HomeMy WebLinkAboutSR_BosAir_ERC_Report_200916_v4_FINALDEPARTMENT OF COMMUNITY
AND ECONOMIC DEVELOPMENT
ERC REPORT LUA20-000161
ENVIRONMENTAL REVIEW COMMITTEE REPORT
ERC MEETING DATE: September 21, 2020
Project File Number: PR20-000190
Project Name: BosAir Addition
Land Use File
Number:
LUA20-000161, ECF, SSDP, SA-A
Project Manager: Alex Morganroth, Senior Planner
Owner: The City of Renton, 1055 S Grady Way, Renton, WA 98057
Applicant/Contact: David Freeman, SFA Architects / 7195 Wagner Way, Ste 201, Gig Harbor, WA 98335
/davesfa@comcast.net
Project Location: 289 E Perimeter Rd (APN 0723059007)
Project Summary: The applicant is requesting Administrative Site Plan Review, Environmental (SEPA)
Review, and a Shoreline Substantial Development Permit to construct a 4,800 sq. ft.
addition to an existing building. The subject project site is located at 287 E Perimeter
Road on the southeast side of the Renton Municipal Airport property (APN
0723059007). The applicant has a ground lease agreement with airport for a section of
land approximately 80,882 sq. ft. in size. The entire airport site totals 167 acres in area
and is located within the Medium Industrial (IM) zone. The applicant is proposing to
expand their existing multi-purpose aircraft hanger and corporate center for general
aviation customers. The proposal includes the construction of a 4,800 sq. ft. addition to
the existing 8,499 sq. ft. building facility that expands the area for maintenance offices
and storage, company offices, and flight training facilities. The addition would be
located on the southwest side of the building and would include a new rolling door
system approximately 100 ft wide and 20 ft tall. The addition would be slightly taller
than the existing building being added onto, but shorter than the main building to the
north. The addition would have a maximum height of approximately 35 feet above
grade. No parking would be removed as part of the proposal. In addition, no vegetation
or trees would be removed as part of the proposal according to the applicant. Access to
the site would remain off of E Perimeter Road. According to COR Maps, the site is
located within a High Seismic Hazard Area as well as the Cedar River (Shoreline of the
State) Reach A High-Intensity Shoreline Overlay district. A Flood Hazard Area pursuant
to the FEMA Flood Insurance Rate Maps (FIRM) is 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
Mean Sea Level (MSL). Due to the existing flood wall to the east of East Perimeter Rd,
the proposed addition is located outside of the 100-year floodplain area. The applicant
submitted a stream assessment, floodplain map and data, geotechnical report, and
drainage report with the application.
Exist. Bldg. Area SF: 8,499 SF Proposed New Bldg. Area (footprint)
Proposed New Bldg. Area (gross):
4,800 SF
4,800 SF
Site Area: 6,640,721 SF (153.2 acres) Total Building Area GSF: 13,299 SF
DocuSign Envelope ID: 8AC0BCC4-38CC-49BF-993D-8D4EEDD86E1A
City of Renton Department of Community & Economic Development Environmental Review Committee Report
BOSAIR ADDITION LUA20-000161, ECF, SSDP
Report of September 21, 2020 Page 2 of 8
ERC REPORT LUA20-000161
STAFF
RECOMMENDATION:
Staff Recommends that the Environmental Review Committee issue a Determination
of Non-Significance – Mitigated (DNS-M).
Project Map
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 Terra
Associates, dated February 1, 2013, and future addenda.
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
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.
