HomeMy WebLinkAboutAtt07_Environmental_DNS_and_SEPA_Checklist
DETERMINATION OF NONSIGNIFICANCE
Description of Proposal: Sound Transit is proceeding in partnership with the Washington State
Department of Transportation (WSDOT) to implement new bus rapid transit (BRT) service along
I-405, a portion of SR 518, and along some local city streets consistent with the I-405 Master
Plan. As part of the I-405 BRT program, Sound Transit proposes to construct the following BRT facilities: Burien Transit Center (new BRT station); new Tukwila International Boulevard
BRT station; new South Renton Transit Center and BRT station; Bellevue Transit Center BRT
station (modifying two existing bus bays and adding off-site bus layover); new Totem
Lake/Kingsgate BRT station and new Kingsgate Park-and-Ride garage; new Brickyard BRT
station; and Lynnwood City Center Transit Station (new BRT station). Other elements of Sound
Transit’s proposal include roadway improvements for transit speed and reliability at the Burien
Transit Center, Tukwila International Boulevard BRT Station, South Renton Transit Center,
Brickyard BRT Station, and the Lynnwood City Center Transit Station. A variety of bicycle and pedestrian improvements are also associated with some of the parking facilities and station locations. Other components of the I-405 BRT program have been reviewed by and will be implemented by WSDOT.
Proponent: Sound Transit (Central Puget Sound Regional Transit Authority)
Location of the Proposal: Burien, Tukwila, Renton, Bellevue, Kirkland, Bothell, Lynnwood,
Washington
Lead Agency: Sound Transit
The lead agency for this proposal has determined that it does not have a probable significant
adverse impact on the environment. An environmental impact statement (EIS) is not required
under RCW 43.21C.030(2)(c). This decision was made after review of the completed
environmental checklist, technical reports, and other information on file with Sound Transit.
This Determination of Nonsignificance (DNS) is issued under WAC 197-11-340 (2) and Sound
Transit’s SEPA rules (Resolution R2018-17). The lead agency will not act on the proposal until
October 14, 2020, which is 14 days from the date of issue below.
Availability of Documents: The SEPA checklist, along with the technical reports, are available
for review at https://www.soundtransit.org/system-expansion/i-405-brt/documents. Electronic copies of the checklist and technical memos are available at no charge by contacting
Kathy Fendt at (206) 689-4856 or Kathy.Fendt@soundtransit.org. Paper copies of the technical
memos are available for $15.00.
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Proposed Temporary Use Permit (TUP)
scope of work is limited to soil remediation
temporary artwork only. All other
improvements referenced in this DNS are
not proposed as part of the TUP application.
ATTACHMENT 7
RECEIVED
Clark Close 07/18/2022
PLANNING DIVISION
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Comments Due: Comments must be submitted by 5:00 p.m., October 14, 2020. Email
comments should be submitted to BRT405-SEPA@soundtransit.org. Written comments should
be mailed to Kathy Fendt, East Corridor Environmental Manager, Sound Transit, 401 S. Jackson
Street, Seattle, WA 98104.
The responsible official may reconsider the DNS based on timely comments and may retain or
modify the DNS or, if the responsible official determines that significant adverse impacts are
likely, withdraw the DNS or supporting documents. If the DNS is retained, it will be final after
the expiration of the comment deadline.
Responsible official: Perry Weinberg
Position/title: Deputy Executive Director, Office of Environmental Affairs and
Sustainability
Phone: (206) 689-4931
Address: Sound Transit Office of Environmental Affairs and Sustainability Union Station, 401 South Jackson St., Seattle, WA 98104-2826
You may appeal this determination to Peter Rogoff, Chief Executive Officer, Sound Transit,
Union Station, 401 South Jackson St., Seattle WA 98104-2826 no later than 5:00 p.m., October
21, 2020, by submitting a written statement requesting an appeal, setting forth the information
required by Sound Transit’s SEPA rules (Resolution No. R2018-17) and by paying the required
fee. You should be prepared to make specific factual objections. Resolution No. R2018-17 is
available online at:
https://www.soundtransit.org/st_sharepoint/download/sites/PRDA/FinalRecords/Resolution%20R2018-17.pdf
Note that Sound Transit’s offices remain closed to the public due to the COVID-19 pandemic. Please contact Perry Weinberg at the phone number above if you would like to discuss alternative arrangements for delivering an appeal.
Date of Issue: September 30, 2020 Signature: __________________________
Perry Weinberg
Auxiliary aids and services and communication materials in accessible format can be arranged
with sufficient notice by calling (206) 398-5000, or (206) 398-5086 for TDD users.
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SEPA Environmental
Checklist
September 2020
Proposed Temporary Use Permit (TUP)
scope of work is limited to soil remediation
and temporary artwork only. All other
improvements referenced in this checklist
are not proposed as part of the TUP
application.
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I-405 Bus Rapid Transit (BRT)
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I-405 Bus Rapid Transit
SEPA Environmental Checklist
September 2020
Prepared for:
Sound Transit
401 South Jackson Street
Seattle, Washington 98104
Prepared by:
WSP USA
999 Third Avenue, Suite 3200
Seattle, Washington 98104
and
ESA
5309 Shilshole Avenue NW, Suite 200
Seattle, Washington 98107
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Table of Contents
ACRONYMS AND ABBREVIATIONS ......................................................................................... V
PROJECT OVERVIEW ............................................................................................................... VII
A BACKGROUND ................................................................................................................ 1
B ENVIRONMENTAL ELEMENTS .................................................................................... 20
1. Earth .................................................................................................................... 20
2. Air ........................................................................................................................ 27
3. Water ................................................................................................................... 29
4. Plants .................................................................................................................. 42
5. Animals ................................................................................................................ 50
6. Energy and Natural Resources ........................................................................... 53
7. Environmental Health .......................................................................................... 53
8. Land and Shoreline Use ...................................................................................... 68
9. Housing ............................................................................................................... 81
10. Aesthetics ............................................................................................................ 81
11. Light and Glare .................................................................................................... 89
12. Recreation ........................................................................................................... 93
13. Historic and Cultural Preservation ....................................................................... 94
14. Transportation ................................................................................................... 103
15. Public Services .................................................................................................. 118
16. Utilities ............................................................................................................... 121
C SIGNATURE ................................................................................................................. 128
GLOSSARY OF TERMS .......................................................................................................... 135
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Tables
Table 1 I-405 BRT project components – Potential approvals and permits prior to
construction ........................................................................................................... 6
Table 2 I-405 BRT project components: Address and Section/Township/Range ............. 19
Table 3 I-405 BRT project components: Slopes ............................................................... 20
Table 4 I-405 BRT project components: Types of soils .................................................... 21
Table 5 Nearest surface waters to project components ................................................... 30
Table 6 Wetland characteristics, rating, and applicable buffer distances in the
Tukwila International Boulevard BRT Station and Roadway Improvements
vicinity .................................................................................................................. 33
Table 7 Wetland characteristics, rating, and applicable buffer distances in the
Brickyard Station and Roadway Improvements vicinity ....................................... 34
Table 8 Summary of new or reduced impervious surface area by project component ..... 40
Table 9 Stormwater management facilities summary ....................................................... 41
Table 10 Estimated vegetation and tree removal by project component ............................ 49
Table 11 Nearest federally listed and state protected species to project components ....... 51
Table 12 Current and adjacent land uses by project component ....................................... 69
Table 13 Current land ownership, long-term land use and temporary use of WSDOT
right-of-way by project component ...................................................................... 70
Table 14 Existing structures on the South Renton Transit Center site ............................... 74
Table 15 Comprehensive Plan designation for each project component ........................... 77
Table 16 Proposed structure heights and building materials .............................................. 82
Table 17 Recorded place names within the vicinity of the South Renton Transit Center
and Roadway Improvements project component ................................................ 98
Table 18 Recorded place names within the vicinity of the Bellevue Transit Center and
Off-site Layover project component..................................................................... 99
Table 19 Recorded place names within the vicinity of the Totem Lake/Kingsgate
Station and Kingsgate Park-and-Ride Garage project component .................... 100
Table 20 Recorded place names within the Brickyard Station and Roadway
Improvements project component ..................................................................... 101
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Attachments
Attachment A Figures
Attachment B I-405 BRT Project Conceptual Engineering Plans – Excerpted Design Sheets
Attachment C I-405 BRT Corridor Ecosystem Resources and Wetland Delineation Technical
Memorandum
Attachment D I-405 BRT Corridor Hazardous Materials Technical Memorandum
Attachment E I-405 BRT Corridor Noise and Vibration Technical Memorandum
Attachment F I-405 BRT Corridor Visual and Aesthetic Resources Technical Memorandum
Attachment G I-405 BRT Corridor Historic and Archaeological Resources Technical
Memorandum
Attachment H I-405 BRT Corridor Transportation Technical Report
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ACRONYMS AND ABBREVIATIONS
ASL air space lease
BAT business access and transit
BMP best management practice
BRT bus rapid transit
BTEX benzene, toluene, ethylbenzene, and total xylenes
CPTED crime prevention through environmental design
DAHP Department of Archaeology and Historic Preservation
dBA A-weighted decibel
DCE Documented Categorical Exclusion
Ecology Washington State Department of Ecology
EDNA Environmental Designations for Noise Abatement
ESA environmental site assessment
ESO Environmental Services Office
ETL express toll lane
FHWA Federal Highway Administration
FTA Federal Transit Administration
GHG greenhouse gas
HGM hydrogeomorphic
hp horsepower
KCWD King County Water District
LOS level-of-service
LUST leaking underground storage tanks
MP mile post
MSAT Mobile Source Air Toxics
MTCA Model Toxics Control Act
NEPA National Environmental Policy Act
NHPA National Historic Preservation Act
NRHP National Register of Historic Places
PAH polycyclic aromatic hydrocarbons
PCB polychlorinated biphenyls
PHS Priority Habitat and Species
ppm parts per million
Project I-405 Bus Rapid Transit Project
PSCAA Puget Sound Clean Air Agency
PSE Puget Sound Energy
SCL Seattle City Light
SEPA State Environmental Policy Act
SR State Route
TCAL temporary construction air space lease
TIBS Tukwila International Boulevard light rail station
TMC Tukwila Municipal Code
TOD transit-oriented development
TSP transit signal priority
TVM ticket vending machine
VMT vehicle miles traveled
WAC Washington Administrative Code
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WDFW Washington Department of Fish and Wildlife
WRIA Water Resource Inventory Area
WSDOT Washington State Department of Transportation
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PROJECT OVERVIEW
Sound Transit proposes to implement the I-405 Bus Rapid Transit (BRT) Project, providing BRT
service for 37 miles between Lynnwood and Burien, along portions of I-5, I-405, State Route
(SR) 518, and some local arterial streets. The proposed I-405 BRT project addressed in this
SEPA Checklist includes construction and operation of the following components (Figure A-1):
• Burien Transit Center BRT station and roadway improvements
• New Tukwila International Boulevard BRT station and roadway improvements
• New South Renton Transit Center and roadway improvements
• Bellevue Transit Center BRT station and off-site layover
• New Totem Lake/Kingsgate BRT station and new Kingsgate Park-and-Ride garage
• New Brickyard BRT station and roadway improvements
• Lynnwood City Center BRT station and roadway improvements
A variety of bicycle and pedestrian improvements are also associated with some of the parking
facilities and station locations. Other elements related to this project have been reviewed in
environmental documents prepared by the Washington State Department of Transportation
(WSDOT), in partnership with Sound Transit. Construction of all project components is expected
to begin in 2022 with BRT service beginning on portions of the line in 2024 and 2025.
Summary of Environmental Elements
As described throughout Section B of the Checklist, the project includes design measures, best
management practices (BMPs), and compliance with Sound Transit’s policies and requirements.
The project is not anticipated to generate significant adverse environmental impacts.
Earth
The project component locations include a range of grades, from flat to steep. The steepest
slopes are at the Tukwila International Boulevard BRT Station and Roadway Improvements
component (with areas of slopes up to approximately 33 percent) and the Lynnwood City Center
Transit Station BRT and Roadway Improvements component (with areas of 15 to 50 percent
along the Poplar Way loop ramp). The project corridor includes a wide range of soil types, from
deposits of soft organic-rich clayey silt, to dense sand and gravel, and areas of sedimentary
rocks. There are no known agricultural lands or soils of long-term commercial significance in the
project corridor.
Each project component would include some clearing and grading activities as well as areas of
filling and excavation. In most cases the project would increase the percent of the site covered
with impervious surfaces; impervious surfaces would be decreased at the South Renton Transit
Center site. The project would implement a temporary erosion and sedimentation control plan
with BMPs to prevent or minimize erosion and the potential for discharge of silt-laden runoff to
nearby bodies of water.
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Areas of geologic instability were identified at the Tukwila International Boulevard BRT Station
and Roadway Improvements, South Renton Transit Center and Roadway Improvements, and
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage. For the South Renton
Transit Center and Roadway Improvements and Totem Lake/Kingsgate Station and Kingsgate
Park-and-Ride Garage components, additional geotechnical studies were conducted to identify
design measures to address potential liquefiable soils. For the Tukwila International Boulevard
BRT Station and Roadway Improvements component, construction procedures would be
developed to maintain or enhance slope stability.
Air
Construction-related activities would result in short-term emissions of air pollutants from worker
and construction vehicle exhaust; no known off-site sources of emissions or odor would affect
the project. If generators are required, the Puget Sound Clean Air Agency (PSCAA) would be
consulted for the appropriate permit action. Measures to control dust during construction would
also be implemented in compliance with PSCAA and Sound Transit requirements. During
project operation, exhaust from buses and from personal vehicles accessing transit facilities
would be a source of local air pollutant emissions. However, regionally, the project would
increase the number of daily bus trips and reduce vehicle miles traveled.
Water
Surface-water bodies, such as streams and wetlands, were identified in proximity to two
locations – near the Tukwila International Boulevard BRT Station and Roadway Improvements
and the Brickyard Station and Roadway Improvements components. While construction
activities at these locations would occur within 200 feet of surface-water features, no in-water
work, temporary or permanent fill of wetlands and streams, or surface-water withdrawals would
be required. Further, these project components would not preclude planned fish passage barrier
improvements by WSDOT on SR 518 and I-405. At the South Renton Transit Center and
Roadway Improvements component, which is located within a mapped 100-year floodplain as
well as within the Cedar Valley Sole Source Aquifer, site design would comply with City of
Renton’s measures specifically aimed at preventing floodplain impacts and protection of the
aquifer.
The project would not withdraw groundwater from a well for any purpose and, other than
potential stormwater infiltration, would not discharge waste material into the ground. For water
runoff, project construction activities would be subject to construction-related stormwater permit
requirements of the Clean Water Act’s National Pollutant Discharge Elimination System
program. For each project component, stormwater management (including drainage patterns,
flow control, and treatment) would be designed and implemented consistent with the adopted
stormwater management code and manual of the appropriate jurisdiction.
Plants
All of the project components are located in highly developed urban environments; existing
plants and trees are primarily limited to street trees and commercial landscaping. Noxious
weeds, primarily Himalayan blackberry and knapweed, were observed as occurring at most
project components. Except for the Bellevue Transit Center and Off-site Layover component,
clearing activities during construction of each project component would remove or alter some
existing vegetation. The vegetation to be removed is primarily grasses and shrubs but also
includes some trees; no threatened or endangered plant species are known to be on or near
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project components. Trees removed within WSDOT right-of-way would be replaced in
compliance with WSDOT’s Roadside Policy Manual (WSDOT 2015). Trees removed within local
jurisdictions, such as the City of Kirkland, would be replaced in compliance with local code
requirements.
Animals
Wildlife species at all project component locations likely include birds (e.g., American robin,
American crow, and common pigeon) and small mammals (e.g., Virginia opossum, eastern
cottontail, and eastern gray squirrel) that are well adapted to living in an urban landscape; no
fish were observed in streams near the Tukwila International Boulevard BRT Station and
Roadway Improvements component. In addition, the project corridor is within the Pacific Flyway,
which extends from Alaska to South America, for migrating birds. No listed threatened or
endangered species are mapped as occurring on or near any project components. Invasive
animal species likely present at each project component include rodents (Old World rats and
mice). While impacts to wildlife are not anticipated, prior to construction clearing activities,
Sound Transit would perform nest surveys in compliance with the Migratory Bird Treaty Act.
Stormwater management measures would also protect waters downstream of project
components.
Energy and Natural Resources
Project construction would require the use of energy and fuel. The project is not anticipated to
affect the potential use of solar energy by adjacent properties. Specific features to enhance
sustainability and maximize energy conservation for the project components would be
determined as the design progresses. For long-term operations, all project components would
require electricity for lighting and electronic systems. The project is anticipated to increase
transit ridership and reduce single-occupancy vehicles in the corridor, which would be expected
to reduce petroleum fuel energy consumption.
Environmental Health
Three of the project components (Burien Transit Center and Roadway Improvements, Tukwila
International Boulevard BRT Station and Roadway Improvements, and a portion of the South
Renton Transit Center and Roadway Improvements) are located in areas mapped by the
Washington State Department of Ecology (Ecology) as potentially having arsenic levels in the
soil as a result of regional historic contamination from the Tacoma Asarco copper smelter. In
addition, on-site contamination is known to exist at the Burien Transit Center and the South
Renton Transit Center site. Hazardous materials release sites are located within 0.125 mile from
most project components, except for the Totem Lake/Kingsgate Station and Kingsgate Park-
and-Ride and the Brickyard Station and Roadway Improvements. There are no transmission
pipelines within 0.125 mile of the project components. Prior to and during construction, the
project would comply with Ecology’s Tacoma Smelter Plume Model Remedies Guidance
(Ecology 2020c); implement procedures to identify, characterize, manage, handle, store, and
dispose of contaminated soil and groundwater; and complete cleanup at the South Renton
Transit Center site. This elimination of hazardous or contaminated materials would be a benefit of
the project, reducing future potential adverse effects to human health and the environment. After
construction, operations at the project components would not include the storage, use, or
generation of hazardous materials. Accidental spills that may occur, such as drips from vehicle
engines, would be handled with on-site cleanup kits or through Sound Transit’s established
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program for responding to emergencies at facilities, which includes a spill response contractor
on call 24/7.
All of the project components are located in highly developed urban environments, which is
reflected in existing noise levels. Construction of the project components would generate
temporary and intermittent noise from construction equipment. Construction noise is exempt
from local agency noise ordinance noise limits, except at residential land uses during nighttime
hours (10 p.m. to 7 a.m.) on weekdays and weekends. If construction is performed during
nighttime hours, the contractor must meet the noise-level requirements or obtain a noise
variance from the governing jurisdiction. In the long-term, noise levels from transit operations at
each of the project components is expected to be below existing noise levels. For proposed
BRT stations located within the SR 518 and I-405 roadways, Sound Transit’s design would
provide passengers with noise shielding as appropriate.
Land and Shoreline Use
Except for the South Renton Transit Center, all of the project components are on land currently
used for transportation; these land uses would not change. Further, no agricultural or forest land
would be converted and none of the project components are located within a designated
shoreline management zone. The land at the South Renton Transit Center has been, and still is,
in commercial use. Sound Transit is in the process of completing the purchase of this site, which
would convert these approximately 8.3 acres of land from commercial to transportation use and
require the demolition of the existing on-site structures. Consistent with agency policy, Sound
Transit is in the process of relocating the three existing businesses currently operating at the
South Renton Transit Center site; all three business relocations would be complete prior to the
start of project construction.
The project components are consistent with the existing and projected land uses, as identified in
local jurisdictions’ comprehensive plans and zoning designations. All project components are
planned to comply with the development standards of each jurisdiction’s zoning code (including
critical areas, setbacks, height, landscaping, and other dimensional standards). If compliance is
not possible, Sound Transit would coordinate with the local jurisdictions, such as to seek
variances or development agreements. The project components would not displace any existing
residences and would not result in people residing or working at them. Sound Transit
maintenance and security staff would conduct regular visits, and bus drivers would stay with
their vehicles during layovers at transit centers. Once the project is constructed, land uses
adjacent to all of the project components would benefit from access to the BRT service that
would provide increased regional mobility and improved transit speed and reliability.
Housing
The project would not provide or eliminate any housing units.
Aesthetics
At each BRT station the tallest feature would be the station pylon/column, which would be
approximately 17 feet tall. Station shelters, where proposed, would be approximately 11 feet tall.
The park-and-ride garages at the South Renton Transit Center and Kingsgate Park-and-Ride
Garage are both proposed to be five-stories, approximately 55 to 60 feet tall.
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At all but one location, the project components are expected to be compatible with the existing
visual character and are not expected to result in a change in the physical characteristics that
would be inconsistent with the existing environment. The addition of a 5-story park-and-ride
garage structure in the southern portion of the existing Kingsgate Park-and-Ride lot would
contrast in scale and form with existing residential structures along the site’s southern boundary.
To address this, landscape enhancements would be provided along the southern boundary of
the site between the park-and-ride garage and the residences to provide additional visual
screening and help to maintain natural visual elements. During construction aesthetic impacts
would be minimized by limiting the clearing of vegetation and trees, screening views of
construction equipment from pedestrians and residential areas as practical, and restoring
disturbed areas after completion of work.
Light and Glare
For all project components, potential construction during evening/nighttime hours would require
lighting. Lights used for nighttime construction would be shielded and directed inward toward the
sites and away from adjacent uses, including residential areas. This lighting would be temporary
and would be required for the safety of construction workers and the traveling public. Once
constructed, the project components would include features that would be lit during hours of
lower natural light and in the evening/nighttime. Because all of the project components are
located in highly developed urban environments with many existing sources of light, the project
is not expected to increase visible or artificial light or glare. Off-site sources of light or glare
would not affect the project. Within the park-and-ride garage structures, screening would be
provided to reduce headlight glare that could be perceived from offsite.
Recreation
While there are designated recreational resources in the vicinity of most project components,
the project would not displace any existing recreational uses. At the Brickyard Station and
Roadway Improvements component, a temporary detour of a short segment of the Tolt Pipeline
Trail along NE 155th Street may be required during construction of the pedestrian bridge
connection to the neighborhood on the east side of I-405. If required, this temporary detour
would provide appropriate signage and access for trail traffic. Once construction is complete,
the trail would be returned to its existing condition or improved as needed.
Historic and Cultural Preservation
A wide variety of sources were reviewed to identify potential historic and cultural resources at
project component locations, including the Washington State Department of Archaeology and
Historic Preservation’s (DAHP’s) Statewide Predictive Model, the Washington Information
System for Architectural and Archaeological Records Data maintained by DAHP, previously
conducted cultural resources surveys, geotechnical reports, historic maps, aerial photographs,
published ethnographies and local histories, and geological maps. Other than at the proposed
South Renton Transit Center site, the project would not impact historic-aged built environment
resources or have the potential to impact buried archaeological resources. On the South Renton
Transit Center site, the project would demolish two commercial historic-aged resources; both
are recommended not eligible for listing in the National Register of Historic Places. The
Statewide Predictive Model classifies the location of the South Renton Transit Center as High to
Very High Risk of encountering precontact-era sites. Prior to construction Sound Transit
proposes to conduct subsurface surveys, via a drilling rig, to further identify the potential for
encountering precontact-era sites.
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Transportation
The project proposes to construct BRT stations and roadway improvements in support of a new
BRT service that would provide transit service within the I-5, I-405, and SR 518 corridors, and
improve inter-connections to other regional transit modes (e.g., light rail). The project has been
designed to minimize changes to general-purpose traffic while optimizing transit speed and
reliability on local streets and freeway on-and off-ramps. No adverse impacts to traffic safety,
nonmotorized facilities, parking, or site access for other facilities are anticipated as a result of
the project. At the South Renton Transit Center and Roadway Improvements component, the
traffic analysis indicates that in the 2042 forecast year additional trips from BRT vehicles would
contribute to expected delay at three intersections. The analysis indicates that optimizing the
signal phasing and timing at these intersections would address the expected impacts. Should the
City of Renton and WSDOT determine that they would implement improvements other than
optimized signal phasing at these locations, Sound Transit would coordinate with the city and
WSDOT to identify an appropriate and proportionate contribution to those improvements.
Public Services
The project would provide increased and improved public transit service and connections within the
I-5, I-405, and SR 518 corridors and in the Puget Sound Region. None of the project components
are expected to increase the need for fire, police, health care, or schools because the project would
not result in any unplanned or induced increases in population. During construction of all project
components, traffic rerouting, lane closures, and construction traffic may affect emergency
response times and the travel times or routes for public service vehicles. Sound Transit would
work with contractors, service providers, and the appropriate jurisdiction to minimize disruption
and ensure that appropriate access through or around construction areas is retained. Once
constructed, the South Renton Transit Center and Kingsgate Park-and-Ride Garage structures
would comply with local building and fire codes to alleviate pressure on emergency services in
case of an emergency. During operations, Sound Transit would contract with local law
enforcement and security contractors to provide security services at facilities.
Utilities
The project is located in a highly urbanized area with many existing utilities on or near project
component locations. Sound Transit would work with local jurisdictions and utility providers to
obtain utility service as needed for the facilities and to ensure utility lines and services are
protected and/or relocated as needed.
The project’s components and their expected impacts on various elements of the environment
are described in more detail below. The project is not anticipated to generate significant adverse
environmental impacts.
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A BACKGROUND
1. Name of proposed project, if applicable:
I-405 Bus Rapid Transit Project (Project)
2. Name of applicant:
Sound Transit (Central Puget Sound Regional Transit Authority) is the project proponent
and the State Environmental Policy Act (SEPA) lead agency.
3. Address and phone number of applicant and contact person:
Kathy Fendt, AICP
East Corridor Environmental Manager
Office of Environmental Affairs and Sustainability
Sound Transit
401 South Jackson Street
Seattle, WA 98104-2826
Tel. (206) 689-4856
Email: kathy.fendt@soundtransit.org
4. Date checklist prepared:
September 2020
5. Agency requesting checklist:
Sound Transit
6. Proposed timing or schedule (including phasing, if applicable):
The Sound Transit Board of Directors will make a decision about whether to advance the
project into final design after completion of the environmental review process. Project
components will likely be delivered through a mixture of design-bid-build and
design-build methods. For project components that would be delivered through the
design-build delivery method, Sound Transit would select a design-build contractor in
2021/2022. Following selection, the design-build contractor would develop a detailed
construction schedule for those project components. Construction of all project
components is expected to begin in 2022. Construction of improvements in the south
corridor (from Burien to Bellevue) is expected to be complete and bus rapid transit (BRT)
service is scheduled to begin in 2024. Construction of improvements in the north corridor
(from Bellevue to Lynnwood) is expected to be complete and BRT service is expected to
begin in 2025.
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7.Do you have any plans for future additions, expansion, or further activity related
to or connected with this proposal? If yes, explain.
The I-405 BRT Project corridor and all project components are shown in Attachment A,
Figure A-1.Sound Transit has no plans for future additions or expansion of this
proposed project.
The project is related to a new maintenance and operations base that Sound Transit
plans to construct (Bus Base North), which would store and service the BRT buses used
along the I-405 BRT corridor, along with other buses. The Bus Base North facility is
proposed to be located on property in the Canyon Park area of Bothell. Sound Transit
has recently completed a separate SEPA environmental review for the Bus Base North
Project. Construction of the Bus Base North Project is anticipated to be completed in
2023 prior to the start of BRT service.
The project is also related to Sound Transit’s proposed SR 522/NE 145th BRT Project,
which would construct improvements along State Route (SR) 522 and NE 145th Street
and operate BRT service between Shoreline/Seattle and Bothell. The SR 522/NE 145th
BRT Project would be implemented on a similar timeline. Service on the two BRT lines
would interconnect with each other in Bothell and would connect to Sound Transit’s Link
light rail and other bus service consistent with Sound Transit’s Regional Transit
Long-Range Plan (Sound Transit, 2014).
Other public agency projects are related to this project, as follows.
Washington State Department of Transportation
The Washington State Department of Transportation (WSDOT) is undertaking a number
of projects throughout the I-405 corridor to implement improvements identified in the
I-405 Master Plan. Those improvements were previously evaluated programmatically,
along with I-405 BRT service, in an environmental impact statement (EIS) (WSDOT,
2002). These projects involve or support public transit facilities that would be used by the
I-405 BRT service as part of the I-405 Master Plan:
•I-405 Renton to Bellevue Widening and Express Toll Lanes – This WSDOT project,
which began construction in 2020, will implement two express toll lanes (ETLs) in
each direction from SR 167 to NE 6th Street in Bellevue. The project will also rebuild
the I-405/NE 44th Street interchange with new direct access ramps and an in-line1
transit station, all of which would be used by the I-405 BRT service. A design-build
contractor has been selected by WSDOT for this project and construction began in
2020, with anticipated completion in 2024. (Note that Sound Transit will construct a
park-and-ride lot for BRT service in the vicinity of the NE 44th Street interchange, as
addressed through WSDOT’s 2018 I-405 Tukwila to I-90 Vicinity Express Toll Lanes
1 An in-line transit station is a station where buses do not have to exit the highway mainline (in this case
the I-405 highway) to pick up and drop off passengers; instead the transit station is located within the
highway right-of-way.
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Project Environmental Assessment and the project’s 2019 Finding of No Significant
Impact and Errata.)
•I-405/NE 85th Street Interchange and In-line BRT Station Project – This WSDOT
project will rebuild the I-405/NE 85th Street interchange, including new direct access
ramps and an in-line BRT station for use by the I-405 BRT service, with construction
anticipated to begin in 2021.
•I-405-SR 522 Vicinity to SR 527 Express Toll Lanes Improvement Project – With this
project, WSDOT proposes to extend the dual I-405 ETL system between SR 522 and
SR 527 (building one new lane in each direction), build a partial direct access ramp
at SR 527 providing connections to the Canyon Park Park-and-Ride and a BRT
station that would be used by the I-405 BRT service, and build a direct access ramp
to a transit hub at SR 522/I-405 that would be used by the I-405 BRT service and
Sound Transit’s SR 522/NE 145th BRT service mentioned above. Construction of the
project is anticipated to begin in 2021 (WSDOT 2020a).
•In addition to implementing projects evaluated through the I-405 Master Plan and
EIS, WSDOT continues to address fish passage barriers along the corridor. Sound
Transit is coordinating closely with WSDOT to ensure that the I-405 BRT project
components do not preclude WSDOT’s ability to correct identified fish passage
barriers along SR 518 and I-405 in the future. Examples of fish barriers in the vicinity
of this project are the following:
o Juanita Creek Fish Barrier Correction – As part of their program to replace
existing culverts that have been identified as fish passage barriers, WSDOT
would replace the culvert for the crossing of Juanita Creek beneath I-405, which
occurs at mile post (MP) 21.94, south of the proposed Brickyard Park-and-Ride
lot. This existing culvert under I-405 has been identified as a fish barrier by the
Washington Department of Fish and Wildlife (WDFW) and the WSDOT
Environmental Services Office (ESO) (WDFW Site ID 998602) due to a water
surface drop and velocity. WSDOT would replace the existing 48-inch-diameter
corrugated steel pipe with a structure that would be designed according to the
2013 WDFW Water Crossing Design Guidelines. The work is anticipated to begin
in 2021/2022, likely along with WSDOT’s construction of Sound Transit’s
Brickyard Station and Roadway Improvements component of the I-405 BRT
Project.
o Everest Creek Fish Passage Barriers – WSDOT has identified fish passage
barriers to be corrected along unnamed tributaries leading to Everest Creek
located at MPs 17.53 and 17.54 along I-405. Currently, correcting these fish
passage barriers to Everest Creek is not included in WSDOT’s list of Stand-alone
Fish Passage Projects planned for Design and/or Construction in the 2019-2021
period (WSDOT 2020b).
o Gilliam Creek Fish Passage Barriers – WSDOT has identified fish passage
barriers to be corrected along Gilliam Creek located at milepost 2.82 along SR
518 and at mileposts 0.42 and 0.61 along I-405, near the proposed Tukwila
International Boulevard BRT Station and Roadway Improvements. WSDOT will
replace these fish passage barriers as part of their fish passage improvement
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program. Currently, correcting these fish passage barriers along Gilliam Creek is
not included in WSDOT’s list of Stand-alone Fish Passage Projects planned for
Design and/or Construction in the 2019-2021 period (WSDOT 2020b).
•WSDOT is also evaluating the feasibility of transit-oriented development (TOD),
along with a park-and-ride garage, on the existing Kingsgate Park-and-Ride site.
This potential TOD and garage would be on the same site as Sound Transit’s
proposed Kingsgate Park-and-Ride Garage component of the I-405 BRT Project
described in Section A.11 below. It is currently anticipated that WSDOT’s potential
TOD-related park-and-ride garage would be structurally interconnected to Sound
Transit’s garage. Sound Transit has coordinated with WSDOT to ensure that the
future potential for TOD and the park-and-ride garage addition on the Kingsgate site
would not be precluded by this I-405 BRT Project.
Renton
•Sound Transit, in partnership with the City of Renton, has evaluated the potential
development of TOD on surplus property that may result adjacent to the South
Renton Transit Center component of this project (described in Section A.11 below).
Sound Transit has coordinated with Renton to ensure that future potential TOD
would not be precluded by this project.
Kirkland
The City of Kirkland will implement the following improvements to NE 85th Street: a
queue jump at 6th Street to improve local transit connections to the BRT station at the
interchange of I-405 and NE 85th Street, a nonmotorized connection between 6th Street
and the BRT station at the NE 85th Street interchange to improve bicycle and pedestrian
access to the BRT station, and an additional eastbound lane between 120th Avenue NE
and 122nd Avenue NE, which will improve existing traffic congestion along NE 85th
Street, thereby also improving the connection of transit to the BRT station.
8.List any environmental information you know about that has been prepared, or
will be prepared, directly related to this proposal.
These previously prepared documents relate to the proposal:
•I-405 Master Plan EIS (WSDOT, 2002)
•Final Supplemental Environmental Impact Statement for the Regional Transit
Long-Range Plan Update (Sound Transit, 2014)
•I-405 – Renton to Bellevue Widening and Express Toll Lanes – Tukwila to I-90 –
Environmental Assessment (WSDOT, 2018)*
•South Renton Transit Center Phase I Environmental Site Assessment (Shannon &
Wilson 2017)
•South Renton Transit Center Phase II Environmental Site Assessment (Shannon &
Wilson 2018)
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•I-405, SR 522 Vicinity to SR 527 Express Toll Lanes Improvement Project
Environmental Assessment (WSDOT 2020a)*
•I-405, 85th/132nd Documented Categorical Exclusion*
WSDOT, in partnership with Sound Transit, has completed the environmental review for
four of the BRT stations that would be used by the BRT service on I-405. These stations
(part of the WSDOT-related projects described in Section A.7 above) are: NE 44th Street
Station and Park-and-Ride; NE 85th Street Station; SR 522/I-405 Transit Hub; and
Canyon Park Station. Sound Transit is relying on the environmental findings of the
documents denoted by an asterisk (*) above in completing this environmental review of
the I-405 BRT Project. Copies of these documents are available from WSDOT or at
Sound Transit. See the contact information in Section A.3 above.
Documentation that has been prepared in support of this expanded checklist is attached
and listed following the table of contents.
9.Do you know whether applications are pending for governmental approvals of
other proposals directly affecting the property covered by your proposal? If yes,
explain.
The Lynnwood City Center transit center is currently undergoing a transformation as part
of Sound Transit’s Lynnwood Link Light Rail Extension Project. Work related to the
Lynnwood Link Extension at the Lynnwood City Center transit center includes
construction of a bus layover area, parking structure, and Link light rail station.
Construction permits for this work are in process, with issuance anticipated in 2020.
No other applications are known for approvals of other proposals directly affecting the
property covered by the I-405 BRT project components.
10.List any government approvals or permits that will be needed for your proposal, if
known.
For each project component, Table 1 provides a list of the currently anticipated
approvals and permits needed from local, state, and federal agencies prior to
construction.
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Table 1 I-405 BRT project components – Potential approvals and permits
prior to construction
Project component Agency Approvals or permit
All project components Puget Sound Clean
Air Agency
•Notice of Intent to Operate Nonroad Engines (generators
greater than 500 horsepower)
•Notice of Construction (generators with cumulative
horsepower greater than 2,000 horsepower)
Burien Transit Center
and Roadway
Improvements
City of Burien •Building Permit, including mechanical, electrical,
plumbing, and clearing and grading for construction of
the shelter structure and amenities
•Sign Permit
•Right-of-Way Permit
King County Metro •Construction and use agreements for work and
improvements within the Burien Transit Center
WSDOT •Temporary Construction Air Space Lease (TCAL) for
work on SR 518
•Air Space Lease (ASL), including an operations and
maintenance agreement, for exclusive transit
improvements on SR 518
•Construction Oversight Agreements
•Utility Franchise
•Design and Project Development approval
•General Permits, including for survey work
•Limited Access Break
Tukwila International
Boulevard BRT Station
and Roadway
Improvements
City of Tukwila •Unclassified Use Permit
•Building Permit, including mechanical, electrical, and
plumbing for the pedestrian bridge and the connection to
the mezzanine of the Link light rail station
City of SeaTac •Site Permit for grading, paving, and drainage activities
within City of SeaTac public right-of-way
•Building Permit for stormwater retaining wall within City of
SeaTac public right-of-way
•Right-of-Way Permit for use and hauling within City of
SeaTac public right-of-way
WSDOT •TCAL for work on SR 518
•ASL, including an operations and maintenance
agreement, for exclusive transit improvements on SR 518
•Construction Oversight Agreements
•Utility Franchise
•Design and Project Development approval
•Tree Replacement approval
•General Permits, including for survey work
•Limited Access Break
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Project component Agency Approvals or permit
Washington State
Department of
Ecology
•National Pollutant Discharge Elimination System
(NPDES) Construction Stormwater General Permit
South Renton Transit
Center and Roadway
Improvements
City of Renton •Type III Conditional Use Permit and Site Plan Review
•Right-of-Way Permit
•Civil Construction Permit
•Building Permit, including mechanical, electrical, and
plumbing
•Sign Permit
•Grading Permit
•Demolition Permit
•Utility Easement Vacation approval
King County
Wastewater Division
•Construction Dewatering approval (if dewatering is
needed)
WSDOT •TCAL for work on SR 167 and within the I-405 limited
access right-of-way
•ASL, including operations and maintenance agreement,
for exclusive transit improvements on SR 167
•Construction Oversight Agreements
•Utility Franchise
•Design and Project Development approval
•General Permits, including for survey work
•Limited Access Break
Washington State
Department of
Ecology
•Underground storage tank removal 30-day notice
•NPDES Construction Stormwater General Permit
Puget Sound Clean
Air Agency
•Asbestos/Demolition Notification Form
Federal Transit
Administration (FTA) •National Environmental Policy Act (NEPA) Documented
Categorical Exclusion (DCE), including related approvals
such as NHPA Section 106. Also see Federal Highway
Administration item below.
Federal Highway
Administration
(FHWA)
•NEPA DCE (FHWA has noted intent to serve as a
cooperating agency with FTA, relying on FTA’s NEPA
findings for this project component)
U.S. Environmental
Protection Agency
•Sole Source Aquifer Consultation
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Project component Agency Approvals or permit
Bellevue Transit Center
and Off-site Layover
City of Bellevue •Land use exemption approval (for minor changes to an
existing land use permit)
•Building Permit – Commercial, Minor Project including
mechanical, electrical, and plumbing for construction of
the shelter structure and amenities
•Clearing and grading permit
•Sign Permit
•Type D Right-of-Way Use Permit
King County Metro •Construction and use agreements for work and
improvements within the Bellevue Transit Center
Totem Lake/Kingsgate
Station and Kingsgate
Park-and-Ride Garage
City of Kirkland •Process I Zoning Permit and Administrative Design
Review approval (for Kingsgate Park-and-Ride Garage)
•Building Permit (which will include approval of clearing
and grading)
•Right-of-Way Permit
•Electrical Permit
•Mechanical Permit
•Sign Permit
King County Metro •Operations agreements at Kingsgate Park-and-Ride and
Totem Lake/Kingsgate Station
WSDOT •NEPA DCE, including related approvals except for
National Historic Preservation Act (NHPA) Section 106.
