HomeMy WebLinkAboutSR_ERC_Report_Windsock_Apron_and_243_Building_241023_FINALDEPARTMENT OF COMMUNITY
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SR_ERC_Report_Windsock Apron and 243 Building_241023_v1
ENVIRONMENTAL REVIEW COMMITTEE REPORT
ERC Meeting Date: October 28, 2024
Project File Number: PR24-000063
Project Name: Renton Windsock and 243 Building Apron Project
Land Use File Number: LUA24-000299, ECF, SME
Project Manager: Alex Morganroth, Principal Planner
Applicant: William Adams / 616 West Perimeter Rd, Renton, WA 98057 / wadams@rentonwa.gov
Contact: Wes Holden / 15325 SE 30th Pl, Ste 300 / Bellevue, WA 98007 / wholden@dowl.com
Owner: City of Renton – Renton Municipal Airport / 616 West Perimeter Rd, Unit A, Renton, WA
98057 / wadams@rentonwa.gov
Project Location: 243 W Perimeter Rd and 749 E Perimeter Rd (APN 0723059007)
Project Summary: The applicant, the City of Renton, is requesting Environmental (SEPA) Review and a Shoreline
Exemption for a maintenance and improvement project at the Renton Municipal Airport site
located at 243 W Perimeter Rd and 749 E Perimeter Rd (APN 0723059007). The airport site
totals 152.5 acres in area and is located within the Medium Industrial (IM) zone. The site is
within the Comprehensive Plan Employment Area (EA) land use designation. The proposed
work includes rehabilitation of pavement sections at two (2) aprons at the airport. The first
apron, designated as the 243 Building Apron, is located at the SW corner of the airport site.
The second apron, designated as the Windsock Apron, is located around the mid-point of the
runway on the east side of the airport adjacent to E Perimeter Rd and the Cedar River. The
applicant is proposing full depth pavement repair, replacement of aircraft tiedowns, and
minor stormwater conveyance system improvements at both project locations. In addition,
the 243 Building Apron includes a publicly accessible parking lot proposed for full depth
pavement repair and restriping. No parking stalls are proposed for removal. Work is proposed
within 100 feet (100’) of the Cedar River ordinary high-water mark (OHWM), but no in-water
work is proposed. A high seismic hazard area, high erosion hazard area, sensitive and
protected slopes, and Wellhead Protection Area Zones 1 and 2 are mapped on the airport
site according to City of Renton (COR) Maps. A Flood Hazard Area pursuant to the FEMA Flood
Insurance Rate Maps (FIRM) is also located on the subject site. The hazard area on the site, a
Special Flood Zone AE (base flood elevation determined), is classified as a 100-year flood
plain. The FIRM maps indicate the base flood elevation to be 26 feet (26’) Mean Sea Level
(MSL). In addition, a portion of proposed improvements are located within Reach A of the
Cedar River, a Shoreline of the State, with an Environmental Designation of Shoreline High
Intensity. No vegetation is proposed for removal.
Exist. Bldg. Area: N/A Proposed New Bldg. Area (footprint):
Proposed New Bldg. Area (gross):
N/A
N/A
Site Area: 6,640,728 SF Total Building Area GSF: N/A
STAFF
RECOMMENDATION:
Staff Recommends that the Environmental Review Committee issue a Determination of
Non-Significance - Mitigated (DNS-M).
Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7
City of Renton Department of Community & Economic Development
Renton Windsock and 243 Building Apron Projectt
Staff Report to the Environmental Review Committee
LUA24-000299, ECF, SME
Report of October 28, 2024 Page 2 of 7
SR_ERC Report_Windsock Apron and 243 Building_241023_DRAFT
Project Location Map
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 with a 14-day appeal period
B. Mitigation Measures
1. The applicant shall comply with the recommendations found in the submitted Geotechnical Report,
prepared by HWA Geosciences, Inc., dated November 2, 2023, and any future addenda.
