facility that provides supplemental capacity to the natural gas system during periods of peak demand or system disruption. Adjacent Parcel Zoning: To the west (across Benson Drive South.) zoning is R-8; to the east (across S. Puget Drive) zoning is a combination of R-14, RM-F and CA; to the north (across intersection of S. Puget Drive and Benson Drive South.) is R-14 and R-8; and to the south is R-8 and RM-F. The proposal will not affect current land uses on nearby or adjacent properties. b. Has the project site been used as working farmlands or working forest lands? If so, describe. How much agricultural or forest land of long-term commercial significance will be converted to other uses because of the proposal, if any? If resource lands have not been designated, how many acres in farmland or forest land tax status will be converted to nonfarm or nonforest use? No, the site has not been used as working farm or forest land. 1. Will the proposal affect or be affected by surrounding working farm or forest land normal business operations, such as oversize equipment access, the application of pesticides, tilling, and harvesting? If so, how? 12 https://ecology.wa.gov/Regulations-Permits/SEPA/Environmental-review/SEPA-guidance/SEPA-checklist-guidance/SEPA-Checklist-Section-B-Environmental-elements/Environmental-elements-8-Land-shoreline-use SEPA Environmental checklist September 2023 Page 17 (WAC 197-11-960) No, the proposal will not affect or be affected by surrounding working farm or forest land. c. Describe any structures on the site. The developed portion of the site consists of a level area containing buried tanks and piping (covered with turf grass), outdoor processing equipment, a single-story building (approximately 5,000 square feet), access driveways and small parking area. The developed pad is currently enclosed with an antiquated chain link fence with barbed wire and security system equipment. d. Will any structures be demolished? If so, what? Portions of the existing 6’- 7’ tall chain link fence will be removed; other sections will remain in place based on site conditions. Some portions of the existing security equipment will be removed and replaced. No building demolition is included in the planned project. e. What is the current zoning classification of the site? Residential-8 f. What is the current comprehensive plan designation of the site? Residential Single Family g. If applicable, what is the current shoreline master program designation of the site? Not applicable; the site is not located within shoreline jurisdiction. h. Has any part of the site been classified as a critical area by the city or county? If so, specify. Rolling Hills Creek flows from south to north through the project site, with flow contained inside an existing culvert through the central developed portion of the site. The stream flows in an open channel through undeveloped portions of the site; entering a culvert at the south margin of the access road. The stream flow is culverted across the developed area of the site for approximately 760 feet. The stream daylights into an open channel just north of the existing fence line, north of the proposed project activities. The northern portion of the property, beyond the fenced developed area, contains a wooded ravine that the stream flows through. Rolling Hills Creek is identified by the city of Renton as a fish bearing stream with a 115-foot buffer for the daylighted SEPA Environmental checklist September 2023 Page 18 (WAC 197-11-960) portions. Refer to the Stream Assessment included with this application (GeoEngineers; December 9, 2025.) Portions of the site are mapped by the city of Renton as containing Geologically Hazardous areas, including Erosion Hazard, Landslide Hazard and Coal Mine Hazard Areas. These features have been previously evaluated by PSE and additional analysis is being provided in support of the proposed project. Refer to the Geologically Hazardous Areas Report included with this application (GeoEngineers; March 5, 2026.) No floodplain areas were identified on the site or in the vicinity. i. Approximately how many people would reside or work in the completed project? None. j. Approximately how many people would the completed project displace? None. k. Proposed measures to avoid or reduce displacement impacts, if any. Not applicable; no people would be displaced as a result of the completed project. l. Proposed measures to ensure the proposal is compatible with existing and projected land uses and plans, if any. Project will not change the existing or projected land use. m. Proposed measures to reduce or control impacts to agricultural and forest lands of long-term commercial significance, if any: Not applicable. 9. Housing Find help answering housing questions13 a. Approximately how many units would be provided, if any? Indicate whether high, middle, or low-income housing. No housing units will be provided as part of the proposed project. 13 https://ecology.wa.gov/Regulations-Permits/SEPA/Environmental-review/SEPA-guidance/SEPA-checklist-guidance/SEPA-Checklist-Section-B-Environmental-elements/Environmental-elements-9-Housing SEPA Environmental checklist September 2023 Page 19 (WAC 197-11-960) b. Approximately how many units, if any, would be eliminated? Indicate whether high, middle, or low-income housing. No housing units would be eliminated as part of the proposed project. c. Proposed measures to reduce or control housing impacts, if any: Not applicable. No impacts to housing will occur related to the proposed project. 