COMMISSION 
AGENDA MEMORANDUM                        Item No.          8c 
ACTION ITEM                            Date of Meeting       August 9, 2022 

DATE:     July 29, 2022 
TO:        Stephen P. Metruck, Executive Director 
FROM:    Keri Stephens, Director, AV Facilities & Capital Programs 
Eileen Francisco, Director, Aviation Project Management Group 
SUBJECT:  Departures Drive Drainage Improvement (CIP #C801036) 
Amount of this request:                 $730,000 
Total estimated project cost:          $1,280,000 
ACTION REQUESTED 
Request Commission authorization for the Executive Director to utilize Port crews and small
works contracts to complete the Departures Drive Drainage project at Seattle-Tacoma
International Airport (SEA). This authorization is for $730,000 for a total estimated project cost
of $1,280,000. 
EXECUTIVE SUMMARY 
This project rehabilitates a portion of the departures drive storm drainage system and existing
bridge expansion joint seal. The storm drainage system has failed along the south end of the
departures drive. An existing catch basin and associated drainage pipe is plugged and has been
paved over. Stormwater currently ponds at this location, leaks through the structure,
deteriorates the departure drive structure and discharges onto rental car customers waiting on
the arrivals curbside below. The project will replace the existing storm drainage facilities,
expansion joint seal, and complete minor paving. 
JUSTIFICATION 
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
project will improve customer service for rental car customers and reduce ongoing maintenance
due to stormwater leaking from the departures drive onto the arrivals curbside. 


Template revised January 10, 2019.

             COMMISSION AGENDA – Action Item No. __8c__                              Page 2 of 4 
Meeting Date: August 9, 2022 
Diversity in Contracting 
The project is utilizing an existing Indefinite Delivery / Indefinite Quantity (IDIQ) contract to
provide design support services.  The contract has an overall requirement for 10% WMBE
participation. Port Construction Services (PCS) will complete the construction portion and will 
work with the Diversity in Contracting (DC) department to outreach to the WMBE community of
any small works opportunities. 
DETAILS 
The project is located at the south end of the departures drive. However, construction will impact
both the arrivals and departures drives. 
This project was originally scoped to replace three existing expansion joints on the departures
drive. However, it became apparent that there was scope overlap with two adjacent projects: 
C800862 Terminal Security Enhancements and C801204 SEA Gateway. After coordinating with
the two adjacent projects the scope of work for this project was reduced resulting in $600,000 in
savings. It was also identified that this project’s scope of work, the drainage piping, needed to
be completed prior to Terminal Security Enhancements’ installation of security bollards along the
arrivals curbside that is planned to start this fall. 
Additionally, the project carried additional contingency related to potholing work necessary to
proof the conceptual design. This work has now been conducted, the conceptual design was
proven, and the additional contingency has been removed from the project. 
Scope of Work 
This project will correct a failure of the existing storm drainage facilities at the south end of the
departures drive. 
(1)   Remove and replace an existing catch basin on the departures drive. 
(2)   Install new storm drainage piping under the departures drive, down an existing column
and across the arrivals drive to an existing catch basin. 
(3)   Replace one existing expansion joint seal on the departures drive. 
(4)   Repave the existing departures drive shoulder and reseal the structure joint to direct
stormwater flow into the new catch basin. 
(5)   Remove and replace a small section of existing storm drainage pipe that has deformed. 
Schedule 
Construction start                                2022 Quarter 3 
In-use date                                       2022 Quarter 4 


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

             COMMISSION AGENDA – Action Item No. __8c__                              Page 3 of 4 
Meeting Date: August 9, 2022 
Cost Breakdown                                     This Request           Total Project 
Design                                                           $0               $550,000 
Construction                                              $730,000               $730,000 
Total                                                           $730,000              $1,280,000 
ALTERNATIVES AND IMPLICATIONS CONSIDERED 
Alternative 1 – Remove and replace all concrete traffic barriers (spandrels) and reconstruct the
existing stormwater drainage system to replicate the existing system that is integral to the
structure. This option includes replacing three local expansion joints. 
Cost Implications: $7,710,000 
Pros: 
(1)   Provides long-term repair of inoperable stormwater drainage system. 
(2)   Improves customer safety and satisfaction. 
Cons: 
(1)   Most costly alternative. 
(2)   New stormwater drainage system will continue to be integral to the drive structure
which is difficult to access and maintain. 
(3)   Construction will result in significant impacts to both departures and arrivals curbsides. 
This is not the recommended alternative. 
Alternative 2 – Install new storm drainage infrastructure that is external to the departures drive,
replace existing expansion joint seal, and repave the departures drive shoulder and reseal the
structure joint. 
Cost Implications: $1,280,000 
Pros: 
(1)   Provides long-term repair of inoperable stormwater drainage system. 
(2)   Improves rental car customer safety and satisfaction. 
Cons: 
(1)   The new stormwater drainage system will be external and attached underneath the
bridge deck. It will not be as aesthetically pleasing or hidden as the original internal
drainage system. 
This is the recommended alternative. 



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

             COMMISSION AGENDA – Action Item No. __8c__                              Page 4 of 4 
Meeting Date: August 9, 2022 
FINANCIAL IMPLICATIONS 
Cost Estimate/Authorization Summary               Capital        Expense           Total 
COST ESTIMATE 
Original estimate                                      $600,00              $0       $600,000 
Previous changes                                 $1,880,000              $0     $1,880,000 
Current change                                   ($625,000)        $25,000      ($600,000) 
Revised estimate                                  $1,255,000         $25,000     $1,280,000 
AUTHORIZATION 
Previous authorizations                              $550,000              $0       $550,000 
Current request for authorization                    $705,000         $25,000       $730,000 
Total authorizations, including this request         $1,255,000         $25,000      $1,280,000 
Remaining amount to be authorized                      $0             $0             $0 
Annual Budget Status and Source of Funds 
This project, CIP C801036, was included in the 2022-2026 capital budget and plan of finance with
a budget of $1,880,000. A budget of $625,000 was transferred to the Aeronautical Reserve CIP
(C800753) resulting in zero net change to the Aviation capital budget. The funding source will be
2021 revenue bond and the Airport Development Fund (ADF).
Financial Analysis and Summary 
Project cost for analysis              $1,280,000 
Business Unit (BU)                  Roadways 
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                       Less than $.01 in 2023 
Future Revenues and Expenses (Total cost of ownership) 
This project will not have a significant impact on Aviation Maintenance annual operating and
maintenance (O&M) costs. The storm drain will replace an existing system that is no longer
functioning. 
ATTACHMENTS TO THIS REQUEST 
(1)   Vicinity Map 
PREVIOUS COMMISSION ACTIONS OR BRIEFINGS 
July 27, 2021 – The Commission authorized design. 

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