2. The applicant shall submit an Archaeological Monitoring and Inadvertent Discovery Plan (MIDP) to the
Department of Archaeology and Historic Preservation (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: SEPA Checklist, prepared on July 18, 2024
Exhibit 3: Neighborhood Detail Map
Exhibit 4: Civil Construction Plans
Exhibit 5: Construction Mitigation Description
Exhibit 6: Geotechnical Report, prepared by HWA Geosciences, Inc, dated November 2, 2023
Exhibit 7: Draft Technical Information Report, prepared by DOWL, LLC, dated June 2024
Exhibit 8: Habitat Data Report, prepared by DOWL, LLC, dated July 22, 2024
Exhibit 9: Stream Assessment, prepared by DOWL, LLC, dated July 22, 2024
Exhibit 10: Duwamish Tribe Comment Letter, dated September 20, 2024
Exhibit 11: City Response to Duwamish Tribe Comments, dated September 20, 2024
Exhibit 12: Advisory Notes
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
Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7
City of Renton Department of Community & Economic Development
Renton Windsock and 243 Building Apron Projectt
Staff Report to the Environmental Review Committee
LUA24-000299, ECF, SME
Report of October 28, 2024 Page 3 of 7
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the proposed development. Staff reviewers have identified that the proposal is likely to have the following probable
impacts:
1. Earth
Impacts: The 6,640,728 square foot (152.5 acres) subject property is currently developed with a municipal
airport including a runway, taxiways, apron areas, and a variety of buildings and uses associated with
aviation. Work proposed by the applicant would be concentrated within two (2) separate apron areas, the
Windsock Apron on the east side of the site at 749 E Perimeter Rd and the 243 Building Apron near the
southwest corner of the site (Exhibit 3). The site topography is almost completely flat with a grade change
of approximately three percent (3%) across the property (Exhibit 6). City of Renton (COR) Maps has
identified a High Seismic Hazard Area, sensitive and protected slopes, and a High Erosion Hazard. As such,
the applicant submitted a Geotechnical Report, prepared by HWA Geosciences, Inc., dated November 2,
2023, with the application (Exhibit 6). A total of 49,091 square feet of regrading and excavation is
proposed at the 243 Building Apron and parking area. A total of 66,725 square feet of regrading and
excavation is proposed at the Windsock Apron. The project would result in 45.69 cubic yards of net fill.
The geotechnical engineer completed a geotechnical investigation on August 21, 2023. The investigation
program included the drilling of seven (7) test pits to assess soil conditions using a truck-mounted drill rig
with hollow stem auger. All borings completed for the geotechnical engineering study were excavated to
depths of approximately 11.5 feet (11.5’). According to the report, subsurface conditions encountered in
the explorations were different at the two (2) sites evaluated. Subsurface conditions adjacent to the 243
Building Apron encountered loose, silty sand and gravel below the existing pavement section. The
Windsock Apron area is primarily underlain by subgrade soils consisting of soft to very soft silt and loose
to very loose silty sand.
At the Windsock Apron site, groundwater seepage was encountered at depths of approximately 3.9, 4.5,
5, and 6 feet below ground surface at various borings. Borings taken near the 243 Building Apron
encountered groundwater seepage at depths of 8 to 10 feet below ground surface. The report notes that
surface water runoff, groundwater recharge, and lake water levels likely all affect groundwater levels at
the airport and that groundwater levels are highest near the end of the wet winter months and lower
during the dry summer months.
According to the geotechnical engineer, results from the various tests indicate the presence of soft to very
soft, fine-grained soils, including layers of peat and organic silt, which will likely require stabilization before
new pavement is constructed. The report also includes other recommendations related to compaction,
excavation and removal of unsuitable soil, and wet weather earthwork. As such, staff recommends a
mitigation measure that the applicant comply with the recommendations found in the submitted
Geotechnical Report, prepared by HWA Geosciences, Inc., dated November 2, 2023 and any future
addenda.
Mitigation Measure: The applicant shall comply with the recommendations found in the submitted
Geotechnical Report, prepared by HWA Geosciences, Inc., dated November 2, 2023 and any future
addenda.
Nexus: State Environmental Policy Act (SEPA) Environmental Review; City of Renton Comprehensive Plan
Policy L-36; RMC 4-3-050 Critical Areas Regulations; and 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
required to complete the proposed project at this site. Project development impacts during construction
activities may include dust as a result of the concrete/asphalt cutting, grading, and paving, as well as
Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7
City of Renton Department of Community & Economic Development
Renton Windsock and 243 Building Apron Projectt
Staff Report to the Environmental Review Committee
LUA24-000299, ECF, SME
Report of October 28, 2024 Page 4 of 7
SR_ERC Report_Windsock Apron and 243 Building_241023_DRAFT
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. Once completed, the site
operations are expected to have minimal air quality impacts since only electric vehicles will be sold and
serviced. Therefore, no further site-specific mitigation for the identified impacts from typical vehicle
exhaust and construction dust is recommended.
Mitigation Measures: No further mitigation recommended.
Nexus: Not applicable.
