COMMISSION 
AGENDA MEMORANDUM                        Item No.          7a 
BRIEFING ITEM                             Date of Meeting     September 25, 2018 
DATE:     August 27, 2018 
TO:        Stephen P. Metruck, Executive Director 
FROM:    Geri Poor, Regional Transportation Manager 
Lindsay Wolpa, Regional Government Affairs Manager 
SUBJECT:  Update on Sound Transit 3 (ST3) West Seattle and Ballard Link Extensions 
EXECUTIVE SUMMARY 
Sound Transit staff will provide an update on the ST3 West Seattle and Ballard Link Extensions 
planning and the preferred alternatives stakeholder process. Commissioners and their Port of
Tacoma colleagues received an initial briefing on the project at their April 3 Northwest Seaport
Alliance  (NWSA)  Managing  Members  meeting.  During  this  briefing,  commissioners  and
executives will have the opportunity to ask questions about related development processes 
from staff coordinating Port of Seattle and NWSA engagement on the project, in advance of
decision making on October 5, 2018. 
OVERVIEW 
In early 2018, Sound Transit launched its extensive stakeholder process related to the ST3 West
Seattle and Ballard Extensions project. Using "representative" alignments presented in the 2016
voter-approved ballot measure, Sound Transit is seeking consensus around "preferred"
alignments for the project before launching the project's environmental review in early 2019.
The nexus between Port of Seattle and Northwest Seaport Alliance operations and the project's
corridors is significant. Through construction and subsequent operations, this project has the
potential of impacting many port facilities: 
Fishermen's Terminal 
Salmon Bay Marina (adjacent to Fishermen's Terminal) 
Interbay/Magnolia cruise terminal, and industrial and seafood product operations
(Terminals 90 and 91) 
Terminal 18 (Harbor Island) 
Terminal 5 (adjacent to West Seattle) 
Terminal 25 (south of T-46 and north of Spokane St.) 
Terminals 102, 104, and 106 
An analysis of potential port impacts can be reviewed in greater detail through the attached
early scoping comments submitted on March 5, 2018. Sound Transit provided an overview of
the West Seattle and Ballard Extensions at the Managing Members' April 3 meetingand has

Template revised April 12, 2018.

COMMISSION AGENDA  Briefing Item No. ____                                Page 2 of 3 
Meeting Date: September 25, 2018 
been working closely with Port and NWSA  staff throughout the preferred alternative
stakeholder process to identify and minimize port effects in the alternatives. 
On September 5, Sound Transit presented the results of their Level 2 screening analysis to the
appointed Stakeholder Advisory Group (SAG) in a public meeting and to several other groups
throughout the month. On September 26, the SAG will provide recommendations on
alternatives to move forward. O n October 5, the Elected Leadership Group will consider the
SAG and other inputs and provide its recommendations to pursue into Level 3 analysis.  After
this additional screening through winter 2019, the Sound Transit board will vote on a preferred
alternative for the West Seattle and Ballard Link Extensions in April 2019. 
BACKGROUND 
Sound Transit's mission is to plan, build and operate mass transit service throughout central
Puget Sound. The initial phase of the regional mass transit system, called Sound Move, was
approved by voters in 1996. The second phase, Sound Transit 2 (ST2), was approved in 2008.
Under ST2, the regional light rail system will more than double in length from just over 20 miles
today to over 50 miles by 2023. Service is also increasing on the 83-mile Sounder commuter rail
line between Everett and Lakewood, and Sound Transit express buses continue to serve major
highways in the region. 
On November 8, 2016, voters of the Central Puget Sound region approved the Sound Transit 3
(ST3) ballot measure. The plan builds 62 new miles of light rail to form a 116-mile system. ST3
extends the Sounder south rail line by two stations at Tillicum and DuPont while extending
station platforms and making other capacity improvements to the south. Bus rapid transit is
built to serve communities north, east, and south of Lake Washington and station area parking
and access improvements are made region wide. These West Seattle and Ballard Extensions
were also approved in the 2016 ballot measure. 
The ballot measure included a "representative project alignment," essentially acting as a
baseline for further development of the link extensions. The "representative" project for the
West Seattle Link Extension builds light rail from West Seattle's Alaska Junction neighborhood
to downtown Seattle primarily on an elevated guideway with a new rail-only fixed span crossing
of the Duwamish River. The West Seattle Link Extension will connect to existing Link service,
continuing north to Lynnwood and Everett. The "representative" projects for the Ballard Link
Extension and downtown Seattle Light Rail Tunnel build light rail from Ballard's Market Street
area through downtown Seattle with both tunneled and elevated sections and a rail-only
movable bridge over Salmon Bay. These connect to Link service, continuing south to Tacoma. 
Sound Transit launched a broad stakeholder process in early 2018 with the goal of building
consensus around a "preferred project alignment" for the West Seattle and Ballard Extensions
in advance of starting the Environmental Impact Statement (EIS) in 2019. That process includes
the formation of an Elected Leadership Group (ELG), interagency staff group and a Stakeholder
Advisory Group (SAG). 

Template revised September 22, 2016.

COMMISSION AGENDA  Briefing Item No. ____                                Page 3 of 3 
Meeting Date: September 25, 2018 

Commissioner Stephanie Bowman is representing NWSA and Port of Seattle interests on the
ELG. She sits on the group along with six Seattle councilmembers, King County Executive Dow
Constantine, Snohomish County Executive Dave Somers, Seattle Mayor Jenny Durkan, and King
County Council Chair Joe McDermott. Port staff is represented on the interagency group and is
also closely monitoring the SAG and other Sound Transit outreach efforts. 
ATTACHMENTS TO THIS BRIEFING 
(1)   Presentation slides 
(2)   Sound Transit Alternative Evaluation Criteria 
(3)   Port of Seattle and Northwest Seaport Alliance ST3 WSBLink Early Scoping Comments 
PREVIOUS COMMISSION ACTIONS OR BRIEFINGS 
April 3, 2018  The Managing Members were briefed on the ST3 West Seattle and Ballard
Link Extensions and related stakeholder process. 












Template revised September 22, 2016.