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Home My WebLink AboutRS_GeohazardsReport_260604_v1 17425 NE Union Hill Road, Suite 250 Redmond, Washington 98052 425.861.6000 March 5, 2026 Puget Sound Energy PO Box 97034 M/S EST-04W Bellevue, Washington 98009-9734 Attention: Kathryn Hodges and Elaine Babby Subject: Revised Geologically Hazardous Areas Report SWARR Station Security Maintenance Project, WO 142003204 2100 Benson Drive South Renton, Washington File No. 9186-184-00 Task 2032 1.0 Introduction and Project Understanding GeoEngineers, Inc. (GeoEngineers) was contracted by Puget Sound Energy (PSE) to perform a geologic hazard and drainage evaluation in support of the SWARR Station Security Maintenance Project (project). The project site was developed by Washington Natural Gas (now Puget Sound Energy) in 1965 as a “peak shaving” facility for periods of high natural gas demand during cold weather. We understand that PSE is proposing to replace the existing 6 to 7-foot-tall chain link fence around the SWARR Station with a new 8- to 12-foot-tall metal mesh fence including intrusion detection and security cameras to meet new Homeland Security requirements and PSE standards. PSE also plans to replace the aging vehicle and pedestrian gates at the main entrance to Benson Drive South in the southwest corner of the site and at the back entrance to South Puget Drive in the northeast corner of the site. The replacement fence alignment will generally follow the existing fence alignment, with some segments shifting further into developed areas. The fence will not move outward away from the developed station footprint. The security system will be updated to current technology, with new security cameras and associated conduit and electrical system adjustments. Conduits will be attached to the fence, to minimize trenching, except at gate crossings and between power source at control building and fence where conduits will be routed below ground. Minor excavation, including augering or hydrovactoring, for fence and camera post installation will also occur as part of the project. Refer to the Project Narrative and project site plan (prepared by PSE) for more detailed information on the proposed work. The property is situated within Section 20 of Township 23 North and Range 05 East of the Willamette Meridian (WM). The reference address for the property is 2100 Benson Drive South in Renton, Washington. The SWARR Station is located on approximately 16.7-acre Parcel No. 2023059071; with the developed portion of the site occupying the southern 8 acres of the property. The proposed fence, gate and security Puget Sound Energy | March 5, 2026 Page 2 File No. 9186-184- 00 Task 2032 maintenance will take place within the developed portion of the site only and will not extend to the undeveloped areas of the parcel. The project location is shown in Figure 1, Vicinity Map. The project and the preliminary fence installation location as provided by PSE is shown in Figure 2, Fence Replacement Site Plan. This report is intended to provide baseline geologic hazard critical areas (landslide, erosion, steep slope and coal mine hazards) and drainage review data to PSE in response to the November 21, 2024, memorandum from the City of Renton (COR) Department of Community and Economic Development summarizing COR’s comments during the November 21, 2024, PRE 24-000335 preapplication meeting with PSE (COR 2024b). This report also generally satisfies the geotechnical soils report as required per the 2022 Renton Surface Water Design Manual (RSWDM), Section C.1.3 (COR 2022). The primary purpose of the required soil report, as per RSWDM Section C.1.3, is to determine the feasibility of infiltrative Best Management Practices (BMPs). No new infiltrative BMPs (e.g. bioswales, new infiltration basins, new previous surfaces) are proposed for the project. Therefore, in our opinion site-specific infiltration testing is not required and was not conducted for the project. Recommendations for on-site BMPs during construction in accordance with RSWDM Appendix C are provided in this report. A summary of our stream assessment services for the project is provided in our Stream Assessment Memorandum dated December 9, 2025 (GeoEngineers 2025b). A summary of our geotechnical engineering testing services associated with the proposed fence replacement is provided in our Geotechnical Design Memorandum dated October 7, 2025 (GeoEngineers 2025a). 2.0 Scope of Services The purpose of our services was to review the Renton Municipal Code (RMC) 4-3-050 and the 2022 RSWDM requirements and exceptions and to perform a desktop-level study and site reconnaissance to characterize geologic hazards, surface soil and bedrock, groundwater seepage and surface water conditions and drainage patterns for the project. The information collected provides a basis for developing recommendations regarding permitting requirements, potential geologic hazards, site drainage, erosion control BMPs and site restoration recommendations to reduce the risk of adversely affecting geologic hazards that may be present at or near the project. Our specific scope of services included the following: 1. Reviewed readily available published geologic, soil and groundwater well data and our in-house files for existing information on soil, geologic hazards and groundwater conditions in the site vicinity. 2. Reviewed RMC 4-3-050 and 2022 RSWDM requirements and exemptions. 3. Reviewed RMC 4-3-050 for Geologic Critical Areas (COR 2024a), 2022 RSWDM, Section C.1.3, King County (KC) (KC 2024), Office of Surface Mining Reclamation and Enforcement (OSMRE; 2024) and the Washington State Department of Natural Resources (DNR 2024a) websites to identify delineated geological hazard areas in the project area and to evaluate requirements for work completed within geologic hazard critical areas. 4. Reviewed COR review comments provided in a memorandum from the COR dated November 21, 2024 (COR 2024b). Puget Sound Energy | March 5, 2026 Page 3 File No. 9186-184- 00 Task 2032 5. Reviewed and interpreted hillshade imagery and topographic maps derived from bare earth Light Detection and Ranging (lidar) data available from DNR (DNR 2024b) for the site and adjacent properties. 6. Completed a site visit to the SWARR Station location to assess the adjacent slopes for surface indications of slope instability, erosion, drainage and groundwater seepage. 7. Evaluated the potential impacts to slope stability, erosion, drainage and coal mine hazards at the project location. 8. Prepared this preliminary letter report summarizing our desktop review, site reconnaissance observations, and preliminary erosion control and site restoration recommendations. 3.0 Desktop Reviews 3.1. GEOLOGIC CONDITIONS As shown in Figure 3, Geology, geologic mapping obtained from the DNR (DNR 2024a) indicates that the project area is underlain by Pleistocene-aged continental glacial till (Qgt). However, the DNR mapping and smaller scale mapping we reviewed (Schuster et al. 2015; Mullineaux, D.R. 1965), indicates that the glacial till is in turn predominately underlain by continental sedimentary rocks of the Puget Sound Group (Tr) consisting of sandstone, siltstone, shale, carbonaceous shale, claystone and coal. We reviewed available well reports from the Washington State Department of Ecology (Ecology; 2024) for geotechnical soil borings completed at the project site and Renton School District at Talbot Hill Elementary School located at 578 23rd Street (approximately 1,500 feet southwest of the project site), where the subsurface geology is mapped as having similar geologic conditions as the project site. Our review of these well logs indicated that the project area is likely underlain by approximately 16 to 25 feet of silt, sandy silt and gravel (glacial till), which are in turn underlain by the Puget Sound Group rocks. 3.2. SOIL CONDITIONS Based on soil information available from the United States Department of Agriculture (USDA) National Resources Conservation Service (NRCS) (USDA-NRCS 2024), the project location is underlain by two distinct surficial soil units. Soil units are shown graphically in Figure 4, Soils and Erosion Hazards. The majority of the site is underlain by a soil unit referred to as the Alderwood gravelly sandy loam, 15 to 30 percent slopes. The soil is described as having a parent material of glacial drift and/or glacial outwash and being a gravelly sandy loam from 0 to 7 inches and very gravelly sandy loam between 7 to 59 inches. This soil unit is classified by the NRCS as having a severe erosion hazard, being moderately well-drained and having a very low to moderately low infiltration rate of between 0.00 and 0.06 inches per hour. The depth to the water table is reported to be 18 to 37 inches. The minor soil unit located along the western boundary of the project is referred to as the Beausite gravelly sandy loam characterized by 6 to 15 percent slopes. The soil is described as having a parent material of till, over weathered soils from sandstone, being a gravelly, ashy sandy loam from 0 to 38 inches, and as bedrock between 38 to 42 inches. This soil unit is classified by the NRCS as having a moderate erosion Puget Sound Energy | March 5, 2026 Page 4 File No. 9186-184- 00 Task 2032 hazard, being well-drained and having a moderately high infiltration rate of between 0.57 and 1.98 inches per hour. The depth to the water table is reported to be more than 80 inches. We did not complete infiltration tests for the project because no new infiltration structures are planned for the project and the project will not alter existing site run-off or infiltration. 