3. Water
a. Stormwater
Impacts: The applicant submitted a Draft Technical Information Report, prepared by DOWL, LLC, dated
June 2024 (Exhibit 7). 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 2022 Renton
Surface Water Design Manual (RSWDM). Based on the city’s flow control map, this site falls within the
Peak Rate Flow Control Standard (Matching Existing Peak Conditions). The Windsock Apron area falls
within Lower Cedar River Basin, and the 243 Building Apron and associated parking lot falls within West
Lake Washington – Seattle South Basin. All nine (9) core requirements and the six (6) special requirements
have been discussed in the TIR.
According to the submitted TIR, the Windsock Apron rehabilitation adds no new impervious surface. The
243 Building Apron and parking lot rehabilitation would add approximately 4,369 square feet of new
impervious surface. The applicant contends the proposed project does not substantially increase flows
and the impact to downstream would be minimal, eliminating the need for offsite analysis. Staff reviewed
the preliminary analysis and determined that while acceptable for the Windsock Apron area, a Level 1
downstream analysis shall be provided for the 243 Building Apron and parking area as part of the Final TIR
submitted with the civil construction permit as the installation of more than 2,000 square feet of new
impervious surface is not exempt.
The TIR contends the Windsock Apron portion of the project is qualified for a flow control exemption since
no new impervious surfaces are proposed and no increase in flows between the developed condition and
existing conditions during the 100-year storm event are anticipated. Staff has reviewed the preliminary
analysis and determined it is conceptually acceptable with further review to occur at the time for formal
civil construction permit review.
Appropriate on-site BMPs satisfying Core Requirement #9 are required to help mitigate the new runoff
created by the development to the maximum extent feasible. On-site BMPs, as described in Section C.1.3
of the 2022 RSWDM, would be evaluated as part of the review of the final drainage plan and drainage
report submitted with the construction permit application. No further site-specific mitigation is
recommended.
Mitigation Measures: No further mitigation recommended.
Nexus: Not applicable.
b. Ground Water
Impacts: The COR mapping system has identified the property as located within the Downtown Wellhead
Protection Zones 1 and 2. No work would occur in the Downtown Wellhead Protection Zone 1. Open
facilities and open conveyance systems may require a liner in accordance with the 2022 Renton Surface
Water Design Manual. The implementation of best management practices (BMPs) for stormwater control
is preferable, and BMPs that rely on infiltration are allowed in Zone 2. Fill materials shall be from a
verifiable source in order to ensure it is clear of contaminants. The city’s grading and excavation
Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7
City of Renton Department of Community & Economic Development
Renton Windsock and 243 Building Apron Projectt
Staff Report to the Environmental Review Committee
LUA24-000299, ECF, SME
Report of October 28, 2024 Page 5 of 7
SR_ERC Report_Windsock Apron and 243 Building_241023_DRAFT
regulations require imported fill in excess of 50 cubic yards within a Wellhead Protection Zone 1, or within
100 cubic yards within a Wellhead Protection Zone 2, to provide a source statement certified by a qualified
professional or confirm the fill was obtained from a Washington State Department of Transportation
(WSDOT) approved source.
Mitigation Measures: No further mitigation recommended.
Nexus: Not applicable.
c. Wetlands, Streams, Lakes Impacts:
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 Windsock Apron project
location. Due to the location of the work proposed on the Windsock Apron, within 200 feet (200’) of the
OHWM of the Cedar River, the applicant submitted a Habitat Data Report, prepared by DOWL, LLC, dated
July 22, 2024 and a Stream Assessment, prepared by DOWL, LLC, dated July 22, 2024 (Exhibits 8 and 9).
According to the Stream Assessment, the Windsock Apron project area is entirely covered with pavement
and the surrounding areas to the south and west are mowed grasses. Therefore, the proposal would not
impact any vegetation in the vicinity of the Cedar River. The Cedar River, which provides instream habitat
for salmonid species and prey species including sculpin and lamprey, serves as an important migration
corridor, and outlets to Lake Washington and eventually to the Puget Sound.
However, the Stream Assessment notes that the reach of the Cedar River flowing through Renton has
limited ecological functions due to significant urban development adjacent to the river. While trees and
shrubs along the bank provide some shading and nutrient input, the riparian corridor is limited due to
adjacent development of the airport site and Boeing manufacturing plant. The report concludes that the
proposal would not result in any impacts to the Cedar River and therefore achieves no net loss of
ecological functions.