10. Aesthetics Find help answering aesthetics questions14 a. What is the tallest height of any proposed structure(s), not including antennas; what is the principal exterior building material(s) proposed? New camera poles will be incorporated into the fence alignment, and will be 15 to 20 feet in height. Approximately thirteen (13) super posts and 2 tech posts are required around the fence perimeter in order to support security equipment and extend the field of vision for cameras along the new alignment. Refer to sheets 7.10 and 7.20 of the Betafence design included in the civil site plan for more detail. b. What views in the immediate vicinity would be altered or obstructed? The proposed project is not anticipated to alter or obstruct views. The Arborist Report anticipates that the tree density following the removals will remain sufficient to provide screening along Benson Dr South. c. Proposed measures to reduce or control aesthetic impacts, if any: Proposed fence alignment has been designed to minimize tree removals to preserve the existing forested buffer surrounding the site. 11. Light and glare Find help answering light and glare questions15 a. What type of light or glare will the proposal produce? What time of day would it mainly occur? None. The proposed project does not include changes or additions to lighting. 14 https://ecology.wa.gov/Regulations-Permits/SEPA/Environmental-review/SEPA-guidance/SEPA-checklist-guidance/SEPA-Checklist-Section-B-Environmental-elements/Environmental-elements-10-Aesthetics 15 https://ecology.wa.gov/Regulations-Permits/SEPA/Environmental-review/SEPA-guidance/SEPA-checklist-guidance/SEPA-Checklist-Section-B-Environmental-elements/Environmental-elements-11-Light-glare SEPA Environmental checklist September 2023 Page 20 (WAC 197-11-960) b. Could light or glare from the finished project be a safety hazard or interfere with views? No light or glare is anticipated from the finish project, and no additional lighting is proposed. The new fence material has a hot dip galvanized finish and will not generate any glare. c. What existing off-site sources of light or glare may affect your proposal? None. The security system and fence are not affected by light or glare. d. Proposed measures to reduce or control light and glare impacts, if any: Not applicable. Since the proposal does not involve any changes that would generate light or glare impacts, no mitigation measures are proposed. Also, the forested buffer surrounding the proposed fence and developed area will be retained for screening. 12. Recreation Find help answering recreation questions a. What designated and informal recreational opportunities are in the immediate vicinity? Thomas Teasdale Park and Talbot Hill Park are both located within a few blocks of the project site on the west side of Benson Drive South. b. Would the proposed project displace any existing recreational uses? If so, describe. No existing recreational uses would be displaced by the proposed project. c. Proposed measures to reduce or control impacts on recreation, including recreation opportunities to be provided by the project or applicant, if any. Not applicable. Since no opportunities or impacts related to recreation will be generated by the project, no mitigation measures are necessary. SEPA Environmental checklist September 2023 Page 21 (WAC 197-11-960) 13. Historic and cultural preservation Find help answering historic and cultural preservation questions16 a. Are there any buildings, structures, or sites, located on or near the site that are over 45 years old listed in or eligible for listing in national, state, or local preservation registers? If so, specifically describe. According to the Department of Archaeology and Historic Preservation’s (DAHP) Washington Information System for Architectural and Archaeological Records Data (WISAARD), no registered properties (i.e. properties that have been listed on the Washington Heritage Register [WHR], the Washington Heritage Barn Register [WHBR], or the National Register of Historic Places [NRHP]) have been documented inside the area of potential impact (API). One registered Historic Property has been recorded within a one-mile radius of the API (Table 1). According to the King County Department of Assessments, one structure, the Puget Sound Energy Warehouse, was constructed in 1965 and remodeled in 1983. The structure has not been documented or evaluated for inclusion in any registers. b. Are there any landmarks, features, or other evidence of Indian or historic use or occupation? This may include human burials or old cemeteries. Are there any material evidence, artifacts, or areas of cultural importance on or near the site? Please list any professional studies conducted at the site to identify such resources. According to the WISAARD Predictive Model, the project site is within an area ranging from low to high risk for encountering archaeological resources. However, the project is located within previously disturbed areas. A review of the 1865 Bureau of Land Management (BLM) General Land Office (GLO) map identified that the project sits on what used to be a hill or near the ridge of a hill that has since been graded down. No cemeteries (or burials or funerary items) or Traditional Cultural Places have been previously recorded in or within one mile of the API. According to WISAARD, since 1995, there have been no cultural resource surveys within the API. Within a one-mile radius, seventeen cultural resource surveys have been conducted. Seven archaeological sites have been documented within a one-mile radius of the API and none within the API. The closest documented site, located 713 feet from the API, is a section of the Talbot Road dam and its retaining walls (Table 4). The project is within the traditional territory of the Duwamish Tribe (Duwamish Tribe 2018 ; Ruby et al. 2010 ; Suttles and Lane 1990 ). c. Describe the methods used to assess the potential impacts to cultural and historic resources on or near the project site. Examples include consultation with tribes and 16 https://ecology.wa.gov/Regulations-Permits/SEPA/Environmental-review/SEPA-guidance/SEPA-checklist-guidance/SEPA-Checklist-Section-B-Environmental-elements/Environmental-elements-13-Historic-cultural-p SEPA Environmental checklist September 2023 Page 22 (WAC 197-11-960) the department of archeology and historic preservation, archaeological surveys, historic maps, GIS data, etc. The PSE Archaeologist completed a literature review of the project area. This included a search of the WISAARD database for all cultural assessment reports, archaeological records, cemetery data, and historic