COMMISSION 
AGENDA MEMORANDUM                        Item No.          8b 
ACTION ITEM                            Date of Meeting       May 24, 2022 

DATE:     May 13, 2022 
TO:        Stephen P. Metruck, Executive Director 
FROM:    Eileen Francisco, Director, Aviation Project Management 
SUBJECT:  Water Reservoir Rehabilitation (C801172) 
Amount of this request:               $1,000,000 
Total estimated project cost:          $3,169,000 
ACTION REQUESTED 
Request Commission authorization for the Executive Director to (1) prepare design and
construction bid documents, and (2) utilize Port of Seattle crews and small works contracts for
the Water Reservation Rehabilitation project at Seattle-Tacoma International Airport. The
amount of this request is $1,000,000. The total estimated project cost is $3,169,000. 
EXECUTIVE SUMMARY
The 2-million-gallon water reservoir at Seattle-Tacoma International Airport is an above ground
steel tank that provides water storage for domestic use and firefighting to the entire airport. The
recent inspection indicates that severe corrosion has appeared in many areas on the reservoir
and, if not addressed, could result in deformation of the structure. Additionally, the presence of
rust also puts the water quality into jeopardy. This project will rehabilitate the structure to extend
its useful life. 
JUSTIFICATION
The Department of Health requires that water reservoirs be kept in good operating condition.
The reservoir was built in the year 2000 as a requirement under the National Fire Protection
Association 24 code, ensuring the airport has reliable water on hand (in a tank) to fight any fire
on the airport. Without the rehabilitation efforts the reservoir is at risk of potential structural
failure and water quality degradation. 
Diversity in Contracting 
This project will utilize the mechanical IDIQ contract P00320719  AMC Engineers and leverage
their established WMBE goal of 17%. 


Template revised January 10, 2019.

COMMISSION AGENDA  Action Item No. __8b__                             Page 2 of 5
Meeting Date: May 24, 2022 
DETAILS 
The water reservoir is located north of the airport off Host Road. The reservoir can hold 2 million 
gallons of fire and domestic water. It is generally recommended that water reservoirs of this type
be inspected and cleaned every 3 to 5 years. Previous inspections include a 2013 dive inspection,
2017 cathodic protection survey, and 2018 dive inspection. The most recent inspections include
a 2021 dive inspection, cathodic protection inspection, and 2022 exterior coating test.
The Department of Health requires that water reservoirs be kept in good, operating condition. 
During construction, the airport's water source will be switched over from the reservoir to Seattle
Public Utilities. Coordination and planning efforts with Aviation Maintenance, Boiler, and the Fire
Department are underway for this event, as well as giving contractors access to the tank during
construction.
Some scope items require that the water reservoir be drained completely. Due to environmental
restrictions, the water cannot be drained directly into the sewer. Therefore, it is likely that
storage tanks will be brought onto the site to hold the water during construction. 
Scope of Work
The scope for this project includes recommendations from the 2021 dive inspection report.
Additional scope items from project stakeholders have also been included. The project scope
seeks to rehabilitate the structure and extend the asset's useful life by 20 years by implementing
the following improvements:
(1)   Complete replacement of interior and exterior coatings 
(2)   Cathodic protection system improvements 
(3)   Rebuild interior and exterior access ladders to meet safety codes 
(4)   Replace weathered tank hardware including nuts, bolts, cables, and pulleys 
(5)   Install tank sampling ports 
(6)   Valve vault improvements and repairs 
(7)   Cleaning/Removing vegetation between the pavement joints and around the perimeter
of the concrete foundation 
(8)   Repairing broken concrete curb around the base of the water reservoir 
Schedule
Activity 
Design start                                       Q2 2022 
Commission construction authorization          Q1 2023 
Construction start                                Q4 2023 
In-use date                                       Q3 2024 


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

COMMISSION AGENDA  Action Item No. __8b__                             Page 3 of 5
Meeting Date: May 24, 2022 
Cost Breakdown                                     This Request           Total Project 
Design                                                  $1,000,000             $1,150,000 
Construction                                                     $0             $2,019,000 
Total                                                         $1,000,000              $3,169,000 
ALTERNATIVES AND IMPLICATIONS CONSIDERED 
Alternative 1  Proceed with only the scope items outlined in the 2021 Inspection Report.
Cost Implications: $3,024,000 
Pros:
(1) Eliminates risk of the tank's structural integrity becoming compromised.
(2) Eliminates risk of jeopardizing water quality.
(3) Decreases direct costs over Alternative 1 by $145K.
Cons:
(1) These scope items will need to be completed at another date, requiring the water
reservoir be drained a second time. 
(2) The project will not include the scope items required by the Washington Administrative
Code.
This is not the recommended alternative. 
Alternative 2  Replace the tank entirely.
Cost Implications: $20,000,000 
Pros:
(1) Eliminates risk of the tank's structural integrity becoming compromised.
(2) Eliminates risk of jeopardizing water quality.
Cons:
(1) Significantly increases project cost with little to no added benefit.
(2) The reservoir will be out of service for a much longer duration.
This is not the recommended alternative. 
Alternative 3  Proceed with the full scope of the Water Reservoir Rehabilitation project.
Cost Implications: $3,169,000 
Pros: 
(1) Eliminates risk of the tank's structural integrity becoming compromised.
(2) Eliminates risk of jeopardizing water quality.
(3) Some of the additional scope items require the tank be empty. Including them in this
project eliminates the need to drain the tank a second time, saving both time and money. 

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

COMMISSION AGENDA  Action Item No. __8b__                             Page 4 of 5
Meeting Date: May 24, 2022 
(4) Including the additional scope items will fulfill requirements set by the Washington
Administrative Code regarding storage requirements and sampling ports for water quality
monitoring. 
Cons: 
(1) Increases direct costs over Alternative 2 by $145K.
This is the recommended alternative. 

FINANCIAL IMPLICATIONS 
Cost Estimate/Authorization Summary              Capital        Expense           Total 
COST ESTIMATE 
Original estimate                                 $1,572,000               $0      $1,572,000 
Current change                                 $1,571,000         $26,000      $1,597,000 
Revised estimate                                $3,143,000         $26,000      $3,169,000 
AUTHORIZATION 
Previous authorizations                            $150,000                0        $150,000 
Current request for authorization                  $974,000         $26,000      $1,000,000 
Total authorizations, including this request       $1,124,000         $26,000      $1,150,000 
Remaining amount to be authorized            $2,019,000             $0     $2,019,000 
Annual Budget Status and Source of Funds 
This project, CIP C801172, was included in the 2022-2026 capital budget and plan of finance with
a budget of $1,572,000. A budget increase of $1,571,000 was transferred from the Aeronautical
Reserve CIP (C800753) resulting in zero net change to the Aviation capital budget. The funding
source will include the Airport Development Fund. 
Financial Analysis and Summary 
Project cost for analysis              $3,169,000 
Business Unit (BU)                  Utilities 
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 2026 
Future Revenues and Expenses (Total cost of ownership) 
No additional maintenance costs are anticipate following the completion of this project. 


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

COMMISSION AGENDA  Action Item No. __8b__                             Page 5 of 5
Meeting Date: May 24, 2022 
ATTACHMENTS TO THIS REQUEST 
(1)   Presentation 
PREVIOUS COMMISSION ACTIONS OR BRIEFINGS 
None. 
















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