The Habitat Data Report identifies little to no habitat features on either the Windsock Apron or 243
Building Apron sites. According to the report, the maintained lawn near the 243 Apron proposed for
removal provides limited habitat for small mammals and city birds. In addition, the Washington
Department of Fish and Wildlife (WDFW) Priority Habitats and Species map tool show there are no priority
wildlife species present of the airport. However, the Cedar River contains priority species including
sockeye (Oncorhynchus nerka), coho (Onchorhynchus kisutch), chinook (Oncorhynchus tshawytscha),
cutthroat trout (Oncorhyncus clarkii), kokanee (Oncorhyncus nerka), steelhead (Oncorhyncus mykiss),
Dolly Varden (Salvelinus malma), and bull trout (Salvelinus confluentus). The report concludes that, similar
to the Stream Assessment, the project would not result in any impacts to wildlife near the airport site and
therefore no specific on-site mitigation is recommended.
Mitigation Measures: No further mitigation recommended.
Nexus: Not applicable.
4. Environmental Health
a. Hazards
Impacts: The Washington State Department of Ecology’s (DOE) Spills and Cleanup map, as well as the
SEPA Checklist (Exhibit 2) identifies three (3) cleanup sites at the Renton Municipal Airport, the Action
Aviation site (ID# 6266). The three (3) sites are associated with aviation facilities on the airport property.
One site has the status “cleanup complete”, one has the status “awaiting cleanup”, and one has the status
“clean up started”. The cleanup sites are outside of the Building 243 Apron and Windsock Apron project
areas and therefore would not be impacted by the proposed work.
Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7
City of Renton Department of Community & Economic Development
Renton Windsock and 243 Building Apron Projectt
Staff Report to the Environmental Review Committee
LUA24-000299, ECF, SME
Report of October 28, 2024 Page 6 of 7
SR_ERC Report_Windsock Apron and 243 Building_241023_DRAFT
Mitigation Measures: No further mitigation recommended.
Nexus: Not applicable.
b. Noise
Impacts: Noise impacts would primarily result from the apron and parking lot rehabilitation work
proposed on the site and associated heavy equipment. The construction noise would be regulated through
the city’s adopted noise level regulations per Chapter 8-7, RMC. The city’s noise regulations limit haul
hours between 8:30 am to 3:30 pm, Monday through Friday unless otherwise approved by the
Development Services Division. Permitted work hours in or near residential areas are restricted to the
hours between seven o’clock (7:00) a.m. and eight o’clock (8:00) p.m. from Monday through Friday. Work
on Saturdays is restricted to the hours between nine o’clock (9:00) a.m. and eight o’clock (8:00) p.m. No
work is permitted on Sundays.
Temporary noise impacts are anticipated that would be commonly associated with the grading, paving,
and utility trenching improvements.
Mitigation Measures: No further mitigation recommended.
Nexus: Not applicable.
5. Historic and Cultural Preservation
Impacts: In the SEPA Environmental Checklist (Exhibit 2), the applicant indicated there are no known
Native American cultural resources present on the site. However, the applicant notes the project is located
within the ancestral lands of the Duwamish people and therefore, there is a higher likelihood of cultural
resources discovery through ground disturbing activity. According to the checklist, the Department of
Archaeology and Historic Preservation (DAHP) Statewide Predictive Model classifies the airport site as
Moderate to Very High Risk for containing precontact-era archaeological resources. In addition, the
checklist identifies 15 recorded archaeological sites within one (1) mile of the airport, including six (6)
precontact-era site and nine (9) historic-era sites as identified by DAHP. Two (2) of the archeological sites
are within the airport site boundaries but outside of where the work would occur. A representative of the
Duwamish Tribe submitted a comment letter (Exhibit 10) to city staff via email on September 20, 2024
indicating the project site is an area the tribe considers a high risk of containing archeological deposits.
The Duwamish Tribe’s comment identifies the high potential for discovery of unknown archeological
deposits and requests notification of any archeological work performed. In addition, the comment
recommends the preparation of an archeological survey as advised by the DAHP WISAARD predictive
model. According to the applicant, two (2) cultural resources surveys have been conducted less than 300
feet (300’) west of the airport, along Rainier Avenue: one for development of a section of the Lake
Washington Loop Trail in 2016, the other for sidewalk and road improvements along Rainier Avenue which
also resulted in the identification and evaluation of historic resources including the Jolly Boy Drive In in
2020. Both surveys directly west of the airport consisted of pedestrian and subsurface archaeological
survey; no archaeological resources were identified as a result.