See FHWA item below
•TCAL for work within the I-405 limited access
right-of-way
•Lease, purchase, or easement of land for the Kingsgate
Park-and-Ride Garage
•Tree Replacement approval
•Construction Oversight Agreements
•Utility Franchise
•Design and Project Development approval
•General Permits, including for survey work
•Limited Access Break
Washington State
Department of
Ecology
•NPDES Construction Stormwater General Permit
FHWA •NHPA Section 106 compliance/approval. Although
WSDOT is delegated NEPA authority, FHWA retains
responsibility for Section 106 compliance/approvals for
non-WSDOT projects on the federal interstate system.
Brickyard Station and
Roadway
Improvements
(construction by
City of Bothell (for
work outside of
WSDOT
right-of-way)
•Right-of-Way Permit
•Grading Permit
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Project component Agency Approvals or permit
WSDOT/all permits to
be obtained by
WSDOT)
Washington State
Department of
Ecology
•NPDES Construction Stormwater General Permit
WSDOT •NEPA Compliance/Approval
Lynnwood City Center
Transit Station BRT
and Roadway
Improvements
City of Lynnwood •Building Permit (includes mechanical,
electrical, and plumbing)
•Grading Permit
•Sign Permit exemption
•Right-of-Way Use Permit
WSDOT •NEPA DCE, including related approvals, except NHPA
Section 106. See FHWA item below
•TCAL for work within the I-405 and I-5 limited access
right-of-way
•ASL, including operations and maintenance agreement,
for exclusive transit improvements on I-405 and I-5
•Construction Oversight Agreements
•Utility Franchise
•Design and Project Development approval
•Tree Replacement approval
•General Permits, including for survey work
•Limited Access Break
Washington State
Department of
Ecology
•NPDES Construction Stormwater General Permit
FHWA •NHPA Section 106 compliance/approval. Although
WSDOT is delegated NEPA authority, FHWA retains
responsibility for Section 106 compliance/approval for
non-WSDOT projects on the federal interstate system.
SOURCE: Sound Transit 2020
11.Give brief, complete description of your proposal, including the proposed uses
and the size of the project and site. There are several questions later in this
checklist that ask you to describe certain aspects of your proposal. You do not
need to repeat those answers on this page. (Lead agencies may modify this form
to include additional specific information on project description.)
Sound Transit proposes to implement BRT service, operating along portions of I-5,
I-405, SR 518, and some local arterial streets. The new BRT service is planned to
operate as two high-capacity transit lines, inter-connecting at the Bellevue Transit Center
near the future Bellevue Downtown Link light rail station. The north BRT line would
operate between the Bellevue Transit Center and the Lynnwood City Center transit
center, and the south BRT line would operate between the Bellevue Transit Center and
the Burien Transit Center. Together, the I-405 BRT lines (north and south) would serve
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11 stations 2, including one new transit center in Renton and one new park-and-ride
garage in Kirkland. In addition, a park-and-ride lot would be constructed to increase
park-and-ride capacity in the I-405 corridor (NE 44th Street, Renton).
As discussed in Section A.7, WSDOT, in partnership with Sound Transit, has completed
environmental review for four of the BRT stations that would be used by the BRT service
on I-405. Since environmental review for these components has been completed, they
are not discussed further in this document. The following provides a more detailed
description of the specific project components that are evaluated with this environmental
review. See Attachment A, Figure A-2 through Figure A-9 for site plans showing detail
for each project component. See Attachment B for the project’s Conceptual Engineering
plans. As noted in Section A.6, construction of all project components is expected to
begin in 2022 with BRT service beginning in the south (between Burien and Bellevue) in
2024 and beginning in the north (between Bellevue and Lynnwood) in 2025.
The I-405 BRT service would have 10-minute headways 3 during peak periods and
15-minute headways the remainder of the day and on weekends. Together, the two
routes would provide direct connectivity and access to Sound Transit’s Link light rail
service at: 1) the Lynnwood City Center Station; 2) the Tukwila International Boulevard
Station; and 3) the Bellevue Downtown Link Light Rail Station near the Bellevue Transit
Center. The route would also interconnect with Sound Transit’s proposed SR 522/NE
145th BRT route to provide further transit flexibility in the region and connectivity into the
light rail system. Peak periods would likely be from 6 a.m. to 9 a.m. and from 3 p.m. to 6
p.m. on weekdays. Service would cover 19 hours per day on weekdays and Saturdays
and up to 17 hours on Sundays.
In large part, the BRT service would operate in ETLs along I-405, including segments of
existing ETLs and segments of ETLs that WSDOT will construct between Bellevue and
Tukwila (WSDOT 2018) and between Canyon Park and Brickyard, as noted in Section
A.7. Along SR 518, the BRT service would primarily operate in general-purpose lanes,
with bus-only lanes approaching and departing from the BRT station (described further
below). BRT buses would operate along local arterial roads to access BRT stations in
Burien, Renton, Bellevue, and Lynnwood. In these cities, along local arterial roads,
transit signal priority 4 (TSP) would be added to all existing traffic signals and would be
included with new traffic signals.
All project components would include a proposed BRT-branded (Stride) uniquely
identifiable pylon (decorative column) at the transit station to alert BRT riders to the
service access point. The pylon may be internally illuminated to be identifiable in the
evening and during hours of less light. In addition, all project components would likely
2 Where transit stations would stand alone (not at a proposed transit center), the term “station” refers to a
station pair involving bus stop locations on opposite sides of a roadway, ramp, or highway median,
serving the opposite directions of bus travel through the corridor.
3 Headway refers to the amount of time between transit vehicle arrivals at a stop.
4 TSP is a general term for a set of operational improvements that use technology to reduce dwell time at
traffic signals for transit vehicles by holding green lights longer or shortening red lights. TSP may be
implemented at individual intersections or across corridors or entire street systems.
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include ticket vending machines (TVMs), security cameras and real-time bus information
signs at stations for passengers. These are considered to be standard elements for all
project components.
Burien Transit Center and Roadway Improvements
See Attachment A, Figure A-2, for a figure of this project component. To access the Burien
Transit Center, westbound vehicles would turn left into the existing transit center driveway
access, circulate south around the main transit center island and then west to the west
transit center island. Within the Burien Transit Center, the existing main transit center
island would be extended approximately 20 feet south to provide additional bus bay
capacity; the height of the transit platform here would remain at 6 inches. The west transit
center island would be reconstructed to provide 9-inch-high platforms and would be
lengthened to the south approximately 60 feet and to the north approximately 50 feet; the
northern portion would also be shifted slightly to be angled to the east. The BRT service
would use the northern portion of the west transit center island. The station would include
a BRT-branded shelter and benches, in addition to the amenities at all project component
stations.
New crosswalks may be added at the northern end of the west transit center island, one
connecting the pedestrian path from the sidewalk on SW 148th Street to the west transit
center island and a second extending east to connect to the main transit center island.
The BRT vehicles would use the layover area in the Burien Transit Center. This project
component may add one layover space to the southwest portion of the existing layover
area. To exit the Burien Transit Center, BRT vehicles would circulate around the transit
center islands to the existing driveway access and then turn right to travel eastbound on
SW 148th Street.
To improve transit speed and reliability, a bus-only lane would be added east of the transit
center entrance for eastbound buses along SW 148th Street that would extend east across
the SR 509/SR 518 interchange and along SR 518 for approximately 400 feet. For
westbound buses, a new bus-only left-turn pocket would be added beginning approximately
240 feet east of the transit center driveway access. Between 1st Avenue S and the Burien
Transit Center, the bus-only lane and the bus-only left-turn pocket on SW 148th Street
would be accommodated by converting the center two-way turn lane and, in the southeast
section, slightly widening the existing roadway. Between the Burien Transit Center and 1st
Avenue S, driveways would become right-in/right-out only. To accommodate the eastbound
bus-only lane on the SR 518 bridge over SR 509, the existing lane striping would be
rechannelized. TSP would be added to the existing traffic signals at the intersection of SW
148th Street and 1st Avenue S, at the intersection of SW 148th Street and the SR 509
southbound on- and off-ramps, and at the intersection of SR 518.
It is anticipated that the contractor would stage the necessary construction equipment
and materials within the Burien Transit Center, including potentially using adjacent
parking areas also owned by King County Metro.
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Tukwila International Boulevard BRT Station and Roadway Improvements
See Attachment A, Figure A-3, for a figure of this project component. Sound Transit
continues to work with WSDOT on the final layout for this component. Sound Transit
understands that the design described below would require the following design
analyses or deviations from WSDOT roadway standards:
•Lane widths through curves (WSDOT DM Exhibit 1240-2a)
•Bus-only lane widths (WSDOT DM Exhibit 1410-1)
•Shoulder widths in a few areas with existing constraints, such as bridge piers
(WSDOT DM Exhibit 1232-2)
•Auxiliary lane length for two-lane off-ramp (WSDOT DM Exhibit 1360-14d)
Nevertheless, this is the design currently proposed in order to minimize critical area
impacts and impacts to existing infrastructure.
The proposed BRT station would be accessed by a new pedestrian bridge that would be
constructed from the mezzanine level of the Tukwila International Boulevard Link light
rail station and extended south across SR 518, connecting to the eastbound and
westbound BRT station platforms. The walking surface of the pedestrian bridge would be
level with the mezzanine floor level of the Link station and roughly level with the existing
Tukwila International Boulevard bridge over SR 518. From the pedestrian bridge, access
down to each BRT station platform would be provided by stairs and an elevator. Sound
Transit is also working to determine if funding is available to provide the southern
extension of the pedestrian bridge to the south, review of which is included in this
checklist. That extension would connect at grade to the eastbound on-ramp to SR 518,
where a new sidewalk would be constructed to meet existing sidewalks on Tukwila
International Boulevard.
The proposed BRT station (eastbound and westbound station platforms) would be
located at-grade within the SR 518 right-of-way in an existing area between the SR 518
travel lanes and the on- and off-ramps to SR 518. In addition to the standard elements,
the BRT station would include a branded shelter, benches, and raised platforms
(approximately 9 inches) for level or near-level passenger boarding. Approaching both
the east and westbound BRT station platforms, bus-only lanes would be added (for a
total length of approximately 1,900 feet eastbound and 2,800 feet westbound) to allow
BRT vehicles to safely decelerate to pick up/drop off at the station platform and
accelerate from the station platforms and merge back onto SR 518 with general-purpose
traffic. The addition of these bus-only lanes would require realigning the center jersey
barrier, regrading, and repaving a portion of the existing SR 518 travel lanes and ramps
to and from the interchange of SR 518 with Tukwila International Boulevard. In the
westbound direction, the bus-only lane would also require widening the existing
westbound SR 518 bridge that passes over the SR 518 off-ramp heading south to
Airport Expressway.
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A stormwater detention facility would be constructed inside the westbound SR 518 off-
ramp loop. The detention pond would include an adjacent retaining wall with a maximum
height of 11 feet. Stormwater would be collected underground and detention would be
provided as required. An access road would be constructed in order to access the
detention facility.
A new retaining wall for fill would be constructed along the west side of the eastbound
bus-only deceleration lane for approximately 900 feet, with a maximum height of 6 feet. On
the south side of SR 518, adjacent to eastbound SR 518, there would be a new retaining
wall for a length of approximately 730 feet, with a maximum height between 10 and 15
feet.
For this project component, the contractor would be expected to stage the necessary
construction equipment and materials within the existing right-of-way for SR 518, likely in
the area between westbound SR 518 and the existing Tukwila International Boulevard
Link light rail station, outside of the active travel lanes and the on- and off-ramps.
South Renton Transit Center and Roadway Improvements
See Attachment A, Figure A-4, for a figure of this project component. The South Renton
Transit Center would be located on the north side of I-405, in the northeast corner of the
intersection of S Grady Way and Rainier Avenue S (SR 167). This new transit facility
would be developed on an 8.3-acre site. Facilities at the South Renton Transit Center
would include the following:
•A new transit center island with eight 120-foot active bus bays with operational space
provided for both BRT and other bus transit service (operated by King County Metro,
with the assumption that they will use 6 active bays) using this facility. In addition to
the standard elements, the BRT station in the transit center island could include a
branded BRT shelter (if the entire transit center island is covered by a single, large
shelter there would only be the pylon) and 9-inch raised platforms for near-level
passenger boarding.
•Ten bus layover bays in the bus loop area.
•A 700-stall, 5-floor park-and-ride garage with drop-off and pick-up stalls on the first
floor. Access to the park-and-ride garage would be from a separate right-turn-only
entrance and exit from Rainier Avenue S, located south of the access to the transit
center bus loop. A second access to the park-and-ride garage would be from Lake
Avenue S; this access would not be restricted to right-in/right-out turns.
•From the third floor of the park-and-ride garage, a pedestrian bridge would potentially
connect the garage to a staircase and elevator connecting to the middle of the transit
center island.
•Pedestrian access to the transit center site would be from the existing and
reconstructed sidewalks along Rainier Avenue S and S Grady Way. A new sidewalk
would be constructed along the eastern side of the transit center, along the frontage
of Lake Avenue S. Pedestrian sidewalks would also be constructed within the transit
center site along the north and south sides of the bus loop, from Rainier Avenue S
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and Lake Avenue S to the park-and-ride garage, from S Grady Way north into the
site, and between the park-and-ride garage and the bus loop.
To access the South Renton Transit Center from I-405, BRT vehicles heading in a
westerly direction (southbound) on I-405 would use the exit onto Rainier Avenue S into
an existing northbound, curbside business access and transit (BAT) lane. BRT buses
would stay in the existing BAT lane across S Grady Way along Rainier Avenue S. BRT
vehicles heading in an easterly direction (northbound) on I-405 would access the South
Renton Transit Center using the existing exit onto Rainier Avenue S. To improve transit
speed and reliability, northbound BRT vehicles would use a new short section of a
bus-only, bus-on-shoulder lane on northbound Rainier Avenue S. that would be
constructed starting at the existing southbound I-405 loop ramp and extending north
approximately 200 feet to connect with the existing BAT lane.
Once across S Grady Way, BRT vehicles heading northbound would turn right into the
transit center’s bus loop from a new signalized intersection at Rainier Avenue S and
Hardie Avenue SW. This new intersection would also be the exit point for buses leaving
the transit center and would be the primary ingress and egress location for the buses.
Within this intersection, the existing raised, landscaped median in Rainier Avenue S
would be removed to allow for turning movements, and crosswalks would be provided at
each of the four roadway crossings. North of this intersection, the existing center median
within Rainier Avenue S would be removed for a new southbound bus-only left-turn
pocket that would allow buses to turn left into the transit center; a small section of a
center median may remain at the southern end of the bus-only left-turn pocket. At the
connection to Rainier Avenue S, Hardie Avenue SW would be reconstructed to realign
the southbound lane adjacent to the northbound lane. This shift would require removing
the northern portion of an existing raised, landscaped island. In place of the existing
southbound lane on Hardie Avenue SW, a landscaped curb would be constructed,
connecting with the remaining portion of the existing island. For general-purpose traffic,
the southbound lane on Hardie Avenue SW would be right-turn only. Buses on Hardie
Avenue SW would be able to travel through the intersection into the transit center.
A secondary bus access into the transit center’s bus loop would be from the east side of
the site from Lake Avenue S. This secondary access would also provide connectivity to
the bus bays and layover spaces at the existing South Renton Park-and-Ride located
just east of the South Renton Transit Center. Access from Lake Avenue S provides bus
circulation and access from S Grady Way, Shattuck Avenue S, and S 7th Street. Parking
for operation and maintenance vehicles would be located parallel to the Lake Avenue S
access to the bus loop.
In the southern portion (adjacent to S Grady Way) and the eastern portion of the site
(adjacent to Lake Avenue S) there is an existing Bonneville Power Administration power
line easement. Along the south boundary, the easement is approximately 100 feet wide.
In the eastern portion of the site the easement is approximately 200 feet wide. Prior to
the start of construction, Sound Transit would coordinate with the Bonneville Power
Administration, and utility providers as needed, to ensure construction activities would
not interfere with their facilities and service. Once constructed, the transit facilities would
not alter, affect, or interfere with this existing 240 kilovolt transmission line across the
site. The easement area under the transmission lines would primarily be green space
(where existing pavement would be removed) or would consist of ground-level
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improvements, such as the driveway into the park-and-ride garage off of Lake Avenue S
and the eastern portion of the transit loop. In addition, the existing sculpture located at
the northeast corner of the intersection of Rainier Avenue S and S Grady Way, adjacent
to the southwest corner of the transit center site, would remain.
BRT vehicles leaving the South Renton Transit Center would turn left onto Rainier
Avenue S into an existing, southbound curbside BAT lane and then onto either
northbound or southbound I-405 using existing on-ramps. Signal-timing improvements
would be made, including adding TSP to the traffic signal at the intersection of S Grady
Way and southbound Rainier Avenue S and at Rainier Avenue S and SW 7th Street.
For construction of the South Renton Transit Center, the contractor would likely stage
the necessary equipment and materials on the site. For construction of the
bus-on-shoulder lane along Rainier Avenue S, the contractor may stage equipment and
materials in the area to the east of Rainier Avenue S, within the existing, unpaved
right-of-way for I-405. Prior to construction, the existing buildings on-site would be
removed and properly disposed of and on-site remediation would be completed as
identified in the Phase II Environmental Site Assessment (Shannon & Wilson 2018) as
discussed in Attachment D. The site would be cleared and graded as needed for the
proposed transit center features and to provide adequate drainage. During construction,
pile driving may be required to construct the foundation of the park-and-ride garage.
Bellevue Transit Center and Off-site Layover
See Attachment A, Figure A-5, for a figure of this project component. At the Bellevue
Transit Center, two existing bus bays would be modified with the standard station
elements for the BRT service. The existing height of the transit center island would
remain, as would the shelter over the transit center island; a BRT-branded pylon would
be installed to identify the bays used for the BRT service. On the north side of the transit
center island, two existing crosswalks across NE 6th Street would be relocated (shifted
slightly west from their current locations). To maintain Americans with Disability Act
accessibility at these relocated crosswalks, the existing curb ramps on the transit center
island and on the north side of NE 6th Street would be re-graded. This regrading would
be coordinated with the City of Bellevue’s Downtown Bellevue Exceptional Intermodal
Connections project to raise the intersections east and west of the transit center (City of
Bellevue 2020).
The BRT vehicles would have on-street layover along 110th Avenue NE in front of the
Bellevue Library, which is less than one-half mile north of the transit center. To access the
layover space from the transit center, BRT vehicles would be anticipated to turn right onto
108th Avenue NE, then right onto NE 12th Street, and then right onto 110th Avenue NE.
In the northern portion of 110th Avenue NE, the roadway cross-section would be
modified. On the west side of 110th Avenue NE the existing on-street parking would be
removed to provide additional bus layover capacity north and south of the existing
driveway into the library parking garage. The one existing southbound through lane
would remain. In the northbound direction, the rechannelization includes shifting the
right-turn-only lane slightly west to provide on-street parking spaces along the east side
of the street to replace what was removed along the west side of the street. Through
re-striping, the existing painted median would be replaced with a left-turn-only pocket
from 110th Avenue NE to NE 12th Street. No changes to the existing sidewalks are
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proposed. The existing raised island in the middle of the intersection of 110th Ave NE
and NE 12th Street would be removed. In the southern portion of 110th Avenue NE, the
existing bus layover space just north of NE 10th Street would remain.
From the layover space, BRT vehicles would be anticipated to access the Bellevue
Transit Center by heading south on 110th Avenue NE, turning right onto NE 8th Street,
left onto 108th Avenue NE, and then left onto NE 6th Street into the transit center.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
See Attachment A, Figure A-6, for a figure of this project component. The existing Totem
Lake Freeway Station is located on the in-line direct access ramps that extend from the
center of I-405 up to the NE 128th Street overcrossing of I-405 (on the north side of NE
128th Street). For the Totem Lake/Kingsgate BRT Station, one bay of each existing
station pair would be transformed into a BRT station with the standard station elements.
TVMs may be installed at the station platform or they may just be located at the
Kingsgate Park-and-Ride Garage. At this station, the existing 6-inch height of the
platforms and the existing shelter over the station platforms would remain. TSP would be
added at the intersection of the in-line ramp terminal and NE 128th Street.
The existing Kingsgate Park-and-Ride lot is located west of the Totem Lake/Kingsgate
Station along 116th Avenue NE. The Kingsgate Park-and-Ride site is approximately 8
acres in size and consists of 502 surface park-and-ride spaces and an existing bus
transit loop currently used by Sound Transit express routes, several King County Metro
routes, and one Community Transit route. The site is owned by WSDOT, considered to
be right-of-way for I-405, and is operated and maintained by King County Metro.
This project component includes adding 400 park-and-ride spaces at the Kingsgate site
by constructing a garage structure in the southern portion of the existing surface
park-and-ride lot to create a total of approximately 900 park-and-ride spaces on the site.
Sound Transit would construct a 5-story park-and-ride garage with approximately 566
park-and-ride stalls. The 566 park-and-ride stalls would replace 166 surface
park-and-ride spaces that would be displaced by the garage and would provide an
additional 400 park-and-ride spaces. The park-and-ride garage would be equipped with
lighting to support operations and as needed for safety and security. Landscaping would
be provided in designated areas in accordance with City of Kirkland and Sound Transit
requirements, including maintenance and irrigation. Security cameras are anticipated to
be used in the vicinity of the garage structure.
Stormwater would be collected underground and detention would be provided either
above grade or below grade as required. Stormwater management facilities would
include modifications to the existing detention pond in the southeast corner of the site, a
bioretention swale along the south side of the garage, and a detention vault that would
be located underground, below the surface park-and-ride stalls.
Access to the Kingsgate site would continue to be through two driveways from 116th
Avenue NE, and the existing on-site circulation would not change. The northern driveway
along 116th Avenue NE would remain as is and would continue to be the only entrance to
the park-and-ride lot, with vehicles southbound on 116th Avenue NE turning right and
vehicles northbound on 116th Avenue NE turning left. To access the park-and-ride garage,
vehicles from 116th Avenue NE would use this northern driveway and then circulate through
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the surface park-and-ride aisles to the main garage entrance/exit on the northwest corner of
the structure or the secondary access on the southwest corner of the structure.
Vehicles exiting the garage would turn right immediately past the proposed single row of
park-and-ride stalls located along the northern side of the garage, drive along the aisle,
and exit the site using the southern driveway to 116th Avenue NE. The existing southern
driveway would be shifted slightly north to accommodate the garage structure. This shift in
the driveway location would result in a slight modification to the existing bus loop, located
just north, that uses this driveway. The existing bus loop would remain on-site. The two
lanes of this driveway would continue to be one right-turn-only and one left-turn-only to exit
the site. Concrete paving would be used for all driveways and bus and large
maintenance vehicle parking areas. Asphalt paving would be provided in areas trafficked
by personal vehicles. Additional work within the Kingsgate site includes providing sidewalks
for pedestrian access from 116th Avenue NE along the north side of the garage to the main
entrance. This sidewalk would connect to the existing crosswalk across 116th Avenue NE to
the covered walkway along the east side that continues south and then east to connect to
the Totem Lake/Kingsgate Station.
For the work at the Totem Lake/Kingsgate Station and the Kingsgate Park-and-Ride
Garage, the contractor would likely stage the necessary equipment and materials on the
Kingsgate site. The Kingsgate Park-and-Ride lot was constructed with Federal Highway
Administration (FHWA) funds. A requirement of this funding is to maintain the existing
502 park-and-ride stalls associated with the lot. During construction of the Kingsgate
Park-and-Ride Garage, a number of the existing surface stalls within the footprint of the
garage and areas needed for construction staging would be inaccessible. Prior to
construction, temporary measures would be taken to maintain the current level of access
to the park-and-ride lot, such as providing temporary parking spaces nearby or additional
shuttle service to the site. Temporary parking spaces would be anticipated to be from
existing, nearby properties with underused parking that could be leased through
temporary construction easements.
Brickyard Station and Roadway Improvements
See Attachment A, Figure A-7, for a figure of this project component. The proposed new
BRT station (northbound and southbound station platforms) would be located at-grade
within the center of the I-405 roadway and right-of-way. A bus-only lane would be added
in both the northbound and southbound direction (for a total length of approximately
4,000 feet southbound and 3,000 feet northbound), to allow BRT vehicles to safely
decelerate to pick up/drop off at the BRT station platform and to accelerate from the
station platforms and merge into I-405 traffic. The addition of these northbound and
southbound bus-only lanes and the BRT station platforms would require realigning and
widening the existing I-405 roadway to the east and west. The BRT station would include
a branded shelter, benches, and raised platforms for level or near-level passenger
boarding, in addition to the standard elements.
A pedestrian bridge over I-405 would connect the two BRT station platforms and would
connect the BRT station to the Brickyard Park-and-Ride lot to the west. Between the
I-405 roadway surface and the bottom of the pedestrian bridge, the proposed vertical
clearance would be approximately 17.5 feet. From each BRT station platform, access to
the pedestrian bridge would be provided by stairs and at least one elevator. Stairs and
an elevator would be provided from the pedestrian bridge to access the Brickyard
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Park-and-Ride lot. Although funding is not currently available, WSDOT, Bothell, Kirkland,
and Sound Transit are currently considering an extension of this pedestrian bridge to the
east side of I-405, with a stairway and ramp, and possibly an elevator, connecting to
116th Avenue NE; review of this east extension is included in this checklist.
New retaining walls would be constructed along the east and west sides of I-405 for
approximately 1,110 feet in the northbound direction and 465 feet in the southbound
direction, with a maximum height of 6 feet.
For this project component, the contractor would be expected to stage the necessary
construction equipment and materials within the existing right-of-way for I-405 and,
potentially, the Brickyard Park-and-Ride lot.
Lynnwood City Center Transit Station BRT and Roadway Improvements
See Attachment A, Figure A-8 and Figure A-9, for a figure of this project component.
BRT buses would access the Lynnwood City Center transit station by using the existing
Alderwood Mall Boulevard exit from I-5 south, traveling along 196th Street SW, turning
left at 44th Avenue W, right at 200th Street SW, left onto 46th Avenue W, and then into
the transit center. Along this routing, TSP would be added to existing traffic signals. To
improve access to and from the transit center, modifications would be made at two
intersections along 46th Avenue W. The first intersection, just north of the transit center,
would include two northbound and two southbound lanes with stop signs controlling the
east and west legs of the intersection. The second intersection, at the entrance to the
transit center, would be modified to include a new traffic signal and to include
crosswalks.
At the existing transit center, one bay in the northeast portion of the transit center loop
would be modified to accommodate the BRT station as a drop-off bay with a 6 to 9-inch
curb height. In the southwest portion of the transit center loop, one bay would be
modified to accommodate BRT pick up and one bay would be converted to a layover
space. At the BRT pick-up bay, in addition to the standard station elements, the platform
and adjacent area would be re-graded for near-level passenger boarding. The existing
shelters over the bays would remain.
Leaving the transit center, BRT vehicles would follow the same routing to 196th Street
SW and then would use the Poplar Way on-ramp to access I-5 north and then I-405
south. Along Poplar Way (south of 196th Street SW) and the I-5 northbound on-ramp,
the roadway and ramp would be widened for a bus-only bus-on-shoulder lane for BRT
vehicles to use to bypass congestion.
For construction at the Lynnwood City Center transit station, the contractor would likely
stage the necessary equipment and materials within the transit center. For construction
of the bus-only lane along Poplar Way and the I-5 on-ramp, the contractor may stage
equipment and materials in the existing, unpaved right-of-way within the center of the
Poplar Way loop ramp onto I-5.
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12. Location of the proposal. Give sufficient information for a person to understand
the precise location of your proposed project, including a street address, if any,
and section, township, and range, if known. If a proposal would occur over a
range of area, provide the range or boundaries of the site(s). Provide a legal
description, site plan, vicinity map, and topographic map, if reasonably available.
While you should submit any plans required by the agency, you are not required
to duplicate maps or detailed plans submitted with any permit applications related
to this checklist.
The I-405 BRT Project involves construction and use of a number of infrastructure
components along a corridor starting in the south in the City of Burien at the Burien
Transit Center (along SW 148th Street), continuing to the east along SR 518, and then
following I-405 from the City of Tukwila in King County to its connection with I-5 in the
north. At the intersection with I-5, the project corridor then heads south on I-5 to the
Lynnwood City Center transit center in the City of Lynnwood in Snohomish County. For
each project component, Table 2 provides the existing address, if applicable, and the
Section, Township, and Range.
All specific project component locations are described in response to Question A.11 and
are shown on the I-405 BRT Project map (Attachment A, Figure A-1).
Table 2 I-405 BRT project components: Address and
Section/Township/Range
Project component
Address (road
improvements are nearby) Section/Township/Range
1. Burien Transit Center and
Roadway Improvements
14900 4th Avenue SW, Burien Sections 19 and 20, Township 23N,
Range 4E
2. Tukwila International
Boulevard BRT Station and
Roadway Improvements
Tukwila International
Boulevard Light Rail Station:
15426 25th Avenue S, Tukwila
Sections 21 and 22, Township 23N,
Range 4E
3. South Renton Transit Center
and Roadway Improvements
750 Rainier Avenue S Section 19, Township 23N, Range 5E
4. Bellevue Transit Center and
Off-site Layover
Bellevue Transit Center:
10903 NE 6th Street, Bellevue
Layover: 1111 110th Avenue
NE, Bellevue
Bellevue Transit Center: Section 32,
Township 25N, Range 5E
Layover: Section 29, Township 25N,
Range 5E
5. Totem Lake
Station/Kingsgate
Park-and-Ride Garage
12837 116th Avenue NE,
Kirkland
Section 28, Township 26N, Range 5E
6. Brickyard Station and
Roadway Improvements
15530 Juanita Woodinville
Way NE, Bothell
Section 17, Township 26N, Range 5E
7. Lynnwood City Center Transit
Station BRT and Roadway
Improvements
Lynnwood City Center: 20100
48th Avenue West, Lynnwood
Roadway Improvements:
Poplar Way/I-5 Interchange
Lynnwood City Center: Section 21,
Township 27N, Range 4E
Roadway Improvements: Sections 15
and 22, Township 27N, Range 4E
SOURCE: Sound Transit 2020
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B ENVIRONMENTAL ELEMENTS
In response to all of the questions of Section B below, where specific project components are
not referenced, the answer provided is intended to refer to all project components.
1.Earth
a. General description of the site: (underline one): flat, rolling, hilly, steep slopes,
mountainous, other
The project component locations include a range of grades, from flat to steep. Table 3
provides details for each project component.
b.What is the steepest slope on the site (approximate percent slope)?
For each project component, Table 3 provides a general description of the existing
topography and a description of slopes that are more than flat.
Table 3 I-405 BRT project components: Slopes
Project component Topography Description (% slope, location)
Burien Transit Center and
Roadway Improvements
Flat; no steep slopes
Tukwila International Boulevard
BRT Station and Roadway
Improvements
Steep slopes in areas Approximately 33% slopes west of SR
99, between SR 99 Bridge and North
Airport Expressway
South Renton Transit Center and
Roadway Improvements
Flat; no steep slopes
Bellevue Transit Center and
Off-site Layover
Slight slopes in areas •Bellevue Transit Center: Slopes
approximately 5% to the east
•Off-site layover: Slopes range from
2% to 3.5% to the east
Totem Lake/Kingsgate Station and
Kingsgate Park-and-Ride Garage
Slight slopes in areas •Totem Lake/Kingsgate Station:
Slopes range from 1.5% to 3%
•Kingsgate Park-and-Ride Garage:
Flat
Brickyard Station and Roadway
Improvements
Slight slopes in areas Slopes range from approximately 2% to
3%
Lynnwood City Center Transit
Station BRT and Roadway
Improvements
BRT station improvements:
Flat; no steep slopes
Roadway improvements:
Steep slopes
Poplar Way roadway improvements:
Approximately 15% to 50% slopes
along roadway ditch, sloping northwest
toward I-5
SOURCE: Sound Transit 2020
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c.What general types of soils are found on the site (for example, clay, sand, gravel, peat,
muck)? If you know the classification of agricultural soils, specify them and note any
agricultural land of long-term commercial significance and whether the proposal
results in removing any of these soils.
The general geologic characteristics within the project corridor include Alluvium (Qa) and
Pleistocene Continental Glacial Drift (Qgd), which encompass a wide range of deposits
from soft organic-rich clayey silt, to very stiff sandy silt, to loose to dense sand and
gravel, to dense to very dense silty sand to sandy gravel and may be interbedded with
laminated clayey silt and silt (WSDOT 2018). Areas of Tertiary sedimentary rocks are
also expected to exist in the study area.
There are no known agricultural lands or soils of long-term commercial significance in
the project corridor (also see B.8).
For each project component, Table 4 provides a description of the types of soils
anticipated to exist at the sites.
Table 4 I-405 BRT project components: Types of soils
Project component Types of soils
Burien Transit Center and Roadway
Improvements
Younger glacial deposits of the Vashon till and Vashon
recessional outwash deposits (Booth and Waldron 2004)
Tukwila International Boulevard BRT
Station and Roadway Improvements
Younger glacial deposits of the Vashon till and Vashon
recessional outwash deposits (Booth and Waldron 2004)
South Renton Transit Center and
Roadway Improvements
Alluvium consisting of sand and gravel deposited by the Cedar
River (Mullineaux 1965)
Subsurface testing at the South Renton Transit Center site
found loose to loose fill soils over alluvial soils primarily
comprised of soft silts and loose sands (Sound Transit 2020f)
Bellevue Transit Center and Off-site
Layover
Younger glacial deposits of the Vashon till deposits (Yount,
Minard, and Dembroff 1993)
Totem Lake/Kingsgate Station and
Kingsgate Park-and-Ride Garage
Vashon recessional outwash deposits (Yount, Minard, and
Dembroff 1993)
Subsurface testing at the Kingsgate Park-and-Ride site found
medium dense to dense fill soils over dense to very dense
advance outwash deposits (sand and gravel) over very stiff to
hard fine-grained soils (glaciolacustrine) (Sound Transit 2020f)
Brickyard Station and Roadway
Improvements
Vashon advanced outwash deposits (Yount, Minard, and
Dembroff 1993)
Lynnwood City Center Transit Station
BRT and Roadway Improvements
Primarily Vashon till deposits with a portion characterized by
Vashon recessional outwash deposits (Smith 1974)
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d.Are there surface indications or history of unstable soils in the immediate vicinity? If
so, describe.
Burien Transit Center and Roadway Improvements
Geologically hazardous areas are defined in Burien Municipal Code 19.40.290 as areas
that, because of their susceptibility to erosion, sliding, earthquake, or other geological
events, are not suited to siting development due to public health and safety concerns.
These areas include, but are not limited to, erosion hazard areas, landslide hazard
areas, and seismic hazard areas.
No geologically hazardous areas are located within or in the immediate vicinity of the
project component.
Tukwila International Boulevard BRT Station and Roadway Improvements
Areas of potential geologic instability are defined in Tukwila Municipal Code 18.45.100
as areas of potential erosion and landslide hazards.
Areas of potential geologic instability were mapped as occurring within the project
component area with a moderate-to-high potential for landslide. These areas are located
just north and south of the proposed location of the BRT station platforms along the
edges of the SR 518 right-of-way, where the topography has a 33 percent slope.
South Renton Transit Center and Roadway Improvements
Geologically hazardous areas are defined in Renton Municipal Code 4.3.050 as areas
with sensitive and protected slopes; medium, high, or very high landslide hazards; high
erosion hazards; high seismic hazards; and medium or high coal mine hazards.
According to the City of Renton’s mapping system, the site contains a potential high
seismic hazard. Recent geotechnical borings conducted for the project indicate that
liquefiable soils are present at this site. Denser soils were encountered below soils that
are subject to liquefaction that are anticipated to provide adequate foundation support
(Sound Transit 2020f).
Bellevue Transit Center and Off-site Layover
Geologically hazardous areas are defined in Bellevue Municipal Code 20.25H.120 as
areas with landslide hazards, steep slopes, coal mine hazards, and seismic hazards.
No geologically hazardous areas are located within or in the immediate vicinity of the
project component.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
Geologically hazardous areas are defined in Kirkland Zoning Code Chapter 85 as areas
with landslide hazards, erosion hazards, and seismic hazards.
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Geologically hazardous areas were mapped as occurring within the project component
area with a medium or mixed liquefaction potential and moderate-to-high susceptibility
for landslides. These areas are located within the footprint of the proposed Kingsgate
Park-and-Ride Garage structure and I-405.
Although the City of Kirkland has mapped this project component in an area with a
medium or mixed liquefaction potential, based on information from recent geotechnical
borings conducted for the project, liquefaction at this site is unlikely (Sound Transit
2020f).
Brickyard Station and Roadway Improvements
Geologically hazardous areas are defined in Bothell Municipal Code 14.04.800 as areas
susceptible to erosion, sliding, earthquake, or other geological events. They pose a
threat to the health and safety of citizens when incompatible development is sited in
areas of significant hazard.
No geologically hazardous areas are located within or in the immediate vicinity of the
project component.
Lynnwood City Center Transit Station BRT and Roadway Improvements
Geologically hazardous areas are defined in Lynnwood Municipal Code 17.10.100 as
those areas that are naturally susceptible to geologic events such as landslides, seismic
activity, and severe erosion.
No geologically hazardous areas are located within or in the immediate vicinity of the
project component.
e.Describe the purpose, type, total area, and approximate quantities and total affected
area of any filling, excavation, and grading proposed. Indicate source of fill.
For each project component, the sources of backfill materials are currently unknown and
may include concrete, imported fill materials (e.g., for pavement subbase), and possibly
excavated site materials if they are found suitable for backfilling purposes.
Burien Transit Center and Roadway Improvements
The estimated total construction area is approximately 152,000 square feet. The
estimated net excavation and removal of soils, most of which is associated with the
roadway improvements, is approximately 11,000 cubic yards. The work for this project
component includes removal and reconstruction of concrete panels and pedestrian
platforms at the transit center; asphalt overlay, new sidewalk, and removal of median
islands within SW 148th Street; and new full-depth asphalt pavement and concrete
median islands on SR 518. Other than materials for paving and pavement subbase, no
fill is anticipated for this project component.
Tukwila International Boulevard BRT Station and Roadway Improvements
The estimated total construction area is approximately 225,000 square feet. The
estimated quantity of soils that may be removed (for construction of the BRT station,
pedestrian bridge stairs and elevator, stormwater detention facilities, and roadwork) is
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approximately 66,000 cubic yards. Estimated fill amount is approximately 7,000 cubic
yards, for a net excavation of approximate 59,000 cubic yards.
South Renton Transit Center and Roadway Improvements
The estimated total construction area is approximately 312,000 square feet. The
estimated quantity of soils that may be removed (for construction of the transit loop
facilities, park-and-ride garage structure, stormwater detention facilities, and roadwork)
is approximately 42,000 cubic yards. Estimated fill amount is approximately 38,000 cubic
yards, for a net excavation of 4,000 cubic yards.
Bellevue Transit Center and Off-site Layover
The estimated total construction area is approximately 5,000 square feet. The estimated
quantity of soils that may be removed for new pavement and crosswalks is
approximately 400 cubic yards. Other than materials for paving and pavement subbase,
no fill is anticipated for this project component.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
No earthwork or ground disturbance would occur for the minor changes at the Totem
Lake Station platforms.
The estimated construction area for the Kingsgate Park-and-Ride features is
approximately 157,000 square feet. The estimated excavation/cut quantity for the
Kingsgate Park-and-Ride Garage structure and stormwater detention facilities is
approximately 45,000 cubic yards of soil, with an estimated fill amount of approximately
8,000 cubic yards, for a net excavation of 37,000 cubic yards.
Brickyard Station and Roadway Improvements
The estimated total construction area is approximately 1,500,000 square feet. The
estimated quantity of soils that may be excavated/cut quantity for this project component
is approximately 30,000 cubic yards of soil, with an estimated fill amount of
approximately 8,500 cubic yards, for a net excavation of approximately 21,500 cubic
yards. Other than materials for paving and pavement subbase, no fill is anticipated for
this project component.
Lynnwood City Center Transit Station BRT and Roadway Improvements
The estimated total construction area is approximately 108,000 square feet. The
estimated grading quantity for the roadwork (including stormwater drainage and ditches)
is approximately 17,000 cubic yards of soil, with an estimated fill amount of
approximately 1,000 cubic yards, for a total net excavation of 16,000 cubic yards.
f.Could erosion occur as a result of clearing, construction, or use? If so, generally
describe.
