PORT OF SEATTLE 
MEMORANDUM 
COMMISSION AGENDA             Item No.      5a 
Date of Meeting    August 2, 2011 

DATE:    July 26, 2011 
TO:      Tay Yoshitani, Chief Executive Officer 
FROM:   Elizabeth Leavitt, Director, Aviation Planning & Environmental Services 
Wayne Grotheer, Director, Aviation Project Management Group 
SUBJECT: Tyee Valley Golf Course Area Mitigation (CIP #C800420, WP #104423) 
Amount of This Request:   $691,000       Source of Funds: Airport Development Fund 
Est. State and Local Taxes:  $44,000 (total project) 
Est. Jobs Created:        15 
ACTION REQUESTED: 
Request Port Commission authorization for the Chief Executive Officer to advertise and execute
a major construction contract for the Tyee Valley Golf Course Area Mitigation, adjacent to
Seattle Tacoma International Airport (Airport). The amount of this request is $691,000 of a total
project cost of $800,000. 
SYNOPSIS: 
This is a regulatory project that will advance wetland permit obligations for the Airport along
with other ongoing projects. These regulato ry obligations will complete the mitigation required
by Natural Resource Mitigation Plan for Master Plan Update (MPU) Improvement Projects and
as required by the MPU Federal 404 and 401 Environmental Permits. This project will entail
preparing the site, removing golf course paths, removing an abandoned culvert, amending the
soil as needed, planting approximately 11.5 acres of wetlands and buffers, and installing 
temporary irrigation systems. Temporary irrigation will be installed, and wetland planting will
include a one-year plant establishment period. In addition to satisfying environmental permit
requirements, this project will convert an open grass field to dense shrub habitat and in doing so
reduce the attraction of wildlife that can be a hazard to airport operations. This request is for
$691,000 of a $800,000 total project budget. 
BACKGROUND: 
The Port was issued two environmental permits that allowed for impacts associated with the
MPU projects. The MPU projects included the Third Runway, which is currently in operation,
as well as the South Aviation Support Area, which was never constructed. Soil borrow sites that
would have affected wetlands were also not used by the MPU projects; however, mitigation was

COMMISSION AGENDA 
Tay Yoshitani, Chief Executive Officer 
July 26, 2011 
Page 2 of 5 
required for the MPU projects. In order to compensate for planned impacts, the permits required
the Port to provide mitigation by enhancing existing, and creating new, wetlands. This original
mitigation package included approximately 15 acres of wetland and wetland buffer site
development on the Tyee Golf Course. 
The Tyee Golf Course mitigation site was to be constructed in 2006 as part of the overall MPU
mitigation program under capital improvement project CIP #C100172. However, the Port
requested the Tyee site be eliminated from the MPU mitigation program due to reduced impacts.
After extensive discussions, the U.S. Army Corps of Engineers (Corps) concluded that the
original planned MPU mitigation site functions were interdependent and the elimination of the
Tyee site could only be assessed after extensive study. In lieu of initiating a costly study that
would contain a high degree of uncertainty in terms of methods and outcome, the Corps,
Washington Department of Ecology (Ecology), and Port Staff cooperatively agreed that a
reduced 11.5-acre wetland development at the Tyee Golf Course would satisfy the MPU
projects' mitigation requirements. 
In consideration of this reduced mitigation project, Port staff evaluated the existing wildlife
hazard presented by the proposed mitigation site. This area had formerly been used by the Golf
Course operator. In September 2009, this area was excluded from the tenant's lease due to
conflicts with the Des Moines Creek Basin Committee Regional Detention Facility Projects. The
unmaintained open grass area lies directly under the aircraft flight path and has been used by
grazing geese and other waterfowl. The conversion of this open grass area to a dense scrubshrub
habitat was seen as a significant benefit to the Airport Operation's Wildlife Hazard
Mitigation Program. 
PROJECT JUSTIFICATION: 
The completion of the Tyee Golf Course Mitigation will fulfill the outstanding Port wetland
mitigation permit obligations associated with the MPU projects. In addition , the project would
mitigate a significant wildlife attractant by converting an open grass area to a dense scrub-shrub
habitat. 
PROJECT STATEMENT AND OBJECTIVES: 
Project Statement: 
The purpose of the project is to design and complete the Tyee Valley Golf Course Area
Mitigation, which includes removing golf cart paths, removing an abandoned culvert, amending
the soil as needed, wetland and buffer planting over approximately 11.5 acres, and installing a
temporary irrigation system, all as required by Natural Resource Mitigation Plan for the MPU
and as required by the MPU 404 and 401 Environmental Permits and in support of the Airport
Operation's Wildlife Hazard Mitigation Program. 
Project Objectives: 
In addition to fulfilling the outstanding wetland permit obligations, this project will serve to
significantly reduce the wildlife hazard that is currently presented by the open grass in the area.
This wildlife mitigation will present a tangible benefit to the Airport Operation's Wildlife