DocuSign Envelope ID: 8AC0BCC4-38CC-49BF-993D-8D4EEDD86E1A
City of Renton Department of Community & Economic Development Environmental Review Committee Report
BOSAIR ADDITION LUA20-000161, ECF, SSDP
Report of September 21, 2020 Page 3 of 8
ERC REPORT LUA20-000161
C. Exhibits
Exhibit 1: Environmental Review Committee (ERC) Report
Exhibit 2: SEPA Checklist
Exhibit 3: Neighborhood Detail Map
Exhibit 4: Site Plan
Exhibit 5: Floor Plan
Exhibit 6: Construction Mitigation Description
Exhibit 7: Conceptual Drainage/Utilities/Grading Plan, prepared by Barghausen Consulting
Engineers, dated June 9, 2020
Exhibit 8: Preliminary Technical Information Report (TIR), prepared by Barghausen Consulting
Engineers, dated June 9, 2020
Exhibit 9: Geotechnical Report, prepared by Terra Associates, dated February 1, 2013
Exhibit 10: Addendum to Geotechnical Report, prepared by Terra Associates, dated May 1, 2020
Exhibit 11: Shoreline Critical Areas Review, prepared by Raedeke Associates, Inc, dated March 19,
2013
Exhibit 12: Addendum to Shoreline Critical Areas Review, prepared by Raedeke Associates, Inc,
dated March June 15, 2020
Exhibit 13: Flood Plain Data, prepared by Barghausen Consulting Engineers, dated May 1, 2020
Exhibit 14: Traffic Control Plan, prepared by Statewide Safety Systems
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 Terra Associates, dated March 19, 2013 (Exhibit 9). The report was
originally prepared for the initial construction of the two existing buildings on site (289 building and 287
building) that were approved and constructed in 2013 under LUA13-000333. The applicant submitted an
Addendum to the Geotechnical Report, prepared by Terra Associates and dated May 1, 2020, that confirmed
that the data collection, staff analysis, and subsequent recommendations in the report were valid for the
new addition. The analysis in the initial report primarily focused on conditions within the 80,882 sq. ft. lease
area where the existing buildings are located and the new addition is proposed.
In early 2013, Terra Associates, Inc. performed cone penetration tests (CPT) on the project site to determine
soil conditions in the lease area. The results of these tests indicated that soils to depths of 1 to 2 feet
consisted of moderate to well-compacted silty, sand fill. Soils underlying the fill included highly variable
interbedded alluvial soils composed of silts, clay, silty clay, and silty sand layers at depths up to 20 feet.
Below this depth the CPT indicated very dense silty sand and sand and gravel.
The results of the exploration of subsurface conditions are included in the Terra Associates’ original report.
The report concluded that the medium dense and soft alluvial soils were be capable of supporting moderate
building loads using spread footing foundations, although cautioned that there would be a corresponding
DocuSign Envelope ID: 8AC0BCC4-38CC-49BF-993D-8D4EEDD86E1A
City of Renton Department of Community & Economic Development Environmental Review Committee Report
BOSAIR ADDITION LUA20-000161, ECF, SSDP
Report of September 21, 2020 Page 4 of 8
ERC REPORT LUA20-000161
risk of potential differential settlement. The report identifies of total potential settlement of between one
and 2.5 inches and concludes the amount would likely not cause structural damage. Identical soil conditions
and the same risk of settlement would be present for the addition and therefore the same
recommendations for foundation design and construction type would apply to the subject project.
The report suggests that due to the fine-grain nature of the sediments in the soil, liquefaction hazard and
the associated risks would be relatively low during the occurrence of a seismic event. Therefore no specific
recommends related to mitigating a liquefaction hazard were included in the report. However, due to the
moisture content of the soil and potential for settlement, the consultant recommends supporting the
conventional spread footing foundation on a minimum of two feet of granular structural fill if needed to
establish the desired building grade for the buildings. Therefore, the same recommendation would apply to
the addition. The report also noted that if wet soils are encountered during construction of the addition
during the winter months, the soil will need to be dried by aeration during dry weather. Due to the likely
construction of the addition during the upcoming winter months, soil aeration is anticipated to be needed.
Other recommendations regarding site preparation, grading, excavation, and the initiation of a surcharge
program to preload the area where the addition will be constructed should be followed during site
preparation and building construction. Due to the inclusion of specific recommendations provided in the
geotechnical report and the Addendum to 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 5,700 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 Terra Associates, dated February 1, 2013, and future addenda.