During construction of each of the project components, minor and temporary soil erosion
could occur as a result of clearing and grading, particularly during precipitation events.
The Tukwila International Boulevard BRT Station and Roadway Improvements, South
Renton Transit Center and Roadway Improvements, Totem Lake/Kingsgate Station and
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Kingsgate Park-and-Ride Garage, Brickyard Station and Roadway Improvements, and
Lynnwood City Center Transit Station BRT and Roadway Improvements project
components would be subject to NPDES permit requirements, which would include
measures to reduce potential erosion from open soils. All applicable regulations
associated with the NPDES permits would be adhered to for these project components.
To reduce the potential for erosion, a Temporary Erosion and Sediment Control Plan
would be prepared, implemented, and kept on-site for each project component. The
potential for erosion would be further minimized by adherence to best management
practices (BMPs) approved by the Washington State Department of Ecology (Ecology)
and the appropriate city municipal code.
g. About what percent of the site will be covered with impervious surfaces after project
construction (for example, asphalt or buildings)?
Burien Transit Center and Roadway Improvements
The majority of the area (approximately 90 percent) is already covered with impervious
surfaces for the existing transit center, SW 148th Street roadway and sidewalks, and the
SR 518 roadway. This project component would increase the impervious surfaces total
by approximately 2,000 square feet for changes at the transit center and roadway
widening along SW 148th Street. There would be no new impervious surfaces within the
SR 518 right-of-way associated with this project component.
Tukwila International Boulevard BRT Station and Roadway Improvements
The majority of the area (approximately 90 percent) is already covered with impervious
surfaces for the existing SR 518 roadway and ramps. This project component would add
a total of approximately 72,000 square feet of new impervious surfaces.
South Renton Transit Center and Roadway Improvements
For the South Renton Transit Center site, the existing impervious surfaces total
approximately 363,000 square feet, nearly 100 percent of the site. The proposed transit
center design would add areas of open space and landscaping that would reduce the
impervious surface areas on-site to approximately 287,000 square feet, a decrease of
approximately 76,000 square feet.
For the roadway improvements, approximately 90 percent of the area is existing
impervious surfaces. Along Rainier Avenue S, north of Grady Way SW, the roadway
improvements would add approximately 9,000 square feet of new impervious surface,
primarily through the removal of the center, vegetated median. Within the Grady Way
SW right-of-way, which includes a strip of land north of the existing sidewalk that is
currently paved, the existing condition has approximately 12,000 square feet of
impervious surfaces. The project component would reduce the existing impervious
surfaces to approximately 9,000 square feet by adding green space within the
right-of-way north of the existing sidewalk, for a decrease of approximately 3,000 square
feet. South of Grady Way SW, along Rainier Avenue S, the project component would not
add new impervious surfaces. Therefore, the total net increase in impervious surfaces
for the roadway improvements is approximately 6,000 square feet.
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Bellevue Transit Center and Off-site Layover
For this project component (including the layover location), nearly 100 percent of the
area is existing impervious surfaces. Small areas of pervious surfaces are associated
with tree wells at the transit center and street trees along 110th Avenue NE in front of
the off-site layover area. This project component would increase the existing impervious
surfaces by approximately 100 square feet at the Bellevue Transit Center for re-angling
and lengthening the existing transit center island. The off-site layover area would not add
impervious surfaces.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
For the Totem Lake/Kingsgate Station, all of the existing area of the Totem Lake
Freeway Station is comprised of impervious surfaces and there would be no increase in
impervious surface at that location. Approximately 67 percent of the Kingsgate
Park-and-Ride site is comprised of existing impervious surfaces, approximately 80,000
square feet. The site modifications for the Kingsgate Park-and-Ride Garage would
replace approximately 7,000 square feet of impervious with pervious surface and
remove the existing pervious landscaping (internal to the site in the vicinity of the new
garage) and replace it with approximately 12,000 square feet of new impervious surface,
for a net total of approximately 5,000 square feet of new impervious surface at the park-
and-ride site.
Brickyard Station and Roadway Improvements
For this project component, most of the area (more than approximately 90 percent) is
existing impervious surfaces for the I-405 roadway. This project component would
increase the existing impervious surfaces total by approximately 170,000 square feet for
roadway widening and new pavement on I-405 to accommodate the BRT station and
bus-only lanes approaching and leaving the BRT station.
Lynnwood City Center Transit Station BRT and Roadway Improvements
For this project component, over 90 percent of the existing area is comprised of
impervious surfaces. There would be no new impervious surfaces at the Lynnwood City
Center transit station. For roadway widening to add the bus-only lane on Poplar Way
and the Poplar Way on-ramp, the project component would add approximately 18,000
square feet of new impervious surfaces.
h.Proposed measures to reduce or control erosion, or other impacts to the earth, if any:
The following measures would be incorporated into the project during construction to
minimize the potential for erosion:
•Implement a temporary erosion and sedimentation control plan with BMPs to prevent
or minimize erosion and the potential for discharge of silt-laden runoff to nearby
bodies of water. The plan would outline additional actions to achieve the intended
environmental performance should any BMP not function as intended.
•Develop appropriate construction procedures to maintain or enhance slope stability
in areas underlain by landslides or with landslide-prone geology (i.e. Tukwila
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International Boulevard BRT Station and Roadway Improvements). The design
through these areas would include suitable wall types, such as soldier piles with
tiebacks, possibly supplemented with enhanced drainage, such as improved surface
drainage or horizontal drains.
•If needed, and in accordance with applicable regulations, drain suspected or
observed seepage (i.e. Tukwila International Boulevard BRT Station and Roadway
Improvements) to reduce the risk of landslide and surface sloughing by using gravel
drainage blankets, French drains, horizontal drains, placement of a surface rock
facing, or other appropriate methods.
2.Air
The following discussion is presented for the project as a whole because air emissions
are a regional concern, and the emissions are similar for all of the proposed project
components.
a.What types of emissions to the air would result from the proposal during construction,
operation, and maintenance when the project is completed? If any, generally describe
and give approximate quantities if known.
Construction of each project component is expected to last between 12 to 24 months,
depending on the component.
Construction-related activities would result in short-term emissions of air pollutants from
worker and construction vehicle exhaust (carbon monoxide, nitrogen oxides, volatile
organic carbon, particulate matter, and a set of pollutants referred to as Mobile Source
Air Toxics (MSATs). MSATs include the following nine compounds: 1,3-butadiene,
acetaldehyde, acrolein, benzene, diesel particulate matter, ethylbenzene, formaldehyde,
naphthalene, and polycyclic organic matter. Particulate matter could also be generated
where soil would be disturbed with ground clearing and preparation, stockpiling of
materials, and in the event that construction vehicles might track soil from sites onto
area streets where other vehicles could stir up and release fugitive dust.
Construction activities are also likely to require temporary diesel-fired generators to
provide power for electric equipment. Such generators would emit nitrogen oxides,
carbon monoxide, particulate matter, and volatile organic carbon. If emergency
generators are required at any facility during construction, the Puget Sound Clean Air
Agency (PSCAA) would be consulted for the appropriate permit action. Disruption of
traffic during construction (such as a temporary reduction of roadway capacity and
increased queue lengths) could result in short-term, elevated concentrations of
pollutants from slowed or idling vehicles.
During project operation, exhaust from buses and from personal vehicles accessing
transit facilities would be a source of air pollutant emissions. As with vehicles used
during construction, common air pollutants from vehicle exhaust are carbon monoxide,
nitrogen oxides, volatile organic carbon, particulate matter, and MSATs. The project may
increase localized air pollutant emissions at new transit facilities from vehicle trips
generated by park-and-ride users, vehicles that pick up or drop off transit passengers,
maintenance staff, and coach drivers. Regionally, the project would increase the number
of daily bus trips by up to 192 per day. The project should also decrease the vehicle
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miles traveled (VMT) due to passenger vehicles by attracting new riders to transit. The
increased VMT associated with bus trips and decrease due to fewer personal vehicles
on the roads would be a small percentage of the regional total VMT and was not
quantified.
All of the project components are located in an area that is designated by the U.S.
Environmental Protection Agency (EPA) as in attainment for all criteria pollutants. Due to
this area’s air quality status, a transportation conformity analysis is not required to
demonstrate compliance with the EPA’s National Ambient Air Quality Standards. The
localized increases in vehicle activity from buses are not likely to cause or contribute to a
potential exceedance of the National Ambient Air Quality Standards since the project is
located in an area that is in attainment for all criteria air pollutants.
If emergency generators are required at any facility once in operation, PSCAA would be
consulted for the appropriate permit action. Emergency combustion engines rated less
than 500 hp are assumed to have a negligible contribution to pollutant emissions.
Greenhouse gas (GHG) emissions from construction of the new park-and-ride facilities
were estimated using the Federal Transit Administration (FTA) Transit GHG Emissions
Estimator (FTA 2018). The FTA tool was used to prepare a simplified estimate for the
facilities associated with each of the proposed project components. Based on the total
size of all new facilities and park-and-ride garages, 23,216 metric tons of carbon dioxide
equivalent are expected to be emitted during construction of the project. GHG emissions
from the facilities during operations would be negligible and limited to the energy
required for lighting, electronic signage, and other electronic features.
b. Are there any off-site sources of emissions or odor that may affect your proposal? If
so, generally describe.
There are no known off-site sources of emissions or odor that would affect the proposed
project.
c. Proposed measures to reduce or control emissions or other impacts to air, if any:
The PSCAA is responsible for enforcing air quality regulations in the Puget Sound
region. The agency has developed fugitive dust regulations contained in Section 9.15 of
Regulation 1 that would be followed during construction.
Sound Transit would prepare an Environmental Compliance Strategy Plan to track
regulatory compliance and address air quality during construction activities. To reduce
air emissions during construction, the project is anticipated to use a suite of best
practices, including some of the following as appropriate:
• Spray exposed soil with water or other dust palliatives to reduce emissions and
deposition of particulate matter.
• Cover all trucks transporting materials, wet materials in trucks, or provide adequate
freeboard (space from the top of the material to the top of the truck) to reduce or
avoid windblown deposition of particulate matter during transportation.
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•Provide wheel washers to remove particulate matter that vehicles would otherwise
carry off-site to decrease deposition of particulate matter on area roadways.
•Remove particulate matter deposited on paved, public roads to reduce mud and
resultant windblown dust on area roadways.
•Route and schedule construction trucks to reduce delays to traffic during peak travel
times to reduce secondary air quality impacts caused by a reduction in traffic speeds
while waiting for construction trucks.
•Place quarry spall aprons where trucks enter public roads to reduce mud track-out.
•Require appropriate emission-control devices on all construction equipment powered
by gasoline or diesel fuel to reduce carbon monoxide and nitrogen oxide emissions
in vehicular exhaust.
•Use relatively new, well-maintained equipment to reduce carbon monoxide and
nitrogen oxide emissions, and prohibit prolonged construction vehicle idling.
•Plant vegetative cover as soon as possible after grading to reduce windblown
particulates in the area.
Implementation of the type of best practices above would reduce construction air
emissions, and no further actions would be needed to address air emissions. Operation
of the project would not result in negative impacts to air quality, and operational
mitigation is not proposed.
3. Water
a. Surface Water:
Is there any surface water body on or in the immediate vicinity of the site
(including year-round and seasonal streams, saltwater, lakes, ponds, wetlands)? If
yes, describe type and provide names. If appropriate, state what stream or river it
flows into.
Based on critical area mapping available from local jurisdictions and fieldwork,
surface-water bodies are present near a number of the project components, as shown in
Table 5. The study areas for this analysis include locations where the ground would be
disturbed (project footprint), either permanently or temporarily, as a result of one of the
project components, as well as an area of 500-feet from the project footprint. Some of
the surface-water features listed in Table 5 are found outside of the study area and are
included for context only.
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Table 5 Nearest surface waters to project components
Project
component
Nearest surface
waters Location
Fish Passage
Barriers Source
Burien Transit
Center and
Roadway
Improvements
Lake Burien South of SW 152nd Street,
approximately 0.7 mile to
the southwest
N/A King County 2020
Unnamed piped
stream
SW 152nd Street and 1st
Avenue S intersection,
approximately 0.25 mile to
the south
None King County 2020
Tukwila
International
Boulevard BRT
Station and
Roadway
Improvements
Gilliam Creek
system
Gilliam Creek originates
on the south side of the
SR 518 eastbound
on-ramp, is piped under
SR 518, and flows east.
Two Gilliam Creek
tributaries (STU-1 and
STU-2) were observed in
the field and detailed
below
WDFW #992651
(STU-1)
WDFW #998886
(unnamed
stream)
King County 2020;
City of Tukwila 2013
South Renton
Transit Center
and Roadway
Improvements
Rolling Hills
Creek
400 feet southeast of the
southern extent of the
project footprint
None City of Renton 2019
Panther Creek
wetland complex
South of the project
footprint along the east
side of Rainier Avenue S
N/A City of Renton 2019
Bellevue Transit
Center and
Off-site Layover
Sturtevant Creek East of I-405,
approximately 0.3 mile
east of the project footprint
None King County 2020
Unnamed
wetland
Northwest corner of Main
Street and 116th Avenue
SE, approximately 0.8 mile
southeast of the project
footprint
N/A King County 2020
Totem
Lake/Kingsgate
Station and
Kingsgate
Park-and-Ride
Garage
North Juanita
Creek tributary
116th Way NE and NE
132nd Street intersection,
approximately 380 feet
north of the project
footprint
None City of Kirkland
2019; King County
2019
Wetlands
associated with
south Juanita
Creek tributary
Along the unnamed
tributaries to Juanita
Creek, approximately 0.2
mile both to the north and
to the south of the project
footprint
N/A U.S. Fish and
Wildlife Service
2019
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Project
component
Nearest surface
waters Location
Fish Passage
Barriers Source
Brickyard Station
and Roadway
Improvements
Sammamish
River
Flows east to west in the
northern portion of the
project footprint near the
I-405/SR 522 interchange
within the study area
None City of Bothell 2020;
City of Kirkland
2020; King County
2020
Sammamish
River tributaries
One begins near the NE
168th Street dead end and
flows northwest under
I-405, and the other begins
between Cedar Park
Church and I-405 flowing
northwest; both are in the
study area
None City of Bothell 2020
Juanita Creek Flows east to west within
the study area crossing
under I-405 approximately
0.65 mile south of the
Juanita Woodinville Way
NE overpass
WDFW #998602 City of Bothell 2020;
City of Kirkland
2020; King County
2020
Juanita Creek
tributary and
associated
wetlands
West of the Juanita
Woodinville Way NE
overpass; tributary flows
south entering Juanita
Creek just south of the
110th Avenue NE and NE
143rd Street intersection in
the City of Kirkland
None City of Kirkland
2020
Isolated
wetlands
East of I-405 near the
Juanita Woodinville Way
NE overpass
N/A City of Bothell 2020
Lynnwood City
Center Transit
Station BRT and
Roadway
Improvements
Scriber Creek
and associated
wetlands
Immediately southwest of
the Lynnwood City Center
transit center parking area
and Interurban Trail
None City of Lynnwood
2016;
Snohomish County
2019
Scriber Creek
left bank
tributary and
associated
wetland
West side of the
Lynnwood City Center
parking area
None City of Lynnwood
2016;
Snohomish County
2019
Poplar Creek Piped under the residential
area to the southwest near
Birch Way
None City of Lynnwood
2016;
Snohomish County
2019
Golde Creek North to east of the project
area
None City of Lynnwood
2016;
Snohomish County
2019
SOURCE: Environmental Science Associates, 2020
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In the immediate vicinity of the project, surface-water bodies were found at only two
project components. Additional information on these surface-water bodies is provided
below.
Tukwila International Boulevard BRT Station and Roadway Improvements
Four wetlands and three streams were observed in the vicinity of the footprint 5 of this
project component.
Streams
Several streams occur in the Tukwila International Boulevard BRT Station and Roadway
Improvements vicinity and form the headwaters of Gilliam Creek (Water Resource
Inventory Area (WRIA) 09.0032), a tributary to the Duwamish/Green River (WDFW
2020). Several branches of Gilliam Creek occur to the south of the eastbound SR 518
on-ramp from Tukwila International Boulevard, where they combine and flow parallel to
the ramp for approximately 350 feet before entering a 36-inch-diameter culvert. This
culvert extends approximately 900 feet downstream (northeast) under the lower end of
the SR 518 on-ramp and both the east and westbound lanes of SR 518 before
discharging to a riparian corridor adjacent to SR 518 near 40th Avenue S (City of
Tukwila 2013). Gilliam Creek then flows primarily through open stream channels on the
north side of SR 518 for approximately 0.9 mile before entering a 54-inch-diameter
culvert near 52nd Avenue S. This culvert flows for approximately 0.5 mile under the
I-5/I-405 interchange and discharges to an area between the northbound I-5 off-ramp to
eastbound I-405 and Tukwila Parkway. The creek then flows an additional 0.5 mile to the
Green River. While these portions of Gilliam Creek are believed to contain suitable
habitat for some anadromous salmonid species (particularly coho salmon, steelhead,
and sea-run cutthroat trout), the lengthy culverts in the lower reaches, particularly the
0.5-mile-long culvert under the I-5/I-405 interchange, are considered complete barriers
to fish passage (WDFW 2020). However, resident fish species (including resident trout)
are likely to occur in the upstream portions of Gilliam Creek, and therefore are
considered Type 2 (F) waters with a corresponding 100-foot buffer requirement per
Tukwila Municipal Code (TMC) 18.45.100.C.
Two unnamed tributary streams to Gilliam Creek were found and surveyed in the
Tukwila International Boulevard BRT Station and Roadway Improvements vicinity. These
streams are located immediately south of SR 518, near 42nd Avenue S (Attachment A,
Figure A-11). Both of these streams (STU-1 and STU-2) are located east of 42nd
Avenue S. These tributary streams appear to originate from groundwater seeps from the
hillside south of SR 518 and generally flow parallel to the highway to reach culverts.
While the culvert outlets could not be determined, it is expected that they extend under
the highway and eventually discharge to Gilliam Creek, which parallels the north side of
the highway. The culverts are not fish passable, and no fish were observed in any of the
surveyed reaches. However, both streams are conservatively assumed to be potential
5 For purposes of assessing impacts to surface water, the project component “footprint” includes the
construction grading and disturbance limits.
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fish-bearing waters (Type F) due to the apparent perennial flows and overall habitat
characteristics and are allotted a 100-foot buffer per TMC 18.45.100.C.
Wetlands
Biologists identified, delineated, and estimated the boundaries of four wetlands (WTU-1,
WTU-2, WTU-3, and WTU-4) within the vicinity of this project component footprint. The
project clearing and grading limits were estimated after the wetlands were delineated.
The clearing and grading limits showed that all wetlands, streams, and buffers were
located outside of the project footprint and would not be impacted, so no formal survey
of the delineations were completed. For this reason, the wetland boundaries are
considered to be estimates. A conservative approach was taken to estimate wetland
boundaries; no formal data plots were established.
Wetland characteristics, ratings, and applicable buffer distances for the four identified
features are summarized in Table 6. The locations of these wetlands are shown in
Attachment A, Figure A-11. Additional information on wetland characteristics (i.e.,
hydrology, soils, vegetation, and functions) is provided in the I-405 BRT Corridor
Ecosystems Resources and Wetland Delineation Technical Memorandum
(Attachment C).
Table 6 Wetland characteristics, rating, and applicable buffer distances in
the Tukwila International Boulevard BRT Station and Roadway Improvements
vicinity
Wetland
name
Estimated
wetland
area in the
project
component
vicinity
(acres)
Hydro-
geomorphic
classification
Cowardin
class1
Wetland
location
Wetland
category
(2004)2
Wetland
category
(2014)3
Habitat
score3
Tukwila
Municipal
Code
required
standard
buffer
distances
(feet)
WTU-1 0.02 Slope PEM West of 42nd
Avenue S
IV III 5 80
WTU-2 0.02 Depressional PEM/PSS/
PFO
East of 42nd
Avenue S
III III 5 80
WTU-3 2.0 Slope PEM/PSS/
PFO
East of 42nd
Avenue S
IV IV 6 50
WTU-4 0.01 Depressional PEM East of 42nd
Avenue S
IV IV 3 50
SOURCE: Environmental Science Associates, 2020
NOTES:
1 PEM = palustrine emergent, PSS = palustrine scrub-shrub, PFO = palustrine forested.
2 Based on 2004 Wetland Rating System for Western Washington (Hruby 2004) per TMC 18.45.080.B.
3 Based on 2014 Wetland Rating System for Western Washington (Hruby 2014) per revised TMC (currently under review by the
City’s Department of Community Development).
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Brickyard Station and Roadway Improvements
WSDOT field data for critical areas in the vicinity of this component was relied on to
determine likely impacts. Three wetlands and one stream (Juanita Creek) are located in
the vicinity of the footprint of this project component. The locations of these wetlands are
shown in Attachment A, Figure A-12. Additional information on wetland characteristics (i.e.,
hydrology, soils, vegetation, and functions) is provided in the I-405 BRT Corridor
Ecosystems Resources and Wetland Delineation Technical Memorandum (Attachment C).
Streams
Juanita Creek is mapped flowing east to west within the study area crossing under I-405
approximately 0.65-mile south of the Juanita Woodinville Way NE overpass and into the
north end of Lake Washington (City of Bothell 2020; City of Kirkland 2020; King County
2020). A tributary to Juanita Creek begins within the wetland complex west of the
Juanita Woodinville Way NE overpass (described below). The tributary flows south
entering Juanita Creek just south of the 110th Avenue NE and NE 143rd Street
intersection in the City of Kirkland (City of Kirkland 2020).
Wetlands
Three Category III wetlands, totaling 0.45 acre, have been delineated (Table 7). Wetland
21.94R is located along Juanita Creek, east of where the stream crosses underneath
I-405 and along the northbound lanes of I-405. Wetland 22.11R is approximately
850 feet north of Wetland 21.94R, adjacent to the northbound lanes of I-405. Wetland
22.24L is located west of I-405 and approximately 500 feet south of the Brickyard
Park-and Ride. The locations of these wetlands are shown in Attachment A, Figure A-12.
Table 7 Wetland characteristics, rating, and applicable buffer distances in
the Brickyard Station and Roadway Improvements vicinity
Wetland
Wetland classification/rating
Total
wetland
size
(acres)
Wetland
size in the
project
component
vicinity
(acres)
Buffer
distance
(feet)4 Cowardin1
Hydrogeomorphic
classification
Ecology
rating2
Local
jurisdiction
Local
jurisdiction
rating3
21.94R PSS/PFO Riverine III Kirkland III 0.32 0.30 105
22.11R PSS Depressional III Kirkland III 0.07 0.00 60
22.24L PSS/PFO Depressional III Bothell III 4.88 0.15 75
Total 5.27 0.45 –
SOURCE: WSDOT, 2020a
NOTES:
1 PEM = palustrine emergent, PSS = palustrine scrub-shrub, PFO = palustrine forested.
2 Based on 2014 Wetland Rating System for Western Washington (Hruby 2014) per Kirkland Wetlands Ordinance described in
Kirkland Zoning Code (KZC) Table 90.551 and City of Bothell Wetlands Ordinance described in Bothell Municipal Code (BMC)
14.04.500.B
3 Wetlands rated according to City of Kirkland Wetlands Ordinance described in KZC 90.55 and City of Bothell Wetlands Ordinance
described in BMC 14.04.500.
4 Wetland buffer width according to City of Kirkland Wetlands Ordinance described in KZC 90.55 and City of Bothell Wetlands
Ordinance described in BMC 14.04.530(F)1.
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Two of the wetlands (Wetland 22.11R and Wetland 22.24L) have hydrogeomorphic
(HGM) classifications of depressional; the third (Wetland 21.94R) has a riverine HGM
classification. All three wetlands are regulated by the U.S. Army Corps of Engineers and
Ecology. Table 7 identifies the total wetland size and provides a summary of the wetland
classification/rating by system: HGM, Ecology, and local jurisdiction.
Will the project require any work over, in, or adjacent to (within 200 feet) the
described waters? If yes, please describe and attach available plans.
The project would require work within 200 feet of the wetland and stream features at the
Tukwila International Boulevard BRT Station and Roadway Improvements and the
Brickyard Station and Roadway Improvements project components (see Table 6 and
Table 7). No in-water or over-water work is proposed, and thus, no direct impacts are
expected at either location.
Estimate the amount of fill and dredge material that would be placed in or
removed from surface water or wetlands and indicate the area of the site that
would be affected. Indicate the source of fill material.
No temporary or permanent fill of wetlands or streams is anticipated as a result of the
project.
Will the proposal require surface water withdrawals or diversions? Give general
description, purpose, and approximate quantities if known.
No temporary or permanent withdrawals or diversions of streams are anticipated as a
result of the project.
Does the proposal lie within a 100-year floodplain? If so, note location on the site
plan.
The only project component that intersects with a 100-year floodplain is the South
Renton Transit Center and Roadway Improvements. A portion of the 100-year floodplain
is mapped by King County as occurring on the south side of S Grady Way, immediately
south of the proposed South Renton Transit Center. This area was likely historically
associated with Panther Creek and the Black River floodplain. It is within the planned
paving extent for the new bus-on-shoulder lane and is currently developed with
commercial buildings and associated parking lots.
Does the proposal involve any discharges of waste materials to surface waters? If
so, describe the type of waste and anticipated volume of discharge.
Other than potential contaminants in stormwater runoff discussed in response to
Sections B.3.c and d below, the project would not involve discharges of waste materials
to surface waters at any location.
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b. Ground Water:
Will groundwater be withdrawn from a well for drinking water or other purposes?
If so, give a general description of the well, proposed uses and approximate
quantities withdrawn from the well. Will water be discharged to groundwater?
Give general description, purpose, and approximate quantities if known.
No, the project would not withdraw groundwater from a well for drinking water or another
purpose at any project component.
Water, which may be used for the purposes of maintenance or landscaping at any facility
(from a standpipe or related outdoor water supply point) would drain into the storm drain
systems with appropriate treatment as required by the adopted stormwater management
code and manual for the jurisdiction where the feature is located. See The stormwater
management for the different project components would be implemented and designed
per the adopted stormwater management code and manual for the jurisdiction where the
feature is located. These requirements cover drainage design for sites that require flow
control and water quality treatment facilities and sites that do not. For project
components that impact runoff from both the local jurisdiction and from WSDOT areas,
the portion of the area within WSDOT would be subject to the requirements in WSDOT’s
Highway Runoff Manual (2019), whereas other portions would be subject to the local
jurisdiction’s manual. See Table 9 for a summary of where water quality treatment and
flow control facilities are required, as well as the applicable stormwater manual. In
addition to these facilities, flow control BMPs would be implemented such as amending
planting material per the stormwater management requirements. For all project
components, the drainage system downstream would be assessed for handling the
project drainage with a Downstream Analysis meeting the applicable manual(s).
Table 9 for a summary of stormwater manuals referenced for the project components.
Water used “indoors” (for utility sinks, bathroom sinks, or toilets, if provided at any of the
project components) would drain into the sanitary sewer system.
At the South Renton Transit Center, which is located within the Cedar Valley Sole
Source Aquifer, water not discharged to a sanitary sewer would comply with City of
Renton’s measures specifically aimed at protecting the aquifer.
Describe waste material that will be discharged into the ground from septic tanks
or other sources, if any (for example: domestic sewage; industrial, containing the
following chemicals. . . ; agricultural; etc.). Describe the general size of the
system, the number of such systems, the number of houses to be served (if
applicable), or the number of animals or humans the system(s) are expected to
serve.
Other than potential stormwater infiltration described above, no waste material would be
discharged into the ground from septic tanks or other sources. No septic tanks would be
installed as part of the project.
The Phase II Environmental Site Assessment conducted at the South Renton Transit
Center site (Shannon & Wilson, Inc. 2018) noted chemical contamination on-site,
primarily petroleum, within soils and groundwater. Prior to construction, Sound Transit
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would develop procedures for all project areas at the South Renton Transit Center to
identify, characterize, manage, handle, store, and dispose of contaminated soil and
groundwater that could be encountered during construction activities. Sound Transit
would continue the ongoing coordination with Ecology for site cleanup and construction
at the site. See Section B.7.a for additional information.
c.Water runoff (including stormwater):
Describe the source of runoff (including storm water) and method of collection
and disposal, if any (include quantities, if known). Where will this water flow? Will
this water flow into other waters? If so, describe.
Burien Transit Center and Roadway Improvements
Sources of runoff for this project component would be the same as currently occurs on
this developed site with stormwater runoff occurring from sidewalks, roadways, and
landscaped areas at the transit center and along SW 148th Street and SR 518.
Currently, stormwater from the transit center is collected in catch basins and the piped
conveyance network flows south through the transit center site to SW 150th Street.
Runoff from SW 148th Street is collected and conveyed in a piped system that flows
through the parcels south of SW 148th Street to SW 150th Street and converges within a
quarter mile of the flows leaving the transit center. Runoff from SR 518 flows south
within the WSDOT SR 509 right-of-way through both roadside ditches and a piped
conveyance network. Runoff from the proposed project improvement areas would
continue to be collected through catch basins and roadside ditches that tie into the
existing storm drainage conveyance systems.
This project component is located in WRIA 9: Duwamish – Green within the Miller Creek
drainage basin and eventually all stormwater discharge goes to Miller Creek.
Tukwila International Boulevard BRT Station and Roadway Improvements
Sources of runoff related to this project component include SR 518 and associated
ramps, a pedestrian bridge crossing SR 518, and a new BRT station, along with the
associated pedestrian access improvements. Runoff through the corridor sheet flows to
catch basins and roadside ditches and is collected in a piped conveyance network.
Runoff from the proposed project component would be conveyed to existing piped storm
drainage and conveyance systems. To minimize the number of flow control facilities, a
detention pond would be located adjacent to the SR 518 off-ramp. An existing
conveyance system along the north side of SR 518 would be modified and directed to
the proposed stormwater detention pond to meet flow control requirements.
After routing stormwater runoff through the detention facility, stormwater would be
reconnected to the existing conveyance system along the north side of SR 518. This
system extends east from the intersection about 1,700 feet before discharging to a short
section of rock-lined channel that connects to Gilliam Creek. The Gilliam Creek Basin is
a tributary of the Green River and is within WRIA 9 – Green/Duwamish Watershed.
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South Renton Transit Center and Roadway Improvements
Sources of runoff for this project component include the proposed new transit center,
which includes a multi-story park-and-ride garage, sidewalk improvements, and roadway
improvements. Sidewalk and roadway improvements would be made to Lake Avenue S,
Rainier Avenue S, and S Grady Way. Runoff from the transit center parcels is currently
collected and conveyed to a storm system within Rainier Avenue S. This system crosses
Rainier Avenue S north of S Grady Way and conveys flow to Springbrook Creek. Runoff
from the proposed project component would be conveyed to existing piped storm
drainage and conveyance systems.
Runoff from S Grady Way is collected and conveyed south to Rolling Hills Creek through
privately owned parcels south of S Grady Way. Rainier Avenue S has two drainage
basins. North of S Grady Way, runoff from Rainier Avenue S is directed to Springbrook
Creek and south of S Grady Way runoff is directed to Rolling Hills Creek. This project
component is located in the Green River subwatershed within WRIA 9: Duwamish –
Green.
Bellevue Transit Center and Off-site Layover
Sources of runoff for this project component would include flows from the same areas as
currently occurs—sidewalk and roadway areas in the transit center and layover areas.
Existing runoff is collected via catch basins and flows to a piped conveyance system and
would continue to be conveyed to existing storm drainage conveyance systems. Runoff
from the proposed project component would be conveyed to existing piped storm
drainage and conveyance systems. Runoff in this area flows to the Sturtevant Creek
drainage basin. This project component is located in the Lake Washington-Sammamish
River subwatershed within WRIA 8: Cedar – Sammamish.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
Sources of runoff for this project component would include the proposed park-and-ride
garage, driveway, and sidewalk areas at the existing Kingsgate Park-and-Ride site and
the existing Totem Lake bus stops on the direct access ramps.
The existing Kingsgate Park-and-Ride surface lot has a WSDOT stormwater detention
pond in the southeast corner of the site. The pond outlets to a piped conveyance
network that collects runoff from the park-and-ride lot and directs it north to a storm drain
system within NE 132nd Street, which eventually discharges to Juanita Creek. Runoff
from the proposed park-and-ride garage, driveway, and sidewalk would be detained in a
new stormwater detention pond, constructed in the southeast corner of the site in the
location of the existing detention pond, and directed north within a pipe system along
116th Avenue NE. The existing WSDOT detention pond would be removed and replaced
with a new underground detention vault located north of the garage, within a portion of
the surface park-and-ride lot. The new detention vault would drain to the existing pipe
system within the park-and-ride lot.
The runoff from the proposed BRT station on the existing direct access ramps is
collected and conveyed within a piped system that flows within I-405 WSDOT
right-of-way to the south and leaves the WSDOT right-of-way near NE 124th Street. The
project component improvements at the BRT station do not trigger detention. This
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system also feeds into Juanita Creek. This project component is located within the Lake
Washington-Sammamish River subwatershed within WRIA 8: Cedar – Sammamish.
Brickyard Station and Roadway Improvements
Sources of runoff related to the project would include I-405 and associated ramps, a
pedestrian bridge crossing the highway, and a new BRT station, along with the
associated pedestrian access improvements. Portions of the stormwater runoff would be
drained to existing conveyance systems located on both sides of I-405. Other portions,
such as roof runoff from the pedestrian bridge, would be collected and piped to these
existing conveyance systems. Flow control and water quality treatment would be
provided as required by WSDOT’s Highway Runoff Manual (WSDOT 2019), and
stormwater facilities would ultimately tie into the existing conveyance systems. Runoff in
this area flows to Juanita Creek. This project component is located within the Lake
Washington-Sammamish River subwatershed within WRIA 8: Cedar – Sammamish.
Lynnwood City Center Transit Station BRT and Roadway Improvements
Sources of runoff associated with these improvements would include roadway
modifications along Poplar Way and the on-ramp to the I-5 northbound lanes and paved
pedestrian areas at the transit center. Runoff from the proposed project component
would be conveyed to existing piped storm drainage and conveyance systems. Drainage
flow paths for the Poplar Way on-ramp and Poplar Way primarily flows to the southwest
and eventually to Golde Creek. The transit center is within the Scriber Creek drainage
basin. This project component is located within the Swamp Creek subwatershed within
WRIA 8: Cedar – Sammamish.
Could waste materials enter ground or surface waters? If so, generally describe.
For all of the project components, waste material associated with vehicular traffic (i.e.
tire dust and oil) could be picked up and transported by stormwater. Such wastes would
be treated as required by local stormwater management codes for water quality
treatment. If infiltration is incorporated as a stormwater management element, treatment
would be provided as required by local current adopted codes prior to discharge to
groundwater. During construction, temporary erosion control and dewatering measures,
where needed, would be implemented to manage runoff and groundwater so as to not
have sediment-laden water entering the stormwater system downstream of the limits of
disturbance. See also response to Section B.7.a for information on management of
on-site contamination.
Does the proposal alter or otherwise affect drainage patterns in the vicinity of the
site? If so, describe.
As noted in Section B.1.g and shown in Table 8, each project component would include
some increase or decrease to the existing amount of impervious surfaces. However, for
each project component, the existing drainage patterns from stormwater runoff would
remain within the same drainage basin and would use the same drainage patterns,
including connecting to the existing drainage system, unless upgrades are required for
capacity and/or to lower the existing drainage system to provide positive gravity flow.
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Table 8 Summary of new or reduced impervious surface area by project
component
Project component
Approximate new or reduced impervious
surface area (in square feet (sf))
Burien Transit Center and Roadway Improvements 2,000 sf increase
Tukwila International Boulevard BRT Station and
Roadway Improvements
72,000 sf increase
South Renton Transit Center and Roadway
Improvements
Transit center site: 76,000 sf decrease
Roadway improvements: 6,000 sf increase
Bellevue Transit Center and Off-site Layover 100 sf increase
Totem Lake/Kingsgate Station and Kingsgate
Park-and-Ride Garage
5,000 sf increase
Brickyard Station and Roadway Improvements 170,000 sf increase
Lynnwood City Center Transit Station BRT and Roadway
Improvements
18,000 sf increase
SOURCE: Sound Transit 2020
d.Proposed measures to reduce or control surface, ground, and runoff water, and
drainage pattern impacts, if any:
Project construction activities would be subject to construction-related stormwater permit
requirements of the Clean Water Act’s National Pollutant Discharge Elimination System
program. Specific regulatory requirements for this type of project are provided in the
Western Washington Phase II Municipal Stormwater Permit, the Construction
Stormwater General Permit, and the various city and county adopted surface water
design manuals. A stormwater and pollution prevention plan would be prepared
identifying BMPs to prevent or minimize the introduction of contaminants into surface
waters and groundwater during construction activities. BMPs for the project could
include, but not be limited to, silt fencing, straw bale barriers, fiber rolls, storm drain inlet
protection, hydraulic mulch, street sweeping, and a stabilized construction entrance. The
stormwater and pollution prevention plan will also include development of site-specific
structural and operational BMPs to prevent and control impacts on runoff quality,
measures to be implemented before each storm event, inspection and maintenance of
BMPs, and monitoring of runoff quality by visual and/or analytical means. As noted in
Section B.2.c, Sound Transit would also prepare an Environmental Compliance Strategy
Plan to help track regulatory compliance through project construction. With
implementation of best practices to prevent or minimize the introduction of contaminants
into surface waters during construction activities, impacts would not be adverse.
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The stormwater management for the different project components would be
implemented and designed per the adopted stormwater management code and manual
for the jurisdiction where the feature is located. These requirements cover drainage
design for sites that require flow control and water quality treatment facilities and sites
that do not. For project components that impact runoff from both the local jurisdiction and
from WSDOT areas, the portion of the area within WSDOT would be subject to the
requirements in WSDOT’s Highway Runoff Manual (2019), whereas other portions
would be subject to the local jurisdiction’s manual. See Table 9 for a summary of where
water quality treatment and flow control facilities are required, as well as the applicable
stormwater manual. In addition to these facilities, flow control BMPs would be
implemented such as amending planting material per the stormwater management
requirements. For all project components, the drainage system downstream would be
assessed for handling the project drainage with a Downstream Analysis meeting the
applicable manual(s).
Table 9 Stormwater management facilities summary
Project component Stormwater manual
Water quality
treatment
facility
proposed
Flow control
facility
proposed
Burien Transit Center and Roadway
Improvements
King County Surface Water
Design Manual1
No2 No2
Tukwila International Boulevard BRT
Station and Roadway Improvements
WSDOT Highway Runoff
Manual
Yes Yes
South Renton Transit Center and
Roadway Improvements
Renton Stormwater Design
Manual1
Yes Yes
Bellevue Transit Center and Off-site
Layover
Department of Ecology’s
Stormwater Management
Manual for Western
Washington3
No2 No2
Totem Lake/Kingsgate Station and
Kingsgate Park-and-Ride Garage
Kirkland Amendment to
King County Surface Water
Design Manual1
Yes Yes
Brickyard Station and Roadway
Improvements
WSDOT Highway Runoff
Manual
Yes Yes
Lynnwood City Center Transit Station
BRT and Roadway Improvements
Department of Ecology’s
Stormwater Management
Manual for Western
Washington1
Yes Yes
SOURCE: Sound Transit 2020
NOTES:
1 WSDOT Highway Runoff Manual applies to segment in WSDOT right-of-way
2 Existing facilities are sufficiently sized
3 As amended by the City of Bellevue Storm and Surface Water Standards (2019)
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4. Plants
Trees at project component locations were evaluated. For areas outside of WSDOT
right-of-way, trees were classified based on the local jurisdiction’s definitions, if
applicable. Trees identified within WSDOT right-of-way were classified per the WSDOT
Roadside Policy Manual (2015) as:
•Category 1: Mature, old-growth, large specimen, or heritage trees greater than 30
inches in diameter
•Category 2: Moderate-sized trees (excluding alder [Alnus rubra] and cottonwood
[Populus balsamifera]) between 4 and 30 inches in diameter
Category 3 trees, as defined by WSDOT, were not part of this assessment.
a.Check the types of vegetation found on the site:
Burien Transit Center and Roadway Improvements
deciduous tree: red alder, bigleaf maple, red maple
evergreen tree: Douglas fir
shrubs: landscape shrubs
grass
pasture: N/A
crop or grain: N/A
orchards, vineyards or other permanent crops.: N/A
wet soil plants: N/A
water plants: N/A
other types of vegetation: Himalayan blackberry
This project component is located in a highly developed urban environment that is
primarily buildings and roads. West of 1st Avenue S, little vegetation is present and is
limited to street trees and commercial landscaping along SW 148th Street to the Burien
Transit Center. East of 1st Avenue S, forested areas occur at the SW 148th Street and
SR 509 on- and off-ramp intersection east and west of SR 509. These forested areas
consist of bigleaf maple, Douglas fir, and various street trees with an understory
dominated by Himalayan blackberry.
