PORT OF SEATTLE 
MEMORANDUM 
COMMISSION AGENDA             Item No.      6b 
Date of Meeting     June 14, 2011 

DATE:    June 8, 2011 
TO:     Tay Yoshitani, Chief Executive Officer 
FROM:    Michael Ehl, Director, Airport Operations 
George England, Program Leader, Aviation Capital Improvement Program 
SUBJECT:  8th Floor Weather Proofing of Airport Main Parking Garage (CIP #C800274) 
Amount of This Request: $12,450,000       Source of Funds: Airport Development Fund
State and Local Taxes paid: $895,000         Jobs Created: 100 
Total Estimated Project Costs: $13,050,000 
ACTION REQUESTED: 
Request authorization for the Chief Executive Officer to: (1) amend the outside professional
services agreement for construction engineering, testing and commissioning services in the
amount of $335,711 with Carl Walker, Inc. for a total contract value of $764,500; (2) perform
project management and contract administration; and (3) advertise for bids and execute a major
public works construction contract for the 8th Floor Weather Proofing project at Seattle-Tacoma
International Airport (Airport). Total value of this request is $12,450,000, bringing the total
authorized amount to $13,050,000. In accordance with RCW 53.19.060, this memorandum
constitutes notification to the Commission that the amended value of the Carl Walker, Inc. 
contract exceeds 50% of the original not to exceed value. A copy of this memo will be made
available at the Bid Desk. 
SYNOPSIS: 
The 8th floor of the main garage functions as a roof for the entire garage and all the floors below.
This project will remove and replace 13.5 acres of failing weatherproofing materials currently
providing protection for the airport main parking garage, and includes preparation of the
underlying slab. Additionally, the project will replace expansion joints and flashing with more
uniform systems while reducing maintenance costs. This project is the first of a series of capital
projects identified to update and protect the airport main parking garage asset. The Commission
previously authorized a total of $966,500 to assess the condition of the main garage and service
tunnel assets, and $600,000 for design of the replacement weatherproofing system. 
The parking garage is a primary source of non-airline revenue for the Airport. In recent years it
has generated in excess of $50 million annually. It is also an important revenue source for the
City of SeaTac through a parking tax. The project aims to protect this critical asset by filling the

COMMISSION AGENDA 
Tay Yoshitani, Chief Executive Officer 
June 8, 2011 
Page 2 of 5 
extensive network of cracks and spalling occurring on Floors 7 and 8. Cracking between the
decks has allowed water to infiltrate lower floors causing lime damage on customer vehicles and
requiring Port staff to close sections of the garage. The garage post-tensioned structural system
is also subjected to the attritional effects of water intrusion and would continue to be at risk
without installing a new 8th Floor weatherproof membrane. Without the improvements, the Port
would be risking future revenues, jeopardize existing operational stalls, and put at risk one of its
most valuable assets. 
BACKGROUND: 
The 8th Floor Weather Proofing project is the first, and most highly prioritized, of a series of
projects intended to rehabilitate, seismically stabilize, and extend the lifespan of the main
parking garage and service tunnel at the airport. The 8th Floor Weather Proofing effort was
considered most critical to stabilizing deterioration of the parking garage structure. This project,
and those that will follow seek to extend the lifespan of these valuable Port assets. 
PROJECT DESCRIPTION/SCOPE OF WORK: 
Project Statement: 
Project will weatherproof the 8th floor (roof) of the airport main parking garage. 
Project Objectives: 
Minimize capital costs and minimize future operating costs 
Provide a solution that has an effective life of 10 or more years with scheduled maintenance 
Preserve and protect a revenue generating Port asset 
Eliminate water infiltration from deck level into elevator lobbies 
Improve customer service by restoring parking capacity (180 spaces) taken out of service due
to water infiltration and damage to vehicle finishes 
Provide a safe and functional facility that performs reliably, requires minimal maintenance,
and generates maximum revenue 
Scope of Work: 
The 8th Floor Weather Proofing project will include the following elements: 
Removal and replacement of 599,000 square feet of failing roof membrane with more
durable materials. The current membrane, which is between 11 and 20 years old (depending
on location), has delaminated, decomposed, or been peeled, cut, burned or gouged and is now
leaking. 
Rout and seal all cracks over a certain size, install drains to minimize ponding, and conduct
other measures to minimize leaking at various locations. 
Remove and replace or upgrade 2,000 feet of existing expansion joints, moving to a common
design standard if possible.

COMMISSION AGENDA 
Tay Yoshitani, Chief Executive Officer 
June 8, 2011 
Page 3 of 5 
Remove and replace failed elevator shaft flashing. 
Install cementitious traffic topping membrane to reduce potential damage in areas of high 
turning movements. 
This requested action authorizes construction, construction support, and commissioning of the 8th 
Floor Weather Proofing project. 
PROJECT SCHEDULE: 
The following is a list of key milestone dates for the 8th Floor Weather Proofing project. 

