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HomeMy WebLinkAboutSR_Boeing Apron_A_ERC_Report_200622_v2_FINALDEPARTMENT OF COMMUNITY AND ECONOMIC DEVELOPMENT Project Location Map ERC REPORT LUA18-000293 ENVIRONMENTAL REVIEW COMMITTEE REPORT ERC MEETING DATE: June 22, 2020 Project File Number: PR20-000115, ECF, SSDP Project Name: Boeing Apron A Stormwater Upgrade Land Use File Number: LUA20-000093 Project Manager: Alex Morganroth, Senior Planner Owner: The City of Renton, 1055 S Grady Way, Renton, WA 98057 Applicant/Contact: Mark Clement, PO Box 3707, MC 66-102, Seattle, WA 98124 Project Location: 616 W Perimeter Road, Renton, WA 98054 Project Summary: The applicant is requesting a Shoreline Substantial Development Permit and Environmental (SEPA) Review for a utilities upgrade project at 616 W Perimeter Rd, the Renton Municipal Airport (0723059007). The site is zoned IM - Medium Industrial and is located in the Employment Area (EA) Comprehensive Plan Land Use designation. Apron A is located on the eastern side of the airport property along the west bank of the Cedar River. The site is located within the Shoreline Jurisdiction of the Cedar River, Reach A, designated as Shoreline High Intensity. The applicant has proposed various storm water conveyance system upgrades for the W-1 parking lot on Apron A as well as the aircraft stall areas (stalls A1-A7) including the installation of 625 linear feet of new conveyance pipe, six modular wetlands, and seven storm drainage catch basins. The project would also include the installation of new spill containment valves, an oil/water separator, and spill diversion system near the A7 aircraft stall area. No above-ground structures are proposed as part of the project. Utility replacement work would occur approximately 40 feet from the Cedar River OHWM at the closest point. No new impervious surface would be added to the area and no trees and/or existing vegetation would be removed as a result of the proposed project. The applicant provided a Stream Study, Drainage Report, and Geotechnical Report with the application. Exist. Bldg. Area SF: N/A Proposed New Bldg. Area (footprint) Proposed New Bldg. Area (gross): N/A N/A Site Area: 6,640,721 SF (153.2 acres) Total Building Area GSF: N/A STAFF RECOMMENDATION: Staff Recommends that the Environmental Review Committee issue a Determination of Non-Significance – Mitigated (DNS-M). City of Renton Department of Community & Economic Development Environmental Review Committee Report BOEING APRON A STORMWATER UPGRADE PROJECT LUA20-000093, ECF, SSDP Report of June 22, 2020 Page 2 of 6 ERC REPORT LUA20-000093 PART ONE: ENVIRONMENTAL REVIEW In compliance with RCW 43.21C.240, the following environmental (SEPA) review addresses only those project impacts that are not adequately addressed under existing development standards and environmental regulations. A. Environmental Threshold Recommendation Based on analysis of probable impacts from the proposal, staff recommends that the Responsible Officials: Issue a DNS-M B. Mitigation Measures 1. The applicant shall comply with the recommendations of the geotechnical report prepared by S&EE, dated March 20, 2020, or an updated report submitted at a later date. 2. If any Native American grave(s) or archaeological/cultural resources (Indian artifacts) are found all construction activity shall stop in accordance with RCW 27.53.060 and 27.44.020, and the owner/developer shall immediately notify the City of Renton planning department, concerned Tribes’ cultural committees, and the Washington State Department of Archeology and Historic Preservation. 3. The applicant shall submit an Archaeological Monitoring and Inadvertent Discovery Plan MIDP to DAHP and any interested Tribes for review prior to the start of any ground disturbing activities. Documentation of the submittal shall be provided to the City of Renton prior to the issuance of building or construction permits. C. Exhibits Exhibit 1: Environmental Review Committee (ERC) Report Exhibit 2: Site Plan Exhibit 3: Grading Plan Exhibit 4: Construction Mitigation Description Exhibit 5: Drainage Report, prepared by DOWL, dated March, 2020 Exhibit 6: Conceptual Drainage/Utilities Plan, prepared by DOWL, dated March 2020 Exhibit 7: Geotechnical Report, prepared by S&EE, dated March, 2020 Exhibit 8: Stream Study, prepared by Wood Environmental and Infrastructure Solutions, dated March 31, 2020 Exhibit 9: Potential Levy Impact Letter, prepared by S&EE, dated March 19, 2020 D. Environmental Impacts The proposal was circulated and reviewed by various city departments and divisions to determine whether the applicant has adequately identified and addressed environmental impacts anticipated to occur in conjunction with the proposed development. Staff reviewers have identified that the proposal is likely to have the following probable impacts: 1. Earth Impacts: The subject site is located in an area with a known seismic hazard. As such the applicant submitted a Geotechnical Report, prepared by S&EE, dated March, 2020 (Exhibit 7). The analysis in the report primarily focused on the area within Apron A where new stormwater improvements are proposed. S&EE relied on the soil characteristics observed in prior geotechnical reports prepared for Boeing for work on Apron A, as well as new laboratory testing of a soil borings collected near the proposed work. City of Renton Department of Community & Economic Development Environmental Review Committee Report BOEING APRON A STORMWATER UPGRADE PROJECT LUA20-000093, ECF, SSDP Report of June 22, 2020 Page 3 of 6 ERC REPORT LUA20-000093 Similar to the results of previous borings near the site, the new borings found fill approximately three to eight feet (3’-8’) in thickness primarily consisting of loose sand with gravel. Native alluvial