3.3. CITY OF RENTON GEOLOGIC CRITICAL AREA MAPPING The COR Geologic Critical Areas, as defined in COR 4-3-050B, include regulated slopes, landslide, erosion, seismic and/or coal mine hazards. Geologic hazards, including regulated slopes, erosion, coal mine and landslide hazards, are shown in Figures 3 through 8. 3.3.1. Potential Erosion Hazard Areas The COR maps potential erosion hazard areas as shown in Figure 4. The COR defines significant erosion hazards as those soils that may experience high erosion (COR 2024a). The central and eastern portions of the project area are mapped within a potential high erosion hazard area. This area generally corresponds to the NRCS mapping of the Alderwood gravelly sandy loam soil units classified as having a severe erosion hazard. 3.3.2. Regulated Slope Hazard Areas We reviewed the Regulated Slope maps available from COR (COR 2024a) to characterize mapped slope steepness at the site. As shown in the Regulated Slopes map, Figure 5, most of the project area and site are mapped with slopes less than 25 percent. However, cut and fill slopes associated with construction activities for the development of the project site, the main entrance to the site off Benson Drive South, Benson Drive South and South Puget Drive are mapped as steep slopes with gradients greater than 15 percent and less than or equal to 25 percent, Sensitive Slopes (slopes which are greater than 25 percent and less than or equal to 40 percent) and/or Protected slopes (slopes which are greater than 45 percent and less than or equal to 90 percent). 3.3.3. Potential Coal Mine Hazard Areas As shown in Figure 6, Coal Mine Hazards, moderate and high coal mine hazards are mapped on the eastern side of the project. Based on our review of information available from DNR, the area was mapped in 1915 to include mine workings and railroad tracks of the Old Talbot Mine workings of the Renton Coal Mine, owned by the Renton Coal Company. The mapped moderate and high coal mine hazards from the COR is overlain on a georeferenced detailed map available from DNR in Figure 6, which indicates that the northeast portion of the project site is located directly over mapped mine shafts related to the coal seams within the 1st and 2nd Levels West of the Old Talbot Mine. Based on our review of the coal mine maps and stratigraphic sections, these mine levels are typically more than 77 and 248 feet below the ground surface, respectively. We reviewed information from the OSMRE regarding reported repairs, subsidence and enforcement actions and no reports of repairs, subsidence or enforcement actions are reported for the site. Based on our communications with Lori Ford of the OSMRE on October 24, 2024, she confirmed that there has not been an investigation or reclamation project associated with the project site recorded or completed by OSMRE in the OSMRE database. Puget Sound Energy | March 5, 2026 Page 5 File No. 9186-184- 00 Task 2032 3.3.4. Potential Landslide Hazard Areas Based on our review of information available from the COR, King County and DNR, the COR Landslide Severity is mapped as High within all but the southwest corner of the project location. COR Landslide Severity mapping is shown in Figure 7, Landslide Severity. Individual landslides or deposits are not mapped within or adjacent to the project location. We also reviewed the most recent lidar hillshade model available from the DNR lidar portal, as shown in Figure 8, Lidar Interpretation (DNR 2024b). Based on our interpretation of the lidar hillshade model, the site is not located on a historic landslide, nor are there historic landslides in the near vicinity of the project location. 3.3.5. Potential Seismic or Volcanic Hazard Areas Based on our review of information available from the COR, King County and DNR, there are no mapped seismically active faults or volcanic hazard areas mapped near the project area. 3.4. GROUNDWATER GeoEngineers (GeoEngineers 2025a) completed nine hand auger borings (HA-1 through HA-9) for our geotechnical work at the site to depths ranging from 0.5 feet to 2.5 feet below the ground surface (bgs) on September 27, 2024, to evaluate soils and groundwater conditions along the proposed project fence line alignment. Groundwater was not observed in the hand auger borings. Based on our explorations, subsurface conditions consist of fill to the depth explored. The fill consists of poorly-graded sand with silt and gravel, silty sand and organic matter and extends to a depth of 2 feet below ground surface (bgs). GeoEngineers (GeoEngineers 2011) installed 10 monitoring wells at the site between 2003 and 2007 as part of a previous environmental study at the site. The approximate locations of the monitoring wells are shown in Figure 2 and Appendix A, Site Plan and Groundwater Elevations – March 2011, Figure A-1, Site Plan. 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 facilities (MW-1 through MW-4, and MW-7 through MW-10) ranged from approximately 2.7 to 11.4 feet bgs in September 2010 and March 2011. Depths to groundwater measured in upgradient well MW-5 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 downgradient well MW-6 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 consistent with previous monitoring events evaluated since 2005 and reflects the topographic slope at the site. Groundwater elevations and the inferred flow direction based on the March 2011 groundwater measurements are shown in Figure A-2, Groundwater Elevations – March 2011. Based on our review of information from the COR, the project site is not located within a Wellhead Protection Area mapped by the COR (COR 2024a). Puget Sound Energy | March 5, 2026 Page 6 File No. 9186-184- 00 Task 2032 3.5. DRAINAGE CONDITIONS Based on our review of information available from COR (COR 2024a), 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 or is not adjacent to an aquifer protection area. Land use in the area includes residential development zone R-8. According to the COR Utility Geographic Information System (GIS) data (COR 2024a), there are multiple stormwater discharge points that direct water towards the SWARR Station parcel from offsite roadways and parking lots. 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 (Figure 2). 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 enters the stormwater drain system and discharges at a point outside of the northwest corner of the project area (Figure 2). As discussed below in Section 4.0 Site Reconnaissance, we observed 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 in the east catch basins flows directly to the catch basins on the west side of South Puget Drive which discharges stormwater onto the slopes on the east side of the project area. As discussed below in Section 4.0, we observed that plastic piping has been installed on the site slopes to capture the discharged water and transport it to the base of the slopes. Based on our surface reconnaissance, the water then flows into the half-rounds that have been installed on the east side of the site access 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, as discussed below in Section 4.0, due to natural topography, water does not directly enter the stream and evidence of standing water was observed just east of the south portion of the site where Rolling Hills Creek enters the culvert (Figure 2). According to COR, Rolling Hills Creek is mapped as an open channel on the north and south sides of the project area. The creek flows through a culvert beneath the ground surface of the project area. As discussed below in Section 4.0, Rolling Hills Creek was observed flowing into the culvert inlet at the south end of the project site and discharging to an open stream channel at the north end of the project site. Puget Sound Energy | March 5, 2026 Page 7 File No. 9186-184- 00 Task 2032 4.0 Site Reconnaissance 4.1. GENERAL A GeoEngineers’ Washington licensed geologist conducted a site reconnaissance on September 12, 2024, to observe site conditions. The project site is situated in the southern portion of the parcel which is located in a northwest-southeast trending drainage of Rolling Hills Creek. The site is situated on a relatively flat to very gently sloping (slope gradients of 0 to 15 percent) ground surface. 