Burien Municipal Code 19.10.493 defines an existing tree to be “significant” if it is
healthy and with a diameter at breast height of at least 6 inches. No trees meeting this
definition were observed in the Burien Transit Center and Roadway Improvements
project component area in City of Burien right-of-way. Within WSDOT right-of-way, no
trees were identified that meet WSDOT’s Category 1 or 2 standards.
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Tukwila International Boulevard BRT Station and Roadway Improvements
deciduous tree: bigleaf maple, willow, red alder, vine maple, Oregon ash, black
cottonwood
evergreen tree: Douglas fir, western red cedar
shrubs: salmonberry, Pacific ninebark, cherry laurel
grass: reed canarygrass, velvet grass
pasture: N/A
crop or grain: N/A
orchards, vineyards or other permanent crops.: N/A
wet soil plants: cattail, soft rush, giant horsetail
water plants: N/A
other types of vegetation: Himalayan blackberry, English holly
Most of this project component is located in a highly developed urban environment that
is primarily commercial and residential buildings and roads. There is a relatively
undisturbed vegetated corridor at the eastern end of the project component area that is
approximately 42 acres in area, located upslope to the south of SR 518, from 42nd
Avenue S to just west of the 51st Avenue S/Klickitat Drive merge. This forested area
contains bigleaf maple, Douglas fir, various willow species, and an understory of a mix of
native and non-native shrubs and herbaceous vegetation. The vegetated corridor
contains multiple streams and wetlands, as discussed in Section B.3.a.
Using WSDOT’s standards, eight Category 2 trees (between 4 and 30 inches in
diameter) were observed within WSDOT right-of-way. Based on aerial imagery, an
estimated two additional Category 2 trees appear to be present within the project
component area, also within WSDOT right-of-way.
South Renton Transit Center and Roadway Improvements
deciduous tree: red maple
evergreen tree: N/A
shrubs: landscape shrubs
grass:
pasture: N/A
crop or grain: N/A
orchards, vineyards or other permanent crops.: N/A
wet soil plants: N/A
water plants: N/A
other types of vegetation: Himalayan blackberry
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This project component is located in a highly developed urban environment that is
primarily buildings and roads. Little vegetation is present and is limited to street trees
and landscaping along Rainier Avenue S and S Grady Way.
While the City of Renton currently does not have a tree protection code or a definition of
what the City considers to be a “significant” tree, trees 4 inches or greater in diameter
were identified, consistent with WSDOT’s definition of a Category 2 tree. A total of 14
trees with a diameter greater than 4 inches were observed within the city’s right-of-way.
Based on aerial imagery, an additional estimated 20 Category 2 trees appear to be
present within the project component study area within WSDOT right-of-way.
Bellevue Transit Center and Off-site Layover
deciduous tree: Alder
evergreen tree: N/A
shrubs: N/A
grass: N/A
pasture: N/A
crop or grain: N/A
orchards, vineyards or other permanent crops.: N/A
wet soil plants: N/A
water plants: N/A
other types of vegetation: N/A
This project component is located in a highly developed urban environment that primarily
consists of buildings and roads. Little vegetation is present and is limited to street trees
and landscaping along the Bellevue Transit Center access road and along both sides of
110th Avenue NE at the off-site layover area. Bellevue Municipal Code Section
20.50.046 defines a “significant” tree as being at least 8 inches in diameter, measured 4
feet above the existing grade. No trees meeting this definition were observed.
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Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
deciduous tree: bigleaf maple
evergreen tree: Douglas fir
shrubs: landscape shrubs
grass:
pasture: N/A
crop or grain: N/A
orchards, vineyards or other permanent crops.: N/A
wet soil plants: N/A
water plants: N/A
other types of vegetation: N/A
This project component is located in a highly developed urban environment that is
primarily buildings, roads, and the existing Kingsgate Park-and-Ride lot. Vegetation is
limited to street trees and landscaping along 116th Avenue NE. Within and surrounding
the park-and-ride, large, established coniferous trees, such as Douglas fir, are also
present.
Using the City of Kirkland’s “significant” tree code (Kirkland Zoning Code 95.10.14), a
total of 15 “significant” trees were observed in the Totem Lake/Kingsgate Station and
Kingsgate Park-and-Ride Garage project component area. Using WSDOT’s standards,
all 15 of these trees are Category 2 trees (between 4 and 30 inches in diameter). Based
on aerial imagery, an additional estimated two significant/Category 2 trees appear to be
present within the project component area.
Brickyard Station and Roadway Improvements
deciduous tree: alder, maple, aspen, other
evergreen tree: fir, cedar, pine, other
shrubs: landscape shrubs
grass:
pasture: N/A
crop or grain: N/A
orchards, vineyards or other permanent crops.: N/A
wet soil plants: cattail, buttercup, bulrush, skunk cabbage, other
water plants: water lily, eelgrass, milfoil, other
other types of vegetation: N/A
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This project component area is primarily located in a highly developed urban
environment that consists primarily of buildings and roads. As noted below, some
portions include forested habitat, based on aerial imagery.
Aerial imagery shows that two forested habitat patches exist on each side of I-405 on the
north end of the study area, from the I-405/SR 522 interchange south to the NE 160th
Street exit. These forested patches appear to contain Category 2 trees, as defined by
WSDOT, primarily large deciduous and coniferous trees, such as Douglas fir and bigleaf
maple.
Lynnwood City Center Transit Station BRT and Roadway Improvements
deciduous tree: bigleaf maple, poplar, red alder
evergreen tree: N/A
shrubs: landscape shrubs, Scotch broom
grass:
pasture: N/A
crop or grain: N/A
orchards, vineyards or other permanent crops.: N/A
wet soil plants: N/A
water plants: N/A
other types of vegetation: Himalayan blackberry
This project component is located in a highly developed urban environment that consists
primarily of buildings and roads. Little vegetation is present and is limited to street trees
and landscaping. Within the project footprint of the Poplar Way roadway improvements,
the existing vegetation is primarily grass interspersed with native and non-native grasses
and shrubs. Based on aerial imagery, and using WSDOT standards, an estimated 15
Category 2 trees (between 4 and 30 inches in diameter) may be present within WSDOT
right-of-way within this area of the project component in a location that would likely be
used for construction staging.
b. What kind and amount of vegetation will be removed or altered?
Vegetation impacts for each project component are discussed below and summarized in
Table 10.
Burien Transit Center and Roadway Improvements
No trees are planned to be removed for construction of this project component.
However, within the City of Burien’s jurisdiction, approximately 0.3-acre of some grasses
and shrubs would be removed or altered from within the Burien Transit Center and to
accommodate road improvements, such as the vegetated raised island within the
median of SW 148th Street. Some vegetation has been estimated to be altered
temporarily for construction staging areas. These temporarily disturbed areas would be
restored once construction is complete.
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Tukwila International Boulevard BRT Station and Roadway Improvements
It is currently estimated that all 10 Category 2 trees identified within WSDOT right-of-way
would be removed for this project component. Approximately 2 acres of vegetation
would be cleared and grubbed in front of the existing Link light rail station for pedestrian
bridge construction and construction staging. Vegetation in this area is a mix of trees,
shrubs, and grasses. Areas temporarily disturbed for construction staging would be
restored once construction is complete.
Additional clearing of vegetation would occur along the roadside of SR 518 to
accommodate the eastbound bus-only lane in areas that are predominantly grasses
interspersed with some trees and shrubs. All vegetation removal would occur in the
WSDOT right-of-way.
South Renton Transit Center and Roadway Improvements
It is currently estimated that the 34 trees identified would be removed for this project
component. Fourteen of the trees anticipated for removal are landscaped street trees
along S Grady Way and Rainier Avenue S, within the City of Renton’s right-of-way.
Twenty trees are Category 2 trees within WSDOT’s right-of-way for Rainier Avenue S
(SR 167). Additionally, approximately 0.3-acre of vegetation removal could occur within
a proposed construction staging area near the I-405 on- and off-ramps for construction
of the bus-on-shoulder along Rainier Avenue S. These temporarily disturbed areas
would be restored once construction is complete. This area is located within the WSDOT
right-of-way and is primarily grasses and Himalayan blackberry.
Bellevue Transit Center and Off-site Layover
No vegetation removal is proposed for this project component as all proposed work
would be within already paved areas.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
It is currently estimated that all 17 trees defined as “significant” by Kirkland’s code, that
are also Category 2 trees as defined by WSDOT, would be removed for this project
component. All trees anticipated for removal are Category 2 Douglas firs located in
interior planting strips or on the perimeter of the existing Kingsgate Park-and-Ride lot.
Four additional trees may be removed from the northern portion of the park-and-ride lot
for construction staging. An additional 0.3-acre of grasses would be cleared for
construction staging and improvements to the existing stormwater detention pond. Since
this site is considered to be WSDOT right-of-way, all vegetation removal at this site
would occur in WSDOT right-of-way; although City of Kirkland requirements may also be
applied at the Kingsgate site, if WSDOT agrees. Vegetation disturbed for staging areas
during construction would be restored once construction is complete.
Brickyard Station and Roadway Improvements
Vegetation removal would occur where the I-405 roadway would be widened and the
pedestrian bridge would be constructed, as well as areas used for construction staging.
All vegetation removal would occur in WSDOT right-of-way. These areas are a mixture
of grasses, trees, and shrubs. Exact areas are not known at this time, but vegetation
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removed would be expected to include some mature and newly planted native trees,
including Douglas fir and bigleaf maple. Vegetation disturbed for staging areas during
construction would be restored once construction is complete.
Lynnwood City Center Transit Station BRT and Roadway Improvements
Work within the transit center would be done within existing paved areas and would not
remove existing vegetation.
Along Poplar Way approximately 0.7 acre of grasses and shrubs would be removed
within City of Lynnwood right-of-way for road improvements. Along the I-5 ramp, within
WSDOT right-of-way, approximately 0.6-acre of grasses and shrubs and an estimated
15 Category 2 trees would be removed for construction staging. Vegetation disturbed for
staging areas during construction would be restored once construction is complete and
trees would be replaced in compliance with WSDOT’s Roadside Policy Manual (2015).
c. List threatened and endangered species known to be on or near the site.
No threatened or endangered plant species are known to be on or near project
components.
d. Proposed landscaping, use of native plants, or other measures to preserve or enhance
vegetation on the site, if any:
For each project component, Table 10 summarizes the vegetation and trees that would
be removed. The majority of trees and vegetation that would be removed are within
WSDOT right-of-way for SR 518, Rainier Avenue S (SR 167), I-405, and I-5. Trees
removed within WSDOT right-of-way would be replaced in compliance with WSDOT’s
Roadside Policy Manual (WSDOT 2015). For Category 2 trees, WSDOT’s manual
requires a 1-gallon replacement tree for each 1 inch of trunk diameter that is removed.
Other landscaping within WSDOT right-of-way would be replaced as needed, in
compliance with the WSDOT Roadside Policy Manual (WSDOT 2015).
Mitigation for trees that would be removed within local jurisdictions would be provided in
compliance with the requirements of the jurisdiction in which the removal occurs (Renton
and Kirkland). In addition, at the transit centers and Kingsgate Park-and-Ride Garage,
improvements would include landscaping as appropriate and as required by the
individual jurisdictions in which they are located.
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Table 10 Estimated vegetation and tree removal by project component
Project component Vegetation removed
Estimated number of
trees removed (locally
significant or WSDOT
standards) Jurisdiction
Jurisdictional
tree
protection
regulations1
Burien Transit Center and
Roadway Improvements
Grasses, shrubs 0 N/A N/A
Tukwila International
Boulevard BRT Station and
Roadway Improvements
Grasses, shrubs,
Category 2 trees
10 WSDOT WSDOT
Roadside
Policy Manual
South Renton Transit
Center and Roadway
Improvements
Grasses, shrubs,
Category 2 street trees
34 City of
Renton and
WSDOT
Renton2
WSDOT
Roadside
Policy Manual
Bellevue Transit Center and
Off-site Layover
None 0 N/A N/A
Totem Lake/Kingsgate
Station and Kingsgate
Park-and-Ride Garage
Grasses, shrubs,
significant Douglas fir
trees
17 City of
Kirkland and
WSDOT
KZC 95.10.14
and WSDOT
Roadside
Policy Manual
Brickyard Station and
Roadway Improvements
Grasses, shrubs,
Category 2 trees3 Unknown3 WSDOT WSDOT
Roadside
Policy Manual
Lynnwood City Center
Transit Station BRT and
Roadway Improvements
Grasses, shrubs,
Category 2 trees
15 City of
Lynnwood
and WSDOT
LMC
17.15.080 and
WSDOT
Roadside
Policy Manual
SOURCE: Sound Transit 2020
NOTES:
1 Specific tree replacement requirements for local jurisdictions can be found in Attachment C, I-405 BRT Corridor Ecosystems
Resources and Wetland Delineation Technical Memorandum.
2The City of Renton currently does not have a tree protection code or a definition of what the city considers to be a “significant” tree.
Prior to removing a tree, coordination with the City of Renton’s Urban Forestry and Natural Resource Manager is required. During
field efforts in Renton, trees 4 inches or greater in diameter at breast height were identified, consistent with WSDOT’s definition of a
Category 2 tree.
3Clearing and grading limits have not been provided by WSDOT, so exact areas are not yet known. As clearing and grading limits
are provided, vegetation impacts in these areas will be re-evaluated.
e. List all noxious weeds and invasive species known to be on or near the site.
Burien Transit Center and Roadway Improvements
According to King County Interactive Mapping (iMap) noxious weed survey data, giant
hogweed (Heracleum mantegazzianum), Dalmatian toadflax (Linaria dalmatica), spotted
knapweed (Centaurea stoebe), and diffuse knapweed (Centaurea diffusa) are mapped
as occurring near this project component. Additional noxious weeds including Himalayan
blackberry (Rubus armeniacus) and reed canarygrass (Phalaris arundinacea) were
observed during site visits.
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Tukwila International Boulevard BRT Station and Roadway Improvements
King County iMap noxious weed survey data shows tansy ragwort (Senecio jacobaea)
and spotted knapweed as occurring within this project component area. Additional
noxious weeds observed during site visits include reed canarygrass and Himalayan
blackberry.
South Renton Transit Center and Roadway Improvements
King County iMap noxious weed survey data shows meadow knapweed (Centaurea
jacea), purple loosestrife (Lythrium salicaria), diffuse knapweed, and spotted knapweed
as occurring within this project component area. Scotch broom (Cytisus scoparius) and
Himalayan blackberry were observed during site visits.
Bellevue Transit Center and Off-site Layover
This project component is largely in the built environment with little vegetation outside of
landscape trees. No invasive or noxious species are mapped as occurring within this
project component area nor were any observed.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
No invasive or noxious species are mapped as occurring within this project component
area, nor were any observed.
Brickyard Station and Roadway Improvements
King County iMap noxious weed survey data shows tansy ragwort (Senecio jacobaea),
meadow knapweed, spotted knapweed, and diffuse knapweed as occurring within the
project component area.
Lynnwood City Center Transit Station BRT and Roadway Improvements
The transit center portion of this project component is largely in the built environment
with little vegetation outside of landscape trees. No invasive or noxious species were
observed within the project area. Within the Poplar Way portion of the study area,
Scotch broom, Himalayan blackberry, and reed canarygrass were observed.
5. Animals
a. List any birds and other animals which have been observed on or near the site or are
known to be on or near the site.
Wildlife species at all of the project component locations likely include birds (e.g.,
American robin, American crow, and common pigeon) and small mammals (e.g., Virginia
opossum, eastern cottontail, and eastern gray squirrel) that are well adapted to living in
a highly altered landscape and can tolerate or benefit from human disturbance. Habitat
features, including snags and/or large woody debris, were limited throughout the
corridor; however, some were observed within the wetland areas near the Tukwila
International Boulevard BRT Station and Roadway Improvements project component.
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As noted in response to B.3.a above, streams occur within or near two project
component areas: the Tukwila International Boulevard BRT Station and Roadway
Improvements and the Brickyard Station and Roadway Improvements. For the Tukwila
International Boulevard BRT Station and Roadway Improvements component, no fish
were observed within the three streams delineated within the footprint. However, these
streams may support resident non-salmonids at some point in their lifecycle.
Additionally, while portions of Gilliam Creek within the vicinity of the project are believed
to contain suitable habitat for some anadromous salmonid species (particularly coho
salmon, steelhead, and sea-run cutthroat trout), the lengthy culverts in the lower
reaches, particularly the 0.5-mile-long culvert under the I-5/I-405 interchange, are
considered complete barriers to fish passage (WDFW 2020).
b. List any threatened and endangered species known to be on or near the site.
According to the WDFW Priority Habitat and Species (PHS) data, no listed threatened or
endangered species are mapped as occurring on or near any of the project components.
For each project component, Table 11 provides information on the nearest federally
listed or state protected species.
Table 11 Nearest federally listed and state protected species to project
components
Project
component
Nearest
feature Location
Federally listed
species
State protected
species
Burien Transit
Center and
Roadway
Improvements
Miller Creek Approximately 0.7
mile south
Chinook salmon
(Oncorhynchus
tshawytscha), steelhead
trout (O. mykiss)
Cutthroat trout (O.
clarkii), Coho salmon
(O. kisutch), Chum
salmon (O. keta)
Tukwila
International
Boulevard BRT
Station and
Roadway
Improvements
Gilliam
Creek1
Approximately 0.6
mile east
None Cutthroat trout, coho
salmon
South Renton
Transit Center
and Roadway
Improvements
Springbrook
Creek
Approximately 0.5
mile south along
Rainier Avenue S
Chinook salmon,
steelhead trout 2
Cutthroat trout, coho
salmon, chum salmon
Bellevue Transit
Center and
Off-site Layover
Sturtevant
Creek
Approximately 0.3
mile to the east on
the east side of I-405
Chinook salmon,
steelhead trout2
Coho salmon, sockeye
salmon (Oncorhynchus
nerka)
Totem
Lake/Kingsgate
Station and
Kingsgate
Park-and-Ride
Garage
North
Juanita
Creek
tributary
Approximately 0.3
mile to the
northwest, north of
NE 132nd Street
None Coho salmon, resident
coastal cutthroat
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Project
component
Nearest
feature Location
Federally listed
species
State protected
species
Brickyard Station
and Roadway
Improvements
Sammamish
River
Near the I-405/SR
522 interchange
Steelhead trout,
Chinook salmon
Cutthroat trout, sockeye
salmon, coho salmon
Juanita
Creek
Approximately 0.65
mile south of the
Juanita Woodinville
Way NE overpass
Steelhead trout,
Chinook salmon
Cutthroat trout, sockeye
salmon, coho salmon
Lynnwood City
Center Transit
Station BRT and
Roadway
Improvements
Scriber
Creek
Approximately 0.3
mile to the west
None Resident coastal
cutthroat
SOURCE: WDFW 2020
NOTES:
1Listed species are mapped as occurring outside of the project component area and are further separated by several culverts that
act as barriers to fish passage along the north side of SR 518 (WDFW 2020)
2Presence of listed species at these reaches of Springbrook and Sturtevant Creeks are only modeled. Documented presence within
these streams are farther downstream and away from the project component area.
c. Is the site part of a migration route? If so, explain.
The entire project corridor is within the Pacific Flyway, which is a flight corridor for
migrating waterfowl and other avian fauna. The Pacific Flyway extends south from
Alaska to South America.
d. Proposed measures to preserve or enhance wildlife, if any:
At all project component locations, wildlife habitat is limited by the highly disturbed and
developed nature of the environment and the lack of habitat features. Therefore, impacts
to wildlife as a result of the project are not anticipated. The project would not impact the
Pacific Flyway, and Sound Transit would perform Migratory Bird Treaty Act nest surveys
prior to vegetation removal, as needed. Although project construction does not require
any in-water work, BMPs, such as stormwater inlet protection, would be put in place to
isolate and protect waters downstream of project components, including those that may
be fish-bearing. With the implementation of stormwater management measures, no
impacts to fish species are anticipated during either construction or operation.
e. List any invasive animal species known to be on or near the site.
Rodents (Old World rats and mice, eastern gray squirrel) are likely present at each
project component.
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6. Energy and Natural Resources
a. What kinds of energy (electric, natural gas, oil, wood stove, solar) will be used to meet
the completed project's energy needs? Describe whether it will be used for heating,
manufacturing, etc.
All project components (stand-alone transit stations and transit centers/park-and-ride
garages) would require electricity to provide lighting and power for electronics such as
signage, TVMs, and security cameras.
b. Would your project affect the potential use of solar energy by adjacent properties? If
so, generally describe.
No, the project is not anticipated to affect the potential use of solar energy by adjacent
properties. The structures with the greatest potential to block any nearby solar energy
sources would be the five-story park-and-ride garages proposed at the South Renton
Transit Center and the Kingsgate Park-and-Ride. For each garage, the proposed
elevator bay on the fifth floor of the garage structure is anticipated to be approximately
55 to 60 feet tall. The location and height of these structures would not block any known
current use of solar energy on adjacent properties.
c. What kinds of energy conservation features are included in the plans of this proposal?
List other proposed measures to reduce or control energy impacts, if any:
Specific features to enhance sustainability and maximize energy conservation for the
project components would be determined as design progresses. Sound Transit follows
the Seattle Energy Code and employs a sustainability checklist to evaluate each
individual component in the search for feasible sustainability measures. For project
components where building permits from local jurisdictions are required, Sound Transit
would also comply with required building codes, including those related to energy
conservation. For park-and-ride garages, such as the proposed Kingsgate
Park-and-Ride Garage at the South Renton Transit Center, additional features may
include design and construction for future photovoltaics and electric vehicle charging
infrastructure.
Project construction would require the use of equipment and energy, such as diesel fuel.
All efforts to minimize air pollutants and GHG emissions during construction have the
benefit of reducing energy use. In addition, once constructed, the project would improve
transit speed and reliability in the I-405 corridor, which is anticipated to increase transit
ridership and reduce single-occupancy vehicles in the corridor. This would be expected
to reduce energy consumption.
7. Environmental Health
a. Are there any environmental health hazards, including exposure to toxic chemicals,
risk of fire and explosion, spill, or hazardous waste that could occur as a result of this
proposal? If so, describe.
Attachment D, I-405 BRT Corridor Hazardous Materials Technical Memorandum,
documents potentially contaminated sites on or near (within 0.125 mile) the project
components where contaminated materials may be encountered in soils or ground water
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that is disturbed during construction. This technical memorandum also provides a
discussion about hazardous materials likely to be used and generated during project
construction or operation.
Describe any known or possible contamination at the site from present or past
uses.
Regionally, more than 1,000 square miles of the Puget Sound Basin have been affected
by arsenic, lead, and other heavy metals that settled on the surface of soils from air
pollution from the historic operations of the Asarco Company copper smelter that was in
Tacoma (Ecology 2020b). The Model Toxics Control Act (MCTA) cleanup regulation for
arsenic is 20 parts per million (ppm). Areas where these levels may be exceeded pose a
risk to human health and the environment and would be subject to cleanup
requirements. According to Ecology’s mapping of predicted concentrations of arsenic in
soils as a result of the Tacoma Smelter Plume, three project components are located in
areas mapped as having predicted arsenic concentrations of 20 to 40 ppm. These
project components are the Burien Transit Center and Roadway Improvements, the
Tukwila International Boulevard BRT Station and Roadway Improvements, and a portion
of the South Renton Transit Center and Roadway Improvements. The remaining project
components are in areas mapped as having predicted arsenic concentrations of under
20 ppm, with limited data.
Burien Transit Center and Roadway Improvements
Contamination, in addition to potential surface soil contamination from the Tacoma
Smelter Plume, is known to exist at the Burien Transit Center. This site is listed with
Ecology (Facility Site Id number 11133, Cleanup Site Id number 12380) as awaiting
cleanup. According to Ecology records dating from 2011, contaminated soil was
discovered on the northwest corner of the Burien Transit Center property during
construction of a stormwater detention system associated with a new parking structure.
On-site soils were contaminated with petroleum hydrocarbons as gasoline, diesel, and
benzene. According to reports, a leaky joint from a former drain line associated with the
adjacent gas station (USA Station 116) was the cause of the contamination. The drain
line was sealed by the contractor approximately 20 feet south of the northern property
boundary between the Burien Transit Center and USA Station 116. The remaining piping
and approximately 50 cubic yards of contaminated soil were removed and sent off-site
for disposal. Soil samples were collected from the sidewalls and bottom of the
excavation and analytical results indicated soils contaminated with petroleum
hydrocarbons as gasoline and benzene remain at the bottom and east wall of the
excavation. The report noted that during the excavation, the design limits of the
stormwater detention system had been reached before all contaminated soil was
removed and King County elected not to excavate further. An impermeable barrier was
placed in the stormwater detention system to isolate contaminated soil in that area.
Groundwater was not encountered during the excavation and it is not known whether
groundwater beneath the site is contaminated. No other reports of excavation or
remediation at the site were available for review in the Ecology database. Construction
at the Burien Transit Center, particularly the northwestern portion of the site, would likely
encounter petroleum hydrocarbons as gasoline and benzene contaminants in the soils.
There is a potential for groundwater beneath the site to be impacted with petroleum
hydrocarbons and benzene.
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Seven other sites within 0.125 mile from the nearest project improvement (see
Attachment D, Figure 4-1) are identified as hazardous material release sites. According
to regional groundwater data, groundwater flow is to the west. Therefore, sites that have
reported releases and are located adjacent to and/or hydraulically upgradient (east) of a
project improvement have the potential to impact subsurface conditions. Based on this
criteria, the sites that have the potential to be a source of contamination encountered
during construction include the Exxon 76969, BBC Dodge, and USA Station 116. These
sites have reported releases to soil, soil vapor and groundwater from leaking
underground storage tanks (LUST) and are undergoing cleanup or remediation. The
contaminants of concern that may be encountered during construction of the Burien
Transit Center and Roadway Improvements include petroleum hydrocarbons as gasoline
and diesel; benzene, toluene, ethylbenzene, and total xylenes (BTEX); non-halogenated
solvents such as naphthalene; and lead.
One of the seven sites, Burien Honda Midas located 750 feet southeast of the transit
center, is listed as having on-site soils impacted with petroleum. Voluntary cleanup was
completed and the site received a “no further action” letter from Ecology. A “no further
action” letter indicates no contamination remains above the applicable cleanup levels
outlined in the state's law, the Model Toxics Control Act. Based on the case closure
status, the distance and direction of this site to the Burien Transit Center and Roadway
Improvements, and the fact that petroleum contamination impacted on-site soils only, the
Burien Honda Midas site is unlikely to be a source of contamination encountered during
project construction.
Tukwila International Boulevard BRT Station and Roadway Improvements
Other than possible surface soil contamination from the Tacoma Smelter Plume, no
contamination is known to exist at this project component. One site identified as WSP
(Washington State Patrol) Tukwila, is located approximately 400 feet south of the
nearest project improvement (see Attachment D, Figure 4-2). The WSP Tukwila site
(Ecology Facility Id number 42844447, Cleanup site Id number 9148) is listed as
reportedly cleaned up but has not received case closure from Ecology. According to the
Ecology database, a LUST case was reported in 1992 with spills to on-site soils only.
The most recent information indicates petroleum hydrocarbons as gasoline are
confirmed above state cleanup levels in soil only. Petroleum hydrocarbons as diesel
have been remediated to below cleanup levels, and benzene and other petroleum
constituents are only suspected in soils at the property. Based on the current status of
cleanup at the WSP Tukwila site, there is a low to moderate probability of this site being
a source of hazardous materials in soil vapors encountered during construction of Sound
Transit’s project. The potential contaminants of concern that may be encountered during
construction include petroleum hydrocarbons and benzene.
South Renton Transit Center and Roadway Improvements
Contamination, in addition to potential surface soil contamination from the Tacoma
Smelter Plume, is known to exist at this project component. Shannon & Wilson
completed a Phase I ESA for Sound Transit for the South Renton Transit Center
property in the fall of 2017 (Shannon & Wilson 2017). The Phase I ESA identified 10
recognized environmental conditions for the property. As a result of the Phase I findings,
Shannon & Wilson also then completed a Phase II ESA for Sound Transit in the spring
of 2018 (Shannon & Wilson 2018).
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The Phase II investigation identified petroleum impacts within soils and groundwater at
the western half of the transit center site. The contamination is likely associated with
numerous former aboveground storage tanks and underground storage tanks. Evidence
of petroleum contamination was encountered in the eastern half of the transit center site
within “hotspots” but was not associated with specific historical features. Five soil
samples and 12 groundwater samples collected had one or more chemical constituents
(metals, petroleum products, and volatile organic compounds) that exceeded Model
Toxics Control Act Method A cleanup levels 6. A single sample location for soil collected
along the former rail corridor near S. Grady Way detected polycyclic aromatic
hydrocarbons associated with creosote-preserved railroad ties. Based on the analytical
data and field observations, the Phase II ESA identified the following constituents that
would likely be in soil, soil vapor, and groundwater encountered during construction
activities on the transit center site: petroleum hydrocarbons as diesel, gasoline, and
motor oil; BTEX; polycyclic aromatic hydrocarbons (PAHs); polychlorinated biphenyls
(PCBs); vinyl chloride; and metals including arsenic, chromium, and lead. This site has
been assigned an Ecology Cleanup Site identification number 6342 and is labeled as
undergoing cleanup.
Six additional sites have been identified in the vicinity of this project component,
between 100 to 800 feet from the transit center. Two of the six sites, Renton Lincoln
Mercury and Les Schwab Tires Renton, both 200 feet from the proposed transit center,
have received a “no further action” letter from Ecology following cleanup activities. Even
with completed cleanup activities, contaminants may have migrated away from these
sites and low levels of contamination below applicable cleanup levels may still be
present. The remaining four sites are between 100 and 800 feet from the transit center
and are undergoing remedial actions. All four sites are identified as having known
groundwater contamination. These sites were assessed as having a Low to Moderate
Risk of being a source for encountering hazardous materials during construction
because of their proximity to areas where construction activities would likely occur and
the fact that contamination could have migrated toward the project component, either in
groundwater or vapor (see Attachment D, Figure 4-3). The chemicals of concern listed at
these sites were benzene, lead, metals-other, petroleum-other, PAHs, metals priority
pollutants, non-halogenated solvents, petroleum-gasoline, and/or petroleum
products-unspecified.
Bellevue Transit Center and Off-site Layover
No contamination is known to exist at this project component. Two LUST sites and/or
hazardous material release sites have been identified in proximity to this project
component (see Attachment D, Figure 4-4). Both of the sites, Quest Corp (660 feet
southeast) and Bravern Phase II (500 feet northeast) received a “no further action” letter
from Ecology following mandatory cleanup. In addition, according to Ecology’s “What’s
In My Neighborhood” database, two additional sites with identified releases are located
west of the proposed bus layover area. They include the PSE Spill site at 1116 108th
Avenue NE, which was granted “no further action” for PCBs and petroleum in soil only.
6 Method A may be used to establish cleanup levels at sites that have few hazardous substances and that
meet the following criteria: Sites undergoing a routine cleanup action as defined in WAC 173-340-200.
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The second site, 1020 Tower at 1020 108th Avenue NE, was granted “no further action”
for unspecified petroleum products in soil only.
Because of completed cleanup operations and their proximity to areas where
construction activities would occur, all four of these sites were assessed as having a low
risk of being a source for encountering hazardous materials during project construction.
Even with completed cleanup at these sites, contaminants may have migrated away
from the sites, either in groundwater or vapor, and low levels of contamination below
applicable cleanup levels may still be present. The chemicals of concern listed at these
sites were arsenic, lead, mercury, metals-other, petroleum-other, PAHs, metals priority
pollutants, non-halogenated solvents, PCBs, and/or petroleum products-unspecified.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
No contamination is known to exist at this project component. No documentation has
been found of any LUST sites and/or hazardous material release sites near this project
component.
Brickyard Station and Roadway Improvements
No contamination is known to exist at this project component. No known LUST sites
and/or hazardous material release sites have been identified near this project
component.
Lynnwood City Center Transit Station BRT and Roadway Improvements
No contamination is known to exist at this project component. Four LUST sites and/or
hazardous material release sites have been documented near this project component
(see Attachment D, Figure 4-7 and 4-8). Three of the four sites received a “no further
action” letter from Ecology following cleanup activities for petroleum products, metals,
and non-halogenated organics in soil and groundwater. Even with completed cleanup at
these three sites, they were assessed as having a low risk for being a source of
contaminated materials encountered during construction as low levels of contamination
below applicable cleanup levels may still be present and because contamination could
have migrated toward the project component, either in groundwater or vapor.
The one site still undergoing cleanup, Chevron 94953 (Ecology facility Id number
58434551, Cleanup site Id number 6340), is approximately 450 feet northeast of the
transit center. In a letter to Chevron from Ecology, dated May 2007, the site has known
soil and groundwater impacts from historical releases. In the 2007 letter, Ecology
determined that based on the quarterly groundwater monitoring results from 2000 to
2007, the site is required to continue remedial actions. Based on the status of this site, it
was assessed as having a moderate risk of being a source of hazardous materials
during construction. The chemicals of concern listed at these sites include BTEX, lead,
metals-others, non-halogenated solvents, other non-halogenated organics, and total
petroleum hydrocarbons as diesel, gasoline, and/or other unspecified products.
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Describe existing hazardous chemicals/conditions that might affect project
development and design. This includes underground hazardous liquid and gas
transmission pipelines located within the project area and in the vicinity.
As noted above, construction at five of the project component sites has some potential to
encounter prior contamination during construction. At all project components, Sound
Transit would appropriately identify, characterize, manage, handle, store, and dispose of
contaminated soil and groundwater encountered during construction activities in
accordance with state and federal regulations (see Section B.7.a.5 below).
According to the National Pipeline Mapping System (NPMS) public viewer, hazardous
liquid/gas transmission pipelines are located near only one project component – the
South Renton Transit Center:
• A natural gas distribution line is located approximately 5,500 feet southeast of the
transit center site (NPMS 2020).
• A hazardous liquid pipeline is located approximately 2,000 feet south of the proposed
transit center.
While the NPMS does not specify the hazardous liquid being carried in this pipeline, the
Revised Code of Washington 81.88.010 defines a hazardous liquid to be petroleum,
petroleum products, or a hydrous ammonia.
Describe any toxic or hazardous chemicals that might be stored, used, or
produced during the project’s development or construction, or at any time during
the operating life of the project.
During construction, relatively small quantities of fuels (including diesel, gasoline, and
propane) for various pieces of small equipment would likely be stored at each project
component site. If petroleum products are stored in quantities greater than 1,320
gallons, in containers with a capacity of 55-gallons or more, and a release could
reasonably contact navigable waters, a written Spill Prevention Control and
Countermeasures Plan would be prepared. The plan would also include inspections.
Heavy equipment fueling would likely occur at each project component using an on-site
fuel delivery provider. Other construction-related materials likely at each project
component would include solvents and adhesives used in relatively small quantities.
After construction, none of the BRT stations, park-and-rides, or transit centers would
store, use, or generate hazardous materials during operations. Accidental small-scale
spills or drips from vehicles parked in the parking garages at the transit centers could
occur. For these instances, emergency spill cleanup kits would either be staged at these
locations or Sound Transit maintenance staff would have these materials with them for
use where needed. Potential pollutants released on the ground at the BRT facilities as a
result of routine bus operations, such as engine leaks or heavy metals from brake dust
during driving or layover parking, would either stay on the site on the ground or could be
washed by rain into stormwater that would be collected in the on-site stormwater
treatment facilities. The stormwater treatment facilities would collect, retain, and provide
treatment to stormwater to remove potential pollutants before releasing the stormwater
off-site. Pollutants that may be deposited on existing roadways as a result of routine
BRT operations/travel between stations, again such as from engine leaks or heavy
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metals from brake dust, would be managed by existing roadway stormwater treatment
facilities unless, as noted in Section B.3.c, upgrades are required for capacity and/or to
lower the existing drainage system to provide positive gravity flow.
Describe special emergency services that might be required.
No special emergency services are expected to be required as a result of operations of
BRT facilities or during project construction. None of the sites would have security
fencing or other infrastructure that would complicate emergency service access, and no
hazardous materials would be stored that might require specialized fire response. In
accordance with National Fire Protection Association 13 2013, 2018 International Fire
Code 903, and current local municipal codes, the park-and-ride garage structures at the
South Renton Transit Center and Kingsgate would be fully installed with sprinklers and
standpipes for firefighting purposes, and a minimum of one standpipe is required for use
during construction of the project.
Sound Transit has an established program for responding to emergencies at its facilities,
including a spill response and hazardous materials handling plan, and a spill response
contractor on call 24/7 for spills to which Sound Transit staff might be unable to respond.
Therefore, the potential of long-term recurring releases of hazardous materials from BRT
facilities or operations would be low. Accidental spills or drips from vehicles parked in the
park-and-ride garages could occur. For these instances, emergency spill cleanup kits
would be staged at these locations. Wastes generated from cleanup activities would be
removed and disposed of in accordance with state and federal regulations for the
removal, treatment, or disposal of contaminated material.
Proposed measures to reduce or control environmental health hazards, if any:
The project is subject to Sound Transit’s safety and security certification process, which
includes an evaluation of hazardous materials used during construction, testing, and
commissioning of facilities, as well as ongoing operations. Sound Transit has a policy to
meet or exceed federal safety and security process requirements on all projects, which
includes measures for controlling hazardous material usage during construction as well
as operation and maintenance of the project.
During construction, all potentially hazardous construction materials used would be
handled and stored in accordance with state and federal hazardous materials handling
requirements. For all project components, procedures to identify, characterize, manage,
handle, store, and dispose of contaminated soil and groundwater encountered during
construction would be implemented. If unanticipated soil or groundwater contamination
were encountered during construction activities, remediation of those materials would
occur as needed. In compliance with the Model Toxics Control Act Cleanup Regulation
(Washington Administrative Code (WAC) 173-340), a cleanup plan would be developed
and implemented to minimize human exposure and for the proper removal and treatment
or disposal of contaminated materials in soils or groundwater. This elimination of
hazardous or contaminated materials would reduce future potential adverse effects to
human health and the environment from exposure at those locations or from potential
migration.
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Operational risks related to the use, storage, generation, or disposal of hazardous
materials would be integrated into a safety and security program or plan specific to the
I-405 BRT Project. The project incorporates BMPs, including commitments to adhere to
applicable regulations and measures for controlling hazardous materials planned for use
within the context of constructing, operating, and maintaining the project.
The Burien Transit Center and Roadway Improvements, the Tukwila International Boulevard
BRT Station and Roadway Improvements, and a portion of the South Renton Transit Center
and Roadway Improvements project components are mapped as having predicted arsenic
concentrations of 20 to 40 ppm from the Tacoma Smelter Plume. Most of the land at these
project components is urban or developed with surface soils that have been previously
disturbed. For these three project components, soils would be sampled and analyzed in
accordance with Ecology’s 2019 Tacoma Smelter Plume Model Remedies Guidance
(Ecology 2020c) prior to initiation of clearing and grading activities. If arsenic or lead above
Model Toxics Control Act (MTCA) cleanup levels were encountered, cleanup would be
coordinated with Ecology and remediation of those materials would occur as needed. A soil
remediation plan would be prepared to minimize human exposure and for the proper
removal and treatment or disposal of contaminated materials in soils or groundwater. The
proposed soil remediation plan would be sent to Ecology for its concurrence that the plan
would likely result in no further action, per MTCA cleanup levels. Construction workers would
be required to be trained in lead awareness, according to 29 CFR 1926.62(l) and also
trained according to 29 CFR 1910.1018(o) for arsenic awareness during excavation
activities. In addition, extra precautions would be taken to avoid dust, soil erosion, and water
erosion during construction.
