COMMISSION 
AGENDA MEMORANDUM                        Item No.          6f 
ACTION ITEM                            Date of Meeting     February 26, 2019 
DATE:     February 15, 2019 
TO:        Stephen P. Metruck, Executive Director 
FROM:    Jeffrey Brown, Director, Aviation Facility and Capital Program 
Michael Ehl, Director, Airport Operations 
Wayne Grotheer, Director, Aviation Project Management Group 
SUBJECT:  Stormwater Pond Bird Deterrent Improvements (CIP #C800980) 
Amount of this request:              $10,192,000 
Total estimated project cost:         $10,492,000 
ACTION REQUESTED 
Request Commission authorization for the Executive Director  to advertise and execute a
construction contract for the Stormwater Pond Bird Deterrent Improvements project at the
Seattle-Tacoma International Airport. This request is for $10,192,000 of a total estimated
project cost of $10,492,000. 
EXECUTIVE SUMMARY 
This is a safety improvement project that will reduce the risk of aircraft-bird strikes by making
the ponds less attractive to wildlife, particularly waterfowl. This project will upgrade or replace
the existing pond netting systems to reduce the likelihood of major failures from snow and ice
loads in the future and to comply with the intent of Federal Aviation Regulations (FAR) 139.337 
and the airport's Wildlife Hazard Management Plan (WHMP). 
The airport has effectively used pond netting systems to prevent bird access to the ponds. This
in turn has reduced the number of bird strikes by aircraft. The pond netting systems on ten
stormwater ponds and three industrial wastewater system (IWS) ponds at the airport were
damaged by snow storms in February 2017. These ponds account for approximately 1.6 million
square feet of area in need of upgraded or replaced bird deterrent system. The accumulated
snow damaged structural and netting components to the extent that they no longer prevent
access to ponds by hazardous birds. Temporary measures were taken in 2017 and 2018 to
ensure compliance with federal regulations. This project will develop a viable long-term
solution for the bird deterrent infrastructure at airport stormwater and IWS ponds. 
This project is included in the 2019-2023 capital budget and plan of finance with a budget of
$10,492,000; funding sources will be the Airport Development Fund and future revenue bonds. 

Template revised April 12, 2018.

COMMISSION AGENDA  Action Item No. __6f__                               Page 2 of 5 
Meeting Date: February 26, 2019 
JUSTIFICATION 
Taking immediate measures to mitigate wildlife hazards complies  with FAR 139.337 and
supports the long-term strategy of the Port's Century Agenda objective to "Meet the region's
air  transportation  needs  at  Seattle-Tacoma International Airport for the next 25 years."
Maintaining the bird deterrent systems for ponds on or near the airport is a substantial part of
the WHMP, which starts with managing the habitat to reduce the attractiveness of the airport
environment to hazardous bird species. 
The project was presented at the Airline Airport Affairs Committee (AAAC) meeting on May 24,
2018, and obtained a favorable majority in interest (MII) vote in Quarter 4 of 2018. 
Diversity in Contracting 
This project will include  a 3  percent  aspirational goal for women and minority  business
enterprises (WMBE) consistent with the Port Commission's Diversity in Contracting Policy
Directive. 
DETAILS 
According to FAA Advisory Circular 150/5200-33B, the FAA requires that areas on or near
airports having open water after 48 hours following a storm event be mitigated using
techniques that prevent access to these areas by wildlife defined as hazardous. Airport
Operations has indicated the ponds must be repaired quickly to comply with the WHMP. This
project will be constructed during the dry season between July and October 2019. 
Following damage by the 2017 snowstorms, temporary repair efforts at the ponds occurred in
2017 and 2018 to ensure compliance with the FAA Advisory Circular. With the exception of the
2017 bird ball installation at Pond SDS4, these efforts were not intended to address the failing
structural components that affect long-term compliance and the durability of the bird netting
infrastructure.
A feasibility study was conducted to develop a viable long-term bird deterrent solution that was
tailored to the specific characteristics of each stormwater and IWS pond. Alternatives for longterm
upgrades or replacement of the existing bird deterrent systems were evaluated including
the use of upgraded fixed netting, fuse system netting (in which a sacrificial weak link fails first
under high load, allowing for easier repairs), bird balls (floating cover), and dense vegetation to
help physically exclude large hazardous birds from accessing the ponds. The evaluation
considered effectiveness, maintainability of the system, water quality, short-term costs, longterm
costs, and the maintainability of the pond facility. Recommendations were made for each
pond based on a scored evaluation of 10 different alternatives for the 13 ponds. 
Based on the feasibility study, netting system upgrades and controlled break fuse systems 
(designed so that only easily replaceable components fail under high load) were chosen as cost
effective for most of the ponds while the bird ball alternative was selected as being cost

Template revised September 22, 2016; format updates October 19, 2016.