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) uphill 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 site are vegetated with evergreen and deciduous trees and shrubs, blackberries, ivy, grass and other understory vegetation. Photographs presented in Figures B-1 and B-14 in Appendix B, Site Photographs. In general, the 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 tank facilities are located on the north side of the project site where the ground surface is vegetated with grass. The south side of the project site contains the main driveway into the site facilities and parking area, east to west trending underground gas pipelines, forested habitat with little understory vegetation and maintained grass areas. The northern portion of the parcel (outside of the fenced facility) is undeveloped and forested with shrub understory. Grading to construct 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 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. Figure 2 provides an overview of the project site. 4.2. REGULATED SLOPES, POTENTIAL EROSION HAZARDS AND POTENTIAL LANDSLIDE HAZARDS During our site visit, we observed that the mapped regulated slopes and landslide hazards on the south side of the project area near the site entrance are associated with the engineered construction fill embankments for the paved driveway into the SWARR Station from Benson Drive South. The slopes are inclined at about 100 percent (1H:1V [Horizontal:Vertical]) and are up to 9 feet high. The slopes are vegetated with grass and blackberries. We did not observe indications of instability or landsliding, surface water, groundwater seepage or erosion on the portions of the slopes that we observed. Slopes and site features are shown in the photographs provided in Figures B-1, B-2 and B-3 in Appendix B. We observed that the mapped regulated slopes and mapped landslide severity hazard on the east side of the project area are associated with native slopes and the engineered construction cut and fill embankments for South Puget Drive and the SWARR Station. The native slopes are inclined up to 65 percent and graded slopes are inclined at about 100 percent (1H:1V) and combined are up to 90 feet high. The slopes are vegetated with grass, evergreen and deciduous trees and shrubs, blackberries, ivy, Puget Sound Energy | March 5, 2026 Page 8 File No. 9186-184- 00 Task 2032 horsetail ferns and other understory herbaceous vegetation. We did not observe indications of instability or landsliding on the portions of this slope that we observed, nor did we observe surface water, groundwater seepage or erosion on these slopes. However, horsetail ferns, plants that prefer extended periods of wet soil conditions, were observed near the toe of the slope near the half-round culvert. Slope and site features are shown in Figure B-4, B-5 and B-6. The regulated slopes and mapped landslide severity hazard on the north side of the project site include graded fill slopes associated with the construction fill pads for the developed northern area of the site. The fill slopes range between 2 and 10 feet high and are inclined at about 100 percent (1H:1V). We did not observe indications of instability (ground cracks, recent or past landsliding, erosion, fallen trees) landslide, surface water or groundwater seepage on the portions of the slopes that we observed. However, we observed a 10- to 15-foot-wide area of erosion on the slope on the north side of the existing fence line where the culvert conveying Rolling Hills Creek beneath the site outlets to an open channel. The water outfall has eroded the slope to be inclined to near vertical at the culvert outlet. The slope along the north side of the site is vegetated with blackberry, ivy, deciduous trees and shrubs as shown in the photographs provided in Figure B-7. We observed that the regulated slopes and mapped landslide severity hazard on the west side of the project area are associated with native slopes and the engineered construction cut and fill embankments for Benson Drive South, the SWARR Station and several 2- to 3-foot-high rock walls and concrete ditch line constructed at the toe of the slopes at the edge of the gravel pad for the building and other SWARR Station facilities. The native slopes are inclined up to 50 percent. The graded slopes are inclined at about 100 percent (1H:1V) and are up to 30 feet high. We did not observe indications of instability or landsliding on the portion of this slope or the rock walls that we observed. Nor did we observe surface water, groundwater seepage or erosion on these slopes, except for indications of surface water flow from the storm drain outlet from Benson Road South in the northwest corner of the site as described in Section 3.5 Drainage Conditions above. We observed sediment and organic material captured on the outside surface of the fence in the northwest corner of the site. Slopes and site features are shown in the photographs provided in Figures B-8, B-9, B-10, B-11 and B-12. The remaining portions of the project site mapped within a severe landslide hazard are related to the relatively flat, graded developed area of the site. No evidence of landsliding or landslide deposits were observed in these areas. 4.3. DRAINAGE CONDITIONS The majority of the precipitation and surface water at the project site generally infiltrates into the vegetated ground surfaces around the perimeter of the site. Surface water near the site building and gravel areas near the building either: ■ Infiltrates into the gravel areas, ■ Flows to the west and south into the concrete swales and catch basins at the base of the rockery walls and then to the vegetated swale located in the northwest corner of the project site (Figures B-8, B-9 and B-10), or Puget Sound Energy | March 5, 2026 Page 9 File No. 9186-184- 00 Task 2032 ■ To the north into the concrete swales, grass-covered underground tank area or to the grass-lined swale located within the underground tank area (Figure B-13). Surface water flowing along the paved and gravel driveways flows off these surfaces into either: ■ Vegetated areas adjacent to these surfaces to infiltrate (Figure B-7), ■ The open half-round culvert on the east side of the driveway to the north side of the developed site and then to Rolling Hills Creek once outside of the fenced project area (B-2), or ■ The concrete swale and culverts located on the west side of the driveway that conveys water to Rolling Hills Creek culvert near the underground tank area. Surface water along Benson Drive South is collected within curbside gutters and enters catch basins located on the east and west sides of Benson Drive South roadway rights-of-way (ROWs). The stormwater then discharges at a point outside of the northwest corner of the project area and flows towards Rolling Hills Creek (Figure 2). We observed evidence of water sheet flow that originated from the storm drain discharge point and flowed northeast through the perimeter site fence in the northwest corner of the site then towards Rolling Hills Creek (Figure B-12). 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 which discharge stormwater directly onto the slopes on the east side of the project area (Figure 2). We observed that plastic piping or half-rounds have been installed on the site slopes to capture the discharged water and transport it to the base of the slopes, where the water is discharged into the half-rounds at the toe of the slopes and on the east side of the driveway. We did not observe evidence of erosion along the slopes that we observed (Figures B-3, B-4, B-5 and B-6). Surface water near the intersection of South Puget Drive and Benson Road South enters a series of catch basins located near the intersection and eventually discharges into a tributary that directs flow westward towards Rolling Hills Creek (Figure 2). We observed that due to the flatter topography at the toe of the slope, the stormwater does not directly flow into the stream and evidence of standing water was observed just east of where Rolling Hills Creek enters the culvert in the south (Figure B-3). Rolling Hills Creek was observed flowing from the south onto the project site in an open channel and then into an underground culvert inlet in the southeast corner of the project site. The culvert conveys the water beneath the site and then discharges the water back to an open channel at the north end of the project site. PSE indicated that when creek flow is too high, water collects at the culvert inlet and some of the water flows into the half-round culvert located east of the creek and the driveway (Figures B-7 and B-14). This water is conveyed within the half-round and segment of underground culvert to the north side of the project site, where the water discharges back to Rolling Hills Creek. We did not observe evidence of erosion along Rolling Hills Creek or half-round, except for minor erosion at the culvert outlet on the north side of the project area as described above in Section 4.1 General. A more detailed description of Rolling Hills Creek is provided in our Stream Assessment Memorandum (GeoEngineers 2025b). Puget Sound Energy | March 5, 2026 Page 10 File No. 9186-184- 00 Task 2032 4.4. POTENTIAL COAL MINE HAZARD AREAS We did not observe indications of settlement or subsidence at the project site where the COR moderate and high coal mine hazards are mapped. PSE representatives attending the September 12, 2024, site reconnaissance indicated that they and PSE have no record of reported settlement or subsidence occurring at the project site. 5.0 City Of Renton Preapplication Review Discussion GeoEngineers reviewed the COR’s review comments provided in a memorandum from the COR dated November 21, 2024 (COR 2024b). Based on the review comments, permitting for the project must comply with the requirements of COR 2022 RSWDM, Section C.1.3 and RMC 4-3-050 for Geologic Critical Areas as applicable for the completed project since the project area contains COR mapped geologic hazards, including erosion, regulated slope, landslide and coal mine hazards. The COR provided the following comments regarding geologic hazards. GeoEngineers’ Reponses to the geologic hazard review comments are included in each section below. Responses to the COR’s storm drainage comments will be provided by others involved in the project. Comment 1: “The site contains critical areas. There is a coalmine hazard with a severity of high, an Erosion Hazard and a Landslide hazard all mapped on-site.” Response 1: Based on our review, we concur that critical areas, including a severe