South Renton Transit Center and Roadway Improvements
Sound Transit would complete cleanup of identified contaminated soil and groundwater
during property redevelopment in coordination with Ecology; the site is designated by
Ecology as Cleanup Site 6342.
Prior to construction, Sound Transit would conduct pre-demolition asbestos and lead
surveys of the existing structures to be removed at the South Renton Transit Center site.
Sound Transit would also evaluate electrical components for the presence of electrical
equipment containing polychlorinated biphenyls or mercury. If these materials are
identified prior to demolition, Sound Transit would remove and dispose of them in
accordance with regulations.
In consideration of the information above, no mitigation measures are needed.
b. Noise
What types of noise exist in the area which may affect your project (for example:
traffic, equipment, operation, other)?
Noise generated from existing surrounding land uses near the project would not affect
any project component, with the possible exception of the freeway stations at the
Tukwila International Boulevard BRT Station, the Totem Lake/Kingsgate BRT Station,
and the Brickyard BRT Station as described below. These proposed BRT stations are
located in a highway environment where existing traffic noise levels are high, and
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Section B.7.b.3 below describes how Sound Transit is assessing and addressing noise
levels that passengers would experience at BRT stations in highway environments.
Existing noise measurements, taken at representative locations along the project
corridor, as described in Attachment E I-405 BRT Noise and Vibration Technical
Memorandum Table 4-1 and Table 4-2, provide information about existing noise levels.
The existing measurements for each of the project components are provided below in
terms of peak or highest one-hour equivalent sound level (Leq), and the 24-hour
day/night (Ldn) level.
Burien Transit Center and Roadway Improvements
Land use around the Burien Transit Center is mostly parking lots and retail shops. Land use
around the roadway improvements on SR 518 is residential. For this project component,
existing noise measurements were taken from a residence located on the north side of SW
148th Street, across from the Burien Transit Center, and at residences adjacent to the north
and south of SR 518, just east of SR 509 (see Attachment E, Figure 4-1).
Existing noise levels were measured in the range of Ldn 60 dBA to 62 dBA near the transit
center and 69 dBA near SR 518, with a one-hour peak Leq of 62 dBA to 69 dBA. These
existing noise levels primarily reflect existing traffic noise on SW 148th Street and SR 518.
Tukwila International Boulevard BRT Station and Roadway Improvements
Outside of the SR 518 right-of-way, land use in the area between 32nd Avenue S and
29th Avenue S, north of SR 518 is residential. Between 38th Lane S and 24th Avenue S,
the land use is industrial, retail, and airport-related. Between 42nd Avenue S and 38th
Lane S, residential land use is located within 100 to 120 feet of SR 518 with noise
barriers on both sides of SR 518. From 51st Avenue S to 42nd Avenue S, residential
land uses are located on both sides. Between 51st Avenue S and 42nd Avenue S the
residences to the north of SR 518 are below grade and Southcenter Boulevard is located
between the residences and SR 518.
For this project component, existing noise measurements were taken at a nearby residence
on the north side of SR 518 and west of Tukwila International Boulevard and at four
residential locations north and south of SR 518, east of the Tukwila International Boulevard
Link light rail station (see Attachment E, Figure 4-2). Existing noise levels at these locations
were measured in the range of Ldn 66 dBA to 71 dBA with a one-hour peak Leq of 61 dBA to
66 dBA. These noise levels primarily reflect traffic noise levels from SR 518.
Because the proposed BRT stations would be located at-grade within the SR 518
roadway, these higher noise levels generated from traffic on SR 518 may have an effect
on passengers waiting at the BRT station platform and Sound Transit’s design would
provide passenger shielding as appropriate.
South Renton Transit Center and Roadway Improvements
Land use around the South Renton Transit Center site is primarily roadways and
commercial retail uses. I-405 is located approximately 0.5 mile south of the transit center
site. For this project component, an existing noise measurement was taken at the
Holiday Inn Seattle-Renton, which is located south of the proposed transit center site
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and just north of I-405 (see Attachment E, Figure 4-3). Existing noise levels at this
location were measured at an Ldn of 72 dBA with a one-hour peak Leq of 68 dBA. This
noise level primarily reflects traffic noise levels from I-405.
Bellevue Transit Center and Off-site Layover
The Bellevue Transit Center is an existing facility in a downtown urban area. The off-site
layover area is adjacent to the downtown library and a residential apartment building
with retail on the ground floor. For this project component, an existing noise
measurement was taken at the Liberty Square Apartments, the closest residential land
use to the off-site layover area (see Attachment E, Figure 4-4). Noise levels at this
location were measured at an Ldn of 72 dBA and a one-hour peak Leq of 74 dBA.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
The future BRT station pair is in the center of I-405 at the existing Totem Lake Freeway
Station; land use east of I-405 is office and retail. Residential land uses are located
north, south, and west of the proposed Kingsgate Park-and-Ride Garage structure, and
the I-405 roadway is located to the east. An existing noise measurement was taken at
the southeast corner of the Kingsgate site, close to the Country Trace Condominiums to
the south (see Attachment E, Figure 4-5). Noise levels at this location were measured at
an Ldn of 68 dBA and a one-hour peak Leq of 65 dBA.
The current shelters at the Totem Lake in-line bus stop provide some reduction in
highway noise levels so as to reduce the noise levels experienced by people waiting for
transit service, and the project would ensure this type of shielding remains in place with
the project.
Brickyard Station and Roadway Improvements
Outside of the I-405 right-of-way, both east and west of I-405, the area adjacent to this
project component consists primarily of residential land uses. North of Juanita
Woodinville Way NE there are some commercial uses along the east side of I-405. On
the west side of I-405 there is a church with an associated school and recreation field.
An existing noise measurement was taken at Braewood Condos, which is the closest
residential land use, located just west of the Brickyard Park-and-Ride lot (see
Attachment E, Figure 4-6). At this location, the existing noise levels were measured at
an Ldn of 75 dBA and a one-hour peak Leq of 74 dBA. These noise levels primarily reflect
traffic noise levels from I-405.
Because the proposed BRT stations would be located at-grade within the I-405 roadway,
noise levels generated from the highway may have an effect on the experience of people
waiting at the BRT station platform, and Sound Transit’s design would provide
passenger shielding as appropriate.
Lynnwood City Center Transit Station BRT and Roadway Improvements
The existing Lynnwood City Center transit center is located in a mixed-use urban area
with commercial, retail, and residential uses. The Poplar Way road improvements are
located in an area with I-5 to the west, commercial uses to the north and east, and
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residential uses to the south. An existing noise measurement was taken on the west side
of the transit center and south of the Poplar Way loop ramp (see Attachment E, Figure
4-7 and Figure 4-8). Existing noise levels at the transit center were measured at an Ldn
of 67 dBA and a one-hour peak Leq of 66 dBA. Temporarily, the BRT station at the
Lynnwood City Center transit center may experience noise from construction of the
Lynnwood Link light rail extension.
What types and levels of noise would be created by or associated with the project
on a short-term or a long-term basis (for example: traffic, construction, operation,
other)? Indicate what hours noise would come from the site.
The potential for operational transit-related noise and vibration impacts was determined
based on application of the FTA General Noise and Vibration Assessment used to
predict noise and vibration levels from BRT transit-related project components, such as
stations, park-and-ride lots, and transit centers. The FHWA Noise Abatement Criteria
were used to predict traffic noise locations where roadway modifications would
substantially change traffic volumes and/or distances from the traffic to existing sensitive
land uses. Based on WSDOT guidance for applying the FWHA criteria, none of the
project roadway modifications would result in a substantial change and FHWA’s traffic
noise abatement analysis is not required. Typical construction noise and vibration levels
were predicted at the different project components using the FTA reference levels.
The State of Washington has a noise control ordinance that applies (together with local
noise regulations) to construction, industrial, commercial, and residential noise sources.
In the absence of local noise control ordinances, the state noise control ordinance
applies. State law exempts mobile noise sources, including freight rail, aircraft in flight,
and vehicles traveling in public right-of-way, as well as safety warning devices (e.g.,
bells). For stationary land uses with noises originating from outside public roadways and
rights-of-way, the Washington State Noise Control Ordinance defines three different
Environmental Designations for Noise Abatement (EDNAs) based on land use, which
can be summarized as residential, commercial, and industrial. The WAC noise
regulations are taken from Chapter 173-60, WAC, Maximum Environmental Noise
Levels, 2000. The ordinance is then written to define the maximum allowable noise level
from one EDNA to another EDNA.
The WAC property line noise standards, adopted by local agency noise ordinances, are
used to assess potential noise impacts from park-and-ride garage and transit center
operations. The FTA noise criteria and FHWA Noise Abatement Criteria are used for the
bus and traffic operation noise.
Maximum permissible sound levels for haul trucks on public roadways are limited to 86
dBA for speeds of 35 miles per hour or less, and 90 dBA for speeds over 35 miles per
hour, when measured at 50 feet (Chapter 173-62, WAC).
Sounds created by backup alarms are exempt, except between 10 p.m. and 7 a.m. when
“beep-beep” backup alarms are essentially prohibited by the WAC and local agency noise
ordinances in urban areas and would be replaced with smart backup alarms, which
automatically adjust the alarm level based on the background level or switch off backup
alarms and replace with spotters. This criterion is included because, just like noise from
construction activities, noise from backup beepers would exceed the WAC nighttime criteria,
even with the allowable exceedance, at large distances from the construction site.
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Although construction activities would vary between each project component,
construction of each project component would create noise from heavy equipment that
generates relatively high noise levels. The most constant noise source at construction
sites is usually engine noise. Mobile equipment generally operates intermittently or in
cycles of operation, while stationary equipment, such as generators and compressors,
generally operates at constant sound levels. Trucks would be present during most
phases of construction, including travel to and from the project sites.
The construction of each project component would increase noise levels in a way that
would be temporary and intermittent, and that would cease once construction is
complete. As an example of the effects of construction, the maximum noise levels of
construction equipment are expected to range from 67 dBA at the Braewood
Condominiums near the Brickyard BRT Station to 84 dBA at the Country Trace
Condominiums, the closest noise-sensitive receivers to the Totem Lake/Kingsgate
Station and Kingsgate Park-and-Ride Garage project component. If piles are needed for
construction of the Kingsgate and South Renton Park-and-Ride garages, and the
construction methods include impact pile driving, maximum noise levels are expected to
be 96 to 99 dBA at the closest noise-sensitive receivers. Working hours of construction
would vary to meet the type of work being performed, and construction activities for each
project component would adhere to local regulations to control construction noise.
Although each city has specified construction hours during the daytime, construction
outside of those hours may be necessary depending on site conditions, construction
activities, and scheduling. Construction outside of the allowable hours, such as nighttime
weekdays and Saturdays, Sundays, and legal holidays, would need to meet the EDNA
noise limits or would require an approved variance from the appropriate city.
Burien Transit Center and Roadway Improvements
Operations at this project component would generate transit-related noise from buses at the
proposed BRT station and layover area at the existing Burien Transit Center, and traveling
in the bus-only lanes along SW 148th Street. Typical noise from buses entering and leaving
the transit center would include noise from tires, propulsion motors, and other auxiliary
equipment on the vehicles which would be predicted to be an Ldn of 57 dBA. The noise
levels generated by the BRT vehicles operating at the Burien Transit Center would not
exceed the FTA Ldn noise impact criteria (58 dBA for a moderate impact and 64 dBA for a
severe impact) and would be below the existing noise level of Ldn 60 dBA at 14654 3rd
Avenue SW, the closest noise-sensitive receiver. The transit center noise levels are
predicted to be below the WAC EDNA for commercial noise sources adjoining a residential
use of a Leq of 57 dBA for daytime and a Leq of 47 dBA for nighttime.
Roadway improvements would improve transit speed and reliability, including a bus-only
lane for eastbound buses along SW 148th Street, across the SR 509/SR 518
interchange and along SR 518 for approximately 400 feet. For westbound buses, a
bus-only left-turn pocket would be added along SW 148th Street between 1st Avenue S
and the Burien Transit Center. These bus-only lanes would not add to the capacity of the
general-purpose lanes or substantially change the vertical or horizontal roadway
alignment. The changes would result in minimal to no change to overall traffic volumes
on the roadway; therefore, no change to overall traffic noise levels is expected.
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Tukwila International Boulevard BRT Station and Roadway Improvements
Operations at this project component would generate transit-related noise from buses at
the BRT freeway station platforms and buses traveling in the bus-only lanes on SR 518.
Typical noise from buses entering and leaving the BRT freeway station platforms would
include noise from tires, propulsion motors, and other auxiliary equipment on the
vehicles which are predicted to be an Ldn of 54 dBA. The noise levels generated by the
BRT vehicles would not exceed the existing Ldn noise level of 71 dBA at 15603 42nd
Avenue S, the closest residential noise-sensitive receiver, and would not exceed the
FTA Ldn noise impact criteria (66 dBA for a moderate impact and 71 dBA for a severe
impact). Additionally, from this project component there are no noise-sensitive land uses
within FTA’s screening distance; the nearest residence is 200 feet from any planned
roadway improvements. On the south side, the residences are at an elevation above SR
518, and the closest residence is 260 feet from the proposed roadway improvements.
Roadway improvements at the Tukwila International Boulevard BRT Station would add
bus-only lanes to the inside of both eastbound and westbound SR 518, providing for
pull-out stops in both directions at the station. The bus-only lanes would not add to the
capacity of the general-purpose lanes or substantially change the vertical or horizontal
roadway alignment. The changes would result in minimal to no change to overall traffic
volumes on the roadway; therefore, no change to overall traffic noise levels is expected.
South Renton Transit Center and Roadway Improvements
Operations at this project component would generate typical noise from vehicles using the
proposed park-and-ride garage and from buses at the transit center and traveling in the
bus-only lanes. With regard to the proposed park-and-ride garage, typical parking lot
sources of noise would include vehicle engine noise, opening and closing of car doors, and
people talking. Typical noise from buses entering and leaving the transit center or traveling
in the bus-only lanes would include noise from tires, propulsion motors, and other auxiliary
equipment on the vehicles, which is predicted to be an Ldn of 57 dBA at 1 S Grady Way, the
nearest noise-sensitive receiver. This is well below the existing measured noise level of an
Ldn of 72 dBA and would not exceed the FTA Ldn noise impact criteria (66 dBA for a
moderate impact and 72 dBA for a severe impact). The park-and-ride garage noise levels
are also predicted to be below the WAC EDNA for commercial noise sources adjoining a
residential use of a Leq of 57 dBA for daytime and a Leq of 47 dBA for nighttime.
Roadway improvements at the South Renton Transit Center would not increase capacity
or substantially change the vertical or horizontal roadway alignment. The improvements
would result in minimal to no change to overall traffic volumes on the roadway; therefore,
no change to the overall traffic noise levels is expected.
Bellevue Transit Center and Off-site Layover
Operations at this project component would generate transit-related noise from buses at
the proposed BRT station at the existing Bellevue Transit Center and at the proposed
off-site layover location along the east side of the Bellevue Library. Typical noise from
buses entering and leaving the transit center and layover area would include noise from
tires, propulsion motors, air conditioning, and other auxiliary equipment on the vehicles,
which is predicted to be an Ldn of 56 dBA at the Liberty Square Apartments and Bravern
Condos, the nearest noise-sensitive receivers. This is well below the existing noise level
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at the Bellevue Transit Center and Off-site Layover area of an Ldn of 72 dBA, and would
not exceed the FTA Ldn noise impact criteria (66 dBA for a moderate impact and 72 dBA
for a severe impact). The transit center and off-site layover noise levels are also
predicted to be below the WAC EDNA for commercial noise sources adjoining a
residential use of a Leq of 57 dBA for daytime and a Leq of 47 dBA for nighttime.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
Operations at this project component, both the BRT station and Kingsgate Park-and-Ride
Garage, would generate typical noise from buses entering and leaving the BRT station
(including noise from tires, propulsion motors, and other auxiliary equipment on the vehicles)
and parking lot sources of noise (such as vehicle engine noise, opening and closing of car
doors, and people talking). The predicted project noise level of the BRT station and
park-and-ride garage is an Ldn of 57 dBA. This is well below the existing Ldn of 68 dBA at the
Country Trace Condominiums, the nearest noise-sensitive receiver, and would not exceed
FTA’s Ldn noise impact criteria (63 dBA for a moderate impact and 69 dBA for a severe
impact). The park-and-ride garage noise levels are also predicted to be below the WAC
EDNA for commercial noise sources adjoining a residential use of a Leq of 57 dBA for
daytime and a Leq of 47 dBA for nighttime.
Brickyard Station and Roadway Improvements
Operations at this project component would generate transit-related noise from buses at
the BRT freeway station platforms and traveling in the bus-only lanes. Typical noise from
buses entering and leaving the BRT freeway station platforms would include noise from
tires, propulsion motors, and other auxiliary equipment on the vehicles, which are
predicted to be an Ldn of 44 dBA. The noise levels generated by the BRT vehicles would
not exceed the existing noise level of an Ldn of 75 dBA at the Braewood Condominiums,
the nearest noise-sensitive receiver, and would not exceed the FTA Ldn noise impact
criteria (66 dBA for a moderate impact and 74 dBA for a severe impact).
Roadway improvements would not increase capacity or substantially change the vertical
or horizontal roadway alignment. The improvements would result in minimal to no
change to overall traffic volumes on the roadway; therefore, no change to traffic noise
levels is expected.
Lynnwood City Center Transit Station BRT and Roadway Improvements
Operations at this project component would generate transit-related noise from buses at
the proposed BRT station at the existing Lynnwood City Center transit center and the
bus-only lanes along the Poplar Way loop ramp. Typical noise from buses entering and
leaving the transit center would include noise from tires, propulsion motors, and other
auxiliary equipment on the vehicles, which are predicted to be an Ldn of 60 dBA, which
would not exceed the measured existing noise level of Ldn of 67 dBA at 20100 48th
Avenue, the nearest noise-sensitive receiver, and would not exceed the FTA Ldn noise
impact criteria (63 dBA for a moderate impact and 68 dBA for a severe impact). The
noise levels from the BRT station in the transit center are predicted to be below the WAC
EDNA for commercial noise sources adjoining a residential use of a Leq of 57 dBA for
daytime and a Leq of 47 dBA for nighttime.
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For this project component, the roadway improvements along Poplar Way would allow
bus-only traffic on the inside shoulder of the loop on-ramp. While these improvements
add an outside lane, it is for buses only and the bus traffic that would be added is farther
away from noise-sensitive receivers and would be traveling at reduced speeds of 35
mph to make the turn on the loop ramp. This improvement does not add to the capacity
of the loop ramp and would not lead to an increase in overall traffic on the ramp. The
noise levels of the bus-only lanes are not expected to increase traffic noise levels.
Proposed measures to reduce or control noise impacts, if any:
Noise levels during construction of each project component are not expected to exceed
state or local thresholds. Therefore, mitigation measures would not be required. Noise
variances from local agencies would be obtained, as needed, if construction activities
occurred outside of specified daytime hours.
Prior to construction, the noise analysis would be revised for each project component
with updated design and construction information. The revised analysis would be
presented as part of an updated Noise Analysis and Control Plan. If the updated
analysis indicates a potential impact, mitigation measures and best practices would be
identified in the updated Noise Analysis and Control Plan which would specify methods
that the contractor would implement to minimize construction equipment noise levels at
sensitive receivers as necessary. The Noise Control Plan would be approved by Sound
Transit and may require additional approval by WSDOT prior to initiating construction.
These measures could include, but would not be limited to, the following:
• Use low‐noise emission equipment
• Use broadband backup warning devices on all vehicles
• Implement noise‐deadening measures for truck loading and operations
• Monitor and maintain equipment to meet noise limits
• Use acoustic enclosures, shields, or shrouds for equipment and facilities
• Install high‐grade engine exhaust silencers and engine‐casing sound insulation
• Minimize the use of generators
• Use movable noise barriers at the source of the construction activity
• Use drilled piles in lieu of impact piles or limit the time of day the activity could occur
for potential pile driving for the foundations of the South Renton Transit Center and
Kingsgate Park-and-Ride Garage.
Based on the FTA General Noise Assessment, predicted future BRT operational noise
levels at the noise-sensitive land uses near each project component are not expected to
increase existing noise levels and would not result in a noise impact. Park-and-ride
garage and transit center noise levels are predicted to be below the WAC EDNA for
commercial noise sources adjoining a residential use. Therefore, mitigation measures
would not be required.
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As design continues for the Tukwila International Boulevard BRT Station, the Totem
Lake/Kingsgate BRT Station, and the Brickyard BRT Station, which would be located in
or directly above the SR 518 or I-405 roadway, noise levels at the BRT station platforms
would be evaluated for compliance with Sound Transit’s criteria of a 1-hour Leq noise
limit of 72 dBA for traffic noise exposure for patrons at the station platform and design
would incorporate noise-minimization features as needed.
8. Land and Shoreline Use
a. What is the current use of the site and adjacent properties? Will the proposal affect
current land uses on nearby or adjacent properties? If so, describe.
Except for the South Renton Transit Center, all of the project components are on land
currently used for transportation; these land uses would not change. The land at the
South Renton Transit Center has been, and still is, in commercial use. Sound Transit is
in the process of completing the purchase of this site, which would convert these
approximately 8.3 acres of land from commercial to transportation use. Upon completion
of construction, a portion of the South Renton Transit Center site may then be deemed
as surplus property, which could be sold and used by the City of Renton, or others, for
TOD with affordable housing.
During construction, some properties adjacent to project components may be affected by
temporary construction easements; the existing land uses on these properties would
remain. Other than these temporary uses during construction and the property being
purchased for the South Renton Transit Center, no other uses of land on adjacent
properties would be altered by the project.
Once the project is constructed, land uses adjacent to all of the project components
would benefit from access to the BRT service that would provide increased regional
mobility and improved transit speed and reliability.
Table 12 identifies the current uses of land where project components would be
developed, as well as land uses on properties adjacent to each element of the
components. Table 13 identifies the current ownership of the project component land
(including right-of-way ownership), whether the project component would require the
long-term acquisition or lease of land from WSDOT, King County Metro, or other
jurisdictions, and whether temporary use of WSDOT right-of-way may be needed during
construction. The locations of long-term leases or property acquisition are shown in the
Conceptual Engineering plans in Attachment B.
Temporary construction easements may also be needed from adjacent properties during
construction, with locations to be determined as design progresses. Sound Transit would
work with property owners to determine the agency’s ability to use such areas, provide
appropriate compensation for the use, and restore all areas after construction.
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Table 12 Current and adjacent land uses by project component
Project component Current land use Adjacent land uses
Burien Transit Center
and Roadway
Improvements
Transportation (transit center,
arterial roadway, and SR 518)
Transit center and SW 148th Street
• Northwest: Residential
• North, south, east, and west: Commercial
retail
SR 518
• North and south: Residential
• East and west: Transportation (SR 518)
Tukwila International
Boulevard BRT Station
and Roadway
Improvements
Transportation (SR 518) BRT station
• North: Transportation (Link light trail
station)
• South: Commercial
• East and west: Transportation (SR 518)
Roadway improvements
• North and south: Residential
• East and west: Transportation (SR 518)
South Renton Transit
Center and Roadway
Improvements
Transit Center
• Commercial retail (currently
mostly vacant, some
auto-oriented uses continue
on-site)
• Bonneville Power
Administration transmission
line easement, along south
and east site boundary
Roadway improvements
• Transportation
• North and west: Transportation (roadways)
and commercial (auto dealerships and
large-scale retail)
• East: Transportation (roadways and
existing park-and-ride lot)
• South: Transportation (roadways) and
commercial (retail and hotel)
Bellevue Transit Center
and Off-site Layover
Transportation Transit center
• North, south, east, and west:
Transportation (roadways), Commercial
(office and retail towers with associated
parking), Residential
• East: City Hall Park and site of Bellevue
Downtown Link light rail station
Layover
• West: Bellevue Library
• East and south: Multi-family residential
• North: Transportation (roadway) and
single-family residential
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Project component Current land use Adjacent land uses
Totem Lake/Kingsgate
Station and Kingsgate
Park-and-Ride Garage
Transportation BRT station
• Immediately north, south, east, and west:
Transportation (I-405)
• East: Commercial (medical facilities)
Kingsgate Park-and-Ride
• North, west, and south: Single and
multi-family residential
• East: Transportation (arterial roadway and
I-405)
Brickyard Station and
Roadway Improvements
Transportation • North, west, and south: Transportation
(I-405 and Brickyard Park-and-Ride lot)
• Northwest: Church with associated school
and recreation field
• East: Single and multi-family residential
Lynnwood City Center
Transit Station BRT and
Roadway Improvements
Transportation BRT station
• North, east, and south: Transportation
(park-and-ride and site of Lynnwood Link
light rail station)
• West: Multi-family residential
Roadway improvements
• North and west: Transportation (I-5)
• East: Commercial
• South: Commercial and single-family
residential
SOURCE: Sound Transit 2020
Table 13 Current land ownership, long-term land use and temporary use of
WSDOT right-of-way by project component
Project
component Current land ownership Long-term land use
Potential temporary use
of WSDOT right-of-way
Burien Transit
Center and
Roadway
Improvements
Transit center
King County Metro
Roadway improvements
• City of Burien public
right-of-way for SW
148th Street
• WSDOT public
right-of-way for SR 518
Transit center
Use agreement with King
County Metro
Roadway improvements
• Burien retains
right-of-way for SW
148th Street
• Air space lease (ASL)
from WSDOT for
transit-only
improvements on SR
518, WSDOT retains
right-of-way
Temporary construction air
space lease (TCAL) for
work in SR 518
right-of-way
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Project
component Current land ownership Long-term land use
Potential temporary use
of WSDOT right-of-way
Tukwila
International
Boulevard BRT
Station and
Roadway
Improvements
WSDOT public right-of-way
for SR 518
ASL from WSDOT for
transit-only improvements
on SR 518, WSDOT
retains right-of-way
TCAL for work in SR 518
right-of-way
South Renton
Transit Center
and Roadway
Improvements
Transit center
Sound Transit is in the
process of acquiring four
privately owned parcels
Roadway improvements
• City of Renton public
right-of-way for local
streets
• WSDOT public
right-of-way for Rainier
Avenue S (SR 167) and
I-405
Transit center
Sound Transit ownership
Roadway improvements
ASL from WSDOT for
transit-only improvements
on Rainier Avenue S (SR
167), WSDOT retains
right-of-way
TCAL for work in Rainier
Avenue S (SR 167)
right-of-way
Bellevue Transit
Center and
Off-site Layover
Transit center
King County Metro operates
and maintains.
Improvements all within City
of Bellevue right-of-way.
Off-site layover
City of Bellevue
right-of-way
Transit center
Use agreements with
King County Metro and
City of Bellevue
Off-site layover
No change from existing
None
Totem
Lake/Kingsgate
Station and
Kingsgate
Park-and-Ride
Garage
Totem Lake/Kingsgate
Station
WSDOT right-of-way for
I-405. Sound Transit has an
ASL for existing bus stops
Kingsgate Park-and-Ride
site
• WSDOT right-of-way
• Operated and
maintained by King
County Metro
Totem Lake/Kingsgate
Station
Existing ASL may need to
be modified for BRT station
improvements
Kingsgate Park-and-Ride
site
Sound Transit to determine
whether to purchase or
lease the land associated
with the park-and-ride
garage
Totem Lake/Kingsgate
Station
Temporary construction
agreement under existing
ASL
Kingsgate Park-and-Ride
site
Construction agreement
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Project
component Current land ownership Long-term land use
Potential temporary use
of WSDOT right-of-way
Brickyard Station
and Roadway
Improvements
BRT station and
pedestrian bridge
• WSDOT right-of-way for
I-405 and Brickyard
Park-and-Ride
• Bothell right-of-way for
(NE 115th Street)
Roadway improvements
WSDOT right-of-way for
I-405
ASL from WSDOT for
transit-only improvements
on I-405 and Brickyard
Park-and-Ride, WSDOT
retains right-of-way
None, construction led by
WSDOT
Lynnwood City
Center Transit
Station BRT and
Roadway
Improvements
Transit center
Property owned by Sound
Transit
Roadway improvements
• 46th Avenue W: City of
Lynnwood right-of-way
and WSDOT limited
access right-of-way
• Poplar Way and loop
ramp: 10 parcels owned
by City of Lynnwood, 1
parcel privately owned1
• I-5: WSDOT right-of-way
Transit center
No change
Roadway improvements
• 46th Avenue W: No
change, improvements
are not transit-only
• Poplar Way and loop
ramp: Partial acquisition
from 5 of the parcels
owned by City of
Lynnwood and the 1
privately owned parcel
• I-5: ASL for transit-only
improvements, WSDOT
retains right-of-way
TCAL within 46th Avenue
W and I-5 limited access
right-of-way
SOURCE: Sound Transit 2020
NOTES:
1 Based on Snohomish County Assessor’s information. However, these parcels may be owned by WSDOT as part of the
right-of-way for I-5. Sound Transit will continue coordination with both the city and WSDOT to determine the ownership of these
parcels.
b. Has the project site been used as working farmlands or working forest lands? If so,
describe. How much agricultural or forest land of long-term commercial significance
will be converted to other uses as a result of the proposal, if any? If resource lands
have not been designated, how many acres in farmland or forest land tax status will
be converted to nonfarm or nonforest use?
The area surrounding the I-405 corridor and some of the project components may have
been used as farmland in the past; however, the highway has existed since the 1960s
and the land around the highway was previously developed and has continued to
develop since that time, and there are currently no farms operating at the project
components and no known farms operating adjacent to the project components.
No agricultural or forest land of commercial significance would be converted as a result
of this project.
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Will the proposal affect or be affected by surrounding working farm or forest land
normal business operations, such as oversize equipment access, the application
of pesticides, tilling, and harvesting? If so, how:
No, there are no nearby working farms or forest land businesses that the project
components would affect or be affected by.
c. Describe any structures on the site.
Burien Transit Center and Roadway Improvements
Two structures are on the Burien Transit Center site:
• On the main transit center island, a large structural steel and glass shelter
(approximately 200 feet long by 20 feet wide) covers the platform, as well as a
restroom facility for transit drivers. The maximum height of this shelter appears to be
approximately 20 feet.
• On the west transit center island is a smaller steel and glass station shelter,
approximately 40 feet long by 12 feet wide. The height of this shelter appears to be
approximately 10 feet.
For the roadway improvements, one bridge structure in the east end of the project
component conveys SR 518 over SR 509. This bridge structure is approximately 300
feet long by 100 feet wide.
Tukwila International Boulevard BRT Station and Roadway Improvements
Four bridge structures cross over SR 518 in this project area:
• S 154th Street bridge, which is approximately 650 feet long and 50 feet wide
• Airport Expressway bridge, which is approximately 600 feet long and 50 feet wide
• Link light rail guideway bridge, which is approximately 500 feet long extending from
the light rail station to the edge of the SR 518 right-of-way (the elevated guideway
continues south to Sea-Tac Airport) and 30 feet wide
• Tukwila International Boulevard bridge, which is approximately 300 feet long and 90
feet wide
In addition, the site includes a portion of the Tukwila International Boulevard Link light
rail station. This light rail station is comprised of three levels: a street level, a mezzanine
level that includes TVMs and rider information, and a station level with platforms. The
station structure is approximately 250 feet long and 100 feet wide. The top station level
is approximately 50 feet above ground level.
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South Renton Transit Center and Roadway Improvements
Table 14 identifies the existing structures on the parcels of the South Renton Transit
Center site and describes previous uses and approximate sizes. Within the roadway
improvements area there is one bridge, conveying I-405 over Rainier Avenue S, that is
approximately 250 feet long and 100 feet wide.
Table 14 Existing structures on the South Renton Transit Center site
Parcel No. Previous use
Building size (square
feet)
192305-9068 Office space and repair garage 3,710 and 480
192305-9035 Auto showroom and lot 46,980
192305-9063 Auto service building 12,260
SOURCE: Sound Transit 2020
In addition, within the Bonneville Power Administration easements on the site there are
three transmission poles along the east side of the property and two along the southern
portion of the property. Each of these transmission poles appears to be approximately
between 40 and 50 feet in height.
Bellevue Transit Center and Off-site Layover
The Bellevue Transit Center site contains an existing bus transit facility with three
covered shelter structures. In the western portion, the shelter structure is approximately
90 feet long by 35 feet wide, and appears to be approximately 18 feet high at the peak,
and includes a restroom for transit drivers. In the center there is a large covered shelter
structure that is approximately 360 feet long and 40 feet wide, and appears to be
approximately 18 to 24 feet high, over the platform. In the eastern portion, the shelter
structure is approximately 60 feet long by 35 feet wide, and appears to be approximately
18 feet high at the peak, and includes a rider information center. There are no structures
on the off-site layover site.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
The site of the proposed Totem Lake/Kingsgate Station is an existing freeway transit
station pair located on an elevated structure in the center of I-405. The existing transit
station platforms are approximately 70 feet wide by 320 feet long. Structures at the
transit stations include shelters with seating. On the east side of the platform there are
two transit shelter structures, each approximately 70 feet long by 8 feet wide and with
staggered steel awning heights of approximately 8 to 12 feet. On the west side of the
platform there is one continuous shelter structure that is approximately 280 feet long and
8 feet wide, with varying steel awning heights of approximately 8 to 12 feet.
The only existing structures on the Kingsgate Park-and-Ride site are located at the bus
loop and include two bus shelters, each approximately 8 feet long and 6 feet wide, and a
small restroom for transit drivers that is approximately 8 feet long by 8 feet wide that
appears to be approximately 8 feet high.
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Brickyard Station and Roadway Improvements
Structures on this project component site include the bridge for the Juanita Woodinville
Way NE overcrossing of I-405, which is approximately 650 feet long and 80 feet wide, as
well as two bus shelters (approximately 16 feet long, 6 feet wide, and 8 to 10 feet high),
one at each of the existing bus stops on the I-405 on- and off-ramps.
Lynnwood City Center Transit Station BRT and Roadway Improvements
At the existing transit center, to the north and south of the transit loop, there are
approximately 10 separate covered shelters, each approximately 50 to 70 feet long and
12 feet wide. On the center transit island there are approximately three groupings of
staggered shelters. The groupings at the west and east ends include five shelters, four
transit shelters that are approximately 30 feet long and 20 feet wide and one walkway
shelter that is approximately 20 feet long and 12 feet wide. The grouping in the center
includes two transit shelters, each approximately 30 feet long by 20 feet wide. All
shelters appear to be approximately 10 to 12 feet high. In the northeast portion of the
transit center site there is an existing single-story building (approximately 65 feet long
and 25 feet wide) used for a rider information kiosk and space for commercial business.
In the southwest portion of the transit center site there is an art sculpture and a
single-story building (approximately 35 feet long and 15 feet wide) for a restroom for
transit drivers.
Within the Poplar Way road improvements area is the 196th Street SW bridge
overcrossing of I-5. This bridge structure is approximately 600 feet long by 70 feet wide
and includes a nonmotorized crossing (separated from motorized traffic by a jersey
barrier) with a ramp on the west end that connects to the Interurban Trail. A cellular
tower is located in the center of the Poplar Way loop ramp where project construction
staging would likely occur.
d. Will any structures be demolished? If so, what?
The existing buildings on the proposed South Renton Transit Center site would be
demolished. No other project components would require removal of structures.
e. What is the current zoning classification of the site?
Burien Transit Center and Roadway Improvements
The current zoning of the Burien Transit Center is Downtown Commercial (DC) (see
Attachment A, Figure A-13). SW 148th Street and SR 518 are public right-of-way.
Tukwila International Boulevard BRT Station and Roadway Improvements
The project component is located within the SR 518 right-of-way. Zoning to the north and
south of SR 518 is Regional Commercial (RC) by the City of Tukwila (see Attachment A,
Figure A-14).
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South Renton Transit Center and Roadway Improvements
The current zoning of the South Renton Transit Center site is Commercial Arterial (CA)
(see Attachment A, Figure A-15). The existing roadways are public right-of-way, which
have not been zoned by Renton.
Bellevue Transit Center and Off-site Layover
The transit center is located within the Downtown Office 1 (DT-O-1) zone and the off-site
bus layover area is within an area zoned Downtown – Residential (DT-R) (see
Attachment A, Figure A-16).
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
The Totem Lake/Kingsgate Station is located within the WSDOT right-of-way and has no
zoning designation. The Kingsgate Park-and-Ride is WSDOT right-of-way and is within
the City of Kirkland’s jurisdiction and is zoned Professional Office Residential, Transit
Oriented Development (PR 1.8) (see Attachment A, Figure A-17).
Brickyard Station and Roadway Improvements
Most of this project component is within public right-of-way for I-405 and has no zoning
designation. The portions of this project component that are located in the City of Bothell
jurisdiction have the following zoning designations: Residential – Activity Center (R-AC),
Office-Professional (OP), and Neighborhood Business (NB). Those portions within the City
of Kirkland are zoned low density residential (RSA 6) (see Attachment A, Figure A-18).
Lynnwood City Center Transit Station BRT and Roadway Improvements
The Lynnwood City Center transit station is located within Lynnwood’s City Center West
(CC-W) zoning designation (see Attachment A, Figure A-19). The roadway
improvements are within public right-of-way, which have not been zoned by Lynnwood.
f. What is the current comprehensive plan designation of the site?
Table 15 provides the existing comprehensive plan designation for each project
component.
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Table 15 Comprehensive Plan designation for each project component
Project component Agency with Jurisdiction Comprehensive Plan designation
Burien Transit Center and
Roadway Improvements
Transit Center and SW 148th
Street: Burien
SR 518: WSDOT
Transit Center and SW 148th Street:
Downtown Commercial
SR 518: No land use designation assigned,
within WSDOT right-of-way
Tukwila International
Boulevard BRT Station and
Roadway Improvements
WSDOT No land use designation assigned, within
WSDOT right-of-way
South Renton Transit Center
and Roadway Improvements
Transit Center and local
roadways: Renton
Rainier Avenue S (SR 167):
WSDOT
Transit Center and local roadways:
Commercial-Mixed Use
Rainier Avenue S (SR 167): No land use
designation assigned, within WSDOT
right-of-way
Bellevue Transit Center and
Off-site Layover
Bellevue Transit Center: Mixed Use-Downtown
Off-site layover: Downtown-Ashwood
Totem Lake/Kingsgate Station
and Kingsgate Park-and-Ride
Garage
Totem Lake/Kingsgate Station:
WSDOT
Kingsgate Park-and-Ride
Garage: WSDOT and Kirkland
Totem Lake/Kingsgate Station: No land use
designation assigned, within WSDOT
right-of-way
Kingsgate Park-and-Ride Garage:
Transit-oriented development
Brickyard Station and
Roadway Improvements
Station and roadway
improvements: WSDOT
East pedestrian bridge landing:
Bothell
Station and roadway improvements: No
land use designation assigned within
WSDOT right-of-way
East pedestrian bridge landing: R-AC, OP,
and NB (Waynita/Simonds/Norway Hill
Comprehensive Plan Subarea)
Lynnwood City Center Transit
Station BRT and Roadway
Improvements
Transit Station: Lynnwood Transit Station: City Center
Roadway Improvements:
WSDOT
Roadway Improvements: No land use
designation assigned, within WSDOT
right-of-way
SOURCE: Sound Transit 2020
g. If applicable, what is the current shoreline master program designation of the site?
None of the I-405 BRT project components are located within a designated shoreline
management zone.
h. Has any part of the site been classified as a critical area by the city or county? If so,
specify.
No critical areas have been identified at the Burien Transit Center and Roadway
Improvements, Bellevue Transit Center and Off-site Layover, or the Lynnwood City
Center Transit Station BRT and Roadway Improvements project components.
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Tukwila International Boulevard BRT Station and Roadway Improvements
City of Tukwila mapped wetlands are within the study area (see Section B.3.a for
additional information). In addition, Tukwila has mapped moderate and high landslide
hazard areas within the study area (see Section B.1.d). As design progresses,
geotechnical borings would be completed at this location to identify existing soil
conditions and provide recommendations for construction and structures.