COMMISSION AGENDA 
Tay Yoshitani, Chief Executive Officer 
July 26, 2011 
Page 3 of 5 
Hazard Mitigation Program. Scrub-shrub vegetation will be selected to match the site-specific
conditions at the golf course ensuring long-term vegetative cover requiring little or no
maintenance once fully established.
PROJECT SCOPE OF WORK AND SCHEDULE: 
Scope of Work: 
This project will plant approximately 11.5 acres of wetlands and buffers within the Tyee Golf
Course to environmental permit standards. The work will also include site preparation, removal
of abandoned golf cart paths and stormwater culverts, soil amendments, and temporary irrigation
systems as needed. 
Schedule: 
Commission Authorization to Advertise    August 2011 
Advertise                       September 2011 
Notice to Proceed                  December 2011 
FINANCIAL IMPLICATIONS: 
Budget/Authorization Summary: 
Original Budget                                 $800,000 
Budget Increase                                      0 
Revised Budget                                     0 
Previous Authorization this CIP                        $109,000 
Current request for authorization                    $691,000 
Total Authorizations, including this                  $800,000 
request 
Remaining budget to be authorized                         $0 
Budget Status and Source of Funds: 
This project is included in the 2011-2015 capital budget and plan of finance as a business plan
prospective project (CIP #C800420). The funding source will be the Airport Development Fund.
Due to the extended period of time since construction of the Third Runway and other MPU
projects, as well as the benefits to Airfield Operations Safety, this project is budgeted through a
new Aviation Division CIP.

COMMISSION AGENDA 
Tay Yoshitani, Chief Executive Officer 
July 26, 2011 
Page 4 of 5 
Financial Analysis and Summary: 
CIP Category                   Compliance 
Project Type                    Health, Safety and Security; Regulatory 
Risk adjusted Discount rate           N/A 
Key risk factors                    N/A 
Project cost for analysis               $800,000 
Business Unit (BU)                 Airfield 
Effect on business performance         NOI after debt service will increase as capital and
operating costs will be fully recovered in landing
fees. 
IRR/NPV                  N/A 
CPE Impact                  CPE impact is less than $0.01 in 2013, but no change
to business plan forecast since this project was
included. 
Lifecycle Cost and Savings: 
The initial one-year plant establishment will be performed by the Maintenance Department for
an estimated amount of $30,000. The MPU mitigation sites are subject to 15 years of
maintenance and monitoring. Invasive weed control is currently performed by the Maintenance
Department. Associated maintenance costs are conservatively estimated to increase by $5,000
per year for 15 years. Monitoring and plant replacement is performed by Aviation
Environmental; their costs would increase by $5,000 per year for 15 years. Recurring annual
costs will be incorporated in future budget authorizations as appropriate. 
ENVIRONMENT AND SUSTAINABILITY:
This wildlife mitigation will augment wetland and wetland buffer enhancements provided by
earlier projects. In doing so, the wetland will provide improved water quality and aquatic habitat
functions to Des Moines Creek. At the same time, the project will reduce waterfowl use of the
former golf course area, providing a tangible benefit to the Airport Operation's Wildlife Hazard
Mitigation Program. Scrub-shrub vegetation will be selected to match the site-specific
conditions at the site ensuring long-term vegetative cover requiring little or no maintenance once
fully established.
STRATEGIC OBJECTIVES: 
This project supports and maintains positive relationships with the environmental agencies,
Ecology, and Corps and reduces wildlife hazard to airport operations.

COMMISSION AGENDA 
Tay Yoshitani, Chief Executive Officer 
July 26, 2011 
Page 5 of 5 
TRIPLE BOTTOM LINE SUMMARY: 
The local economy and community will benefit by this project because it helps to ensure the
continued safe operation of the Airport, while meeting permit obligations. Completion of the
Tyee Valley Golf Course Mitigation will fulfill all outstanding Port wetland permit obligations
associated with the MPU projects. The Airport Operations wildlife hazard will be reduced. 
ALTERNATIVES CONSIDERED AND THEIR IMPLICATIONS: 
1)  Do nothing.  This alternative would entail notifying the agencies that the Port will not
complete any additional MPU wetland mitigation and refuse to complete other studies. 
This alternative would significantly damage ongoing relationships with the Corps and
Ecology. It is likely that the Corps and Ecology would maintain their positions and issue
an enforcement action under the Clean Water Act. The enforcement action would likely
require full mitigation plus penalty. The Port would be required to either comply or
appeal the action in court. Legal fees alone would be substantial relative to the costs
associated with Alternative 3. Some degree of mitigation would likely be required. This
is not the recommended alternative. 
2)  Complete a functional assessment study and develop required mitigation bases on the
results.  It is assumed that the study would cost approximately $100,000 to complete.
Once submitted, the report would again be open to agency review and interpretation. It is
expected that such a study would take up to a year to complete, negotiate and be
approved. Given the subjective nature of the study, it is assumed that the Corps would at
most accept some reduced mitigation at Tyee. It is also possible that the Corps would
add a penalty due to time delays and in the end the Port may end up planning the entire
Tyee mitigation. This is not the recommended alternative. 
3)  Construct 11.5-acre wetland mitigation site.  The new wetland mitigation would fulfill
the Port's MPU wetland mitigation obligations. Relationships with the agencies would
remain positive, which will benefit the Airport as it completes the 15-year wetland
monitoring tasks and in future permitting efforts. In addition, the project would reduce a
wildlife hazard presented by the existing grass field. This is the recommended
alternative. 
OTHER DOCUMENTS ASSOCIATED WITH THIS REQUEST: 
Map of Tyee Mitigation Site and Vegetation Changes. 
PREVIOUS COMMISSION ACTIONS OR BRIEFINGS: 
1)  On June 22, 1999, Commission authorized the initial work on this project under CIP
#C100172 to be performed under the Third Runway Project.
2)  On February 8, 2011, Commission authorized $109,000 for 100% design level
construction documents in conjunction with a design Service Directive.