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 description provided by the applicant (see Exhibit 6).
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 Technical Information Report (TIR) prepared by Barghausen
Consulting Engineers, dated June 9, 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
map, the site falls within the Peak Rate Flow Control Standard area matching Existing Site Conditions and is
DocuSign Envelope ID: 8AC0BCC4-38CC-49BF-993D-8D4EEDD86E1A
City of Renton Department of Community & Economic Development Environmental Review Committee Report
BOSAIR ADDITION LUA20-000161, ECF, SSDP
Report of September 21, 2020 Page 5 of 8
ERC REPORT LUA20-000161
within the Lower Cedar River Drainage Basin. The site also falls into Zone 1 of the City’s Aquifer Protection
Area (APA) where conveyance systems and BMP’s that rely on infiltration are prohibited. All nine core
requirements and the six special requirements have been discussed in the TIR, however Special Requirement
#6 should be updated in the final TIR to address the APA restrictions.
Based on the submitted documents, the project would not add more than 5,000 SF of new and replaced
pollution generating impervious area. If the project scope changes and both new and replaced pollution
generating impervious surface exceeds 5,000 SF, the applicant would be required to provide enhanced basic
water quality treatment, which would be reviewed at the time of Construction Permit submittal. Per the
RSWDM, the applicant is required to submit a Leachable Materials Covenant for the new roof area to ensure
that the roof is not made of Pollution Generating Materials.
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 2017 RSWDM, would be evaluated as part of the review of the final drainage plan and drainage report
submitted with the construction permit application. The 2020 Surface water system development fee is $0.76
per square foot of new impervious surface, but no less than $1,900.00. The fee is payable prior to issuance of
the construction permit and is subject to change based on the calendar year the construction permit is issued.
Mitigation Measures: No further mitigation required.
Nexus: Not applicable
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 location of
the proposed addition within 200 feet of the OHWM of the Cedar River, the applicant submitted a Shoreline
Critical Areas Review, prepared by Raedeke Associates, Inc, dated March 19, 2013 (Exhibit 11). The report was
originally prepared for the initial construction of the two existing buildings on site (289 building and 287
building) that were approved and constructed in 2013 under LUA13-000333. The applicant submitted an
Addendum to Shoreline Critical Areas Review, prepared by Raedeke Associates, Inc, and dated June 15, 2020
(Exhibit 12). The addendum addresses the specific impacts related to the addition and includes a conclusion
with regards to the potential impacts of the addition and associated work on the Cedar River.
The proposed addition would be located approximately 80 feet from the OHWM of the Cedar River. The
original report identified riparian and aquatic conditions in the area directly adjacent to the existing BosAir
buildings. The conditions identified in the report have not changed in the time between 2013 and present day.
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 provide little ecological function. The report concludes
that regardless of how the areas function, work on the proposed project would occur far outside of these
narrow riparian areas and would not impact the Cedar River’s aquatic or riparian habitats. In addition, the
report highlights that the fact that the project is designed to minimize impacts to the river by expanding the
proposed building away from the river and reducing the area of pavement subject to oil and gas leakage or
spillage from vehicles.
No trees or riparian vegetation would be removed and no work on the project would occur below the OHWM
of the Cedar River. Existing light source are proposed to be relocated from the west façade of the existing
building to the west side of the new addition. Due the lighting sources being relocated farther away from the
river and continuing to face west, light levels at the river are not anticipated to increase. Therefore the project
is not expected to adversely affect habitat for listed salmonid fish species inhabiting the 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 6). Therefore based on the finding of no net
DocuSign Envelope ID: 8AC0BCC4-38CC-49BF-993D-8D4EEDD86E1A
City of Renton Department of Community & Economic Development Environmental Review Committee Report
BOSAIR ADDITION LUA20-000161, ECF, SSDP
Report of September 21, 2020 Page 6 of 8
ERC REPORT LUA20-000161
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. Environmental Health
Impacts: The site lies within the Airport Influence Area, the “Sideline Approach/Departure Zone” (Zone 5)
and/or “Traffic Pattern Zone” (Zone 6), where a higher percentage of incidents occur. Building height in
relation to proximity of aircraft is a factor.