South Renton Transit Center and Roadway Improvements
This project component is located within a City of Renton designated wellhead protection
zone and a high seismic hazard (see Section B.1.d). As stated in Section B.3.b the area
is also within a federally designated Sole Source Aquifer area. The project component
would not discharge untreated water to groundwater and, therefore, would not impact
the wellhead protection area. The roadway improvements along Rainier Avenue S, south
of S Grady Way, intersect with a mapped Federal Emergency Management Agency
flood zone (zone AH), which is defined as an area of shallow flooding (usually areas of
ponding) where average depths are between 1 and 3 feet. In this area, the roadway
improvements include some additional paving and re-striping for a new bus-on-shoulder
lane. The roadway improvements would not change the elevation of the roadway, and
stormwater detention would be provided.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
This project component is located in an area with a medium or mixed liquefaction
potential. However, as discussed in Section B.1.d, preliminary evaluation of existing soils
from geotechnical borings on site suggest that liquefaction at this site is unlikely (Sound
Transit 2020f). The eastern edge of the Kingsgate Park-and-Ride site is also mapped as
having moderate-to-high susceptibility for landslides.
Brickyard Station and Roadway Improvements
King County has mapped wetlands and creeks within the study area for this project
component (see Section B.3.a for additional information). Juanita Creek flows under
I-405 where the interstate would be widened to allow room for bus access to the
proposed new transit station.
King County landslide, erosion, and liquefaction hazard areas are mapped near the
north end of the I-405 roadway improvements, along the slope just south of the
Sammamish River and I-405/SR 522 interchange. Kirkland has mapped high and
moderate susceptibility landslide hazard areas throughout the south portion of the
project area. As WSDOT progresses with design, geotechnical analysis would be
completed to identify existing soil conditions and provide recommendations for
construction and structures.
i. Approximately how many people would reside or work in the completed project?
None of the completed project components would have people residing or working at
them. However, agency maintenance and security staff would visit the sites regularly.
Bus drivers would also stay with their vehicles during layovers at the Lynnwood City
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Center transit station, the Bellevue layover area, and the Burien Transit Center and
would use the driver restroom facilities provided at these locations.
j. Approximately how many people would the completed project displace?
None of the project components would displace any existing residences.
The only project component where businesses and their employees would be displaced
is at the South Renton Transit Center. At the South Renton Transit Center, there are
three existing businesses under two ownerships: Sound Ford and Sound Collision under
one ownership and Walkers Renton Mazda under another. Sound Transit has leases in
place with these businesses and is currently in the process of relocating them. Sound
Ford is no longer operating on the site. Sound Collision is still operating on-site until able
to complete the relocation to its new site, which is expected in summer 2020. Walkers
Renton Mazda is still operating on-site and relocation efforts are beginning in
preparation for its move, which will occur once its new location is finished being built. All
three businesses would be completely relocated in advance of the start of project
construction.
k. Proposed measures to avoid or reduce displacement impacts, if any:
Sound Transit is complying with the requirements of the Uniform Relocation Assistance
and Real Property Acquisition Act (1970) and Sound Transit’s Revising Real Property
Acquisition and Relocation Policy, Procedures and Guidelines (Sound Transit 2002),
under which any displaced party is eligible for relocation benefits, and with the terms of
its leases with the business owners on the South Renton Transit Center site.
l. Proposed measures to ensure the proposal is compatible with existing and projected
land uses and plans, if any:
Sound Transit strives to locate its major transit facilities where they would also be
compatible with projected land uses and plans. As a regional transit authority facility,
project components are recognized as an Essential Public Facility per the Washington
State Growth Management Act (Revised Code of Washington 36.70A.200) for
consideration by local governments and compliance with their development plans and
policies.
As noted below, the project components are consistent with the existing and projected
land uses, as identified in local jurisdictions’ comprehensive plans and zoning
designations. In addition, all project components are planned to be in compliance with
the development standards of each jurisdiction’s zoning code (including setbacks,
height, landscaping, and other dimensional standards). If compliance is not possible,
Sound Transit would coordinate with local jurisdictions, such as to seek variances or
development agreements.
The following comprehensive plans were evaluated to determine project consistency:
• Burien Transit Center and Roadway Improvements: Burien Comprehensive Plan
(December 2018), Conceptual Framework for the Town Square, the Downtown
Master Plan and the downtown policies. Transit center improvements are considered
to be a government facility use, which is a permitted use within the Downtown
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Commercial zone. Roadway improvements in SW 148th Street are consistent with
the existing roadway land use. Roadway improvements in SR 518 do not have a land
use designation assigned as they are within WSDOT right-of-way.
• Tukwila International Boulevard BRT Station and Roadway Improvements: Tukwila
Comprehensive Plan (2015) and SeaTac Comprehensive Plan (November 2019)
were reviewed. No land use designation is assigned within WSDOT right-of-way. The
Link light rail station is on the parcel owned by Sound Transit that is zoned “Regional
Commercial” (RC) by the City of Tukwila. An Unclassified Use Permit would be
required from the City of Tukwila to demonstrate compliance with its land use
policies. City of SeaTac land use and zoning standards generally do not apply in
WSDOT right-of-way.
• South Renton Transit Center and Roadway Improvements: Renton 2015
Comprehensive Plan. A transit center is a conditional use within the “Commercial
Arterial” (CA) zone, which also has an overlay of “Automall Overlay, District B.”
Conditional use permit approval would ensure the project component’s land use
compatibility.
• Bellevue Transit Center and Off-site Layover: Bellevue Comprehensive Plan (2016)
designates the existing transit center as “Mixed Use – Downtown.” Bellevue’s zoning
code designates the site as “Downtown Office 1 District” (DT-O-1). The transit center
and off-site layover would obtain land use exemption approvals, which would ensure
the project component’s land use compatibility.
• Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage:
o Kingsgate Park-and-Ride Garage: Kirkland Comprehensive Plan (2016)
designates the Kingsgate site as TOD within the Totem Lake Business District &
Urban Center. While the Kingsgate Park-and-Ride site is considered WSDOT
right-of-way, WSDOT will apply the City of Kirkland’s development standards of
the Professional Office Residential, Transit Oriented Development zone to the
proposed park-and-ride garage. The park-and-ride garage would be a
government facility use, which is a permitted use. The City of Kirkland is currently
in the process of amending the design standards of this zone; the park-and-ride
garage would comply with the amended zoning code.
o Totem Lake/Kingsgate Station: No land use designation assigned as the station
is within WSDOT right-of-way.
• Brickyard Station and Roadway Improvements: Kirkland Comprehensive Plan (2016)
and Imagine Bothell…Comprehensive Plan (2015) were reviewed. No land use
designation is assigned as the project component is within WSDOT right-of-way.
• Lynnwood City Center Transit Station BRT and Roadway Improvements:
o Transit Center: 2015 Lynnwood Comprehensive Plan. The zoning designation of
the transit center is “City Center West” or (CC-W) with a “PSRC Regional Growth
Center” overlay. In this zone, transit centers are considered an Essential Public
Facility use, which are permitted with approval of a development agreement. This
project component would be considered a minor modification to the existing
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transit center and would not need to modify the existing development agreement.
Therefore, it is compatible with existing and proposed land uses.
o Roadway Improvements: Although the Poplar Way loop ramp is comprised of 11
parcels, the City of Lynnwood has not assigned a land use designation to them
as they are also within WSDOT’s limited access right-of-way for I-5.
m. Proposed measures to reduce or control impacts to agricultural and forest lands of
long-term commercial significance, if any:
No measures are required. The project would not affect agricultural or forest lands of
long-term commercial significance.
9. Housing
a. Approximately how many units would be provided, if any? Indicate whether high,
middle, or low-income housing.
The proposed project would not provide any housing units.
b. Approximately how many units, if any, would be eliminated? Indicate whether high,
middle, or low-income housing.
The project would not eliminate any housing units.
c. Proposed measures to reduce or control housing impacts, if any:
No measures to control housing impacts are warranted.
10. Aesthetics
For more detailed information on visual and aesthetic resources at the project
components, see Attachment F, I-405 BRT Corridor Visual and Aesthetic Resources
Technical Memorandum. Figures 4-1 through 4-7 of the attachment provide existing
aerial and street view photographs of the project components. Figure 5-1 through 5-9 of
Attachment F provide existing photographs and photosimulations, at key viewpoints, for
project components that were identified as having a greater change to the visual
environment, such as the Kingsgate Park-and-Ride Garage, and at the Lynnwood City
Center transit center as a representative example of a BRT station at an existing transit
center.
a. What is the tallest height of any proposed structure(s), not including antennas; what is
the principal exterior building material(s) proposed?
At each BRT station the proposed pylons are anticipated to be approximately 17 feet tall
and would likely be the tallest feature. Although the architectural materials for the pylons
would be determined during final design, it is anticipated that they would be constructed
of a durable and relatively easily cleanable surface such as glass and/or steel, designed
to fit the aesthetic of the rest of the BRT station elements. Other station elements include
the TVMs which are typically boxes that are 4 feet in height and the real-time information
signs that are currently anticipated to be attached underneath the station shelter
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structure, either the existing shelter or the proposed new shelter. TVMs and real-time
information signs are typically made of steel.
At the Burien Transit Center, the Tukwila International Boulevard BRT Station, and the
Brickyard Station, the BRT-branded station shelters are anticipated to be approximately
11 feet tall and approximately 48 feet long. At the South Renton Transit Center, either a
similarly sized BRT station shelter would be added or the entire transit center island may
be covered by a single, large shelter with a height that may be around 17 feet.
Although the architectural materials for the station shelters at all locations would be
determined during project final design, as with the pylons, it is anticipated that the
principal exterior material would likely be steel and glass; the materials and design of the
shelters would be coordinated with that of the pylons.
The South Renton Transit Center and Roadway Improvements and the Totem
Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage are the only two project
components with buildings proposed. Both of these buildings are five-story park-and-ride
garages, approximately 55 to 60 feet tall.
In addition to the pylons, TVMs, and real-time information signs that were described
above, Table 16 identifies the likely tallest heights and principal exterior building
materials of proposed structures for each project component.
Table 16 Proposed structure heights and building materials
Project component Structure(s) Approx. maximum height
Potentialbuilding
materials
BRT station elements –
all locations
BRT-branded pylon 17 feet Steel and glass
Ticket vending machine 4 feet
Real-time info signs 1 foot, attached underneath
the station shelter
Burien Transit Center
and Roadway
Improvements
BRT-branded station
shelter
11 feet Steel and glass
Tukwila International
Boulevard BRT Station
and Roadway
Improvements
BRT-branded station
shelter
11 feet Steel and glass
Pedestrian bridge,
staircase, and elevator
40 feet (height over SR 518
roadway, which is below
adjacent elevations)
Reinforced concrete
Retaining walls Ranging from 6 to 13 feet Reinforced concrete
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Project component Structure(s) Approx. maximum height
Potentialbuilding
materials
South Renton Transit
Center and Roadway
Improvements
Park-and-ride garage 55 to 60 feet Reinforced concrete and
steel
Pedestrian bridge,
staircase, and elevator
(third floor of garage)
33 feet Reinforced concrete and
steel
Shelter over the transit
center island
17 feet Steel and glass
Retaining wall 6 feet Reinforced concrete
Traffic signal pole/mast
arm
35 feet Steel
Bellevue Transit Center
and Off-site Layover
See all project components
Totem Lake/Kingsgate
Station and Kingsgate
Park-and-Ride Garage
Park-and-ride garage 55 to 60 feet Reinforced concrete and
steel
Brickyard Station and
Roadway
Improvements
Pedestrian bridge,
staircase, and elevator
33 feet (height over I-405
roadway, which is below
adjacent elevations)
Reinforced concrete and
steel
BRT-branded station
shelter
11 feet Steel and glass
Lynnwood City Center
Transit Station BRT and
Roadway
Improvements
Transit center: Traffic
signal pole/mast arm
35 feet Steel
Poplar Way: Ramp meter
signal
22 feet Steel
SOURCE: Sound Transit 2020
b. What views in the immediate vicinity would be altered or obstructed?
Overall, the project components are not expected to result in a notable change in the
physical characteristics of the existing environment and would be expected to be
compatible with the existing visual character. Attachment F provides more detail on the
assessment of potential changes to views and visual quality from the project
components, following FHWA’s Guidelines for the Visual Impact Assessment of Highway
Projects.
Burien Transit Center and Roadway Improvements
There are no designated scenic or protected views in the vicinity of this project
component.
The revisions to the transit center itself (transit islands and BRT shelter) would be
constructed within the existing facility and would be consistent with the type, scale, size,
shape, and form of the transit center. The roadway improvements on SW 148th Street,
SR 509, and SR 518 would not be visually discernable over time from the existing
conditions and would be compatible within the context of an existing four-lane road in a
suburban environment and a state route. The roadway improvements would have similar
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visual characteristics such as materials, colors, form, height, and shape to the existing
roadway features.
The project would not degrade views of sensitive natural visual resources such as
mature trees at Dottie Harper Park, would not substantially change landform, and would
not obstruct desired views. Roadway improvements and signal modifications would be
minor and within the existing paved right-of-way. Overall, this project component would
not affect existing views or visual quality, and it would be visually consistent and
compatible with the existing visual environment. No adverse impacts are anticipated.
Tukwila International Boulevard BRT Station and Roadway Improvements
There are no designated scenic or protected views in the vicinity of this project
component.
The proposed BRT station shelter would be consistent with the scale and visual character
of the existing SR 518 roadway, which is a major transportation facility. The pedestrian
bridge, stairs, and elevators would be consistent with the scale, materials, and visual
character of the adjacent, large light rail station structure and elevated guideway and
overpasses over SR 518. Changes to visual resources associated with this project
component would mainly be viewed by travelers along SR 518, the interchange with
Tukwila International Boulevard, and Airport Expressway. The Tukwila International
Boulevard Station area is highly developed. The light rail station and track guideway rise
nearly 100 feet over SR 518 and are currently visually dominant for many viewers. This
project component would include similar materials and character as the existing light rail
infrastructure and the nearby Tukwila International Boulevard freeway overpass.
Existing vegetation is primarily located along SR 518 and in the residential areas
northeast and southeast of SR 518, obscuring views from adjacent residential, retail, and
commercial viewers. For this project component, mostly lower growing and immature
roadside vegetation along SR 518 would be removed for roadway widening. As noted in
Section B.5.a, approximately 10 trees with a trunk diameter between 4 and 30 inches
would be removed. This is not anticipated to alter the existing natural visual character.
Proposed roadway modifications, bus-only lanes, lighting, signage, and utilities would
add visual elements similar to the existing visual character. Large numbers of travelers
and viewers from the commercial/retail areas would see the changes in visual resources.
However, once constructed, both travelers and commercial/retail neighbors would have
low sensitivity to the change. Directional and roadway signage, traffic lights, street
lighting, parking lot lighting, retail/commercial advertising and signage, and utilities are
also ubiquitous in the existing visual environment. Therefore, the overall impacts to
visual quality would be neutral. No adverse impacts are anticipated.
South Renton Transit Center and Roadway Improvements
There are no designated scenic or protected views in the vicinity of this project
component.
This project component, including the park-and-ride garage and the transit center
facilities, would be compatible with the scale, form, materials, and visual character of the
existing commercial/retail area and the existing electrical transmission lines on-site and
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in the area. The architectural elements of the park-and-ride garage remain to be finalized
as design progresses; the facility would comply with the applicable City of Renton
development standards. Proposed site lighting, signage, pedestrian connections,
roadway elements, and utilities would be similar to existing conditions in the
commercial/retail area. While the project component would introduce new visual
elements for residential viewers, the transit center would be located within an existing
retail/commercial area and would replace existing commercial structures of similar scale
and form.
The current location of the proposed South Renton Transit Center is highly developed.
Although, Section B.5.a states that there are approximately 34 trees with a diameter
between 4 and 30 inches in this area, most of which are existing street trees that have
been identified as needing to be removed for the project. Otherwise, there is very little
vegetation on and around the site and almost no natural visual character exists. With this
project component, the extensive green space, stormwater treatment, parking islands,
and other landscaping required by the City of Renton would substantially increase
natural elements and benefit the overall natural character.
To improve transit speed and reliability, eastbound BRT vehicles would use a new short
section of a bus-only lane on Rainier Avenue S. Other local roads would have only minor
changes with this project such as a traffic light along Rainier Avenue S at Hardie Avenue
S. The visual character of the roadway improvements would be compatible with the
existing roadway and the nearby area.
Large numbers of travelers along surface streets would see visual changes with the
project. Similarly, there may be large numbers of viewers from the commercial/retail
areas; however, both the travelers and commercial/retail neighbors would have low
sensitivity to the visual changes from the project component. The project component
would be visible to a small number of residential viewers; however, with the existing
visual context, residential viewers would likely have low sensitivity.
The visual character of this project component would be visually consistent and
compatible with the existing visual environment. Therefore, the overall impacts of the
South Renton Transit Center project component would be to enhance the existing visual
quality. No adverse impacts are anticipated.
Bellevue Transit Center and Off-site Layover
There are no designated scenic or protected views in the vicinity of this project
component.
At this location, the BRT station elements within the transit center would be consistent
with the type, scale, size, shape, and form of the existing transit center. Existing
vegetation, such as ornamental landscaping in the right-of-way or fronting residential
and commercial high-rise buildings, would remain.
Roadway improvements associated with the layover area adjacent to the Bellevue
Library would consist of re-striping the roadway along 110th Avenue NE to move existing
on-street parking from the west side of the street to the east side and create additional
bus layover spaces along the west side of the roadway. A center painted island and a
right-turn-only lane would be removed to maintain one northbound and one southbound
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travel lane. These roadway improvements would not move vehicles closer to the
adjacent library and would not expand the existing paved roadway. The visual character
of this project component would be visually consistent and compatible with the existing
visual environment. Therefore, the overall impact of this project component to visual
quality would be neutral. No adverse impacts are anticipated.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
There are no designated scenic or protected views in the vicinity of this project
component.
The proposed BRT station elements would be consistent with the scale, form, materials,
and visual character of the existing Totem Lake Freeway Station. These changes would
occur within the existing I-405 visual context and the overall impact to visual quality from
the proposed BRT stations would be neutral.
The Kingsgate Park-and-Ride Garage would be a new structure on an existing paved
park-and-ride lot. The new structure would be compatible with the scale and materials of
existing commercial and retail buildings on the east side of I-405. Proposed site lighting,
signage, pedestrian connections, and utilities would be similar to existing conditions in
commercial/retail areas and along 166th Avenue NE and I-405.
The Kingsgate Park-and-Ride Garage structure would contrast in scale, form, materials,
and character to adjacent residential structures. While the park-and-ride garage
structure would contrast in scale and form with these residential structures, it would not
be visible from the majority of residences. It would not be visible to residences located to
the west of the Kingsgate site as these views are limited by the existing vegetation and
land form, which includes a raised berm, along the western boundary of the site. It would
not be visible to residences to the north of the site because these residences would be
approximately 1,600 feet from the park-and-ride garage and their views are screened by
existing mature trees. Therefore, for most residential viewers, the park-and-ride garage
would have a neutral effect on views and visual quality.
However, moving west to east along the southern boundary of the Kingsgate site the
existing vegetation of tall, mature evergreen trees thins and the existing berm
diminishes, resulting in minimal existing visual screening between the Kingsgate site and
the residential neighbors directly adjacent to the south (see the photosimulation in
Attachment F, Figure 5-8). To address this potential compatibility issue, landscape
enhancements would be provided along the southern boundary of the site between the
park-and-ride garage and the residences to provide additional visual screening and help
to maintain natural visual elements. Enhancements would be in keeping with crime
prevention through environmental design (CPTED) and Sound Transit security
standards. This additional landscaping would help soften and screen the visual contrast
and massing of the park-and-ride garage structure as viewed by the residences to the
south; however, from the perspective of these few residential viewers there would still be
an adverse effect to visual quality.
Aesthetic treatments would be included in the park-and-ride structure, which would
provide visual interest and increase the visual compatibility of the park-and-ride garage
with the adjacent residences. Aesthetic treatments may include architectural screening,
colors and finishes such as stainless steel, glazing, brick, stone, or concrete that would
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provide long-lasting, low-maintenance visual elements that would abate the adverse
effect to visual quality.
Approximately 17 mature trees in existing parking islands within the interior of the
WSDOT-owned Kingsgate site and along the perimeter would need to be removed for
construction of the garage. WSDOT’s Roadside Policy Manual requires that trees
removed be replaced, and such replacement is expected to be required on the
Kingsgate site. This would be accomplished as part of the proposed additional
landscaping along the southern site boundary. The development of the park-and-ride
garage structure and stormwater treatment infrastructure would comply with City of
Kirkland landscaping requirements and would add natural elements.
Brickyard Station and Roadway Improvements
There are no designated scenic or protected views in the vicinity of this project
component.
The proposed BRT station shelter, pedestrian bridge, and roadway improvements would
be consistent with the scale, form, materials, and visual character of I-405. The roadway
improvements would be compatible with the surrounding roadway. Large numbers of
travelers along I-405 would experience changes to their visual environment; however, all
changes would be within the existing visual context of I-405 which includes overpass
structures, retaining walls, sound walls, traffic-control barriers, and extensive pavement.
Vegetation removal would occur where the I-405 roadway would be widened and the
pedestrian bridge would be constructed, as well as areas used for construction staging.
All vegetation removal would occur in WSDOT right-of-way. This is not anticipated to
alter the existing natural visual character of vegetation alongside the I-405 roadway.
Further, the removal of trees would require replacement planting in compliance with
WSDOT’s Roadside Policy Manual.
A few residential neighbors would be able to see the potential extension of the
pedestrian bridge to the east, where it would connect to an existing local street. While
this would introduce a new element into the view, the structure would be consistent with
the scale of the surrounding two story residential structures and would not be visible to
many residences.
In addition, this project component would be implemented in coordination with WSDOT’s
Context Sensitive Solutions approach. Therefore, no adverse impacts to views are
anticipated.
Lynnwood City Center Transit Station BRT and Roadway Improvements
There are no designated scenic or protected views in the vicinity of this project
component.
At the transit center, the BRT station elements would be consistent with the existing
materials, colors, form, height, and shape. The roadway improvements would be
compatible with the surrounding existing road right-of-way. There would be no adverse
impacts to resources of the natural environment at Scriber Creek, Scriber Creek Park, or
Sprague Pond Mini Park. Road improvements along Poplar Way would add a bus-only
bypass lane for buses heading southbound on Poplar Way and continuing along the
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Alderwood Mall Parkway I-5 northbound on-ramp. These road improvements would only
slightly expand paved surfaces and would be visually consistent with the existing road
network. Approximately 15 Category 2 trees, with a trunk diameter of between 4 and 30
inches, would be removed for the roadway improvements. This is not anticipated to alter
the existing natural visual character of vegetation alongside the I-5 roadway. Further, the
removal of trees would require replacement planting in compliance with WSDOT’s
Roadside Policy Manual.
This project component would not degrade sensitive natural visual resources, and
roadway improvements would be minor and visually coherent with the transportation
network of a developed suburban area. Therefore, the overall impacts to visual quality
would be neutral. No adverse impacts are anticipated.
c. Proposed measures to reduce or control aesthetic impacts, if any:
During the construction phase, the following actions would minimize temporary impacts
on visual quality and aesthetics:
• Preserve existing vegetation and minimize the clearing of mature trees where
possible. Use existing hard/paved areas for staging materials and equipment where
practical.
• Limit construction to daylight hours, as practical. Include directional work and safety
lighting to direct lights toward work areas and away from residential areas where
nighttime construction is necessary. Shield light sources to avoid light spillover.
• Screen views of construction equipment and materials from pedestrians and
residential areas, as practical.
• Restore landscaping disturbed by construction-related activities after completion of
work.
No long-term visual quality and aesthetic impacts are anticipated as a result of the
proposed project components, with the exception of the long-term impacts for one set of
viewers from the new Kingsgate Park-and-Ride Garage. At this location, a limited
number of residential neighbors immediately south of the proposed park-and-ride garage
would perceive the scale of the garage structure as being larger and contrasting with
their residential area. To address this potential compatibility issue, landscape
enhancements would be provided along the southern boundary of the site between the
park-and-ride garage and the residences to provide additional visual screening and help
to maintain natural visual elements. Also addressing the visual impact at the Kingsgate
Park-and-Ride location, the proposed garage would include aesthetic treatments that
may include architectural screening, colors and finishes such as stainless steel, glazing,
brick, stone, or concrete that would provide long-lasting, low-maintenance visual
elements. This type of aesthetic treatment would also be used in the design of the South
Renton Transit Center garage.
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To further avoid the potential for long-term adverse impacts at any project component,
design features include the following:
• Plant suitable vegetation where appropriate within each component site and in
adjoining rights-of-way, per local landscape codes, to provide visual screening.
• Incorporate CPTED strategies during subsequent design phases to confirm that
security and visual quality are complementary.
11. Light and Glare
For additional details on light and glare within the project corridor, see Attachment F,
I-405 BRT Corridor Visual and Aesthetic Resources Technical Memorandum.
a. What type of light or glare will the proposal produce? What time of day would it mainly
occur?
At all project components, potential construction during evening/nighttime hours would
likely require lighting (including flashing lights). This lighting would be temporary and
would be required for the safety of construction workers and the traveling public.
At all project components, lighting would be provided for safety and security. Lighting
levels would comply with the requirements of Sound Transit’s Design Criteria Manual,
which includes a requirement to eliminate light trespass onto nearby windows and
adjacent properties (Sound Transit 2020e). In addition, at all project components the
project would comply with Sound Transit’s Design Criteria Manual requirement to
provide street and highway lighting that conforms to the criteria and standards of the city
or WSDOT.
Burien Transit Center and Roadway Improvements
This project component would include new sources of light within the existing transit
center at the proposed BRT station, such as the BRT-branded pylon that may be lit and
visible during hours of lower natural light and in the evening/nighttime. The lighting at the
transit station itself would remain similar to today. Because this project component is in a
highly developed urban area with many existing sources of light, the lighting at the BRT
station would not be expected to increase visible or artificial light or glare at the site or on
adjacent parcels. No new lighting is anticipated with the proposed roadway
improvements.
Tukwila International Boulevard BRT Station and Roadway Improvements
Additional, new lighting of the roadway improvements to SR 518 is not anticipated.
At the BRT station, there would be a slight increase in overall visible artificial lighting
from lights to safely illuminate the stairs, elevators, pedestrian bridge, and station
platforms, along with the BRT-branded pylon that may be lit. The new lighting would
operate during hours of lower natural light and throughout the evening/night. The lighting
level would be coordinated with WSDOT to ensure it would not cause a safety hazard to
drivers.
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The new lighting of the BRT station and pedestrian bridge would be visible to drivers
along SR 518 as they approach from the east or west. Because drivers are traveling at
high freeway speeds, this new lighting would only be visible for a brief amount of time
along their trip. In addition, the lighting would be consistent with existing lighting sources
along SR 518 and a driver’s expectation of lighting features of the roadway and signage
for safety and driver information.
Because the BRT station is at the level of the SR 518 roadway, which is lower than the
adjacent uses, lighting at the station and of the stairs leading down to the station is not
expected to be visible to commercial and residential uses adjacent to the highway to the
north and south. The pedestrian bridge would be at a height similar to the Tukwila
International Boulevard overcrossing of SR 518, which includes street lights, and lower than
the top level of the light rail station that currently has lighting. Additional lighting from the
pedestrian bridge is not expected to be visible from the uses adjacent to SR 518, which
include a commercial parking lot and a rental car facility to the south and the light rail station
to the north. Lighting from the pedestrian bridge is not expected to be visible from the distant
residential areas, to the east and west, that are on either side of SR 518.
South Renton Transit Center and Roadway Improvements
There would be a slight increase in visible artificial lighting at this project component
where lights would be used to safely illuminate the stairs, elevator, and park-and-ride
garage structure; the transit center island; and the potentially illuminated BRT-branded
pylon. Lights would also be used to illuminate the site following CPTED standards to
help create a safer environment. This increased lighting would occur in low levels of
natural light and in the evening and night but would not be expected to noticeably
increase lighting levels in the surrounding area.
The nearest residential uses are approximately 1,000 feet northeast of the proposed
park-and-ride garage structure. Lighting of the five-story park-and-ride garage would be
at a greater height than exists today. While lighting from the upper stories of the garage
may be visible from some of these residences, existing lighting from I-405, local road
street lights, and adjacent commercial uses is already pervasive, and the lighting
associated with the project component is not expected to noticeably increase lighting
levels in the surrounding area.
Bellevue Transit Center and Off-site Layover
As with the Burien Transit Center, the lighting at the existing Bellevue Transit Center
would not be expected to change. The BRT-branded pylon, likely lit for visibility, would
be an additional source of light during times of low natural light, evening, and night, but
this minimal lighting would not be expected to increase existing nighttime light levels.
At the off-site layover area, no new street lighting is proposed. There would be an
increase in the number of bus layover bays from two to four, and an associated 12
additional buses per hour during service hours (19 hours on weekdays and Saturday
and 17 hours on Sunday) that would have headlights on during times of low natural light
while traveling to and from the layover site on 110th Avenue NE. While there are
residential uses along the east side of 110th Avenue NE, across from the layover area,
the ground floors of these buildings are commercial or parking garage uses. Headlights
from the buses would not be expected to be visible from the floors above ground level.
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Therefore, this project component would not increase visible or artificial light or glare at
the site or on adjacent parcels.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
Lighting levels are expected to increase at the Kingsgate Park-and-Ride with the
addition of a five-story park-and-ride garage structure compared to the existing surface
lot condition. Lights would be used to safely illuminate the stairs, elevator, and floors of
the proposed parking garage structure. Lights would also be used to illuminate the site
following CPTED standards to help create a safer environment. This increased lighting
would occur during low levels of natural light and in the evening and throughout the
night. Ambient light conditions currently include light spilling from I-405, local roads, and
retail/commercial areas. The additional lighting of the park-and-ride garage would be
shielded by the existing dense, mature trees and berm along the west property line and
would not be visible from the residences to the west. Lighting of the park-and-ride
garage would be visible to the residences to the south. As noted in Section 11.a, the
park-and-ride garage would be designed to provide effective screening, including
screening of light to minimize the increase in light to these residences.
At the Totem Lake Station, the BRT-branded pylon would likely be lit and would be
visible during times of low natural light, evening, and night. This minimal lighting would
not be expected to increase existing nighttime light levels, which already includes
lighting from the transit station and of I-405 that would not change.
Brickyard Station and Roadway Improvements
Additional, new lighting of the roadway improvements to I-405 is not anticipated.
At the BRT station, there would be a slight increase in visible artificial lighting from lights
to safely illuminate the stairs, elevators, pedestrian bridge, and station platforms that
would be at the same level as I-405. These lights would be on during hours of lower
natural light and throughout the evening/night. The lighting levels would be coordinated
with WSDOT to ensure they would not cause a safety hazard to drivers.
This new lighting of the BRT station and pedestrian bridge would be visible to drivers along
I-405 as they are approaching the station from the north or south. Because drivers are
traveling at high freeway speeds, this new lighting would only be visible for a brief amount of
time along their trip. In addition, the lighting would be consistent with existing lighting
sources along I-405 and a driver’s expectation of lighting features of the roadway and
signage for safety and driver information. Because the station is at the roadway level, which
is lower than the adjacent uses, lighting at the station and the stairs leading down to the
station is not expected to be visible to the residential areas to the east and west of I-405.
The pedestrian bridge would be at a similar elevation to Juanita Woodinville Way NE
which includes some street lights. At the location of the pedestrian bridge, the use
adjacent to the west of I-405 is the Brickyard Park-and-Ride lot; lighting of the pedestrian
bridge would not be expected to increase existing levels of light at the park-and-ride lot,
which is already lit for safety. To the east of I-405, the pedestrian bridge may be
extended with a stairway and ramp (and possibly an elevator) to connect to NE 155th
Street. Between NE 155th Street and the nearest residential homes, which are oriented
perpendicular/away from I-405 and NE 155th Street, there are existing rows of dense
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mature evergreen trees that would provide a visual screen, including for light or glare.
Therefore, additional lighting from the pedestrian bridge is not expected to be visible
from those residential uses.
Lynnwood City Center Transit Station BRT and Roadway Improvements
At the Lynnwood City Center station, the BRT-branded pylon may be lit for visibility,
during times of low natural light, evening, and night. This light would be consistent with
other lighting at the transit center. The proposed road improvements would not involve
new streetlights or changes to street lighting. This project component would not increase
visible or artificial light or glare at the site or on adjacent parcels
b. Could light or glare from the finished project be a safety hazard or interfere with
views?
As discussed in Section B.11.a, light or glare from the project components is not
anticipated to be a safety hazard or interfere with views. Exterior lighting on the new
pedestrian bridges at the Tukwila International Boulevard and Brickyard stations and the
two new park-and-ride garages would be screened or shielded to ensure that light
sources do not shine directly toward off-site areas. The new structures would be
composed of materials that would not create glare that would be a safety hazard or
interfere with views.
c. What existing off-site sources of light or glare may affect your proposal?
There are no existing off-site sources of light or glare that may affect the proposed
project.
d. Proposed measures to reduce or control light and glare impacts, if any:
Lights used for nighttime construction would be directed inward toward the sites and
away from adjacent uses, including residential areas.
Several design features and actions would be incorporated into the design of each
project component, including the following:
• Direct lighting for the BRT stations, park-and-ride garages, transit centers, and
pedestrian walkways downward to avoid light spilling into adjacent areas, and shield
exterior lighting to ensure that light sources do not shine directly toward off-site
areas.
• Provide light screening within the park-and-ride garage structures to reduce
headlight glare.
• Use materials with low sheen and non-reflective treatments.
• Where applicable, add small trees, shrubs, and other vegetation to provide a visual
screen for adjacent neighbors.
• Since there would be no adverse light or glare impacts from construction or operation
of the project components, no mitigation measures are required.
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12. Recreation
a. What designated and informal recreational opportunities are in the immediate vicinity?
Burien Transit Center and Roadway Improvements
As shown in Figure A-20, four recreational resources are located within the immediate
vicinity of this project component: Community Center Annex (The Annex) Park, 4th
Avenue Trail, Dottie Harper Park, and Mathison Park. The Annex Park, approximately
1,000 feet northwest of the Burien Transit Center, occupies the former Burien
Community Center building and includes a skate park, basketball court, picnic tables,
and open grassy spaces. The 4th Avenue Trail is a 1.3-mile trail on public streets,
connecting The Annex to Hazel Valley Park to the north. Dottie Harper Park, located
approximately 500 feet northwest of the Burien Transit Center, is a 3.5-acre wooded
park that also includes a remodeled playground, picnic space, amphitheater, and
walking trails. Mathison Park is a 5.3-acre recreational park with a playground and trails,
located approximately 200 feet north of SR 518 in the City of Burien.
Tukwila International Boulevard BRT Station and Roadway Improvements
As shown in Figure A-21, the South 156th Way Trail is in the immediate vicinity of the
Tukwila International Boulevard Station, along S 154th Street, approximately 600 feet
north of the proposed BRT station. It is a 1.9-mile segment of the Lake to Sound Trail, a
regional multi-purpose recreational trail that, once complete, will be a 16-mile
recreational trail from the south end of Lake Washington in Renton to the shoreline of
Puget Sound in Des Moines.
South Renton Transit Center and Roadway Improvements
There are no designated or informal recreational opportunities in the immediate vicinity
of this project component.
Bellevue Transit Center and Off-site Layover
As shown in Figure A-22, there are three recreational facilities in the immediate vicinity
of this project component. City Hall Park is located at Bellevue’s City Hall (450 110th
Avenue NE) just east of the Bellevue Transit Center, across 110th Avenue NE. On the
west side of the Bellevue Library, just west of the off-site layover area, is the Ashwood
Playfield. On the north side of NE 12th Street, approximately 400 feet northwest of the
off-site layover area, is Robert E. McCormick Park, a 2.83-acre park with a sitting area,
flower gardens, and trails.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
As shown in Figure A-23, Josten Park, featuring natural green space, is located
approximately 600 feet west of the Kingsgate Park-and-Ride site at NE 129th Street and
112th Place NE.
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Brickyard Station and Roadway Improvements
As shown in Figure A-24, the Tolt Pipeline Trail is in the immediate vicinity of the
Brickyard Park-and-Ride lot (along NE 160th Street) and is on the east side of I-405
along NE 155th Street, in the immediate vicinity (approximately 80 feet east) of the
potential pedestrian bridge landing east of I-405. It is a 14.8-mile regional multi-purpose
recreational trail.
Lynnwood City Center Transit Station BRT and Roadway Improvements
As shown in Figure A-25, there are four recreational facilities in the immediate vicinity of
this project component. The Interurban Trail, a 24-mile regional trail from Shoreline to
Everett, is located approximately 900 feet south of the Lynnwood City Center transit
station. Scriber Creek Park is located approximately 500 feet west of the Lynnwood City
Center transit station; this park extends diagonally to the southeast and includes
forested wetlands, wildlife habitats, and nature trails. Scriber Creek Trail, on the south
side of Scriber Creek Park, links the park with the Interurban Trail.
Lynnwood Heritage Park is located approximately 400 feet southwest of the roadway
improvements at Poplar Way. Lynnwood Heritage Park includes five historic structures
that have been renovated and repurposed as community resource facilities.
b. Would the proposed project displace any existing recreational uses? If so, describe.
None of the project components would displace any existing recreational uses.
There may be a need to provide a temporary detour of a short segment of the Tolt
Pipeline Trail along NE 155th Street for construction of the pedestrian bridge overpass
that may connect the neighborhood on the east side of I-405 to the BRT stations and
over to the Brickyard Park-and-Ride lot on the west side of the freeway.
c. Proposed measures to reduce or control impacts on recreation, including recreation
opportunities to be provided by the project or applicant, if any:
During construction of the Brickyard Station and Roadway Improvements project
component, if it is determined that construction staging or activities would need to
temporarily detour the Tolt Pipeline Trail, maintenance of trail traffic, appropriate
signage, and access would be provided for the duration. Once construction is complete,
the trail would be returned to its existing condition or improved as needed.
There are no other anticipated impacts to recreational resources or opportunities
resulting from the project components; therefore, no measures to reduce or control
impacts are proposed.
13. Historic and Cultural Preservation
For additional information on historic and cultural resources see Attachment G, I-405
Bus Rapid Transit Technical Memorandum: Historic and Archaeological Resources.
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a. Are there any buildings, structures, or sites, located on or near the site that are over
45 years old listed in or eligible for listing in national, state, or local preservation
registers? If so, specifically describe.
Burien Transit Center and Roadway Improvements
Ten aboveground buildings, structures, or sites 45 years or older (historic-aged built
environment resources), have been identified in the vicinity of this project component
(see Attachment G, Page A-1). None of the identified buildings, structures, or sites are
located within the project component area.
• One single-family residence, built in 1954, is adjacent to the roadway improvements
and was recommended eligible for the National Register of Historic Places (NRHP)
in 2005. The historic property inventory conducted for this project in 2019 concurs
with this recommendation.
• One building, the City of Burien Community Center (built in 1970), is approximately
0.25 mile from the transit center and was previously Determined Eligible for listing in
the NRHP.
• Eight other aboveground historic-aged built environment resources are located
adjacent to the transit center and roadway improvements. These resources include
six commercial buildings and three single-family residences; all are being
recommended as not eligible for listing in the NRHP.
No local register-listed (either Determined Eligible or recommended for listing)
aboveground historic-aged built environment resources are within 0.25 mile of the
project component.
Tukwila International Boulevard BRT Station and Roadway Improvements
One commercial historic-aged built environment resource was identified adjacent to the
pedestrian bridge and roadway improvements; none were identified within the project
component area (see Attachment G, Page A-2). This resource is recommended not
eligible for listing in the NRHP.
No local or national register-listed 7 aboveground historic-aged built environment
resources were identified within 0.25 mile of the project component.
7 “Register listed” refers to resources that are either Determined Eligible for listing or previously
recommended for listing by others.
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South Renton Transit Center and Roadway Improvements
The following six historic-aged built environment resources were identified within or
adjacent to this project component (see Attachment G, Page A-3):
• Two commercial historic-aged built environment resources are located on the
proposed South Renton Transit Center site. Both are recommended not eligible for
listing in the NRHP.