COMMISSION AGENDA  Action Item No. __6f__                               Page 3 of 5 
Meeting Date: February 26, 2019 
effective for three of the westside stormwater ponds due to the larger surface area of those
ponds and the long service life of the bird  balls. The bird balls were evaluated for
maintainability, performance, service life and water quality impacts at both the SDS4 and the
Terminal Radar Approach Control (TRACON) Ponds, where bird balls are currently installed. 
The testing data indicated that no significant impact to water quality was detected from the
bird balls. Based on the environmental testing, the decision was made to proceed with
replacing the existing netting system at certain ponds with bird ball deterrent. In addition, the
project scope was reviewed with the near term Sustainable Airport Master Plan (SAMP)
projects and Pond F was identified to be ultimately impacted by SAMP. The refore, the less
costly and shorter-lived option of replacing the netting system over Pond F will be used to meet
project objectives and the SAMP schedule. 
Scope of Work 
The main scope items are listed as follows: 
(1)    Upgrade the existing netting system at Stormwater Ponds SDN1, NEPL and SDE4 and
IWS Lagoon 3; 
(2)    Install controlled break fuses system at IWS Lagoon 1 and Lagoon 2 and Stormwater
Ponds M, SDN1 and SDE4; 
(3)   Replace the existing netting system at Stormwater Pond F with a shorter service life
netting system; 
(4)    Remove the existing netting system at Ponds C, D and G and replace with floating bird
balls. 
Schedule 
Activity 
Construction start                             2019 Quarter 3 
In-use date                                    2019 Quarter 4 
Cost Breakdown                                      This Request           Total Project 
Design                                                           $0              $300,000 
Construction                                            $10,192,000            $10,192,000 
Total                                                        $10,192,000             $10,492,000 
ALTERNATIVES AND IMPLICATIONS CONSIDERED 
Alternative 1 Continue temporary repairs as needed to comply with the WHMP and FAR Part
139 requirements. 
Cost Implications: $150,000 annual expense cost 
Pros: 
(1)    No capital cost in 2019, freeing up funds for other airport purposes. 

Template revised September 22, 2016; format updates October 19, 2016.

COMMISSION AGENDA  Action Item No. __6f__                               Page 4 of 5 
Meeting Date: February 26, 2019 
Cons: 
(1)    Continued  interim  repairs  to  the  netting  system  will  be  required  to  keep  us  in
compliance but will fail to fix underlying structural deficiencies and leave netting
systems at risk to all future storms. This increases the potential of bird-aircraft strikes. 
(2)    The  increased  habitual  use  of  ponds  on  or  near  the  airport  by  birds  is  well
documented. The interim repairs are vulnerable to intrusion by birds and require
additional vigilance by Airfield Operations and Maintenance to ensure the ponds are
not becoming wildlife attractants. 
(3)    Ongoing annual expense for temporary repairs of the existing netting system. 
This is not the recommended alternative. 
Alternative 2   Upgrade/Replace the existing pond netting system for airport IWS and
stormwater ponds in the dry season of 2019. 
Cost Implications: $10,192,000 
Pros: 
(1)    Reduce the access of birds to the ponds on or near the airport and the presence of the
waterfowl in the area to maintain air traffic safety. 
(2)    Complies with FAR Part 139 requirements, FAA Advisory Circular 150/5200-33B, and
the airport WHMP. 
(3)    Uses the dry season between July and October for the best access to perform work in
the ponds. 
Cons: 
(1)    Capital spending in 2019 
This is the recommended alternative. 
FINANCIAL IMPLICATIONS 
Cost Estimate/Authorization Summary               Capital        Expense           Total 
COST ESTIMATE 
Original estimate                                $11,384,000               $0     $11,384,000 
Previous changes  net                           $(892,000)                0      $(892,000) 
Revised estimate                               $10,492,000                0     $10,492,000 
AUTHORIZATION 
Previous authorizations                            $300,000                0        $300,000 
Current request for authorization               $10,192,000                0     $10,192,000 
Total authorizations, including this request      $10,492,000                0     $10,492,000 
Remaining amount to be authorized                    $0             $0             $0 


Template revised September 22, 2016; format updates October 19, 2016.

COMMISSION AGENDA  Action Item No. __6f__                               Page 5 of 5 
Meeting Date: February 26, 2019 
Annual Budget Status and Source of Funds 
The Stormwater Pond Bird Deterrent Improvements (CIP #C800980) is included in the 2019-
2023 capital budget and plan of finance with a budget of $10,492,000. The funding sources will
be the Airport Development Fund and future revenue bonds. 
Financial Analysis and Summary 
Project cost for analysis              $10,492,000 
Business Unit (BU)                  Airfield Movement Area 
Effect on business performance     NOI after depreciation will increase 
(NOI after depreciation) 
IRR/NPV (if relevant)                N/A 
CPE Impact                        $0.04 in 2021 
Future Revenues and Expenses (Total cost of ownership) 
A feasibility study was conducted to evaluate replacement/upgrade alternatives for each pond.
Long-term cost is one of the criteria and is used to determine the recommended alternatives.
With approximately 20 years' service life, bird balls will require minimal maintenance and have
low annual repair/replacement cost. Upgrading the existing netting system will increase the
service life of the overall system and reduce the annual repair cost. The installation of fuses will
control the damage to an area that is readily repairable to improve maintainability and reduce
the maintenance cost. 
ATTACHMENTS TO THIS REQUEST 
(1)   Presentation slides 
PREVIOUS COMMISSION ACTIONS OR BRIEFINGS 
June 12, 2018   The Commission authorized $250,000 to design and prepare
construction bid documents for the Stormwater Pond Bird Deterrent Improvements
project at the Seattle-Tacoma International Airport. 
June 27, 2017  The Commission authorized $455,000 to use Port Construction
Services to repair damaged stormwater pond nets at Seattle-Tacoma International
Airport in 2017. 




Template revised September 22, 2016; format updates October 19, 2016.