soils with varying degrees of density then extend approximately 100 feet below the fill. Older alluvial soils consisting of medium dense to dense sand, silt and silty clay were found up to a depth of between 150 and 170 feet. S&EE estimates that the depth of the groundwater is approximately four to seven feet below the ground surface and is likely to fluctuate due to Apron A’s close proximity to the river. According to the City of Renton Critical Areas Maps, the project site is located in a seismic hazard area. The submitted geotechnical report concluded that the project site is located in an area of high liquefaction potential due the close proximity to the Seattle Fault. Even with the high potential for liquefaction near the project area during an earthquake, the report finds the use of a conventional spread concrete footings to be acceptable for any light-weight structures associated with the project (i.e. small utility structures). Due to the close proximity to the river and high saturation potential of the soil, S&EE also makes recommendations regarding the temporary excavations required during construction including recommendations on slope angle and shoring methods. Lastly, the report makes a number of recommendations on the repaving of the apron area including proof-rolling before pouring new concrete in order to find soft spots, introduction of woven geotextile for subgrade stabilization, and the use of particular asphalt pavement types that would be most appropriate for the soil on the site. Due to the inclusion of specific recommendations provided in the geotechnical report, staff recommends as a mitigation measure that the applicant comply with the recommendations in the provided report or an updated report submitted with the construction permit. The geotechnical report would be required to be submitted with the construction permit application for the utility work and compliance with the recommendations would be reviewed at that time. The applicant has indicated the project would result in approximately 21,745 square feet of replaced impervious area. The project would not increase the impervious coverage on-site overall. Mitigation Measures: The applicant shall comply with the recommendations of the geotechnical report prepared by S&EE, dated March 20, 2020, or an updated report submitted at a later date. Nexus: SEPA Environmental Review, RMC 4-4-060 Grading, Excavation and Mining Regulations 2. Air Impacts: It is anticipated that some temporary air quality impacts could be associated with site work and building construction required to complete the proposed project at this site. Project development impacts during construction activities may include dust as a result of concrete replacement and utility work, as well as exhaust from construction vehicles, equipment and/or machinery. These emissions would be temporary and are anticipated to rapidly dissipate. Dust control would be mitigated through the use of temporary erosion control measures, watering or other best management practices as identified in the construction mitigation memo provided by the applicant (see Exhibit 4). No further site specific mitigation is recommended for the identified impacts from typical vehicle and construction exhaust. Mitigation Measures: No further mitigation recommended. Nexus: N/A 3. Water a. Storm Water Impacts: The applicant submitted a Preliminary Drainage Plan and Technical Information Report (TIR) prepared by DOWL, dated March 20, 2020 (Exhibit 8). The project contains greater than 2,000 square feet of replaced impervious surface and therefore the development is subject to Full Drainage Review in accordance with the 2017 Renton Surface Water Design Manual (RSWDM). Based on the City of Renton’s flow control City of Renton Department of Community & Economic Development Environmental Review Committee Report BOEING APRON A STORMWATER UPGRADE PROJECT LUA20-000093, ECF, SSDP Report of June 22, 2020 Page 4 of 6 ERC REPORT LUA20-000093 map, the site falls within the Peak Rate Flow Control Standard area matching Existing Site Conditions and is within the Lake Washington and Cedar River Drainage Basin. All nine core requirements and the six special requirements have been discussed in the TIR. The project site is located within the Lake Washington and Cedar River drainage basin. The flowpath from the project site discharge point is less than a half mile to the 100-year floodplain of Lake Washington; therefore, the project qualifies for the direct discharge exemption in accordance with Section 1.2.3.1 of the 2017 RSWDM and must adhere to all requirements thereof. The project is classified as a redevelopment project in accordance with the definition of redevelopment project provided in the RSWDM. As a redevelopment project, the project is exempt from Core Requirement #8 – Water Quality as it meets the exemption criteria outlined in Section 1.2.8 of the RSWDM - #3 Cost Exemption for Parcel Redevelopment Projects. However, the applicant has elected to provide enhanced water quality treatment prior to discharge in order to provide a benefit to Lake Washington and its aquatic habitat. Project water quality treatment will consist of surface water conveyance to oil/water separator vaults, which will direct surface water to several Linear Modular Wetland systems prior to discharge to the outfalls in Lake Washington. A Construction Stormwater General Permit from Department of Ecology will be required if grading and clearing of the site exceeds one acre. A Stormwater Pollution Prevention Plan (SWPPP) is required for this site. b. Wetlands, Streams, Lakes Impacts: The project site is located along the western shore of the Cedar River, a Shoreline of the State. Reach A of the Cedar River Shoreline is designated as High Intensity at the project