• Four commercial historic-aged built environment resources are located adjacent to
the South Renton Transit Center and associated roadway improvements. None of
these buildings are recommended eligible for listing in the NRHP.
No local or national register-listed aboveground historic-aged built environment
resources were identified within 0.25 mile of the proposed project component.
Bellevue Transit Center and Off-site Layover
• No historic-aged built environment resources are adjacent to or within the Bellevue
Transit Center and Off-site Layover. No local or national register-listed resources
were identified on or within 0.25 mile of this project component.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
• No historic-aged built environment resources are adjacent to or within this project
component. No local or national register-listed aboveground historic-aged built
environment resources were identified within 0.25 mile of this project component.
Brickyard Station and Roadway Improvements
• No historic-aged built environment resources are adjacent to or within the BRT
station.
• As of December 2019, the Washington Information System for Architectural and
Archaeological Records Data contained a record of the Henry and Bell Miller
residence, located northeast of the BRT station and adjacent to roadway
improvements at the corner of the I-405 northbound on-ramp and NE 160th Street.
This historic-aged built environment resource was recorded in 1988 and 2004 and
had been Determined Eligible for listing in the NRHP in 2005. However, the building
has since been demolished, and a commercial building, built in 2008, now exists
within this parcel.
• No local or national register-listed aboveground historic-aged built environment
resources were identified within 0.25 mile of the project component.
Lynnwood City Center Transit Station BRT and Roadway Improvements
• No resources were identified within or adjacent to this project component.
• One building, the Wickers Building (built in 1919), is located within 0.25 mile of
roadway improvements and is listed on the Washington Heritage Register. This
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building was moved from its original location in 2003 to its current location within
Lynnwood Heritage Park. In addition to the Wickers Building, three aboveground
historic-aged resources and one historic-aged rail car are located within Heritage
Park. One of the resources has been determined not eligible for listing in a historic
register.
• No local register-listed properties were identified on or within the vicinity of the
project component.
b. Are there any landmarks, features, or other evidence of Indian or historic use or
occupation? This may include human burials or old cemeteries. Are there any material
evidence, artifacts, or areas of cultural importance on or near the site? Please list any
professional studies conducted at the site to identify such resources.
The I-405 BRT Project’s study area is located within the traditional territory of the
Southern Coast Salish cultural group, which includes but is not limited to: Duwamish
dxʷdəwʔabš (people of the inside), Skopamish sqʷəpábš (Green River [White River]
people), Snoqualmie sdukʷalbixʷ (people of the moon), Suquamish dxʷsəq ̓ʷəb (place of
clear water), and Snohomish sduhúbš (Haeberlin and Gunther 1930; Spier 1936; Suttles
and Lane 1990; Tweddell 1974). Southern Coast Salish have used the study area since
time immemorial for various levels of habitation and resource gathering (Haeberlin and
Gunther 1930; Spier 1936; Suttles and Lane 1990; Tweddell 1974). No known
ethnographic place names were identified within the project component areas of impact.
However, several recorded place names are located within the vicinity of four of the
project components, as discussed below. The place names identified are associated
with village sites and waterways. These place names indicate use of these areas by
Native Americans.
Burien Transit Center and Roadway Improvements
No previously recorded archaeological sites, cemeteries, traditional cultural properties,
or known ethnographic place names are on or within 0.25 mile of this project component.
Six professional studies have been conducted for areas within 0.25 mile of this project
component (CH2MHILL 2014; Iversen et al. 2000; Larson Anthropological
Archaeological Services 2007; Rooke 2010; and Tingwall and Naoi Goetz 2006a, 2006b;
see Attachment G, Table 5-2). None of the assessments identified cultural resources on
or within 0.25 mile of the project component.
The planned improvements are located in an area that appears to have been subject to
widespread and shallow surface grading and paving. The Statewide Predictive Model for
encountering precontact-era sites classifies this location as Moderately Low to Moderate
Risk (Department of Archaeology and Historic Preservation [DAHP] 2010). This model
does not take into account potential impacts from previous development. Due to the
probable lack of significant natural depositions during the Holocene epoch, this area is
unlikely to have contained deeply buried archaeological resources prior to urbanization.
Tukwila International Boulevard BRT Station and Roadway Improvements
No previously recorded archaeological sites, cemeteries, traditional cultural properties,
or known ethnographic place names are on or within 0.25 mile of this project component.
Three professional studies have been conducted for areas within 0.25 mile of the project
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component (Curtois et al. 1999; Elder and Sparks 2010; and Rooke 2010; see
Attachment G, Table 5-3). None of the assessments identified cultural resources on or
within 0.25 mile of the project component.
The planned improvements are located in an area that appears to have been subject to
widespread cutting, grading, and paving. The Statewide Predictive Model for
encountering precontact-era sites classifies this location as Moderately Low to Moderate
Risk (DAHP 2010). This model does not take into account potential impacts from
previous development. Due to the probable lack of significant natural depositions during
the Holocene epoch, this area is unlikely to have contained deeply buried archaeological
resources prior to urbanization. Archaeological sites, if present, are expected to have
been located at or near the ground surface, and are unlikely to have remained intact with
cutting and grading.
South Renton Transit Center and Roadway Improvements
No previously recorded cemeteries or traditional cultural properties are on or within 0.25
mile of this project component. Three archaeological sites are within 0.25 mile of the
project component; all are historic in age and none are within or adjacent to the project
component (see Attachment G, Table 5-4). However, pre-contact archaeological sites
have been recorded just beyond 0.25 mile of the project component. Seven known
ethnographic place names were identified within the vicinity of the South Renton Transit
Center and Roadway Improvements project component, as shown in Table 17.
Table 17 Recorded place names within the vicinity of the South Renton
Transit Center and Roadway Improvements project component
Approximate
location
Lushootseed
name
Lushootseed
translation
Waterman
name Description Citation1
Lake
Washington
x ̌aču? Lake
(Washington)
-- Lake Washington Hilbert et al.
2001:40
Black River spapɬx ̌ad Marshes, bogs,
wetlands
Spa’pLxad “marshes” for marshes at the
south end of Lake Washington to
the east of Black River
Hilbert et al.
2001:94 (119)
Black River -- -- Pa’pxwEtsût Riffle, “place where water is
swift,” for a place in the Black
River where a creek enters from
the east
Hilbert et al.
2001:148
(235)
Black River dəxʷudidəw Place of little
cedar river
Tuxudidû3 Black River, for a spring in
Renton site of an important town
Hilbert et al.
2001:148
(235a)
Cedar River Dəxʷəbqʷuʔ Place where
fresh water
thrown
TuwE’b-qo A village at the confluence of the
Cedar River and the Black River
(Cedar River)
Hilbert et al.
2001:148
(237)
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Approximate
location
Lushootseed
name
Lushootseed
translation
Waterman
name Description Citation1
May Creek š(a)balʔtxʷ Dry house Cbal3tu May Creek – “a place where
things are dried” great quantities
of red fish were taken here
Hilbert et al.
2001:94 (116)
Coal Creek -- -- SqE’bEqsId Coal Creek Hilbert et al.
2001:94 (114)
SOURCE: Hilbert et al., 2001
NOTES: 1 Parenthetical numbers are map locations used in the publication.
Ten professional studies have been conducted for areas within 0.25 mile of the project
component (Berger 2007; Berger and Hartmann 2009; Bowden and Dampf 2005; Bundy
2008; Juell 2001; Kaehler 2007; Rooke 2010, 2012; Smith and Hoffman 2007; and Smith
et al. 2014; see Attachment G, Table 5-5). None of the assessments identified cultural
resources on or within 0.25 mile of the proposed transit center and roadway
improvements.
The planned improvements are located in an area that appears to have been subject to
widespread and shallow surface grading and paving. The Statewide Predictive Model for
encountering precontact-era sites classifies this location as High to Very High Risk
(DAHP 2010). This model does not take into account potential impacts from previous
development. Due to the significant natural deposition during the Holocene epoch, this
area has the potential to contain deeply buried archaeological resources prior to
urbanization. Archaeological sites, if present, may be present at depths deeper that
previous grading.
Bellevue Transit Center and Off-site Layover
No previously recorded archaeological sites, cemeteries, or traditional cultural properties
are on or within 0.25 mile of the project component. Two known ethnographic place
names were identified within the vicinity of this project component, as shown in Table 18.
Table 18 Recorded place names within the vicinity of the Bellevue Transit
Center and Off-site Layover project component
Approximate
location
Lushootseed
name
Lushootseed
translation
Waterman
name Description Citation1
Lake
Washington
x ̌aču? Lake
(Washington)
-- Lake Washington Hilbert et al.
2001:40
Mercer
Slough
-- -- Sa’tsakaL Mercer Slough “water at head
of Bay” and old village site
Hilbert et al.
2001:89 (115)
SOURCE: Hilbert et al., 2001
NOTES:1 Parenthetical numbers are map locations used in the publication.
Two professional studies have been conducted for areas within 0.25 mile of the project
component (Schultz and Jongsma 2006; and Unknown 2005a.; see Attachment G, Table
5-6). None of the assessments identified cultural resources on or within 0.25 mile of the
project component.
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The planned improvements are located in an area that appears to have been subject to
widespread surface grading and paving. The Statewide Predictive Model for
encountering precontact-era sites classifies this location as Moderately Low to Moderate
Risk (DAHP 2010). This model does not take into account potential impacts from
previous development. Due to the probable lack of significant natural deposition during
the Holocene epoch, this area is unlikely to have contained deeply buried archaeological
resources prior to urbanization. Archaeological sites, if present, are expected to have
been located at or near the ground surface and are unlikely to have remained intact with
grading.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
No previously recorded archaeological sites, cemeteries, or traditional cultural properties
are on or within 0.25 mile of this project component. Two known ethnographic place
names were identified within the vicinity of this project component, as shown in Table 19.
Table 19 Recorded place names within the vicinity of the Totem
Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage project component
Approximate
location
Lushootseed
name
Lushootseed
translation
Waterman
name Description Citation1
Northup
Creek Mouth
-- -- Tc!utsid Mouth of Northup
Creek
Hilbert et al. 2001:90
(103)
Northup
Creek
-- -- Tc!u Northup Creek Hilbert et al. 2001:90
(104)
SOURCE: Hilbert et al., 2001
NOTES: 1 Parenthetical numbers are map locations used in the publication.
Three professional studies have been conducted for areas within 0.25 mile of the project
component (Bundy 2009; Robbins and Dugas 2000; and Cooper and Jenks 2019; see
Attachment G, Table 5-7). None of the assessments identified cultural resources on or
within 0.25 mile of the project component.
The planned improvements are located in an area that appears to have been subject to
widespread surface grading and paving. The Statewide Predictive Model for encountering
precontact-era sites classifies this location as Moderately Low to Moderate (DAHP
2010). This model does not take into account potential impacts from previous
development. Due to the probable lack of significant natural deposition during the Holocene
epoch, this area is unlikely to have contained deeply buried archaeological resources prior to
urbanization. Archaeological sites, if present, are expected to have been located at or near
the ground surface, and are unlikely to have remained intact with grading.
Brickyard Station and Roadway Improvements
No previously recorded archaeological sites, cemeteries, or traditional cultural properties
are on or within 0.25 mile of this project component. Three known ethnographic place
names were identified within the vicinity of this project component, as shown in Table 20.
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Table 20 Recorded place names within the Brickyard Station and Roadway
Improvements project component
Approximate
location
Lushootseed
name
Lushootseed
translation
Waterman
name Description Citation1
Juanita Creek təb(ɬ)tubixʷ Red marked
land/people
TE’btubĭu Juanita Creek “loamy
place”
Hilbert et al.
2001:82 (98)
Sammamish
River
sc ̓əp Deep water
hole
Sts!ap Sammamish River for
Squak Slough “crooked”
Hilbert et al.
2001:82 (91a)
North Creek -- -- Ctcel North Creek Hilbert et al.
2001:110 (148)
SOURCE: Hilbert et al., 2001
NOTES:1 Parenthetical numbers are map locations used in the publication.
Six professional studies have been conducted for areas within 0.25 mile of the project
component (Bundy 2009; Gilpin et al. 2012; Knapp 1995; Naoi Goetz and Warner 1997;
Rooke and Gantz 2008; and Unknown 2005b; see Attachment G, Table 5-8). None of
the assessments identified cultural resources on or within 0.25 mile of the project
component.
The planned improvements are located in an area that appears to have been subject to
widespread surface grading and paving. The Statewide Predictive Model for encountering
precontact-era sites classifies this location as Moderately Low to Moderate Risk (DAHP
2010). This model does not take into account potential impacts from previous development.
Due to the probable lack of significant natural deposition during the Holocene epoch, this
area is unlikely to have contained deeply buried archaeological resources prior to
urbanization. Archaeological sites, if present, are expected to have been located at or near
the ground surface, and are unlikely to have remained intact with grading.
Lynnwood City Center Transit Station BRT and Roadway Improvements
No previously recorded cemeteries or traditional cultural properties are on or within 0.25
mile of the project component. Two archaeological sites are within 0.25 mile of the
project component; both are historic in age and neither is within or adjacent to the facility
(see Attachment G, Table 5-9). One known ethnographic place name is identified within
the vicinity of the facility, dxʷɬ(ə)q ̓ab, for Swamp Creek, meaning “a wide place” (Hilbert
et al. 2001).
Six professional studies have been conducted for areas within 0.25 mile of the project
component (Berger 2016; Childley 2008; Damp and Gilpin 2008; Early and Shantry
2014; Hartmann 2008; and Robbins and Johnson 1999.; see Attachment G, Table 5-10).
Two of the assessments (Early and Shantry 2014 and Chidley 2008) identified cultural
resources within 0.25 mile of the project component; none were identified within the
project component. These resources consist of a historic-aged railroad site and
historic-aged aboveground built environment resources.
The planned improvements are located in an area that appears to have been subject to
widespread surface grading and paving. The Statewide Predictive Model for encountering
precontact-era sites classifies this location as Low to Moderate Risk (DAHP 2010). This
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model does not take into account potential impacts from previous development. Due to the
probable lack of significant natural deposition during the Holocene epoch, this area is
unlikely to have contained deeply buried archaeological resources prior to urbanization.
Archaeological sites, if present, are expected to have been located at or near the ground
surface, and are unlikely to have remained intact with grading.
c. Describe the methods used to assess the potential impacts to cultural and historic
resources on or near the project site. Examples include consultation with tribes and
the department of archeology and historic preservation, archaeological surveys,
historic maps, GIS data, etc.
The following types of documents were reviewed to identify potential cultural resources
in the vicinity of the project components: the DAHP’s Statewide Predictive Model and the
Washington Information System for Architectural and Archaeological Records Data
maintained by DAHP, previously conducted cultural resources surveys, geotechnical
reports, historic maps, aerial photographs, published ethnographies and local histories,
and geological maps.
Archaeological monitoring during geotechnical borings at the South Renton Transit
Center was conducted in October of 2019 (Appendix G, Section 5.4.4). Preliminary
results indicate mixed fill deposits from the surface to approximately 8 feet, followed by
bedded alluvial deposits ranging from silt/fine sand to gravels. Occasional organic-rich
peat layers were also observed bedded within the alluvium. This stratigraphic sequence
is consistent with geological mapping.
Local historic registers and tax assessor records were also reviewed, including King and
Snohomish Counties. Under an Interlocal Agreement with the King County Historic
Preservation Program, municipalities within King County use the King County
Landmarks Register for listing historic properties (DAHP 2020).
Buildings and structures, within and adjacent to the Area of Impacts for the project
components, that will be older than 45 years in 2021 were inventoried, recorded on
Historic Property Inventory forms, and recommendations made regarding their
Register-eligibility.
d. Proposed measures to avoid, minimize, or compensate for loss, changes to, and
disturbance to resources. Please include plans for the above and any permits that
may be required.
Construction of all components would proceed under the terms of an Archaeological
Resources Inadvertent Discovery Plan, which would set forth the procedures and
protocols to be followed in the event that archaeological resources are inadvertently
discovered during construction. If cultural resources were inadvertently discovered during
construction of any project component, Sound Transit would comply with all laws requiring
the protection of cultural resources and human remains. Sound Transit would temporarily
halt work in the immediate vicinity of the identified resources and notify the DAHP and
Affected Tribes to determine appropriate mitigation and/or avoidance measures.
Due to the proximity to previously recorded ethnographic place names, the Statewide
Predictive Model (DAHP 2010), and observation of Holocene-aged alluvial soils during
archaeological monitoring of geotechnical borings within the South Renton Transit
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Center site, Sound Transit proposes to conduct subsurface surveys via a drilling rig,
prior to construction at this particular component. No other locations on this project
warrant additional pre-construction survey work such as this.
14. Transportation
a. Identify public streets and highways serving the site or affected geographic area and
describe proposed access to the existing street system. Show on site plans, if any.
For additional information on transportation, see Attachment B, I-405 BRT Conceptual
Engineering Plans and Attachment H, I-405 BRT Corridor Transportation Technical
Report.
Burien Transit Center and Roadway Improvements
Site access for buses is currently via a dedicated transit-only driveway to/from SW 148th
Street. General traffic currently accesses the park-and-ride facility from the south and
west. No changes to the transit center site access would be included with this project
component. However, the three driveways on SW 148th Street between the transit
center and 1st Avenue S would be restricted to right-only access due to the proposed
center-running bus-only lanes.
As described in Section 14.d, to improve transit speed and reliability, a bus-only lane
would be added past the transit center entrance for eastbound buses along SW 148th
Street that would extend east across the SR 509/SR 518 interchange and along SR 518
for approximately 400 feet. For westbound buses a bus-only left-turn lane would be
provided along SW 148th Street between 1st Avenue S and the Burien Transit Center.
Between 1st Avenue S and the Burien Transit Center, the two bus-only lanes on SW
148th Street would be accommodated by converting the center two-way turn lane and
slightly widening the existing roadway. To accommodate the eastbound bus-only lane on
the SR 518 bridge over SR 509, the existing lane striping would be rechannelized. TSP
would be added to the existing traffic signals at the intersection of SW 148th Street and
1st Avenue S, at the intersection of SW 148th Street and the SR 509 southbound
on- and off-ramps, and at the intersection of SR 518. To allow for implementation of the
bus-only lanes on SW 148th Street, turning-movement restrictions would be imposed at
key driveways (up to three locations) to prohibit left turns.
Tukwila International Boulevard BRT Station and Roadway Improvements
For this project component the BRT stations would be located at-grade within the SR
518 right-of-way in an existing area between the SR 518 travel lanes and the on- and
off-ramps to SR 518, see Attachment A, Figure A-3. SR 518 is the primary highway and
roadway serving the site or affected geographic area.
The BRT service would operate on SR 518 to access the BRT stations within the SR 99
interchange area. The SR 518 mainline consists of two lanes in each direction plus
auxiliary lanes to/from SR 99 and the North Airport Expressway. On-/off-ramps are
currently provided in the eastbound direction to S 154th Street and the North Airport
Expressway, while westbound ramps connect to SR 99, S 154th Street, and the North
Airport Expressway.
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South Renton Transit Center and Roadway Improvements
The proposed new transit center would be constructed near the existing South Renton
Park-and-Ride lots northeast of the Rainier Avenue S/Grady Way intersection and would
serve as a major regional transit hub for BRT routes (existing and future), as well as
several local connecting bus routes. A park-and-ride garage would also be constructed
with a capacity of 700 stalls along with a new signalized intersection at Rainier Avenue
S/Hardie Avenue, as described in Question 14.d. The South Renton Transit Center is
shown in Attachment A, Figure A-4.
Public streets and highways serving the site or affected geographic area include:
• I-405/Northbound and Southbound on- and off-ramps
• Rainier Avenue S
• SW/S 7th Street
• Hardie Avenue SW
• Lake Avenue S
• SW/S Grady Way
The proposed BRT routing and parking garage access is shown in Attachment A, Figure
A-26. BRT buses would access the transit center via Rainier Avenue S. Transit center
visitors may access the parking garage via the Rainier Avenue S entrance on the west
side of the garage or the Lake Avenue S entrance on the east side of the garage.
Based on information provided in the 2025 Metro Connect Service Plan, the other Sound
Transit and King County Metro routes would access the site via Rainier Avenue S and
the Rainier Avenue S entrance on the west side of the garage or the Lake Avenue S
entrance on the east side of the garage and via Hardie Avenue SW. From the eastside
these routes access the transit center via S Grady Way/Shattuck Avenue S/Lake
Avenue. All bus routes would converge in the transit center.
Bellevue Transit Center and Off-site Layover
The proposed BRT station would be located at the existing Bellevue Transit Center
station in Bellevue, as shown in Attachment A, Figure A-5. The bus layover area is
located on 110th Avenue NE in front the Bellevue Public Library. Public streets and
highways serving the site or affected geographic area include:
• NE 6th Street
• 112th Avenue NE
• 108th Avenue NE
• NE 8th Street
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• 110th Avenue NE
• NE 10th Street
• NE 12th Street
The proposed BRT routing and bus layover area is shown in Attachment A, Figure A-5.
BRT buses would access the existing transit center to/from I-405 via NE 6th Street from
I-405 and would travel to the bus layover area via NE 6th Street/108th Avenue NE/NE
12th Street and back to the station from the layover area via 110th Avenue/NE 8th
Street/108th Avenue NE/NE 6th Street.
Layover for the BRT routes are proposed along the west side of 110th Avenue NE, south
of NE 12th Street. This would expand the existing bus layover area on 110th Avenue NE
near the Bellevue Library by removing existing street parking south of the library
driveway. Approximately 120 feet of curb space would be added to the existing layover
area. Half of this curb space would be north of the Bellevue Library garage entrance.
The existing layover serves Route 550. This location could serve other routes after East
Link light rail opens for service in 2023. This location is approximately 0.5 mile from the
Bellevue Transit Center, and buses would be provided convenient access to the
Bellevue Transit Center by using 110th Avenue NE. As described in Section 14.d,
channelization, signage, and signal detection work would be required to modify lane
configurations and add parking on the east side of the street; however, these changes
are not expected to adversely affect traffic operations in the area.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
The proposed Totem Lake/Kingsgate Station would be located at the existing Totem
Lake Freeway Station and the Kingsgate Park-and-Ride Garage would be located on the
existing Kingsgate Park-and-Ride site. See Attachment A, Figure A-6. Public streets and
highways serving the site or affected geographic area include:
• I-405/I-405 direct access (center) ramps/ETLs
• NE 128th Street
• Totem Lake Boulevard
• 116th Street NE
• NE 132nd Street
The BRT service would operate on I-405 and access the freeway flyer stops at
Kingsgate via the I-405 ETLs, as shown in Attachment A, Figure A-6. Park-and-ride lot
access is provided via 116th Avenue NE and NE 128th Street or NE 132nd Street. The
only planned change for park-and-ride site access is an approximately 25-foot shift of
the south driveway to the north.
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Brickyard Station and Roadway Improvements
For this project component, the BRT stations would be located at-grade within the center
of the existing I-405 roadway, see Attachment A, Figure A-7. I-405 is the primary
highway and roadway serving the site or affected geographic area.
The BRT service would operate on I-405 to access the BRT station. The I-405 mainline
currently consists of four general-purpose traffic lanes and one ETL in each direction.
The station would be located just south of the I-405 interchange with NE 160th Street.
As described in Section 14.d, the project component would add a bus-only lane in each
direction for decelerating to approach the station and accelerating back into traffic.
Lynnwood City Center Transit Station BRT and Roadway Improvements
The proposed BRT station would be located at the existing Lynnwood City Center transit
center in Lynnwood, as shown in Attachment A, Figure A-8. Public streets and highways
serving the site or affected geographic area include:
• I-5/I-5 Poplar Way on-ramp
• Poplar Way
• 196th Street SW
• 44th Avenue W
• 46th Avenue W
• 48th Avenue W
• 200th Street SW
• 202nd Street SW
The BRT buses would access the Lynnwood Transit Center by using the Alderwood Mall
Boulevard exit from I-5 south, traveling west along 196th Street SW, turning south on
44th Avenue W, west on 200th Street SW, and south onto 46th Avenue W. Access to
the transit center is provided by a BAT lane on 46th Avenue W, and access to the
drop-off/pick-up area is provided via 202nd Street NW, as shown in Attachment A,
Figure A-8.
b. Is the site or affected geographic area currently served by public transit? If so,
generally describe. If not, what is the approximate distance to the nearest transit stop?
Burien Transit Center and Roadway Improvements
The existing facility primarily serves King County Metro bus routes but also
accommodates regional Sound Transit service, providing connections to ST Express
560 and King County Metro F Line and King Country Metro routes 120, 121/122, 123,
131, 132, 166, 180, and 631.
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Tukwila International Boulevard BRT Station and Roadway Improvements
There is no existing transit service at the proposed station location on SR 518. However,
frequent Link light rail service is provided at the Tukwila International Boulevard light rail
transit station.
South Renton Transit Center and Roadway Improvements
Immediately adjacent to the east of the proposed South Renton Transit Center site,
there is an existing South Renton Park-and-Ride that is owned by WSDOT and served
by transit, currently Sound Transit Routes 560 and 566 and King County Metro buses,
including RapidRide F Line and routes 101, 102, 148, 153, 167, and 169.
Bellevue Transit Center and Off-site Layover
The Bellevue Transit Center is currently an active transit center with transit service from
Sound Transit and King County Metro, including Metro routes 226/241, 232, 234, 235,
237, 240, 241, 246, 249, 271, 342, and RapidRide B Line, and ST Express routes 532,
535, 550, 555, 556, 560, and 567. To the east of the Bellevue Transit Center, Sound
Transit’s Bellevue Downtown Link light rail station will open in 2023. ST Express routes
currently use the layover area along 110th Avenue NE.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
The existing Totem Lake Freeway Station is served by Sound Transit routes 532 and
535. King County Metro bus routes 234/235, 238, 244, 252/257, 255, 277, and 930
provide service at the nearby Kingsgate Park-and-Ride lot off of 116th Avenue NE.
Community Transit Route 424 also serves the Kingsgate Park-and-Ride lot.
Brickyard Station and Roadway Improvements
King County Metro currently provides transit service to the existing Brickyard
Park-and-Ride station, which is located on the west side of I-405. King County Metro
service includes routes 236, 237, 255, 311, 342, and 952 and ST Express 532 and 535
routes at the ramp stops. The proposed BRT station would connect to this park-and-ride
lot with a pedestrian bridge.
Lynnwood City Center Transit Station BRT and Roadway Improvements
The Lynnwood Transit Center offers direct connections to the local and express bus
system and to future Sound Transit Lynnwood Link light rail service. Three Sound
Transit routes (routes 511, 512 and 535) and 17 Community Transit routes (routes 107,
112, 113, 115/116, 120, 130, 196, 201, 202, 402, 421/422, 425, 810, 821, and 855)
serve the transit center.
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c. How many additional parking spaces would the completed project or non-project
proposal have? How many would the project or proposal eliminate?
Burien Transit Center and Roadway Improvements
Parking would not be added or eliminated at this project component. The existing
park-and-ride garage and lot would remain. There is currently no on-street parking along
SW 148th Street.
Tukwila International Boulevard BRT Station and Roadway Improvements
Parking would not be added or eliminated at this project component. The existing
park-and-ride lot with the Link light rail station would remain.
South Renton Transit Center and Roadway Improvements
This project component adds a new 700-stall, 5-floor park-and-ride garage with pick-up
and drop-off spaces provided. The existing 373 spaces at the South Renton
Park-and-Ride lot adjacent to the east would remain.
Bellevue Transit Center and Off-site Layover
Parking would not be added or eliminated at the existing Bellevue Transit Center.
Layover for the I-405 BRT vehicles is proposed on 110th Avenue NE in front of the
Bellevue Public Library. On the west side of the street, 110th Avenue NE would be
modified to remove existing on-street automobile parking and provide two new bus
layover bays, one north and one south of the existing driveway into the library parking
garage. On the east side of the street, the existing right-turn lane would be modified to
accommodate on-street parking spaces. A total of 5 parking spaces (approximately 93
feet) on the west side of the street would become 11 parking spaces (approximately 206
feet) on the east side of 110th Avenue N, resulting in a net gain of 6 parking spaces.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
The existing Kingsgate Park-and-Ride lot consists of 502 surface parking stalls for
general-purpose vehicles. The project component would add a net of 400 park-and-ride
stalls on the Kingsgate site. The proposed project includes adding a new five-story
park-and-ride garage structure in the southern portion of the existing Kingsgate surface
park-and-ride lot. The garage would temporarily displace approximately 166 surface lot
parking spaces during construction and, upon completion, would provide a net 400 new
spaces for a total of approximately 566 park-and-ride stalls; 336 surface park-and-ride
stalls would remain, for a total of 902 park-and-ride spaces on the site.
Brickyard Station and Roadway Improvements
Parking would not be added or eliminated at this project component.
Lynnwood City Center Transit Station BRT and Roadway Improvements
Parking would not be added or eliminated at this project component.
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d. Will the proposal require any new or improvements to existing roads, streets,
pedestrian, bicycle or state transportation facilities, not including driveways? If so,
generally describe (indicate whether public or private).
The project proposes to construct BRT stations and roadway improvements in support of
new BRT service within the I-5, I-405, and SR 518 corridors. As described in Section
A.12, the proposed project includes the following public roadway improvements.
Proposed improvements to existing transportation facilities are shown in Attachment B,
Conceptual Engineering plans.
Burien Transit Center and Roadway Improvements
To accommodate the eastbound bus-only lane on the SR 518 bridge over SR 509, the
existing lane striping would be rechannelized. TSP would be added to the existing traffic
signals at the intersection of SW 148th Street and 1st Avenue S, at the intersection of
SW 148th Street and the SR 509 southbound on- and off-ramps, and at the intersection
of SR 518.
Tukwila International Boulevard BRT Station and Roadway Improvements
The total bus-only ramp lengths, including tapers for merging, are approximately 1,900
feet (eastbound) and 2,800 feet (westbound). In both the east and westbound directions,
the addition of these bus-only lanes would require realigning the center jersey barrier,
regrading, and repaving a portion of the existing SR 518 travel lanes and ramps. In the
westbound direction, the bus-only lane would also require widening the existing
westbound SR 518 bridge that passes over the SR 518 off-ramp heading south to
Airport Expressway.
A pedestrian bridge over SR 518 would connect the two BRT stations and would
connect the BRT stations to the mezzanine level of the Link light rail station to the north.
The surface of the pedestrian bridge would be approximately 25 feet above the level of
SR 518, roughly level with the mezzanine level of the Link station and the existing
Tukwila International Boulevard bridge over SR 518. From the BRT stations, access to
the pedestrian bridge would be provided by stairs and an elevator. If funding is available,
the pedestrian bridge would also extend to the south and would connect at-grade to a
new sidewalk on the eastbound on-ramp to SR 518, which would connect to sidewalks
on Tukwila International Boulevard.
South Renton Transit Center and Roadway Improvements
Signal-timing improvements would be made to all signals along Rainier Avenue S. In
addition, TSP would be implemented at the intersections of Rainier Avenue S/S Grady
Way, Rainier Avenue S/S 7th Street, and at a new signalized transit center intersection
at Rainier Avenue S/Hardie Avenue, which would include a southbound bus-only lane
into the transit center from Rainier Avenue S for King County Metro buses.
Bellevue Transit Center and Off-site Layover
The existing on-street parking (approximately 197 feet) and the existing ST Route 550
bus stop would be removed to provide additional layover space. On the east side of the
street, the existing right-turn lane would be modified to accommodate on-street parking
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spaces. The existing painted median on 110th Avenue NE would be replaced with a
left-turn pocket.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
No change is proposed to the Totem Lake Freeway Station. TSP is proposed at the
intersection of the in-line ramp terminal and NE 128th Street. At the Kingsgate
Park-and-Ride, a new crosswalk is proposed at the south driveway entrance off of 116th
Way NE. No other transportation facility improvements are proposed.
Brickyard Station and Roadway Improvements
The BRT stations would be located at-grade within the center of the I-405 right-of-way. A
pedestrian bridge over I-405 would provide access to both BRT stations and would
connect the stations to the existing Brickyard Park-and-Ride lot. From the BRT stations
and the Brickyard Park-and-Ride lot, access to the pedestrian bridge would be provided
by stairs and an elevator. The pedestrian bridge may also extend to the east side of
I-405, with a stairway connecting to 116th Avenue NE.
Roadway improvements include bus-only lanes within I-405 that would connect the
northbound and southbound stations to the ETL. The bus-only lane lengths are
approximately 700 feet in both the northbound and southbound directions. The addition
of these bus-only lanes and the BRT station platforms would require widening the
existing I-405 roadway to the east and west.
Lynnwood City Center Transit Station BRT and Roadway Improvements
Within the vicinity of the Lynwood Transit Center, roadway improvements are being
designed and constructed as part of the Sound Transit Lynnwood Link Extension light
rail project either by the City of Lynnwood or Sound Transit.
Improvements to existing transportation facilities under the proposed I-405 BRT Project
include TSP at existing signals at 200th Street SW/46th Avenue W as well as
improvements at the Poplar Way/I-5 on-ramp.
As part of the Lynnwood Link Extension project, to improve access to and from the
transit center for all bus routes, a traffic signal is proposed along 46th Avenue W. The
signal would be located at the entrance to the transit center. A second intersection, just
north of the transit center entrance, would be modified with stop control (stop signs) for
the east/west street connections. Additionally, the channelization is proposed to be
modified from three southbound lanes/one northbound lane to two southbound lanes/two
northbound lanes.
Along Poplar Way (south of 196th Street SW) and the I-5 northbound on-ramp, the
roadway and ramp would be widened for bus-on-shoulder for BRT vehicles to use to
bypass congestion. Additional modifications in the area inside the Poplar Way loop ramp
include relocating and modifying the existing ramp meter mast, and modifications to the
existing retaining wall for the proposed roadway widening, as well as modification to the
northbound I-5 ramp to end the bus lane and begin/end the merge lane onto I-5.
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e. Will the project or proposal use (or occur in the immediate vicinity of) water, rail, or air
transportation? If so, generally describe.
None of the project components would use or occur within 0.25 mile of water, commuter
rail, or air transportation.
The proposed BRT station at Tukwila International Boulevard would connect to the
Tukwila International Boulevard Link light rail station. While Sea-Tac Airport is located
approximately 1 mile from the proposed station, it is not in the immediate vicinity and the
proposal would not use air transportation.
The proposed South Renton Transit Center would be located approximately 1.2 miles
from the Renton Municipal Airport; it is not in the immediate vicinity and the proposal
would not use air transportation.
The proposed BRT station at the Bellevue Transit Center will be near the Link light rail
Bellevue Downtown station when it opens in 2023. The Lynnwood Transit Center BRT
station also occurs in the immediate vicinity of the future Link light rail station.
f. How many vehicular trips per day would be generated by the completed project or
proposal? If known, indicate when peak volumes would occur and what percentage of
the volume would be trucks (such as commercial and nonpassenger vehicles). What
data or transportation models were used to make these estimates?
Trip generation resulting from the I-405 BRT Project was based on Sound Transit’s I-405
BRT service plan of 10-minute headways during peak periods (6 buses per hour). Trip
generation during the hours of operation between 4:00 a.m. and 12:00 a.m. assumed
that the system would operate 6 buses per hour at most, which would generate up to
192 bus trips daily on the corridor. The project should also decrease VMT by passenger
vehicles by attracting new riders to transit. The decrease in VMT is a small percentage
of the regional total and was not quantified.
Site-specific traffic operations for each station and trip generation at the South Renton
Transit Center and Kingsgate Park-and-Ride are described below. More details on how
estimated trips were calculated are provided in Attachment H, I-405 Corridor
Transportation Technical Report and the I-405 Corridor Transportation Methods and
Assumptions Report. Additionally, construction impacts are briefly described below.
Overall, these impacts would be minimal at each location. Required street closures
and/or detours would be developed in coordination with each city prior to construction.
If for a particular project component, the No Build condition already results in a
level-of-service (LOS) that exceeds the governing standard, then the project would
address the impact based on the following:
• Based on agreed methodology, if the authority with jurisdiction does not have an
adopted policy on how to address this situation, Sound Transit would provide
proportionate mitigation if the project resulted in an additional 15 seconds or more of
delay to a given intersection or corridor that is projected to exceed the established
standard under the No Build conditions. The mitigation contribution will be based on
the proportionate amount of delay that will be added by the project.
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• For the City of Kirkland, mitigation is required if the LOS is E and the project would
add a 15 percent proportional impact to the intersection, or LOS is at F and the
project would add a 5 percent proportional share impact. The WSDOT freeway
threshold for I-405 is LOS D.
Burien Transit Center and Roadway Improvements
Six BRT trips per hour in each direction would access the Burien Transit Center.
A study was conducted to assess the potential impacts of traffic redistributing to these
alternative paths. The volume shifts show very modest changes in traffic flow or delays
at study area intersections. As such, no changes in the roadway infrastructure or signal
systems would be needed to address the effects of volume shifts due to bus-only lanes
along SW 148th Street.
Existing entrances and exits to surrounding retail businesses would be maintained.
While some driveways would be converted to right-in/right-out only, there are minor
detour routes that would maintain access to surrounding uses.
Bus trips and roadway improvements would not adversely affect long-term traffic
operations and LOS along the BRT pathway in Burien.
During the anticipated 12 months of construction, beginning in 2022, lane closures would
be necessary for the roadway modifications on SW 148th Street and SR 509. Short-term
full street closures on SW 148th Street may also be required. In some cases, short-term
full closures might be substituted for extended partial closures to reduce overall impacts.
To minimize disruption to the traveling public, street closures for construction may be
limited to nighttime, weekend, and off-peak travel hours. Detours for vehicular, transit, or
nonmotorized traffic could also be required. Street closures would be coordinated with
the City of Burien.
Tukwila International Boulevard BRT Station and Roadway Improvements
Six BRT trips per hour in each direction would operate on SR 518 to access the BRT
stations within the SR 99 interchange area.
Construction of this project component is anticipated to begin in 2022. The duration of
construction is anticipated to be approximately 24 months. On SR 518, temporary lane
closures in both the eastbound and westbound directions would be necessary during
construction. For SR 518, the contractor would be expected to develop a construction
traffic control plan and a maintenance of traffic plan that would require approval by
WSDOT. Full closures could also be required depending on the construction methods
and sequencing. In some cases, short-term full closures might be substituted for
extended partial closures to reduce the overall duration. To minimize the disruption to
the traveling public, SR 518 construction closures would be expected to be limited to
nighttime, weekend, and off-peak travel hours. Detours for vehicular and freight traffic
and transit service could also be required. Any necessary transit detours would be
coordinated with the transit agencies.
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South Renton Transit Center and Roadway Improvements
At the transit center, 6 BRT coaches per direction (12 BRT coaches in total) would be
entering and exiting the site per hour in the AM and PM peak. Additionally, King County
Metro service would account for an additional 34 trips per hour in the AM peak and 26 trips
per hour in the PM peak with ST Express Route 566 adding another 4 trips in each direction
per hour in the AM and PM peaks. Total peak trips, per hour, in and out of the transit center,
including BRT service, would equate to 44 in the AM peak and 36 in the PM peak.
The proposed 700-stall park-and-ride garage would be located adjacent to the existing
South Renton Park-and-Ride, owned by WSDOT. The existing park-and-ride has
approximately 385 parking spaces. The existing park-and-ride is full on a typical
weekday. By 2042, it is assumed that the 700-stall park-and-ride garage would reach full
capacity. Each park-and-ride stall would generate one vehicle trip. The park-and-ride is
assumed to fill within a three-hour AM peak period and empty within a three-hour PM
peak period, consistent with other large park-and-rides in the Sound Transit service
area. With the BRT frequency and span of service, there would be some arrivals to the
park-and-ride during the PM peak period.
The AM and PM peak hour general-purpose vehicle volumes generated from the new
park-and-ride garage were estimated from observed peak-hour/peak-period data
gathered at the Northgate and Kenmore Park-and-Rides, and from the existing South
Renton Park-and-Ride. Based on the assumption that the expanded park-and-ride would
be full, vehicle trips into and out of the facility throughout a day were estimated by using
the existing traffic increased at the same proportion as the increase in parking spaces.