The proposed building has a lower elevation than the existing buildings. The tallest existing building adjacent
to the proposed addition is approximately 42 feet. The ridge level of the new building would be 32 feet.
Building heights are regulated by “Federal Aviation Regulation (FAR) Part 77 Surfaces Applicable to the Renton
Municipal Airport.” The Airport ground elevation is 32 feet above mean sea level (msl). The maximum building
height allowed at this location is 110 feet (142 feet FAR Part 77 less 32 feet ms l). The proposed building
elevation, at 62 feet above mean sea level, does not penetrate the FAR Part 77 surface area.
Mitigation Measures: No further mitigation required.
Nexus: Not applicable
5. 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 Shoreline Critical Areas Review and
Addendum to the Shoreline Critical Areas Review submitted by the applicant (Exhibits 11 and 12), 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 and nearby river bank, the lack of
vegetation removal in the proposal, and the fact the addition would be separated from the river by an existing
building, road, and flood wall.
Mitigation Measures: None
Nexus: Not applicable
6. Historic and Cultural Preservation
Impacts: In the SEPA Environmental Checklist (Exhibit 2), 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.
DocuSign Envelope ID: 8AC0BCC4-38CC-49BF-993D-8D4EEDD86E1A
City of Renton Department of Community & Economic Development Environmental Review Committee Report
BOSAIR ADDITION LUA20-000161, ECF, SSDP
Report of September 21, 2020 Page 7 of 8
ERC REPORT LUA20-000161
Due to parts of the proposed project that would occur under the existing pervious surface, staff recommends
that the applicant 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 Department of Archaeology and Historic Preservation (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 the
Washington State Department of Archeology and Historic Preservation 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.
Copies of all Review Comments are contained in the Official File and may be attached to this report.
DocuSign Envelope ID: 8AC0BCC4-38CC-49BF-993D-8D4EEDD86E1A
ERC REPORT LUA20-000161
CITY OF RENTON
DEPARTMENT OF COMMUNITY AND ECONOMIC DEVELOPMENT
STAFF REPORT TO THE ENVIRONMENTAL REVIEW COMMITTEE
EXHIBITS
Project Name:
BosAir Addition
Land Use Number:
LUA20-000161, ECF, SSDP, S-A
Date of Meeting
September 21, 2020
Staff Contact
Alex Morganroth
Senior Planner
Project Contact/Applicant
David Freeman, SFA Architects / 7195
Wagner Way, Ste 201, Gig Harbor, WA
98335 /davesfa@comcast.net
Project Location
289 E Perimeter Rd
(APN 0723059007)
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: Site Plan
Exhibit 5: Floor Plan
Exhibit 6: Construction Mitigation Description
Exhibit 7: Conceptual Drainage/Utilities/Grading Plan, prepared by Barghausen Consulting
Engineers, dated June 9, 2020
Exhibit 8: Preliminary Technical Information Report (TIR), prepared by Barghausen Consulting
Engineers, dated June 9, 2020
Exhibit 9: Geotechnical Report, prepared by Terra Associates, dated February 1, 2013
Exhibit 10: Addendum to Geotechnical Report, prepared by Terra Associates, dated May 1, 2020
Exhibit 11: Shoreline Critical Areas Review, prepared by Raedeke Associates, Inc, dated March 19,
2013
Exhibit 12: Addendum to Shoreline Critical Areas Review, prepared by Raedeke Associates, Inc,
dated March June 15, 2020
Exhibit 13: Flood Plain Data, prepared by Barghausen Consulting Engineers, dated May 1, 2020
Exhibit 14: Traffic Control Plan, prepared by Statewide Safety Systems
DocuSign Envelope ID: 8AC0BCC4-38CC-49BF-993D-8D4EEDD86E1A