8h. Memo

Water Main Improvements

AGENDA MEMORANDUM                        Item No.          8h 
ACTION ITEM                            Date of Meeting    September 13, 2022 

DATE:     September 6, 2022 
TO:        Stephen P. Metruck, Executive Director 
FROM:    Keri Stephens, Director, AV Facilities & Capital Programs 
Eileen Francisco, Director, Aviation Project Management Group 
SUBJECT:  1947 Water Main Improvements (CIP #C801224) 
Amount of this request:               $1,025,000 
Total estimated project cost:          $4,319,000 
Request Commission authorization for the Executive Director to complete design of the 1947
Water Main Improvements project at Seattle-Tacoma International Airport. The requested
authorization amount is $1,025,000 for a total authorization of $1,100,000. 
The Utility Master Plan has identified the existing 1947 water transmission main to be deficient
or nearing the end of serviceable lifespan. This deficient water main will be addressed by a
program of three projects, including this 1947 Watermain Improvement project. The selected
portion of water main for this project provides the primary feed to the Central Plant cooling
towers, North Toll Plaza, Light Rail Station; and secondary feed to large fire flow facilities such as
Delta Hangar, Alaska Hangar, Main Garage and Fuel Farm. The pipe needs to be restored to 
protect the integrity of Port’s water system. Instead of a costly and highly impactful traditional
remove-and-replace method, the Port is pursuing restoration by pipelining, namely Cured-In-
Place-Pipe. The design of this project will include analyzing the best pipe rehabilitation method. 
This project will support the Century Agenda goal to advance this region as a leading tourism
destination and business gateway by meeting the region’s air transportation needs through
improving vital facilities and infrastructure in a sustainable and cost-effective manner. This water 
main has reached the end of its serviceable life and has experienced multiple failures requiring
emergency repairs, most recently in January 2021. This project will extend the serviceable life of
the water main, and the low-impact method of installation will also minimize traffic delays and
overall construction duration. 

Template revised January 10, 2019.

             COMMISSION AGENDA – Action Item No. 8h                                  Page 2 of 4 
Meeting Date: September 13, 2022 
Diversity in Contracting 
The design of this project will utilize an existing Indefinite Delivery / Indefinite Quantity (IDIQ) 
Contract to provide design services. The contract has a 10% over-all WMBE participation goal.
The project team will work with Diversity in Contracting department to establish additional
WMBE goals for the construction contract. 
The project will restore the water main from where it begins south of the S 182nd St intersection
with International Blvd adjacent to the light rail guideway, traveling north under the Northern
Airport Expressway (NAE) (located east of the Main Garage), and ending under the NAE
approximately, north of the light rail pedestrian bridge. The entire length of watermain addressed
will be approximately 2,400 linear feet. 
Scope of Work 
The 16-inch steel water main will be restored by pipe lining, which is more cost-effective and less
operationally impactful than the traditional remove-and-replace methodology. Additionally, the
project will replace existing tees and provide access vaults or manholes to ease future access
needs for reaching the water main, which is twenty feet deep in some locations under the NAE. 
Design start                                       2022 Quarter 3 
Commission construction authorization          2023 Quarter 3 
Construction start                                2024 Quarter 1 
In-use date                                       2024 Quarter 3 
Cost Breakdown                                     This Request           Total Project 
Design                                                  $1,025,000             $1,100,000 
Construction                                                     $0             $3,219,000 
Total                                                         $1,025,000              $4,319,000 
Alternative 1 – Continue addressing emergency failures 
Cost Implications: $500,000 per event based upon past failures 
(1)   Requires no capital investment 
(1)   Emergency failures cause unexpected damage and disruption to operations 
(2)   Does not address water main pipe that is beyond its serviceable life. Will likely require
more frequent emergency repairs. 

Template revised June 27, 2019 (Diversity in Contracting).

             COMMISSION AGENDA – Action Item No. 8h                                  Page 3 of 4 
Meeting Date: September 13, 2022 
This is not the recommended alternative. 
Alternative 2 – Remove-and-replace water main 
Cost Implications: $12,000,000 
(1)   Completely replaces the 74-year-old pipe with new piping providing a fifty-year service 
(2)   Potential for increased capacity 
(1)   Major disruption to operations (lane closures, detours, roadway capacity reduction) 
(2)   Requires significant capital investment 
This is not the recommended alternative. 
Alternative 3 – Restore the pipe by lining 
Cost Implications: $4,319,000 
(1)   Reasonably priced solution 
(2)   Design service life is fifty-years 
(3)   Minimizes impacts to operations (only access pits at tee and valve replacement
(1)   Relies on existing pipe to form and house liner 
(2)   Minimally reduces inner pipe diameter, which may reduce flow capacity 
This is the recommended alternative. 
Cost Estimate/Authorization Summary              Capital        Expense           Total 
Original estimate                                 $2,263,000               $0      $2,263,000 
Current change                                $2,056,000              $0      $2,056,000 
Revised estimate                                $4,319,000              $0      $4,319,000 
Previous authorizations                             $75,000               $0         $75,000 
Current request for authorization                $1,025,000               $0      $1,025,000 
Total authorizations, including this request       $1,100,000               $0      $1,100,000 
Remaining amount to be authorized            $3,219,000             $0     $3,219,000 

Template revised June 27, 2019 (Diversity in Contracting).

             COMMISSION AGENDA – Action Item No. 8h                                  Page 4 of 4 
Meeting Date: September 13, 2022 
Annual Budget Status and Source of Funds 
This project, CIP C801224, was included in the 2022-2026 capital budget and plan of finance with
a budget of $2,263,000. A budget of $2,056,000 was transferred from the Utility Master Plan 
Reserve CIP (C801267) resulting in a zero net change to the Aviation capital budget. The funding
sources will be the Airport Development Fund (ADF) and revenue bonds. 
Financial Analysis and Summary 
Project cost for analysis              $4,319,000 
Business Unit (BU)                  Utility storm water project would be recovered through
utility internal charge that would impact 80.8% to
Effect on business performance     NOI after depreciation will increase due to inclusion of
(NOI after depreciation)             capital (and operating) costs in airline rate base. 
IRR/NPV (if relevant)                N/A 
CPE Impact                       $.01 in 2025 
Future Revenues and Expenses (Total cost of ownership) 
The operations and maintenance costs are anticipated to be minimal. 
(1)   Vicinity Map 

Template revised June 27, 2019 (Diversity in Contracting).


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