coal mine hazard, an erosion hazard and a landslide hazard, are mapped at the site. Based on our desktop study and site reconnaissance, our findings regarding the mapped hazards are summarized below: ■ Severe Coal Mine Hazard: no recorded investigations or reclamation projects associated with the project site recorded or completed by OSMRE and we did not observe indications of settlement or subsidence at the project site where the COR moderate and high coal mine hazards are mapped. ■ Erosion Hazard: the central and eastern portions of the project area are mapped within a potential high erosion hazard area. This area generally corresponds to the NRCS mapping of the Alderwood gravelly sandy loam soil units classified as having a severe erosion hazard. We did not observe evidence of erosion within the project area, except for minor erosion at the Rolling Hills Creek culvert outlet on the north side of the project area and the evidence of water sheet flow from the discharge point that flows northeast through the northwest corner of the existing fence line towards Rolling Hills Creek. ■ Landslide Hazards: the project site is mapped within a COR mapped high landslide hazard area within all but the southwest corner of the project, which is mapped within a COR moderate landslide area location. The mapped landslide hazards along the perimeter of the site are associated with the unretained graded slopes on the north, east, south and west sides of the project site. The remaining portions of the project site mapped within a severe landslide hazard are related to the relatively flat, graded developed area of the site. We did not observe evidence of recent landsliding or landslide deposits within the project site during our site reconnaissance. In our opinion, there is a low risk that the project would adversely affect the stability of the mapped coal mine, erosion and landslide hazard areas and site slopes because: (1) the fence posts and electrical Puget Sound Energy | March 5, 2026 Page 11 File No. 9186-184- 00 Task 2032 conduit excavations will be shallow and unlikely to affect the stability of any underground mine shafts or workings; (2) the fence post installation would occur at the base of the slope but do not require significant excavation that would cut the toe of the slope; (3) the project does not include grading that could affect the stability of the slope; and (4) the project will not result in increased drainage, erosion or water flow that could erode and destabilize the slope. The project will disturb the site and therefore, must provide erosion and sediment controls during construction to prevent, to the maximum extent practicable, the transport of sediment from the project site to downstream drainage facilities, water resources and adjacent properties. We understand that PSE will develop a project-specific Erosion and Sediment Control Plan (ESCP) to be implemented during construction to satisfy this requirement. The current COR Surface Water Standard Plans and standard details will be utilized in the development of erosion and sediment control and stormwater pollution prevention control plans for the proposed project. Comment 5: “A geotechnical soils report for the site is required per the 2022 Renton Surface Water Design Manual Section C.1.3. Information on the water table and soil permeability (measured infiltration rates), with recommendations of appropriate on-site BMPs per Core Requirement #9 and Appendix C shall be included in the report. The report should also include information concerning the soils, geology, drainage patterns and vegetation present shall be presented in order to evaluate the drainage, erosion control and slope stability for site development. The applicant must demonstrate the development will not result in soil erosion and sedimentation, landslide, slippage, or excess surface water runoff.” Response 5: This report generally satisfies this requirement. The primary purpose of the required soil report, as per RSWDM Section C.1.3, is to determine the feasibility of infiltrative BMPs. No new infiltrative BMPs (e.g. bioswales, new infiltration basins, new previous surfaces) are proposed for the project. Therefore, in our opinion site-specific infiltration testing is not required and was not conducted for the project. Recommendations for on-site BMPs during construction in accordance with RSWDM Appendix C, are provided later in this report. Additional geotechnical information and a summary of our geotechnical engineering testing services associated with the proposed fence replacement is provided in our Geotechnical Design Memorandum dated October 7, 2025 (GeoEngineers 2025a). Comment 6: “Erosion control measures to meet the City requirements shall be provided.” Response 6: Understood, no comment. 6.0 Conclusions 6.1. CRITICAL AREAS Based on our evaluation as presented herein, there is a low risk of the proposed fence installation adversely affecting the regulated slopes adjacent to the project site. Furthermore, in our opinion the project will not result in soil erosion and sedimentation, landsliding or excess surface water runoff. In our opinion, the project will not increase the threat of geologic hazards to adjacent or abutting properties; and the project will not adversely impact other critical areas; and the project can be safely accommodated at the site if the project is completed following our recommendations below. Puget Sound Energy | March 5, 2026 Page 12 File No. 9186-184- 00 Task 2032 The majority of the project site is mapped as either a moderate or high coal mine hazard. In our opinion there is a low risk of the project adversely affecting these mapped hazards because no infiltrative BMPs are proposed for the project, only shallow trenching for camera electrical conduit is required for the project and no new impervious surfaces will be created as part of the project. The excavation and site restoration of impervious surfaces will not result in new additional development-related runoff or infiltration that could increase the risk of subsidence. Conversely, in our opinion there is a low risk of subsidence resulting from the mapped coal mine hazard adversely affecting the project work primarily because the mapped mine shafts are more than 50 feet beneath the ground surface of the project area. 6.2. CITY OF RENTON STORM DRAINAGE As discussed in Section 5.0 City of Renton Preapplication Review Discussion, in our opinion the project would require a development of an erosion and sediment control plan and implementation of that plan during construction to prevent, to the maximum extent practicable, the transport of sediment from the project site to downstream drainage facilities, water resources and adjacent properties. The required Erosion and Sediment Control (ESC) measures and Stormwater Pollution Prevention and Spill Control (SWPPS) measures provided in an ESCP and Construction Stormwater Pollution Prevention (CSWPP) Plan for the project will be developed and implemented during the project in compliance with the 2022 RSWDM. 7.0 Recommendations We recommend preparing an ESCP and CSWPP plan to be included in the project permit submittals. Development of the ESCP will require a topographic survey to accurately depict site topography and drainage directions, existing structures and slopes on or directly adjacent to the site, existing impervious and pervious surfaces, and existing drainage structures (e.g. catch basins) so that a complete ESCP can be developed and appropriate erosion control BMPs can be chosen and shown on the ESCP. We anticipate that ESC and CSWPP measures would include but may not be limited to: construction limits fencing, silt fence, ditch check dams, catch basin inserts, temporary soil stockpile plastic covering, maintaining construction entrances, and approved concrete washouts and handling procedures. 8.0 Limitations GeoEngineers has prepared this report in general accordance with the limitations of our scope of work. Within the limitations of scope, schedule and budget, our services have been executed in accordance with the generally accepted practices for critical areas reports including geologic hazard identification and evaluation in this area at the time this report was prepared. No warranty or other conditions, express or implied, should be understood. This report has been prepared for the exclusive use of PSE, their authorized agents and regulatory agencies following the described methods and information available at the time this report was prepared. No other party may rely on the product of our services unless we agree in advance to such reliance in writing. The information contained herein should not be applied for any purpose or project except the one originally contemplated. Puget Sound Energy | March 5, 2026 Page 13 File No. 9186-184- 00 Task 2032 Please refer to Appendix C, Report Limitations and Guidelines for Use for additional information pertaining to use of this report. 9.0 References City of Renton (COR) 2024a. COR Map Viewer Interactive mapping tool. Accessed October 10, 2024 from COR Maps | City of Renton (rentonwa.gov). City of Renton (COR) 2024b. Preapplication Meeting For PSE SWARR Station – Security Perimeter Maintenance, 2100 Benson DR S (APN 2023059071, PRE-24-000335. November 21, 2024. City of Renton Municipal Code (RMC) 4-3-050. Accessed October 10, 2024 from City of Renton Municipal Code. City of Renton Surface Water Design Manual (RSWDM). 