The AM peak hour is expected to be 7:30 a.m. to 8:30 a.m. and the PM peak hour is
4:30 p.m. to 5:30 p.m. In the AM peak hour, this resulted in 268 entering vehicles, or 38
percent of the 700 entering vehicles. There were an estimated 40 vehicles exiting during
the AM peak hour. The PM peak-hour trip generation resulted in 273 exiting vehicles, or
39 percent of the 700 exiting vehicles. There were an estimated 56 entering vehicles
during the PM peak hour. Additionally, based on observations at other park-and-ride
facilities, the pick-up/drop-off area was estimated to have 30 vehicles entering and
existing in the AM peak and 32 vehicles entering and leaving the site in the PM peak.
A detailed traffic analysis of this area is included in Attachment H. The LOS standard for the
intersections in the project study area is LOS E mitigated, indicating that congestion should
be mitigated when peak-hour LOS falls below LOS E. Twelve study intersections were
analyzed to assess potential impacts for the year 2024 and 2042 AM and PM peak hours.
Of those 12, only 1 was expected to exceed the LOS standard in 2024—Rainier Avenue S
and SW Grady Way is expected to operate at LOS F in the PM peak hour in both the No
Build and Build conditions, with an increase in delay of 3 seconds in the Build condition. In
2042, 5 of the 12 intersections are expected to operate at LOS F in either the AM or PM
peak hours in the No Build and Build conditions. The Build condition does not cause any
intersection to drop from an LOS that meets the standard to one that does not meet the
standard. However, the project does affect the expected average vehicle delay by 15
seconds or more at 3 of these 5 intersections predicted to operate below the standard:
• Rainier Avenue S and Grady Way (delay increase of 16 seconds in AM peak hour)
• Grady Way and Talbot Road (delay increase of 15 seconds in AM peak hour)
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Talbot Road and I-405 southbound off-ramp (delay increase of 52 seconds in AM
peak hour)
In 2021, 24 months of construction is anticipated to begin with no planned full street
closures. To minimize the disruption to the traveling public, lane closures for construction
staging activity may be limited to nighttime, weekend, and off-peak travel hours. Detours
for vehicular, transit, or nonmotorized traffic could also be required. Any necessary
transit detours would be coordinated with the transit agencies.
Bellevue Transit Center and Off-site Layover
Currently 46 Sound Transit buses access the Bellevue Transit Center per direction per
hour. In 2024 and 2042, 12 BRT vehicles are anticipated to access the facility per
direction per hour, replacing the current volumes from ST 535 and ST 550. This
one-for-one replacement of traffic volumes would result in no traffic impacts. To re-stripe
the BRT layover area on 110th Avenue NE, temporary lane closures would likely be
necessary. Full street closures are not anticipated. To minimize the disruption to the
traveling public, lane closures for construction may be limited to nighttime, weekend, and
off-peak travel hours. Detours for vehicular, transit, or nonmotorized traffic could also be
required. Lane closures are not anticipated to construct improvements at the Bellevue
Transit Center. Disturbance of bus bays within the transit center would be coordinated
with King County Metro to ensure adequate customer signage and information.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
The proposed 566-stall Kingsgate Park-and-Ride Garage would be located at the
existing park-and-ride surface lot which replaces approximately 166 of the existing 502
parking stalls and adds an additional 400 new spaces, for a total of 902 park-and-ride
spaces on the site. Based on the assumption that the expanded park-and-ride would be
full, vehicle trips into and out of the facility over the course of a day were estimated by
using the existing traffic increased at the same proportion as the increase in parking
spaces. The AM and PM peak-hour general-purpose vehicle volumes generated from
the new park-and-ride garage were estimated from peak-hour/peak-period data. The AM
peak hour is 6:45 a.m. to 7:45 a.m. and the PM peak hour is 5:15 p.m. to 6:15 p.m. In
the AM peak hour, this resulted in an additional 220 entering vehicles, and an estimated
additional 50 vehicles exiting during the AM peak hour. The PM peak-hour trip
generation resulted in 160 additional exiting vehicles. There were an estimated
additional 50 entering vehicles during the PM peak hour.
A traffic analysis was conducted to assess potential effects at three intersections near
this project component—NE 128th Street/Totem Lake Boulevard, NE 128th Street/116th
Street NE, and NE 128th Street/I-405 direct access ramps. The results show there would
be minimal changes to intersection delay, with the only LOS change at the NE 128th
Street/116th Avenue NE intersection in the 2024 AM peak period. In 2024, the NE 128th
Street/116th Avenue NE intersection would change from LOS D in the No Build condition
to LOS E in the Build condition. However, this LOS change represents only 5 seconds of
added delay (an 8 percent increase in delay). Compared to the No Build condition, the
maximum increase in delay for the Build condition at the NE 128th Street/116th Avenue
NE intersection would be 6 seconds in the 2042 PM peak period (a 10 percent increase)
and 6 seconds in the 2024 and 2042 AM peak period (a 9 percent increase). Even with
this additional delay, the impact would result in less than a 15 percent increase, and both
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the No Build and Build conditions would be LOS E. These levels-of-service impacts do
not exceed the LOS standard for the City of Kirkland.
Construction of the Kingsgate Park-and-Ride Garage would be expected to occur on the
existing park-and-ride site. Street and lane closures on 116th Avenue NE are not
anticipated. King County Metro and Community Transit bus operations at the Kingsgate
Park-and-Ride are not anticipated to be relocated. During construction, the number of
park-and ride stalls temporarily displaced during construction would be mitigated to
provide a comparable level of access. Construction of improvements at the Totem
Lake/Kingsgate Station would be minimal. Traffic disruptions would be coordinated with
and approved by WSDOT.
Brickyard Station and Roadway Improvements
The six additional BRT trips per hour in each direction would operate on I-405 to access
the BRT station within the I-405 mainline. Because the station would be accessed by
new bus-only lanes and general-purpose lanes would remain, no traffic impacts would
occur on the I-405 mainline. In this location, at the interchange of I-405 and NE 160th
Street, the existing bus stops on the northbound off-ramp and the southbound on-ramp
to I-405 would be removed and replaced by the BRT station. The removal of these bus
stops would be expected to improve traffic operations on the ramps as buses would no
longer be pulling in and out of traffic to serve the stops.
Construction of this project component is anticipated to begin in 2022. The duration of
construction is anticipated to be approximately 24 months. On I-405, temporary lane
closures in both the southbound and northbound directions would be necessary during
construction. The contractor would be expected to develop a construction traffic control
plan and a maintenance of traffic plan that would require approval by WSDOT. Full
closures could also be required depending on the construction methods and sequencing.
In some cases, short-term full closures might be substituted for extended partial closures
to reduce the overall duration. To minimize the disruption to the traveling public, I-405
construction closures would be expected to be limited to nighttime, weekend, and
off-peak travel hours. Detours for vehicular and freight traffic and transit service could
also be required. Any necessary transit detours would be coordinated with the transit
agencies.
Lynnwood City Center Transit Station BRT and Roadway Improvements
Traffic analysis was conducted to assess the potential effects of six BRT buses per
direction per hour on intersections along the BRT pathway. All intersections operate at
LOS D or better under the 2024 Build conditions. The 44th Avenue W and 196th Street
SW intersection and 44th Avenue W and 200th Street SW intersection both show LOS E
in No Build and Build conditions in 2042 due to forecasted future volume growth with a
maximum delay increase of 2 seconds between No Build and Build conditions.
During 12 months of construction beginning in 2022, a temporary lane closure would be
expected in order to construct the new bus-only lane along Poplar Way. Full street
closure of Poplar Way would not be expected. To minimize the disruption to the traveling
public, lane closures may be limited to nighttime, weekend, and off-peak travel hours.
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Construction of the new traffic signal at the Lynnwood City Center transit center
driveway and rechannelization of 46th Avenue W may require temporary lane closures
and temporary rerouting of buses to 48th Avenue W.
g. Will the proposal interfere with, affect or be affected by the movement of agricultural
and forest products on roads or streets in the area? If so, generally describe.
No. The proposed project is not expected to affect or be affected by the movement of
agricultural and forest products on roads or streets in the area. WSDOT’s Freight
System Plan defines those corridors that are critical to the movement of goods in the
state. The 2017 Washington State Freight System Plan identifies Critical Urban Freight
Corridors that are designated by WSDOT or the region’s Metropolitan Planning
Organization, Puget Sound Regional Council. Critical Urban Freight Corridors are those
public roads within urbanized areas (with populations greater than 50,000) that meet one
of the following criteria: connects intermodal facilities to the primary highway freight
system, interstate highway system or intermodal facility; located within a corridor of a
route on the primary highway freight system and providing an alternate highway option
important to the movement of goods; or important to freight movement as determine by
the Metropolitan Planning Organization or state. The I-405 corridor is a primary highway
freight network corridor and interstate; however, there are no Critical Urban Freight
Corridors identified in the vicinity of the following project components:
• Burien Transit Center and Roadway Improvements
• South Renton Transit Center and Roadway Improvements
• Bellevue Transit Center and Off-site Layover
• Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
• Brickyard Station and roadway improvements
• Lynnwood City Center transit station BRT and roadway improvements
S 154th Street in the City of Tukwila is designated by the Puget Sound Regional Council
as a Critical Urban Freight Corridor between the SR 518 off-ramp and 24th Avenue S.
This corridor segment is approximately 0.12 mile northeast of the proposed Tukwila
International Boulevard BRT Station. The proposed project component would not impact
the designated corridor and therefore is not expected to affect or be affected by the
movement of agricultural and forest products in the area.
h. Proposed measures to reduce or control transportation impacts, if any:
The project has been designed to minimize changes to general-purpose traffic and to
optimize transit speed and reliability. Further, no adverse impacts to traffic safety,
nonmotorized facilities, parking, or site access for other facilities are anticipated as a
result of the I-405 BRT Project.
The following provides a brief summary of design measures to avoid impacts for each
project component.
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Burien Transit Center and Roadway Improvements
No mitigation measures would be needed for this project component. A beneficial impact
for transit could occur with the inclusion of TSP. TSP at all signals along the roadway
would allow for the BRT service and other bus service to bypass traffic and left turns
from oncoming traffic.
Tukwila International Boulevard BRT Station and Roadway Improvements
No mitigation measures would be needed for this project component.
South Renton Transit Center and Roadway Improvements
The project would not have adverse impacts in the 2024 year of opening but would
contribute to the expected delay at three intersections in the 2042 forecast year:
• Rainier Avenue S and Grady Way (delay increase of 16 seconds in AM peak hour)
• Grady Way and Talbot Road (delay increase of 15 seconds in AM peak hour)
• Talbot Road and I-405 southbound off-ramp (delay increase of 52 seconds in AM
peak hour)
Analysis indicates that optimizing signal phasing and timing at these intersections would
mitigate the expected impacts. Sound Transit will coordinate with the City of Renton and
WSDOT to identify an appropriate and proportionate contribution to improvements at
these locations should the city and state determine that they would implement
improvements other than optimized signal phasing.
Four intersections would require mitigation in the South Renton study area; however,
minor changes to the signal-timing plans would be able to achieve compliance with LOS
standards.
• For the 2042 AM peak period at Rainier Avenue S and S Grady Way, changing the
intersection signal offset from 86 seconds to 76 seconds could decrease Build delays
to 115 seconds, which again is within the 15-second impact window between Build
and No Build scenarios.
• For the 2042 PM peak at Lake Avenue S and Grady Way, the eastbound and
westbound left phases could be removed because of their relatively low volumes.
Additional offset optimization could reduce the delay to 49 seconds, which is 13
seconds higher than the No Build delay.
• For the 2042 AM peak at Grady Way and Talbot Road, a shift of two seconds of
green time from the east-west phase to the north-south phase could reduce overall
delay to 134 seconds, which is 11 seconds higher than the No Build delay.
• For the 2042 AM peak period at the SR 515 and the Renton Village/I-405
southbound off-ramp, shortening the westbound through/left and eastbound left
phase to allow more green time for northbound through and northbound left could
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reduce the delay below 127 seconds, or about 14 seconds higher than the No Build
condition.
Bellevue Transit Center and Off-site Layover
No mitigation measures would be necessary at this project component.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
No mitigation measures would be necessary at this project component.
Brickyard Station and Roadway Improvements
No mitigation measures would be necessary at this project component.
Lynnwood City Center Transit Station BRT and Roadway Improvements
No mitigation would be necessary at this project component.
15. Public Services
a. Would the project result in an increased need for public services (for example: fire
protection, police protection, public transit, health care, schools, other)? If so,
generally describe.
The project would provide increased and improved public transit service and
connections within the I-5, I-405, and SR 518 corridors and in the Puget Sound region.
None of the project components are expected to increase the need for fire, police, health
care, or schools because the project would not result in any unplanned or induced
increases in population. In addition, Sound Transit has examined the potential for crime
to increase at transit facilities such as transit stations, park-and-ride lots and garages,
and transit centers, and has found that crime at these facilities generally reflects the
conditions in the surrounding neighborhoods. A majority of these crimes are
quality-of-life crimes (e.g., vandalism, drunkenness, panhandling) and property crimes; a
small percentage of these crimes are violent crimes. As described in Section 15.b,
Sound Transit addresses crime by contracting with local law enforcement and security
contractors to provide security services at its facilities.
The potential for fires associated with the transit stations and park-and-ride garages has
also been examined and determined to be unlikely because of the limited activities that
would occur within the stations or garages, the likely building materials (primarily steel,
concrete, and glass), and the fact that these features would be constructed in
compliance with applicable fire codes. For the park-and-ride garages, in addition to the
use of fire-resistant building materials, the fire code requirements include the installation
of a fire-suppression system and fire truck/apparatus access to all sides of the structure.
During construction of all project components, traffic rerouting, lane closures, and
construction traffic may affect emergency response times and the travel times or routes
for public service vehicles. Section 15.b describes how Sound Transit would address the
issue of proximity and potential impacts to emergency services to avoid impacts.
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For the purpose of this checklist, major public service facilities include the following:
• Emergency services such as fire, safety, and police. These emergency services are
provided by cities, counties, and special purpose districts and by Washington State
Patrol throughout the project area.
• Primary, urgent, and special care clinics.
Burien Transit Center and Roadway Improvements
The following major public service facilities are within approximately one-half mile of this
project component:
• Kaiser Permanente Burien – 140 SW 146th Street
• Burien Police Department – 14905 6th Avenue SW
Tukwila International Boulevard BRT Station and Roadway Improvements
The following major public service facilities are within approximately one-half mile of this
project component:
• Washington State Patrol District 2 Seattle S Detach – 15666 International Boulevard
• Tukwila Police Department Neighborhood Resource Center – 14661 International
Boulevard
• City of SeaTac Fire Station 47– 3215 S 152nd Street
South Renton Transit Center and Roadway Improvements
The following major public service facilities are within approximately one-half mile of this
project component:
• Renton Police Department – 1055 S Grady Way
Bellevue Transit Center and Off-site Layover
The following major public service facilities are within approximately one-half mile of this
project component:
• Virginia Mason Clinic – Bellevue – 222 112th Avenue NE
• Kaiser Permanente Bellevue – 11511 NE 10th Street
• Blood Bank Bellevue – 1021 112th Avenue NE
• Overlake Hospital Medical Center – 1035 116th Avenue NE
• Bellevue Police Department – 450 110th Avenue NE
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Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
The following major public service facilities are within approximately one-half mile of this
project component:
• Fire Station 27 – 11210 NE 132nd Street
• Virginia Mason Clinic Kirkland – 13014 120th Avenue NE
• Pacific Medical Totem Lake – 12910 Totem Lake Boulevard
• Evergreen Health Medical Center – 12040 NE 128th Street
• Kirkland Police Department – 11750 NE 118th Street
Brickyard Station and Roadway Improvements
There are no major public service facilities located within approximately one-half mile of
this project component.
Lynnwood City Center Transit Station BRT and Roadway Improvements
The following major public service facilities are within approximately one-half mile of this
project component:
• Lynnwood Police Department – 19321 44th Avenue W
• Community Health Center of SNO CO-LYNN – 4111 194th Street SW
• Group Health Cooperative – 20200 54th Avenue W
b. Proposed measures to reduce or control direct impacts on public services, if any.
Some disruption to the transportation network would occur during construction, which
could impact the ability for emergency service vehicles to move through the area. Sound
Transit would work with contractors, service providers, and the appropriate jurisdiction to
minimize disruption and ensure that appropriate access through or around construction
areas is retained. As part of construction planning and permitting, Sound Transit would
work with each municipality to minimize the duration and impact of lane closures that
may affect public services by: (a) maintaining through- traffic, where practical, except for
temporary lane closures that would typically be limited to nighttime, weekend, and
off-peak travel hours; (b) establishing detour routes on nearby arterials for temporary
lane closures; and (c) maintaining traffic management systems. These measures would
be included in a maintenance of traffic plan that would address all travel modes, which
would be prepared prior to construction and would require approval by each municipality.
Sound Transit contracts with local law enforcement and security contractors to provide
security services at its facilities. The project’s design will incorporate CPTED principles.
Sound Transit also conducts threat and vulnerability assessments for all new projects to
identify and address potential security concerns. In addition, cameras connected to a
security camera system would be installed at each BRT station and park-and-ride
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garage. Camera systems have been found to deter and detect crime, public disorder,
unlawful behavior, and inappropriate conduct.
At the South Renton Transit Center and Kingsgate Park-and-Ride Garage structures,
standpipes would be installed for firefighting purposes and fire extinguishers would be
provided according to design criteria and local authority requirements. Sound Transit
design criteria require fire alarm systems installed at parking garages and passenger
stations to include automatic fire detection, alarm, and controls to allow emergency
response personnel to formulate proper responses and alleviate pressure on emergency
services in case of an emergency.
16. Utilities
a. Underline utilities currently available at the site.
The following is based on as-built drawings provided by local jurisdictions and utility
providers.
Burien Transit Center and Roadway Improvements
electricity, natural gas, water, refuse service, telephone/communications, sanitary sewer,
septic system, other.
Tukwila International Boulevard BRT Station and Roadway Improvements
electricity, natural gas, water, refuse service, telephone/communications, sanitary sewer,
septic system, other.
South Renton Transit Center and Roadway Improvements
electricity, natural gas, water, refuse service, telephone/communications, sanitary sewer,
septic system, other.
Bellevue Transit Center and Off-site Layover
electricity, natural gas, water, refuse service, telephone/communications, sanitary sewer,
septic system, other.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
electricity, natural gas, water, refuse service, telephone/communications, sanitary sewer,
septic system, other.
Brickyard Station and Roadway Improvements
electricity, natural gas, water, refuse service, telephone/communications, sanitary sewer,
septic system, other.
Lynnwood City Center Transit Station BRT and Roadway Improvements
electricity, natural gas, water, refuse service, telephone/communications, sanitary sewer,
septic system, other.
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b. Describe the utilities that are proposed for the project, the utility providing the service,
and the general construction activities on the site or in the immediate vicinity which
might be needed.
No utility services would be needed for project construction. Temporary connection to
electrical utilities may be proposed in specific instances, for example, where nighttime
construction requires the use of lighting. However, it is anticipated that the contractor
would be equipped with their own generator for nighttime work and would not require
temporary connection to electrical utilities.
Operation of the two proposed park-and-ride garages is anticipated to require utility
services typical for the operation of a parking garage structure of this approximate size,
which would generally require the following:
• Electrical service for providing lighting to the stairways and throughout the garage
floors, and lighting and power to the elevators
• Stormwater tie-ins or upgrades to existing connections where new impervious
surface are added
• Communication tie-ins connections for real-time information systems and TVMs
• Water for site maintenance and fire protection
• Water and sanitary sewer service for restrooms for transit drivers, where provided
The BRT stations along the corridor would require the following:
• Electrical and communications services as described for the park-and-ride garages
• Water access, possibly, for site maintenance
Some roadway improvements may require the following:
• Electrical service, new or changed, for proposed or required streetlights or traffic
signals
The following describes the project’s specific operational utility needs, as well as
construction work that may occur around utilities in the vicinity of each project
component.
Burien Transit Center and Roadway Improvements
• Electricity: Puget Sound Energy (PSE) and Seattle City Light (SCL) are the service
providers in the area. Although it is known that there is electricity on-site, it is not
currently known which of the two utilities provides that service here. This will be
explored further with survey and coordination with each utility franchise. Because
there is electricity to the existing transit center, it is anticipated that service to the
new BRT station elements at the transit center could be provided via on-site
interconnection to the existing line. No electrical needs, such as from new street
lighting, are anticipated for the roadway improvements.
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• Communications: It is anticipated that this project component would tie into the
WSDOT communication line that currently serves the Burien Transit Center, located
on the south side of SW 148th Street.
The following utilities are in the project vicinity but would not be required for operation of
this project component or be impacted during construction:
• Sanitary sewer: The Southwest Suburban Sewer District has a sewer main crossing
1st Avenue S between the Burien Transit Center and 1st Avenue S, as well as sewer
mains running north-south on 1st Avenue S. There are no apparent potential impacts
to these facilities.
• Water: King County Water District (KCWD) 49 has a 2-inch irrigation line running
along the north side of SW 148th Street and along the middle of 1st Avenue S. There
are no apparent potential impacts to these facilities.
• Storm drainage: A City of Burien 6-inch storm drainage pipe crosses SW 148th
Street in the vicinity of the Burien Transit Center, connected to a main line running
east-west on the north side of SW 148th Street. There are no apparent impacts to
these facilities.
• Communications: Additional communication utilities nearby that would not serve this
project component include the following:
o CenturyLink – South side of SW 148th Street serving the Burien Transit Center
and east side of 1st Avenue S
o Comcast – West side of 1st Avenue S
o Verizon – Within 1st Avenue S running north-south
Tukwila International Boulevard BRT Station and Roadway Improvements
• Electricity: PSE and SCL are the service providers in the area, and although it is
known that there is electricity on-site, specific power facilities and their provider have
not been identified in the vicinity of the proposed improvements. This will be explored
further with the survey and coordination with each utility franchise. The project would
require electricity to illuminate the stairs, pedestrian bridge, station platforms, and
operate and illuminate the elevators. Because there is electricity to the existing light
rail station and SR 518 highway lighting, it is anticipated that new service to the new
BRT station elements, elevator, and pedestrian bridge would be able to extend
access, as needed, from the existing line. No new lighting is proposed along SR 518
that would require electricity.
• Storm drainage: In the vicinity of this project component, WSDOT has storm
drainage piping on the north and south sides of SR 518 that the BRT station would
connect to. The City of SeaTac owns a 12-inch storm drain line on the east and west
sides of Tukwila International Boulevard; the City of SeaTac line on the west side
may need to be relocated as a result of a proposed retaining wall.
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• Communications: This project component would require fiber service and would tie
into WSDOT’s existing underground fiber line along SR 518. On-site service would
be routed from the tie-in point at the existing control vault to the necessary locations
on the site, requiring some trenching. CenturyLink owns telecommunication facilities
on the west side of the Tukwila International Boulevard overpass over SR 518.
Service would be routed from this tie-in point to the necessary locations on the site.
• The following utilities are in the project vicinity but would not affect operation of this
project component or be impacted during construction:
• Water: KCWD 125 has an existing 10-inch water main on the east side of the
Tukwila International Boulevard overpass over SR 518. There are no apparent
potential impacts to this facility.
• Sanitary sewer: This area is within the Valley View Sewer District’s service area.
There are no apparent facilities in the vicinity of proposed improvements.
South Renton Transit Center and Roadway Improvements
• Electricity: It is anticipated that new service connections would be established for the
proposed transit center and park-and-ride garage; the specific connection and utility
service has not yet been identified. The following existing utilities are available:
o SCL owns overhead transmission lines running north-south on the east portion of
the project site. These lines would be maintained, and setbacks would be
coordinated with SCL.
o PSE owns both underground and overhead lines running northwest-southeast
along the north side of S Grady Way, underground lines on the west side of
Rainier Avenue S, and underground lines within the site, with one line in direct
conflict with the proposed garage.
o The City of Renton owns underground power along both the west and east sides
of Rainier Avenue S powering the illumination system.
• Water: The City of Renton owns 8-inch water lines running through where the new
park-and-ride garage is proposed. These lines would need to be relocated. It is
anticipated that new service connections to existing water lines in Rainier Avenue S
or S Grady Way would be established for the proposed transit center and
park-and-ride garage.
• Sanitary sewer: The City of Renton owns 8-inch sewer lines running through where
the new park-and-ride garage is proposed. These lines would need to be relocated.
In addition, if a restroom facility is provided, it could connect to this relocated line.
• Storm drainage: The City of Renton owns an 8-inch storm drainage line that runs
through where the new park-and-ride garage is proposed. These lines would need to
be relocated. There is also a 12-inch storm drainage line in the southwest corner of
the proposed transit center site and along the east side of Rainier Avenue S that may
conflict with the new storm drainage system. This will be further evaluated as project
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design progresses. It is anticipated that new service connections would be
established for this project component.
• Communications: This project component would tie into WSDOT’s existing fiber
communication line that currently runs underground near this project component.
Service would be connected from the nearest tie-in point to the necessary locations
on the site.
The following utilities are in the project vicinity and would not be required for operation of
this project component; however, they would be impacted during construction:
• Communications:
o CenturyLink owns a communication line on the west side of Rainier Avenue S
and within the western portion of the site that would likely conflict with the project
component’s proposed storm drainage system and would need to be relocated.
o Comcast owns a line along the east side of Rainier Avenue S that would conflict
with the proposed park-and-ride garage and would need to be relocated.
Bellevue Transit Center and Off-site Layover
• Electricity: Both PSE and City of Bellevue underground conduits are in the vicinity of
the proposed BRT station at the transit center. Relocating the curb ramps could
impact these existing conduits. At the Bellevue Transit Center, the BRT-branded
pylon may require electricity if it is lighted. The off-site layover area does not require
new electrical connections.
• Communications: This project component would connect to WSDOT’s
communication line. Service would be routed from the tie-in point to the necessary
locations on the site; construction is anticipated to require a horizontal directional
bore.
• The following utilities are in the project vicinity but would not affect operation of this
project component or be impacted during construction:
• Water/sanitary sewer/storm drainage: The Bellevue Transit Center is currently
served by utilities owned by the City of Bellevue. Service will be maintained and
protected during construction.
• Communications: Comcast and CenturyLink own communication lines that run along
the north, east, and west edges of the Bellevue Transit Center, but do not appear to
conflict with the proposed improvements. This will be explored further with survey.
Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
• Electricity: This project component would be served by electricity from PSE. PSE
owns underground power running north-south along 116th Avenue NE. New service
connections would be established for the proposed park-and-ride garage and
possibly the BRT-branded pylon at the station if it is lighted.
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• Water: The Northshore Utility District provides water service in this area. A 12-inch
water main runs along the west side of 116th Avenue NE that shifts to within the
roadway toward the south section of the site. In addition, a 10-inch water main under
the proposed park-and-ride garage would need to be relocated. Water for the new
fire-suppression system would be routed on-site to serve the proposed park-and-ride
garage.
• Sanitary sewer: An 8-inch sanitary sewer line owned by the Northshore Utility District
runs along the west side of 116th Avenue NE with an existing connection routed to
the existing Kingsgate site. If a restroom facility is provided, it would connect to this
line.
• Storm drainage: The City of Kirkland owns an 8- and 12-inch storm collection system
within the existing Kingsgate site, routed to NE 132nd Street, that would be modified
by the project component. There is also a 12-inch stormwater line under the
proposed park-and-ride garage and a stormwater facility that would need to be
relocated. New connections to the storm sewer system would be established for the
proposed park-and-ride garage.
• Communications: This project component would require fiber service and would tie
into WSDOT’s existing fiber line along I-405. The required on-site service would be
routed from the tie-in point to the necessary locations on the site.
The following utilities are in the project vicinity but would not be required for operation of
this project component or be impacted during construction:
• Communications: Additional communication utilities nearby that will not serve this
project component include the following:
o Comcast: A conduit runs along the south side of the site that does not appear to
be impacted.
o Level 3: A conduit runs north-south on the east side of 116th Avenue NE.
o Zayo: A conduit runs north-south on the west side of 116th Avenue NE that
appears to conflict with the new storm drainage system.
Brickyard Station and Roadway Improvements
• Electricity: It is anticipated that new electrical service connections would be
established for the proposed BRT station, pedestrian bridge, stairs, and elevator.
Electrical service would tie into existing connections at the Brickyard Park-and-Ride
lot. PSE owns overhead power lines that run north-south along I-405, north-south
along Juanita Woodinville Way NE, east-west near NE 155th Street, and buried
power east-west along NE Woodinville Drive.
• Water: It is anticipated that new water service would connect to the existing water
line at the Brickyard Park-and-Ride lot.
• Storm drainage: WSDOT has storm drainage piping on the east and west sides of
I-405 that the BRT station would connect to. There is a storm connection located
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near the Sonoma Villero Condominiums with a culvert conveyance system that runs
north-south along I-405. Stormwater facilities would ultimately tie into existing
conveyance systems, and there are no anticipated impacts to these facilities.
• Communications: This project component would tie into WSDOT’s existing fiber
communications line in I-405. On-site service would be routed from the nearest tie-in
point to the necessary locations on the site.
The following utilities are in the project vicinity but would not affect operation of this
project component or be impacted during construction:
• Sanitary sewer: The Northshore Utility District owns the sanitary sewer main that
runs north-south near Juanita Woodinville Way NE, north-south along 116th Avenue
NE, and north-south along I-405. The City of Bothell owns the sanitary sewer main
that runs east-west along NE Woodinville Drive and east-west along SR 522.
• Water: Seattle Public Utilities and the Northshore Utility District both own water lines
that run east-west near NE 155th Street and water lines that run east-west near
Juanita Creek. The Northshore Utility District also owns water lines that run
north-south on Juanita Woodinville Way NE. The City of Bothell and WSDOT own
water lines that run east-west along NE Woodinville Drive.
• Communications: Additional communication utilities nearby that would not serve this
project component include the following:
o Northshore School District: Owns buried fiber that run east-west along NE
Woodinville Drive. Frontier and Comcast both own buried communication lines
that run east-west along NE Woodinville Drive.
o Frontier: Owns buried communication lines that run east-west near NE 155th
Street and north-south along 160th Avenue NE.
o Unknown: Buried communication line that runs east-west near NE 155th Street.
Lynnwood City Center Transit Station BRT and Roadway Improvements
• Electricity: This project component is currently served by electricity from the
Snohomish Public Utility District. Underground power is primarily along 46th Avenue
W. At the transit center, the BRT-branded pylon may require electricity if it is lighted.
The roadway improvements at Poplar Way do not require new lighting or electrical
needs.
• Storm drainage: At Poplar Way the project improvements would connect to
WSDOT’s storm drainage piping in I-5. The Lynnwood City Center transit center is
currently served by the culvert conveyance system operated by the City of
Lynnwood. These storm pipes run east-west under the proposed improvements and
may be impacted by the excavation.
• Communications: This project component would tie into Sound Transit's existing fiber
communications line at 44th Avenue W and 200th Street SW. On-site service would
be routed from the tie-in point to the necessary locations on the site.
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•The following utilities are in the project vicinity but would not affect operation of this
project component or be impacted during construction:
•Water: No apparent Alderwood Water & Wastewater District facilities are in the
vicinity of this project component. This project component is currently served by
water from the City of Lynnwood and ties into the existing district main water
distribution line along the west, south, and east sides of the site.
•Sanitary sewer: This project component is currently served by the existing sanitary
sewer main that runs north-south along the west side of 48th Avenue W. This line is
operated by the City of Lynnwood. Additionally, an unknown-sized pipe runs along
the east side of the Lynnwood City Center transit center.
•Communications: Additional communication utilities nearby that would not serve this
project component include the following:
o Comcast, Level 3-Verizon, and WAVE have communication lines underground
along the perimeter of the transit center.
o Level-3 Verizon, Comcast, WAVE, and Zayo have conduit near the Poplar Way
improvements.
C SIGNATURE
The above answers are true and complete to the best of my knowledge. I understand
that the lead agency is relying on them to make its decision.
Signature: _____________________________________________________________
Name of Signee: ____________________________________________________
Position and Agency/Organization: __________________________________________
Date Submitted: ________________________________________________________
Kathy Fendt
9/25/20
Corridor Environmental Mgr, Sound Transit
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527 Express Toll Lanes Improvement Project.
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Barriers. Internet website: https://wsdot.wa.gov/projects/fishpassage/project-delivery-plan.
Accessed May 8, 2020.
Yount, J.C., J.P. Minard, G.R. Dembroff. 1993, Geologic Map of Surficial Deposits in the Seattle
30' x 60' Quadrangle, Washington: U.S. Geological Survey Open-File Report 93-233, 2 sheets,
scale 1:100,000.
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GLOSSARY OF TERMS
Archaeological resource: Pre-contact archaeological resources are places on the landscape
that contain the physical remnants of activities carried out by Native Americans during the
pre-contact period (as late as AD 1769). Historical archaeological resources are post–European
contact resources that may include remnants of early settlements. See also Cultural resource.
Best management practice (BMP): Methods designed to minimize adverse effects on the
environment, such as practices for erosion and sedimentation controls, watering for dust control,
silt fences, rice straw bales, and sediment basins.
Borings: A technique used to explore the underground surface, typically used to determine if it
is capable of holding up a building by making or enlarging a hole to survey fragments.
Contaminants: Hazardous materials (e.g., solid, liquid, or gaseous vapor) that physically
remains on a person, animal, or object.
Cultural resource: A resource related to the tangible and intangible aspects of cultural
systems, living and dead, that is valued by a given culture or contains information about the
culture. Cultural resources include historical and archaeological resources such as sites,
structures, buildings, districts, and objects associated with or representative of people, cultures,
and human activities and events.
dBA: A-weighted decibels which account for human perception of sound and unwanted noise.
Dewatering: The process of draining or removing water (typically ground water) from sediment.
Ecosystem: An interconnected network of living organisms, including people, and their local
physical environment; often considered as an ecological unit.
Effect: A change in the condition or function of an environmental resource or environmental
value as a result of human activity.
Emergency services: Emergency response by fire, law enforcement, and emergency services
to fire, seismic events, or other emergency situations.
Endangered species: Any species listed under the federal Endangered Species Act as being
in danger of or threatened with extinction throughout all or most of its range.
Greenhouse gas (GHG): A class of air pollutants believed to contribute to the global warming
effect, including CO2, hydrocarbons, and NOx.
Groundwater: Water contained and transmitted through open spaces within rock and sediment
below the ground surface.
Habitat: An environment where plants or animals occur; an ecological setting used by animals
for a particular purpose, (e.g., roosting habitat, breeding habitat).
Hazardous material: Any material that, because of quantity, concentration, or physical or
chemical characteristics, poses a significant present or potential hazard to human health and
safety, or to the environment if released.
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Impact: A change in the condition or function of an environmental resource or environmental
value as a result of human activity.
Impervious surface: Surface covered by impenetrable materials, such as pavement and
buildings, that increases the potential for water runoff and reduces the potential for groundwater
recharge.
Level-of-service (LOS): A rating that uses qualitative measures to characterize operational
conditions within a traffic stream and the perception by motorists and passengers.
Mitigation: Action or measure to minimize, reduce, eliminate, or rectify the adverse impacts of a
project, practice, action, or activity.
National Pollutant Discharge Elimination System (NPDES): Under Section 402 of the Clean
Water Act, the NPDES Program regulates all point source discharges, including
construction-related runoff discharges to surface waters and some post-development
discharges.
National Register of Historic Places (NRHP): An official list of historic properties eligible for
federal protection under Section 106 of the National Historic Preservation Act.
Noise-sensitive receivers: Premises used for purposes sensitive to noise and require
protection, such as domestic premises, hotels, educational institutions, and hospitals.
Runoff: The flow of water over land from rain, snowmelt, or other sources.
Sediment: Fragments of ground material originating from the physical or chemical weathering
of rocks and minerals, decomposition of organic matter, and atmospheric fallout. Clay, mud, and
sand are all types of sediment.
Visual quality: An assessment of what viewers like and dislike about visual resources that
compose the visual character.
Visual resources: The natural and artificial features of a landscape that characterize its form,
line, texture, and color.
Wetlands: An area of land with soil that is saturated with moisture, either permanently or
seasonally. According to the U.S. Army Corps of Engineers Wetlands Delineation Manual, three
criteria must be satisfied to classify an area as a jurisdictional wetland: hydrophytic vegetation,
hydric soils, and wetland hydrology. Types of wetlands include the following:
Palustrine emergent (PEM) – Palustrine emergent systems include all nontidal wetlands
dominated by persistent emergent species and all such wetlands that occur in tidal areas
where salinity due to ocean-derived salts is below 0.5 parts per thousand.
Palustrine scrub-shrub (PSS) – Palustrine scrub-shrub systems include all nontidal
wetlands dominated by shrub species and all such wetlands that occur in tidal areas where
salinity due to ocean-derived salts is below 0.5 parts per thousand.
Palustrine forested (PFO) – Palustrine forested systems include all nontidal wetlands
dominated by trees and all such wetlands that occur in tidal areas where salinity due to
ocean-derived salts is below 0.5 parts per thousand.
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Figures
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Figure A-1 I-405 BRT Project map
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Figure A-2 Burien Transit Center and Roadway Improvements
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Figure A-3 Tukwila International Boulevard BRT Station and Roadway Improvements
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Figure A-4 South Renton Transit Center and Roadway Improvements
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Figure A-5 Bellevue Transit Center and Off-site Layover
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Figure A-6 Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
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Figure A-7 Brickyard Station and Roadway Improvements
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Figure A-8 Lynnwood City Center Transit Station BRT and Roadway
Improvements
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Figure A-9 Lynnwood City Center Transit Station BRT and Roadway
Improvements: Poplar Way Roadway Improvements
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Figure A-10 Wetlands and streams within the west end of the Tukwila
International Boulevard BRT Station and Roadway Improvements study area
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Figure A-11 Wetlands and streams within the east end of the Tukwila
International Boulevard BRT Station and Roadway Improvements study area
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*Figure produced by WSDOT
Figure A-12 Locations of wetlands delineated by WSDOT in the Brickyard Station
and Roadway Improvements study area
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Figure A-13 Burien Transit Center and Roadway Improvements zoning map
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Figure A-14 Tukwila International Boulevard BRT Station and Roadway
Improvements zoning map
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Figure A-15 South Renton Transit Center and Roadway Improvements zoning
map
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Figure A-16 Bellevue Transit Center and Off-site Layover zoning map
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Figure A-17 Totem Lake/Kingsgate Station and Kingsgate Park-and-Ride Garage
zoning map
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Figure A-18 Brickyard Station and Roadway Improvements zoning map
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Figure A-19 Lynnwood City Center Transit Station BRT and Roadway
Improvements zoning map
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Figure A-20 Recreational facilities in the vicinity of Burien Transit Center and Roadway Improvements
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Figure A-21 Recreational facilities in the vicinity of Tukwila International Boulevard BRT Station and Roadway
Improvements
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Figure A-22 Recreational facilities in the vicinity of Bellevue Transit Center and
Off-site Layover
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Figure A-23 Recreational facilities in the vicinity of Totem Lake/Kingsgate Station
and Kingsgate Park-and-Ride Garage
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Figure A-24 Recreational facilities in the vicinity of Brickyard Station and Roadway Improvements
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Figure A-25 Recreational facilities in the vicinity of Lynnwood City Center Transit Station BRT and Roadway
Improvements
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Figure A-26 Bus routing at South Renton Transit Center and Roadway Improvements
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I-405 BRT Project Conceptual Engineering Plans –
Excerpted Design Sheets
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September 2020
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I-405 BRT Corridor Ecosystem Resources and
Wetland Delineation Technical Memorandum
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I-405 BRT Corridor Hazardous Materials
Technical Memorandum
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September 2020
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I-405 BRT Corridor Noise and Vibration
Technical Memorandum
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September 2020
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I-405 BRT Corridor Visual and Aesthetic
Resources Technical Memorandum
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September 2020
AE 0054-17 | SEPA Environmental Checklist
I-405 BRT Corridor Historic and Archaeological
Resources Technical Memorandum
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September 2020
AE 0054-17 | SEPA Environmental Checklist
I-405 BRT Corridor Transportation
Technical Report
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soundtransit.org/i405brt
brt@soundtransit.org
206-398-5470
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