Design Complete               July, 2011 
Bid Advertisement              July, 2011 
Construction Start                October 2011 
Construction Complete            October 2012 
FINANCIAL IMPLICATIONS: 
Budget/Authorization Summary: 
This budget and authorization summary is for the 8th Floor Weather Proofing (CIP #C800274): 
Original Budget                                            $13,050,000 
Budget Increases                                                  $0 
Budget Transfers                                                  $0 
Revised Budget                                           $13,050,000 

Previous Authorizations                                          $600,000 
Current Request for Authorizations                                 $12,450,000 
Total Authorizations, Including this Request                           $13,050,000 
Remaining Budget to be Authorized                                 $0 
Project Cost Breakdown: 
Contractor Cost                                              $9,327,000 
Sales Tax                                                   $895,000 
Outside Professional Services                                      $2,070,000 
Port Costs                                                     $758,000 
Total                                                   $13,050,000

COMMISSION AGENDA 
Tay Yoshitani, Chief Executive Officer 
June 8, 2011 
Page 4 of 5 
Source of Funds: 
The 8th Floor Weather Proofing project (CIP #C800274) is included in the 2011-2015 capital
budget and plan of finance as a committed project. The source of funds for this project, as
identified in the plan of finance, is the Airport Development Fund. 
Financial Analysis Summary: 
The main parking garage is the principal non-airline revenue generator at the Airport, with recent
revenues of approximately $50 million per year. Portions of the facility have been in service for
over 40 years, with the newest sections having been in service for more than 10 years. Parking
revenues are expected to expand over time with special event parking driven by the advent of
light rail service to the Airport, and the addition of several floors of new public parking when the
Rental Car Facility opens in 2012.
The 8th Floor Weather Proofing project is categorized as a Renewal/Replacement project. 
CIP Category                 Renewal/Replacement 
Project Type                  Business Expansion 
Risk adjusted Discount Rate        N/A 
Key risk factors                 Time span and phasing of construction 
Project cost for analysis            $13,050,000 
Business Unit (BU)             Operations, Landside
Effect on Business Performance      See below 
IRR/NPV                N/A, see below 
CPE Impact                 None 
ECONOMIC IMPACTS: 
The Airport parking garage provides a primary revenue source for both the Port of Seattle and
the City of SeaTac through a parking tax. The garage generated $51.9 million for the Port during
2009. Correcting the roofing system failures on the 8 th floor will restore the facility to its full
revenue generating potential.
ENVIRONMENT AND SUSTAINABILITY: 
The 8th Floor Weather Proofing project will restore and extend the life of one of the Port of
Seattle's most heavily used assets. Preserving and restoring this valuable asset is in keeping with
Port environmental policy as it is environmentally sustainable, and conserves resources. By
extending the useful life of this asset, reconstruction can be delayed, which is the most

COMMISSION AGENDA 
Tay Yoshitani, Chief Executive Officer 
June 8, 2011 
Page 5 of 5 
environmentally compatible outcome in this scenario, for both the Port and the surrounding
community.
STRATEGIC OBJECTIVES: 
This project supports the Port's strategy to "Ensure Airport Vitality" and to "Exhibit
Environmental Stewardship through our Actions."
TRIPLE BOTTOM LINE SUMMARY: 
The 8th Floor Weather Proofing project protects a valuable Port asset, returns it to full revenue
generating capacity, and preserves it in a manner that will extend its useful service life. This
maximizes the return on investment realized from this facility over time, and minimizes the
environmental impact of the facility, while maximizing the benefit to both the Port and the
surrounding community. 
ALTERNATIVES CONSIDERED/RECOMMENDED ACTION: 
Complete the Project  Under this alternative the 8th floor of the main parking garage will
receive a new roofing system; to include removal and replacement of the existing roofing
membrane, slab preparation, flashing and expansion joints. This will preserve and protect the
Port's asset, create the least environmental impact, and allow the garage to operate at full
capacity throughout the year. This is the recommended alternative. 
Do-Nothing  Under this alternative the existing roofing system would be repaired on an asneeded
basis as is currently done. The number of parking spaces that had to be removed from
service has increased from 120 spaces in 2008 to 180 spaces in 2009. Water infiltrating the
existing 8th floor roofing system is now leaking several floors below the 8th floor. The main
parking garage is the largest single revenue source at the airport for the Port. This asset will
continue deteriorating at an accelerating rate under this alternative. This alternative also has long
term structural impacts to the integrity of the garage. This is not the recommended alternative. 
PREVIOUS COMMISSION ACTION: 
Previous Commission funding actions on CIP 800274 included the following: 
On March 27, 2007, the Commission authorized $966,500 for the Parking Garage/Service
Tunnel Pre-Design Project at Seattle-Tacoma International Airport. 
On February 23, 2010, the Commission authorized $600,000 for the design portion of the 8th 
Floor Weather Proofing project. 
OTHER DOCUMENTS ASSOCIATED WITH THIS REQUEST: 
No Attachments