2022. Accessed October 10, 2024 from City of Renton Surface Water Design Standards. GeoEngineers, Inc. (GeoEngineers) 2025a. Geotechnical Design Memorandum, SWARR Station – Security Perimeter Maintenance Project. 2100 Benson Drive South, Renton, Washington. Prepared for Puget Sound Energy and dated October 7, 2025. GEI File No. 9186-184-00 Task 2032. GeoEngineers, Inc. (GeoEngineers) 2025b. Stream Assessment at the SWARR Station. Prepared for Puget Sound Energy and dated December 9, 2025. GEI File No. 9186-184-00 Task 2032. GeoEngineers, Inc. (GeoEngineers). 2011. September 2010 and March 2011 Groundwater Monitoring Report, Swarr Station, Renton Washington for Puget Sound Energy dated July 18, 2011. GEI File No. 0186-596-01. King County (KC) 2024. King County iMap; Interactive mapping tool. Accessed October 10, 2024 from https://kingcounty.gov/services/gis/Maps/imap.aspx. Mullineaux, D.R. 1965. Geologic map of the Renton quadrangle, King County, Washington; 1:24,000-scale; United States Geological Survey Map GQ-405; 1965; Accessed October 10, 2024 from NGMDB Product Description Page (usgs.gov). June 13, 2023. Office of Surface Mining Reclamation and Enforcement (OSMRE 2024). Accessed on October 25, 2024 from OSMRE Home Page. Schuster, J.E., Cabibbo, A.A., Schilter, J.F., and Hubert, I.J. 2015. Geologic Map of the Tacoma 1:100,000- scale quadrangle, Washington: Washington Division of Geology and Earth Resources Map Series 2015-03. United States Department of Agriculture-National Resources Conservation Service (UDSA-NRCS). 2024. Accessed October 10, 2024 from Web Soil Survey - Home (usda.gov). Washington State Department of Ecology Well Report Viewer (Ecology). 2024. Accessed October 10, 2024 from Well Report Search Options. Puget Sound Energy | March 5, 2026 Page 14 File No. 9186-184- 00 Task 2032 Washington State Department of Natural Resources (DNR) Geologic Information Portal. 2024a. Accessed October 10, 2024 from Washington Geologic Information Portal. Washington State Department of Natural Resources (DNR) Light Detection and Ranging (LiDAR) Data Portal. 2024b. Accessed October 10, 2024 from http://lidarportal.dnr.wa.gov/. Questions regarding the information provided in this letter report should be directed to Carla Woodworth 425.861.6012 or Brian Ranney at 503.603.6675. Sincerely, GeoEngineers, Inc. Carla R. Woodworth, LG Project Geologist Brian C. Ranney, LG, LEG Principal Engineering Geologist CRW:BCR:kjb Attachments: Figure 1. Vicinity Map Figure 2. Fence Replacement Site Plan Figure 3. Geology Figure 4. Soils and Erosion Hazards Figure 5. Regulated Slopes Figure 6. Coal Mine Hazards Figure 7. Landslide Severity Figure 8. Lidar Interpretation Appendix A. Site Plan and Groundwater Elevations – March 2011 Figure A-1. Site Plan Figure A-2. Groundwater Elevations – March 2011 Appendix B. Site Photographs Appendix C. Report Limitations and Guidelines for Use Disclaimer: Any electronic form, facsimile, or hard copy of the original document (email, text, table, and/or figure), if provided, and any attachments are only a copy of the original document. The original document is stored by GeoEngineers, Inc. and will serve as the official document of record. EXP. 02/09/2027 Brian C. Ranney Digitally signed by Brian C. Ranney Date: 2026.03.05 08:40:18 -08'00' Figures 78th Ave S 80th Ave SS124thSt S 1 2 6t h S t 85th Ave S 76th Ave S S 128th St Renton AveS Renton Municipal Airport 28ft 492 ft SW 7th St S 1 32nd St Shattuck Ave S S W 1 2 t h S t S 133rd St S 135th St Powell Ave SW S Langston Rd S W S unsetBlvd R a i n i e r A v e S Lind Ave SW R e nto n A veS S W G r a d y W a y E Valley Rd Mill Cr eek State Route 167 Talbot Rd S Talbot Rd S S 188th St SW 41st St Oakesdale Ave SW SW 27th St SW 43rd St 72nd Ave S S 180th St S 192nd St S 192nd St SW 39th St Lind Ave SW E Valley Rd 84th Ave S E Valley H wy W Valley Hwy TalbotRdS Olympia Ave NE NE 7 t h S t NE 9th St NE 4 t h St NE 6th St Redmo n d A veNE N 10th S t Logan Ave N S u nset BlvdNE Park Ave N NE 4th StN4thSt SE 162nd St 116th Ave SE SE 160th St Puget Dr S ES18thSt SE18th S t SE 5thSt Renton Ave S High Ave S SE 158thSt N E 3 r d S t N 3rd St S 2nd St Talbot Rd S Benson Dr S Maple V a ll e y Hwy Renton 488 ft Panth e r C r e e k B ig Soos Cr e e k Talbot Rd S 113th Ave SE 108th Ave SE SE 172nd St SE 168th St SE 192nd St 1 2 4 th Ave SE106th Ave SE 106th Ave SE 120th Ave SE 102nd Ave SE 112th Ave SE SE 164th St 129th Pl S E 118th Ave SE 108th Ave SE 108th Ave SE B e n s o n D r S SE C a rr R d SE Petrovitsky Rd S E 151stSt I-405 GRA-25 P01 Vicinity Map Puget Sound Energy SWARR Station - Security Perimeter Maintenance Project Renton, Washington Figure 1 1 0 2,000 Feet Legend Site P:\9\9186184\GIS\9186184_2024_Q4\9186184_2024_Q4.aprx\918618400tsk2032_F01_VicinityMap_Geology Date Exported: 12/18/24 by glohrmeyer Source(s):• Basemap from ESRI Coordinate System: NAD 1983 HARN StatePlane Washington North FIPS 4601 Feet Disclaimer: This figure was created for a specific purpose and project. Any use of this figurefor any other project or purpose shall be at the user's sole risk and without liability to GeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of the figure, or data containedtherein. The file containing this figure is a copy of a master document, the original of which isretained by GeoEngineers and is the official document of record. 3 99 Billy Frank Jr. Nisqually National Wildlife Refuge Tacoma 18 410 90Kent Renton Redmond Seattle G !¡ !¡ D D D DD D D D D D D D "å "å "å "å "å "å "å "å "å "å"å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å"å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å"å "å "å "å"å "å "å "å "å "å "å "å "å "å "å "å "å "å "å "å!¡ @ Stream EntersUnderground Culvert @ StormwaterDitch @ Rolling Hills CreekOutlets to Channel Rol l i n g H i l l s C r e e k @ 115 Foot Buffer @ 115 Foot Buffer Be n s o n D r S S P u g e t D r @ Pedestrian Gate @ 16-Foot Vehicle Gate;Access from S. Puget Drive @Pedestrian Gate andMain Entry Vehicle Gate @ Tanks @Tanks @ Culvert D D D D D D D D D D D D D D D D D D D D D D D D D DD D D D D D D D D D D D D D D DDDDDDDDDDDDDDDDDDD D D D D D DDD D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D DDDDDDDDDD !¡ !¡ !¡ #rÑ##rÑ##rÑ# #rÑ# #rÑ# #rÑ# #rÑ# #rÑ##rÑ# E a g l e L n S Burn e t t A v e S Ea g l e R i d g e D r S S 16th St S 1 8 t h S t Bu r n e t t P l S Bu r n e t t P l S Ea g l e L n S Ta l b o t R d S S 19th St Ea g l e L n S Hi l l s i d e V i l l a g e A p t A c R d Ea g l e L n S Ea g l e L n S HA-4 MW-2 HA-5HA-6 HA-7 HA-8 MW-3HA-9 HA-3 MW-1 HA-1 HA-2 Fence Replacement Site Plan SWARR Facility Fence Replacement Renton, Washington Figure 2 1 0 150 Feet Legend D D Rebuild Fence - Approximate Location (2,133.3 feet) D D Existing Fence (2,976.8 feet) Parcel Boundary (731,015 square feet) Culvert Forested and Shrub Vegatation Cover (506,838 square feet) Pedestrian Gate and Vehicle Entry "å City Catch Basin City Storm Drain !¡City Discharge Point D City Virtual Drainline !¡Monitoring Well Location #rÑ#Hand Auger Location P:\9\9186184\GIS\9186184_2024_Q4\9186184_2024_Q4.aprx\918618400tsk2032_F02_SitePlan Date Exported: 01/16/26 by glohrmeyer Notes: 1. No changes to parking or new buildings proposed Source(s):• Drawing updated with proposed fence alignment 10/3/24.• Streams and critical areas obtained from City of Renton GIS, http://rentonwa.gov/government/.• Roads, 2015 aerial, contours and parcel boundaries from King County GIS. http://www.kingcounty.gov/services/gis.aspxCoordinate System: NAD 1983 HARN StatePlane Washington North FIPS 4601 Feet Disclaimer: This figure was created for a specific purpose and project. Any use of this figure for any other project or purpose shall be at the user's sole risk and without liability toGeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of thefigure, or data contained therein. The file containing this figure is a copy of a master document, the original of which is retained by GeoEngineers and is the official document ofrecord. Morris Ave S Morris Ave S Smithers Ave S Whitworth Ave S S P u g e t D r S 1 4 t h S t S 15th St Talbot Rd S Be nson Dr S Morris Ave S TalbotRdS S 17th St S 19th St S 16th St S 20th St Benson Dr S Talbot Hill Reservoir Park Talbot Hill 191ft S 23rd St S 23rd St TalbotR d S Smithers Ave S S 21st St Benson Dr S Thomas Teasdale Park GenCare Lifestyle Renton at The Lodge at Eagle Ridge E a gle RidgeDr S S Eagle Ridge Dr S 18th St S P u g e t D r B e n s o n R d S S P u g e t D r S Puget Dr EagleRidge DrS S 18thSt Eagl e Ln S Eag le Ln S E agle Ln S Eagle L n S Eag l e L n S B e n s o n R d S S P u g e t D rWells Ct S S 22 n d Ct B e n s o n R d S Victoria Hills S 2 3 r d S t A C D Grant A v e S Tho m a s Ln Thomas L n S Puget Dr D D D D D D D D D D D D D D D D D D D D D D DDDDDDDDDD D D DD D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D DDDDD Qsr af Tr Qis Qgt Tr Geology Puget Sound Energy SWARR Station - Security Perimeter Maintenance Project Renton, Washington Figure 3 1 0 300 Feet Legend Site Parcel Boundary King County) D Rebuild Fence - Approximate Location (2,133.3 feet) D Existing Fence (2,976.8 feet) Geologic Units (DNR 24k) Qgt - Pleistocene continental glacial till Qis - Pleistocene continental glacial drift Qsr - Pleistocene continental glacial drift Tr - Tertiary sedimentary rocks and deposits af - Holocene artificial fill and modified land P:\9\9186184\GIS\9186184_2024_Q4\9186184_2024_Q4.aprx\918618400tsk2032_F03_Geology Date Exported: 12/18/24 by glohrmeyer Source(s):• Geology from Wa Dept of Natural Resources, 