Pursuant to RCW 27.53.060 and 27.44.020, if any Native American grave(s) or archaeological/cultural
resources (Indian artifacts) are found, all construction activity shall stop 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. Due to the potential presence
of cultural resources on the site, staff recommends as a mitigation measure that the applicant be required
to submit an Archaeological Monitoring and Inadvertent Discovery Plan (MIDP) to Department of
Archaeology and Historic Preservation (DAHP) and any interested tribes for review prior to the start of
Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7
City of Renton Department of Community & Economic Development
Renton Windsock and 243 Building Apron Projectt
Staff Report to the Environmental Review Committee
LUA24-000299, ECF, SME
Report of October 28, 2024 Page 7 of 7
SR_ERC Report_Windsock Apron and 243 Building_241023_DRAFT
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.
Mitigation Measure: The applicant shall submit an Archaeological Monitoring and Inadvertent Discovery
Plan (MIDP) to Department of Archaeology and Historic Preservation (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: State Environmental Policy Act (SEPA) Environmental Review; City of Renton Comprehensive Plan
Policies L-45; RCW 27.53 Archaeological Sites and Resources; and RCW 27.44 Indian Graves and Records.
6. Transportation
Impacts: According to the applicant, no transportation facility construction or improvements are
proposed. The on-site parking lot near the 243 Building Apron, which is proposed to be reconstructed and
redesigned, would result in the elimination of approximately nine (9) parking stalls for a new total of 15
stalls. The applicant is proposing the addition of ADA stalls, 45-degree parking, and landscaping in order
to provide better traffic circulation and improve the overall functionality of the parking lot. The applicant
has proposed 12 new stalls within the 243 Building Apron adjacent to the existing parking lot. The parking
lot and new stalls in the apron area will provide a new total of 27 parking stalls. No new vehicle trips are
anticipated and therefore no site-specific mitigation is recommended.
Mitigation Measure: No further mitigation recommended.
Nexus: Not applicable.
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 “Advisory Notes to Applicant” (Exhibit 12).
✓ Copies of all Review Comments are contained in the Official File and may be attached to this report.
The Environmental Determination decision will become final if the decision is not appealed within the 14-day
appeal period (RCW 43.21.C.075(3); WAC 197-11-680).
Environmental Determination Appeal Process: Appeals of the environmental determination must be filed in
writing on or before 5:00 p.m. on November 12, 2024. Appeals must be submitted electronically to the City Clerk
at cityclerk@rentonwa.gov or delivered to City Hall 1st floor Lobby Hub Monday through Friday. The appeal fee,
normally due at the time an appeal is submitted, will be collected at a future date if your appeal is submitted
electronically. The appeal submitted in person may be paid on the first floor in our Finance Department. Appeals
to the Hearing Examiner are governed by RMC 4-8-110 and additional information regarding the appeal process
may be obtained from the City Clerk’s Office, cityclerk@rentonwa.gov.
Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7
CITY OF RENTON
DEPARTMENT OF COMMUNITY AND ECONOMIC DEVELOPMENT
STAFF REPORT TO THE ENVIRONMENTAL REVIEW COMMITTEE
EXHIBITS
Project Name:
Renton Windsock and 243 Building Apron
Projectt
Land Use File Number:
LUA24-000299, ECF, SME
Date of Meeting
October 28, 2024
Staff Contact
Alex Morganroth
Principal Planner
Project Contact/Applicant
William Adams / 616 West
Perimeter Rd, Renton, WA
98057 /
wadams@rentonwa.gov
Project Location
243 W Perimeter Rd and 749
E Perimeter Rd (APN
0723059007)
Renton, WA 98055
The following exhibits are included with the ERC Report:
Exhibit 1: Environmental Review Committee (ERC) Report
Exhibit 2: SEPA Checklist
Exhibit 3: Neighborhood Detail Map
Exhibit 4: Civil Construction Plans (Site Plan, Grading Plan, Utilities Plan)
Exhibit 5: Construction Mitigation Narrative
Exhibit 6: Geotechnical Report, prepared by DOWL, LLC, dated November 2, 2023
Exhibit 7: Draft Technical Information Report, prepared by DOWL, LLC., dated June 2024
Exhibit 8: Habitat Data Report, prepared by DOWL, LLC, dated July 22, 2024
Exhibit 9: Stream Assessment, prepared by DOWL, LLC, dated July 22, 2024
Exhibit 10: Duwamish Tribe Comments, dated September 20, 2024
Exhibit 11: City Response to Duwamish Tribe Comments, dated September 20, 2024
Exhibit 12: Advisory Notes
Docusign Envelope ID: D31D61AF-180E-439C-B708-0C917E2644A7