8c. Memo

South 188th St Tunnel Improvements

AGENDA MEMORANDUM                        Item No.          8c 
ACTION ITEM                            Date of Meeting      January 24, 2023 
DATE:     January 13, 2023 
TO:        Stephen P. Metruck, Executive Director 
FROM:    Keri Stephens, Director, AV Facilities & Capital Programs 
Eileen Francisco, Director Aviation Project Management 
SUBJECT:  S. 188th St. Tunnel Improvements (C801157) 
Amount of this request:       $0 
Total estimated project cost:   $24,500,000 to $33,000,000 
Request commission authorization for the Executive Director to amend a professional services
agreement to increase the contract value by $1,200,000 in support of the S. 188th St. Tunnel
Improvement project at Seattle-Tacoma International Airport. 
The S. 188th St. tunnel structure is located beneath Runway 34R and was originally constructed
circa 1960.  Based upon an existing easement, SEA owns the tunnel structure, and the City of
SeaTac owns the S. 188th St. roadway. This project has assessed the current conditions of various
systems original to the tunnel. Based on the findings of that assessment, many of the existing
systems are no longer functioning as intended. This project will address the lighting, life safety
and other systems to ensure the tunnel is brought to a satisfactory level of service. 
This request will increase authorization for the design professional services agreement but not
the project authorization. The design is being completed under a project specific agreement with
a contract value of $2,700,000. The project scope has increased due to regulatory requirements 
and needs to incorporate jet fans for ventilation and close existing ventilation portals. This has 
increased the need for additional design support. This request will add $1,200,000 for a revised
contract value of $3,900,000 that will support design services through Ready to Bid documents.
An increase in authorization will be required to provide design support services through
construction and additional project budget associated with the anticipated estimated cost
increasing from $24,500,000 to $33,000,000 (pending finalization of design and estimate review).
This increase in authorization will be included in the future Commission authorization for
construction request planned in Q2 2023. 
There are no attachments to this memo. 

Template revised April 12, 2018.

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