24k• Parcels from King County• Basemap from ESRI Coordinate System: NAD 1983 StatePlane Washington North FIPS 4601 Feet Disclaimer: This figure was created for a specific purpose and project. Any use of this figurefor any other project or purpose shall be at the user's sole risk and without liability to GeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of the figure, or data containedtherein. The file containing this figure is a copy of a master document, the original of which isretained by GeoEngineers and is the official document of record. Morris Ave S Morris Ave S Smithers Ave S Whitworth Ave S S P u g e t D r S 1 4 t h S t S 15th St Talbot Rd S Benso n Dr S Morris Ave S TalbotRdS S 17th St S 19th St S 16th St S 20th St Benson Dr S Talbot Hill Reservoir Park Talbot Hill 191 ft S 23rd St S 23rd St TalbotR d S Smithers Ave S S 21st St Bens on Dr S Thomas Teasdale Park GenCare Lifestyle Renton at The Lodge at Eagle Ridge A Block E a gle RidgeDr S S Eagle Ridge Dr S 18th St S P u g e t D r B e n s o n R d S S P u g e t D r S Puget Dr E agleRidge Dr S S18thSt Eagl e Ln S Eagle Ln S E agle Ln S Eagle L n S Eagle L n S B e n s o n R d S S P u g e t D rWells Ct S S 22 n d Ct B e n s o n R d S Victoria Hills A C D E Grant Av e S Tho m a s Ln Grant Ave S Thomas L n S Puget Dr D D D D D D D D D D D D D D D D D D D D D D DDDDDDDDDD D DDD D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D DDDDD Beausite gravelly sandy loam, 15 to 30 percent slopes Urban land Alderwood gravelly sandy loam, 8 to15 percent slopes Alderwood gravelly sandy loam, 15 to30 percent slopes Alderwood gravellysandy loam, 15 to 30 percent slopes Beausite gravelly sandy loam, 6 to15 percent slopes Soils and Erosion Hazards Puget Sound Energy SWARR Station - Security Perimeter Maintenance Project Renton, Washington Figure 4 1 0 300 Feet Legend Site Parcel Boundary King County) D D Rebuild Fence - Approximate Location (2,133.3 feet) D D Existing Fence (2,976.8 feet) High Erosion Hazard (City of Renton) Soil Unit Erosion Hazard Not rated Moderate Severe P:\9\9186184\GIS\9186184_2024_Q4\9186184_2024_Q4.aprx\918618400tsk2032_F04_SoilErosion Date Exported: 12/18/24 by glohrmeyer Source(s):• Soils from NRCS• High Erosion Hazard from City of Renton• Parcels from King County• Basemap from ESRI Coordinate System: NAD 1983 StatePlane Washington North FIPS 4601 Feet Disclaimer: This figure was created for a specific purpose and project. Any use of this figurefor any other project or purpose shall be at the user's sole risk and without liability to GeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of the figure, or data containedtherein. The file containing this figure is a copy of a master document, the original of which isretained by GeoEngineers and is the official document of record. Morris Ave S Morris Ave S Smithers Ave S Whitworth Ave S S P u g e t D r S 1 4 t h S t S 15th St Talbot Rd S Benso n Dr S Morris Ave S TalbotRdS S 17th St S 19th St S 16th St S 20th St Benson Dr S Talbot Hill Reservoir Park Talbot Hill 191 ft S 23rd St S 23rd St TalbotR d S Smithers Ave S S 21st St Bens on Dr S Thomas Teasdale Park GenCare Lifestyle Renton at The Lodge at Eagle Ridge A Block E a gle RidgeDr S S Eagle Ridge Dr S 18th St S P u g e t D r B e n s o n R d S S P u g e t D r S Puget Dr E agleRidge Dr S S18thSt Eagl e Ln S Eagle Ln S E agle Ln S Eagle L n S Eagle L n S B e n s o n R d S S P u g e t D rWells Ct S S 22 n d Ct B e n s o n R d S Victoria Hills A C D E Grant Av e S Tho m a s Ln Grant Ave S Thomas L n S Puget Dr D D D D D D D D D D D D D D D D D D D D D D DDDDDDDDDD D DDD D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D DDDDD Regulated Slopes Puget Sound Energy SWARR Station - Security Perimeter Maintenance Project Renton, Washington Figure 5 1 0 300 Feet Legend Site Parcel Boundary (King County) D Rebuild Fence - Approximate Location (2,133.3 feet) D Existing Fence (2,976.8 feet) Slope (City of Renton, Percent) >15% & <=25% >25% & <=40% (Sensitive) >40% & <=90% (Protected) >90% (Protected) P:\9\9186184\GIS\9186184_2024_Q4\9186184_2024_Q4.aprx\918618400tsk2032_F05_RegulatedSlopes Date Exported: 12/18/24 by glohrmeyer Source(s):• Slope data from City of Renton• Parcels from King County• Basemap from ESRI Coordinate System: NAD 1983 StatePlane Washington North FIPS 4601 Feet Disclaimer: This figure was created for a specific purpose and project. Any use of this figurefor any other project or purpose shall be at the user's sole risk and without liability to GeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of the figure, or data containedtherein. The file containing this figure is a copy of a master document, the original of which isretained by GeoEngineers and is the official document of record. Morris Ave S Morris Ave S Smithers Ave S Whitworth Ave S S P u g e t D r S 1 4 t h S t S 15th St Talbot Rd S Benso n Dr S Morris Ave S TalbotRdS S 17th St S 19th St S 16th St S 20th St Benson Dr S Talbot Hill Reservoir Park Talbot Hill 191 ft S 23rd St S 23rd St TalbotR d S Smithers Ave S S 21st St Bens on Dr S Thomas Teasdale Park GenCare Lifestyle Renton at The Lodge at Eagle Ridge A Block E a gle RidgeDr S S Eagle Ridge Dr S 18th St S P u g e t D r B e n s o n R d S S P u g e t D r S Puget Dr E agleRidge Dr S S18thSt Eagl e Ln S Eagle Ln S E agle Ln S Eagle L n S Eagle L n S B e n s o n R d S S P u g e t D rWells Ct S S 22 n d Ct B e n s o n R d S Victoria Hills A C D E Grant Av e S Tho m a s Ln Grant Ave S Thomas L n S Puget Dr D D D D D D D D D D D D D D D D D D D D D D DDDDDDDDDD D DDD D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D DDDDD Coal Mine Hazards Puget Sound Energy SWARR Station - Security Perimeter Maintenance Project Renton, Washington Figure 6 1 0 300 Feet Legend Site Parcel Boundary (King County) D Rebuild Fence - Approximate Location (2,133.3 feet) D Existing Fence (2,976.8 feet) Coalmine Hazards (City of Renton) Severity High Moderate P:\9\9186184\GIS\9186184_2024_Q4\9186184_2024_Q4.aprx\918618400tsk2032_F06_CoalMineHazards Date Exported: 12/18/24 by glohrmeyer Source(s):• Coalmine data from City of Renton• Parcels from King County• Basemap from ESRI Coordinate System: NAD 1983 StatePlane Washington North FIPS 4601 Feet Disclaimer: This figure was created for a specific purpose and project. Any use of this figurefor any other project or purpose shall be at the user's sole risk and without liability to GeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of the figure, or data containedtherein. The file containing this figure is a copy of a master document, the original of which isretained by GeoEngineers and is the official document of record. Morris Ave S Morris Ave S Smithers Ave S Whitworth Ave S S P u g e t D r S 1 4 t h S t S 15th St Talbot Rd S Benso n Dr S Morris Ave S TalbotRdS S 17th St S 19th St S 16th St S 20th St Benson Dr S Talbot Hill Reservoir Park Talbot Hill 191 ft S 23rd St S 23rd St TalbotR d S Smithers Ave S S 21st St Bens on Dr S Thomas Teasdale Park GenCare Lifestyle Renton at The Lodge at Eagle Ridge A Block E a gle RidgeDr S S Eagle Ridge Dr S 18th St S P u g e t D r B e n s o n R d S S P u g e t D r S Puget Dr E agleRidge Dr S S18thSt Eagl e Ln S Eagle Ln S E agle Ln S Eagle L n S Eagle L n S B e n s o n R d S S P u g e t D rWells Ct S S 22 n d Ct B e n s o n R d S Victoria Hills A C D E Grant Av e S Tho m a s Ln Grant Ave S Thomas L n S Puget Dr D D D D D D D D D D D D D D D D D D D D D D DDDDDDDDDD D DDD D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D DDDDD Landslide Severity Puget Sound Energy SWARR Station - Security Perimeter Maintenance Project Renton, Washington Figure 7 1 0 300 Feet Legend Site Parcel Boundary (King County) D D Rebuild Fence - Approximate Location (2,133.3 feet) D D Existing Fence (2,976.8 feet) Landslide Severity (City of Renton) High Moderate P:\9\9186184\GIS\9186184_2024_Q4\9186184_2024_Q4.aprx\918618400tsk2032_F07_LandslideSeverity Date Exported: 12/18/24 by glohrmeyer Source(s):• Landslide data from City of Renton• Parcels from King County• Basemap from ESRI Coordinate System: NAD 1983 StatePlane Washington North FIPS 4601 Feet Disclaimer: This figure was created for a specific purpose and project. Any use of this figurefor any other project or purpose shall be at the user's sole risk and without liability to GeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of the figure, or data containedtherein. The file containing this figure is a copy of a master document, the original of which isretained by GeoEngineers and is the official document of record. Ta l b ot Rd S S P u g e t D r Be n s on D r S 204 ft Ta l b o t Rd S S 16th St Be ns o n D r S Talbot Hill Reservoir Park S 21st St Willia m s A ve S Be ns o n D r S Altitude Apartments Eag l e Ridg eDr S S 1 8 t h S t S P u g e t D r S P u g e t D r S Puget D r Eag le Rid g e D r S S 1 8th S t Ea g l e L n S Eag l e Ln S E ag l e L n S E a gle Ln S Eagle Ln S Ea g l e L n S B e n s o n R d S S P u g e t D r Wel l s C t S S 2 2 n d Ct B e n s o n R d S D D D D D D D D D D D D D D D D D D D DD D D D D D D D D D D DDDDDDDDDDDDDDD D D D DDD D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D DDDDDDD 32 0 31 0 300290 28 0 27 0 26 0 2 0 24 0 22 0 21 0 20 0 18 0 17 0 16 0 1 0 1 4 0 13 0 34 033 0 32 0 310 22 0 210 200 110 100 210 200 33 0 23 0 190 12 0 3 0 2 6 0 90 3 3 0 290 280 23 0 1 8 0 13 0 13 0 8 0 Lidar Interpretation Puget Sound Energy SWARR Station - Security Perimeter Maintenance Project Renton, Washington Figure 8 1 0 200 Feet Legend Site Parcel Boundary (King County) D D Rebuild Fence - Approximate Location (2,133.3 feet) D D Existing Fence (2,976.8 feet) 2-foot Contour 10-foot Contour P:\9\9186184\GIS\9186184_2024_Q4\9186184_2024_Q4.aprx\918618400tsk2032_F08_LidarInterpretation Date Exported: 12/18/24 by glohrmeyer Source(s):• Topography from King County Lidar, 2021• Parcels from King County• Basemap from ESRI Coordinate System: NAD 1983 StatePlane Washington North FIPS 4601 Feet Disclaimer: This figure was created for a specific purpose and project. Any use of this figurefor any other project or purpose shall be at the user's sole risk and without liability to GeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of the figure, or data containedtherein. The file containing this figure is a copy of a master document, the original of which isretained by GeoEngineers and is the official document of record. Appendices Appendix A Site Plan and Groundwater Elevations – March 2011 MW-3 MW-4 MW-2 PUGET SOUND ENERGY PROPERTY MW-10 MW-8 MW-9 MW-7 MW-1 MW-5 Below Ground Above & Below Ground Culvert Above Ground Monitoring WellMW-1 Reference: Drawing entitled "Swarr Station, Drainage Plan" dated 04/01/03, by Standby Systems Inc. discussed in a related document. 