register data within a one-mile radius of the project area. The PSE Archaeologist reviewed the Duwamish Tribal website, historical map tools, historical aerial photographs, and BLM databases for relevant information pertaining to the area. d. Proposed measures to avoid, minimize, or compensate for loss, changes to, and disturbance to resources. Please include plans for the above and any permits that may be required. The API is in an area of variable probability for encountering cultural resources due to slopes and historic modification. The project area has been historically logged and graded and the facility has been in place since 1965. All disturbing activities will take place in previously disturbed areas. Therefore, the PSE Archaeologist recommends that an Inadvertent Discovery Plan (IDP) be prepared in accordance with applicable regulations, including RCW 68.60, RCW 27.44, and RCW 68.50 and adopted during construction. 14. Transportation Find help with answering transportation questions17 a. Identify public streets and highways serving the site or affected geographic area and describe proposed access to the existing street system. Show on site plans, if any. The site is bounded by State Route 515 (also known as Benson Drive South) to the west and South Puget Drive to the east. Primary access to the site is via an existing paved driveway off Benson Drive South at South 21st Street. A secondary access is located on the west side of South Puget Drive, approximately 750 feet south of the intersection with Benson Drive South. No change is proposed to either of these access points. b. Is the site or affected geographic area currently served by public transit? If so, generally describe. If not, what is the approximate distance to the nearest transit stop? The nearest transit stop is approximately 650 feet west of the site on South 21st St. 17 https://ecology.wa.gov/Regulations-Permits/SEPA/Environmental-review/SEPA-guidance/SEPA-checklist-guidance/SEPA-Checklist-Section-B-Environmental-elements/Environmental-elements-14-Transportation SEPA Environmental checklist September 2023 Page 23 (WAC 197-11-960) c. Will the proposal require any new or improvements to existing roads, streets, pedestrian, bicycle, or state transportation facilities, not including driveways? If so, generally describe (indicate whether public or private). No. The proposal will not require any new or improvements to existing roads, streets, pedestrian, bicycle or state transportation facilities. d. Will the project or proposal use (or occur in the immediate vicinity of) water, rail, or air transportation? If so, generally describe. No, the project is not in the immediate vicinity of or use water, rail or air transportation. e. How many vehicular trips per day would be generated by the completed project or proposal? If known, indicate when peak volumes would occur and what percentage of the volume would be trucks (such as commercial and non-passenger vehicles). What data or transportation models were used to make these estimates? No change from existing vehicular trips would result from the completed project. f. Will the proposal interfere with, affect, or be affected by the movement of agricultural and forest products on roads or streets in the area? If so, generally describe. The proposed project will not interfere with, affect, or be affected by the movement of agricultural and forest products on roads or streets in the area. g. Proposed measures to reduce or control transportation impacts, if any: Not applicable; no transportation impacts would occur as a result of the project. 15. Public services Find help answering public service questions18 a. Would the project result in an increased need for public services (for example: fire protection, police protection, public transit, health care, schools, other)? If so, generally describe. The project would not result in an increased need for public services. The modern fence and security system should serve to reduce the need for police protection at the site. b. Proposed measures to reduce or control direct impacts on public services, if any. 18 https://ecology.wa.gov/regulations-permits/sepa/environmental-review/sepa-guidance/sepa-checklist-guidance/sepa-checklist-section-b-environmental-elements/environmental-elements-15-public-services SEPA Environmental checklist September 2023 Page 24 (WAC 197-11-960) Not applicable. No direct impact to public services would occur as a result of the project, thus no mitigation measures are proposed. 16. Utilities Find help answering utilities questions19 a. Circle utilities currently available at the site: electricity, natural gas, water, refuse service, telephone, sanitary sewer, septic system, other: b. Describe the utilities that are proposed for the project, the utility providing the service, and the general construction activities on the site or in the immediate vicinity which might be needed. Modifications will be needed to the existing electrical and telecommunication utility systems at the site to support the updated security equipment and gate operators. The work will be performed by PSE’s contractor, and PSE is the electric service provider at this location. The majority of conduit required for these utility adjustments will be attached to the new fence, but in some cases – primarily at the gates and where removeable fence panels are planned – the conduit will be trenched underground. C. Signature Find help about who should sign20 The above answers are true and complete to the best of my knowledge. I understand that the lead agency is relying on them to make its decision. X Type name of signee: Philip Puzon Position and agency/organization: Manager System Controls and Protection Date submitted: 6/8/2026 19 https://ecology.wa.gov/regulations-permits/sepa/environmental-review/sepa-guidance/sepa-checklist-guidance/sepa-checklist-section-b-environmental-elements/environmental-elements-16-utilities 20 https://ecology.wa.gov/Regulations-Permits/SEPA/Environmental-review/SEPA-guidance/SEPA-checklist-guidance/SEPA-Checklist-Section-C-Signature Phil Puzon