location. Due to the utility work being located within 200 feet of the OHWM of the Cedar River, the applicant prepared a Standard Stream Study Narrative prepared by Wood Infrastructure and Environmental Solutions and dated March 31, 2020 (Exhibit 8). The submitted report identified existing riparian and aquatic conditions in the area directly adjacent to the proposed utility work on Apron A. Due to the channeling of the river and highly-developed nature of both river banks, the report states that the extremely limited riparian areas near the project site likely provide little ecological function. The report concludes that regardless of how the areas function, work on the proposed project would occur outside of these narrow riparian areas and are unlikely to impact the Cedar River’s aquatic or riparian habitats. The proposed project would be confined to the airport property and no trees or riparian vegetation would be removed. No new lighting is proposed as part of the project and no components of the subject project would occur below the OHWM of the Cedar River. According to the consultant, the project would result in no net loss of ecological function in either the Cedar River’s riparian zone or aquatic zone within 100 feet upstream and downstream of the project site. In addition, the applicant submitted a Construction Mitigation Description that identifies erosion control best practices that would be utilized to prevent contaminants from entering the river (Exhibit 4). Therefore based on the finding of no net loss of ecological functions from the consultant and proposed erosion control measures, staff does not recommend any specific mitigation measures related to impacts to the Cedar River. Mitigation Measures: No further mitigation required. Nexus: Not applicable 4. Wildlife Impacts: According to the Environmental Checklist submitted by the applicant, the project is located in an area of threatened species under the Endangered Species Act, the Puget Sound Chinook salmon and Puget Sound steelhead trout. The utility work proposed would occur as close as 20 feet away from the Cedar River OHWM, a distance within the 200 foot shoreline buffer. Based on the Standard Stream Study Narrative submitted by the applicant (Exhibit 8), no net loss of ecological function is anticipated as a result of the project. According to the report, the no net loss determination is primarily a result of the developed nature of the site City of Renton Department of Community & Economic Development Environmental Review Committee Report BOEING APRON A STORMWATER UPGRADE PROJECT LUA20-000093, ECF, SSDP Report of June 22, 2020 Page 5 of 6 ERC REPORT LUA20-000093 and nearby river bank, the lack of vegetation removal in the proposal, and the fact that no new lighting is proposed. Mitigation Measures: None Nexus: N/A 5. Historic and Cultural Preservation Impacts: In the SEPA checklist the applicant indicated that they completed a search of the Washington State Information System of Architectural and Archaeological Records Data. The Checklist concludes that the system did not identify any properties within the project area as being on the historic property inventory or register. The northern portion of the airport was once under the surface of Lake Washington. In addition the Black River used to run out of the lake, flow south through the airport and then west. Based on the probability of the subject site being along the banks of an old river channel and lake shore there is a higher likelihood of cultural resources discovery, through ground disturbing activity. As such, staff recommends as a mitigation measure that if any Native American grave(s) or archaeological/cultural resources (Indian artifacts) are found all construction activity shall stop in accordance with RCW 27.53.060 and 27.44.020, and the owner/developer shall immediately notify the City of Renton planning department, concerned Tribes’ cultural committees, and the Washington State Department of Archeology and Historic Preservation. The SEPA checklist indicates that if any archaeological resources are encountered a professional Archaeologist would be called to assess the significance of the find. Due to parts of the proposed project that would occur under the existing pervious surface, the applicant is recommended to hire a professional archeologist to monitor ground disturbing activities. In addition, the applicant shall prepare an archaeological monitoring and inadvertent discovery plan (MIDP) to be submitted to DAHP and the interested Tribes for review prior to any ground disturbance. Mitigation Measures: 1. If any Native American grave(s) or archaeological/cultural resources (Indian artifacts) are found all construction activity shall stop in accordance with RCW 27.53.060 and 27.44.020, and the owner/developer shall immediately notify the City of Renton planning department, concerned Tribes’ cultural committees, and the Washington State Department of Archeology and Historic Preservation. 2. The applicant shall submit an Archaeological Monitoring and Inadvertent Discovery Plan MIDP to DAHP and any interested Tribes for review prior to the start of any ground disturbing activities. Documentation of the submittal shall be provided to the City of Renton prior to the issuance of building or construction permits. Nexus: SEPA Environmental Review, RCW 27.53 Archaeological Sites and Resources, and RCW 27.44 Indian Graves and Records. E. Comments of Reviewing Departments The proposal has been circulated to City Department and Division Reviewers. Where applicable, their comments have been incorporated into the text of this report and/or listed under Exhibit 10 “Plan Review Comments to Applicant.”  Copies of all Review Comments are contained in the Official File and may be attached to this report.