2. This drawing is for information purposes. It is intended to assist in the identification of features 1. The locations of all features shown are approximate. Notes: Figure A-1 Site Plan PSE Swarr Station W E N Legend Feet Facility Boundary Aboveground Storage Tank HIGHWAY 515 - BENSON DRIVE SOUTH Below Ground Above & Below Ground Culvert Above Ground Reference: Drawing entitled "Swarr Station, Drainage Plan" dated 04/01/03, by Standby Systems Inc. document. 2. This drawing is for information purposes. It is intended to assist in showing features discussed in an attached 1. The locations of all features shown are approximate. Notes: Figure A-2 Groundwater Elevations - March 2011 PSE Swarr Station Feet Legend Monitoring Well Groundwater Contour (03/23/11) Groundwater Elevation (03/23/11) Groundwater Flow Direction Appendix B Site Photographs Figure B-1 Site Photographs September 12, 2024 Photograph 1. At site entrance gate, looking east along entrance driveway and area to south of driveway. Photograph 2. At site entrance gate, looking south along entrance driveway and area to south of driveway. Puget Sound Energy SWARR Station Renton, Washington 91 8 6 -18 4 -00 T a s k 2 0 3 2 D a t e E x p o r t e d : 1 0 / 1 4 / 2 0 2 4 C R W Disclaimer: This figure was created for a specific purpose and project. Any use of this figure for any other project or purpose shall be at the user's sole risk and without liability to GeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of the figure, or data contained therein. The file containing this figure is a copy of a master document, the original of which is retained by GeoEngineers and is the official document of record. Residential Properties Site Entrance Driveway Figure B-2 Site Photographs September 12, 2024 Photograph 3. At site entrance gate, looking north towards proposed fence location and area to north of driveway. Photograph 4. At site entrance gate, looking east along entrance driveway and area to north of driveway. 91 8 6 -18 4 -00 T a s k 2 0 3 2 D a t e E x p o r t e d : 1 0 / 1 4 / 2 0 2 4 C R W Disclaimer: This figure was created for a specific purpose and project. Any use of this figure for any other project or purpose shall be at the user's sole risk and without liability to GeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of the figure, or data contained therein. The file containing this figure is a copy of a master document, the original of which is retained by GeoEngineers and is the official document of record. Existing Fence Line Benson Drive South Proposed Fence Line Site Entrance Driveway Puget Sound Energy SWARR Station Renton, Washington Figure B-3 Site Photographs September 12, 2024 Photograph 5. East of site entrance gate, looking east towards east slopes, existing and proposed fence location and Rolling Hills Creek. Photograph 6. Rolling Hills Creek, looking south towards Rolling Hills Creek, culvert under site and outfall from South Puget Drive . 91 8 6 -18 4 -00 T a s k 2 0 3 2 D a t e E x p o r t e d : 1 0 / 1 4 / 2 0 2 4 C R W Disclaimer: This figure was created for a specific purpose and project. Any use of this figure for any other project or purpose shall be at the user's sole risk and without liability to GeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of the figure, or data contained therein. The file containing this figure is a copy of a master document, the original of which is retained by GeoEngineers and is the official document of record. Site Entrance Driveway and Shoulder Existing Fence Line Rolling Hills Creek Outfall Flow Channel and standing water from South Puget Drive Rolling Hills Creek Culvert Conveying Rolling Hills Creek under Project Site Puget Sound Energy SWARR Station Renton, Washington Figure B-4 Site Photographs September 12, 2024 Photograph 7. On east side of site, looking north along driveway. Photograph 8. Northeast side of site, looking north along driveway. 91 8 6 -18 4 -00 T a s k 2 0 3 2 D a t e E x p o r t e d : 1 0 / 1 4 / 2 0 2 4 C R W Disclaimer: This figure was created for a specific purpose and project. Any use of this figure for any other project or purpose shall be at the user's sole risk and without liability to GeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of the figure, or data contained therein. The file containing this figure is a copy of a master document, the original of which is retained by GeoEngineers and is the official document of record. Site entrance driveway and shoulder Slope drain outlet Proposed fence line Culvert that conveys stormwater to north side of site Proposed fence line Existing fence line Half-round culvert and flow direction Half-round culvert and flow direction Slope up to South Puget Drive Puget Sound Energy SWARR Station Renton, Washington Figure B-5 Site Photographs September 12, 2024 Photograph 9. Along east side of driveway, looking east towards South Puget Drive. Photograph 10. Slope drain and half-round culvert along east side of driveway, looking southeast towards slope. 91 8 6 -18 4 -00 T a s k 2 0 3 2 D a t e E x p o r t e d : 1 0 / 1 4 / 2 0 2 4 C R W Disclaimer: This figure was created for a specific purpose and project. Any use of this figure for any other project or purpose shall be at the user's sole risk and without liability to GeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of the figure, or data contained therein. The file containing this figure is a copy of a master document, the original of which is retained by GeoEngineers and is the official document of record. South Puget Drive Existing Fence Line Slope drain from South Puget Drive Half-round culvert and flow direction Puget Sound Energy SWARR Station Renton, Washington Figure B-6 Site Photographs September 12, 2024 Photograph 11. Near north end of site looking south. Photograph 12. Near north end of site looking southeast up slope towards South Puget Drive. 91 8 6 -18 4 -00 T a s k 2 0 3 2 D a t e E x p o r t e d : 1 0 / 1 4 / 2 0 2 4 C R W Disclaimer: This figure was created for a specific purpose and project. Any use of this figure for any other project or purpose shall be at the user's sole risk and without liability to GeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of the figure, or data contained therein. The file containing this figure is a copy of a master document, the original of which is retained by GeoEngineers and is the official document of record. Half-round culvert Site Entrance Driveway and Parking Area Slope drain from South Puget Drive South Puget Drive Existing fence line Puget Sound Energy SWARR Station Renton, Washington Figure B-7 Site Photographs September 12, 2024 Photograph 13. Looking west along fence line on north side of site towards Benson Drive South. Photograph 14. Fence line along north of site at area of erosion near Rolling Hills Creek and surface water erosion looking north. 91 8 6 -18 4 -00 T a s k 2 0 3 2 D a t e E x p o r t e d : 1 0 / 1 4 / 2 0 2 4 C R W Disclaimer: This figure was created for a specific purpose and project. Any use of this figure for any other project or purpose shall be at the user's sole risk and without liability to GeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of the figure, or data contained therein. The file containing this figure is a copy of a master document, the original of which is retained by GeoEngineers and is the official document of record. Benson Drive South Existing Fence Line Erosion at Rolling Hills Creek and swale outlet Existing Fence Line Puget Sound Energy SWARR Station Renton, Washington Figure B-8 Site Photographs September 12, 2024 Photograph 15. At northeast corner of the building, looking south. Photograph 16. North of site entrance gate, looking west towards Benson Drive South and area to north of driveway. 91 8 6 -18 4 -00 T a s k 2 0 3 2 D a t e E x p o r t e d : 1 0 / 1 4 / 2 0 2 4 C R W Disclaimer: This figure was created for a specific purpose and project. Any use of this figure for any other project or purpose shall be at the user's sole risk and without liability to GeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of the figure, or data contained therein. The file containing this figure is a copy of a master document, the original of which is retained by GeoEngineers and is the official document of record. Building Benson Drive South Swale and flow direction Proposed Fence LineDitch line Swale Existing Fence Line Puget Sound Energy SWARR Station Renton, Washington Figure B-9 Site Photographs September 12, 2024 Photograph 17. At west side of site, looking southwest along fence line towards slope and Benson Drive South. Photograph 18. On west side of building, looking south along proposed fence line location. 91 8 6 -18 4 -00 T a s k 2 0 3 2 D a t e E x p o r t e d : 1 0 / 1 4 / 2 0 2 4 C R W Disclaimer: This figure was created for a specific purpose and project. Any use of this figure for any other project or purpose shall be at the user's sole risk and without liability to GeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of the figure, or data contained therein. The file containing this figure is a copy of a master document, the original of which is retained by GeoEngineers and is the official document of record. Benson Drive South Existing Fence Line Benson Drive South Proposed Fence Line 2- to 3-foot-high rock wall and concrete ditch line Puget Sound Energy SWARR Station Renton, Washington Figure B-10 Site Photographs September 12, 2024 Photograph 19. On west side of site structures, looking south along proposed fence line and rock wall. Photograph 20. Southeast corner of site facility, looking west towards Benson Drive South. 91 8 6 -18 4 -00 T a s k 2 0 3 2 D a t e E x p o r t e d : 1 0 / 1 4 / 2 0 2 4 C R W Disclaimer: This figure was created for a specific purpose and project. Any use of this figure for any other project or purpose shall be at the user's sole risk and without liability to GeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of the figure, or data contained therein. The file containing this figure is a copy of a master document, the original of which is retained by GeoEngineers and is the official document of record. 2- to 3-foot-high rock wall and concrete ditch line and catch basin Proposed Fence Line 2- to 3-foot-high rock wall and concrete ditch line Proposed Fence Line Puget Sound Energy SWARR Station Renton, Washington Figure B-11 Site Photographs September 12, 2024 Photograph 21. At site entrance gate, looking northwest towards Benson Drive South, existing and proposed fence location and area to north of driveway. Photograph 22. North of site entrance gate, looking west towards Benson Drive South and area to north of driveway. 91 8 6 -18 4 -00 T a s k 2 0 3 2 D a t e E x p o r t e d : 1 0 / 1 4 / 2 0 2 4 C R W Disclaimer: This figure was created for a specific purpose and project. Any use of this figure for any other project or purpose shall be at the user's sole risk and without liability to GeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of the figure, or data contained therein. The file containing this figure is a copy of a master document, the original of which is retained by GeoEngineers and is the official document of record. Benson Drive South Site Entrance Driveway Shoulder Existing Fence Line Benson Drive South Existing Fence Line Proposed Fence Line Site Entrance Driveway Proposed Fence Line Puget Sound Energy SWARR Station Renton, Washington Figure B-12 Site Photographs September 12, 2024 Photograph 23. At northwest corner of site, looking west towards slope up to Benson Drive South 91 8 6 -18 4 -00 T a s k 2 0 3 2 D a t e E x p o r t e d : 1 0 / 1 4 / 2 0 2 4 C R W Disclaimer: This figure was created for a specific purpose and project. Any use of this figure for any other project or purpose shall be at the user's sole risk and without liability to GeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of the figure, or data contained therein. The file containing this figure is a copy of a master document, the original of which is retained by GeoEngineers and is the official document of record. Existing Fence Line Sediment and organic material captured behind fence Puget Sound Energy SWARR Station Renton, Washington Figure B-13 Site Photographs September 12, 2024 Photograph 24. At gravel walkway to building, looking south along parking area and concrete swale. Photograph 25. At gravel walkway to building, looking northwest towards underground tank area north of building and along concrete swale. 91 8 6 -18 4 -00 T a s k 2 0 3 2 D a t e E x p o r t e d : 1 0 / 1 4 / 2 0 2 4 C R W Disclaimer: This figure was created for a specific purpose and project. Any use of this figure for any other project or purpose shall be at the user's sole risk and without liability to GeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of the figure, or data contained therein. The file containing this figure is a copy of a master document, the original of which is retained by GeoEngineers and is the official document of record. Site driveway and parking area Existing Fence Line Concrete drainage swale and flow direction Benson Drive South Concrete drainage swale Puget Sound Energy SWARR Station Renton, Washington Figure B-14 Site Photographs September 12, 2024 Photograph 26. At southeast corner of Project area, looking west towards Benson Drive South along site entrance driveway and Rolling Hills Creek. Photograph 27. At southeast corner of Project area and Rolling Hills Creek, looking east towards overflow half round. 91 8 6 -18 4 -00 T a s k 2 0 3 2 D a t e E x p o r t e d : 1 0 / 1 4 / 2 0 2 4 C R W Disclaimer: This figure was created for a specific purpose and project. Any use of this figure for any other project or purpose shall be at the user's sole risk and without liability to GeoEngineers. The locations of features shown may be approximate. GeoEngineers makes no warranty or representation as to the accuracy, completeness, or suitability of the figure, or data contained therein. The file containing this figure is a copy of a master document, the original of which is retained by GeoEngineers and is the official document of record. Benson Drive South Site Entrance Driveway Rolling Hills Creek and culvert inlet Proposed Fence Line Existing fence line Overflow half-round Rolling Hills Creek and culvert inlet Puget Sound Energy SWARR Station Renton, Washington Appendix C Report Limitations and Guidelines for Use Puget Sound Energy | March 5, 2026 Page C-1 File No. 9186-184-00 Task 2032 Appendix C Report Limitations and Guidelines for Use1 This appendix provides information to help you manage your risks with respect to the use of this report. REPORT USE AND RELIANCE This report has been prepared for Puget Sound Energy. GeoEngineers structures its services to meet the specific needs of its clients. No party other than Puget Sound Energy may rely on the product of our services unless we agree to such reliance in advance and in writing. Within the limitations of the agreed scope of services for the project, and its schedule and budget, our services have been executed in general accordance with the Statement of Work #CW2263712, our Master Services Agreement with the Client # CW2233188 dated November 18, 2014, and generally accepted geotechnical practices in this area at the time this report was prepared. We do not authorize, and will not be responsible for, the use of this report for any purposes or projects other than those identified in this report. If changes to the project or property occur after the date of this report, GeoEngineers cannot be responsible for any consequences of such changes in relation to this report unless we have been given the opportunity to review our interpretations and recommendations in the context of such changes. Based on that review, we can provide written modifications or confirmation, as appropriate. INFORMATION PROVIDED BY OTHERS GeoEngineers has relied upon certain data or information provided or compiled by others in the performance of our services. Although we use sources that we reasonably believe to be trustworthy, GeoEngineers cannot warrant or guarantee the accuracy or completeness of information provided or compiled by others. CONDITIONS CAN CHANGE This report is based on conditions that existed at the time the study was performed. The findings and conclusions of this report may be affected by the passage of time, by events such as construction on or adjacent to the site, new information or technology that becomes available subsequent to the report date, or by natural events such as floods, earthquakes, slope instability or groundwater fluctuations. If more than a few months have passed since issuance of our report or work product, or if any of the described events may have occurred, please contact GeoEngineers before applying this report for its intended purpose so that we may evaluate whether changed conditions affect the continued reliability or applicability of our conclusions and recommendations. PROFESSIONAL JUDGMENT It is important to recognize that the geoscience practices (geotechnical engineering, geology, and environmental science) rely on professional judgment and opinion to a greater extent than other engineering and natural science disciplines, where more precise and/or readily observable data may exist. 1 Developed based on material provided by ASFE, Professional Firms Practicing in the Geosciences; www.asfe.org. Puget Sound Energy | March 5, 2026 Page C-2 File No. 9186-184-00 Task 2032 To help clients better understand how this difference pertains to its services, GeoEngineers includes these explanatory “limitations” provisions in its reports. Please confer with GeoEngineers if you need to know how these “Report Limitations and Guidelines for Use” apply to your Project or site.