COMMISSION 
AGENDA MEMORANDUM                        Item No.          6d 
ACTION ITEM                            Date of Meeting       June 12, 2018 
DATE:     April 24, 2018 
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:                 $250,000 
Total estimated project cost:         $10,492,000 
ACTION REQUESTED 
Request  Commission  authorization  for  the  Executive  Director  to  design  and  prepare
construction bid documents for the Stormwater Pond Bird Deterrent Improvements project at
the Seattle-Tacoma International Airport in an amount not to exceed $250,000 with a total
estimated project cost of $10,492,000. 
EXECUTIVE SUMMARY 
This is a safety improvement project that will reduce the risk of aircraft strikes with birds. This
project will upgrade or replace the existing pond netting systems to prevent future failures
from snow and ice loads and to comply with the Wildlife Hazard Management Plan (WHMP), a
section of the airport's Federal Aviation Administration (FAA) approved Airport Certification
Manual. 
Ponds attract wildlife, particularly waterfowl. The airport has effectively used pond netting
system to prevent access to the ponds by birds. This in turn has reduced the number of bird
strikes by aircraft. The pond netting systems on ten storm water ponds and three industrial
wastewater system (IWS) ponds at the airport were damaged by snow storms in February 2017.
The accumulated snow damaged structural and netting components so they no longer prevent 
access to ponds by birds. Federal Aviation Regulations (FAR) Part 139.337 require airports to
take immediate measures and mitigate wildlife hazards whenever hazards are detected. 
Temporary measures were taken in 2017 to ensure compliance with federal regulations. This
project will develop a viable long-term  solution for  the bird deterrent infrastructure  for
stormwater IWS ponds at the airport. 
This project is included in the 2018-2022 capital budget and plan of finance; funding sources
will be the Airport Development Fund and future revenue bonds. 

Template revised September 22, 2016.

COMMISSION AGENDA  Action Item No. __6d__                              Page 2 of 6 
Meeting Date: June 12, 2018 
JUSTIFICATION 
Taking immediate measures to mitigate wildlife hazards support 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 significant to air traffic safety. 
This project is planned to be constructed over two construction seasons starting in 2019 and
completing in 2020. In 2019, the existing netting system at stormwater pond SDN1, NEPL and
SDE4 and IWS pond Lagoon 3 will be upgraded to increase load-bearing capacity and service
life. A controlled break fuses system (designed so that only easily replaceable components
would fail under high load) will be implemented at IWS Lagoon 1, Lagoon 2 and Pond M. In
addition, the netting system at Pond F will be replaced with bird balls that are not ballasted 
because they are less costly and their performance has been acceptable in ponds with steep
side slopes. As recommended in the feasibility study, before implementing the bird balls at
other ponds, they will be evaluated one year after the installation at SDS4 and Pond F for
maintainability, performance, stability, and the environmental impacts such as water quality. If 
unballasted bird balls prove successful they will be used at Pond C, D and G in 2020. 
The project was presented at the Airline Airport Affairs Committee (AAAC) meeting on May 24,
2018 with no objection received. A majority-in-interest (MII) vote will not occur before the
Commission meeting on June 12 for the design authorization of this project. We do not
anticipate this project to be controversial and expect MII approval. 
A Project Labor Agreement (PLA) was evaluated in collaboration with Port of Seattle Labor
Relations and will not be utilized based on the location of the project and the potential impact
of a PLA on small business opportunities. This project will include goals for small business. 
DETAILS 
According to Federal Aviation Administration (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 be in
compliance with the WHMP. The best time to perform work in the ponds is during the July to
October dry season. 
Ballasted bird balls partially filled with potable water to increase their stability were installed at
SDS4 pond through a small works contract in 2017. Temporary repair efforts at other ponds
occurred in 2017 to ensure compliance with the FAA Advisory Circular. However, those 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 long-

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

COMMISSION AGENDA  Action Item No. __6d__                              Page 3 of 6 
Meeting Date: June 12, 2018 
term upgrades or replacement of the existing bird deterrent systems were evaluated including
the use of upgraded fixed netting, fuse system netting (sacrificial weak link fails first under high
load, allowing easy repair), bird balls  (floating cover), and exclusionary vegetation. The
evaluation considered effectiveness, maintainability of the system, water quality, short-term
costs, long-term 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. 
Scope of Work 
The main scope items are listed as follows: 
(1)   Upgrade the netting system at Stormwater Pond SDN1, NEPL and SDE4 and IWS Pond
Lagoon 3; 
(2)   Install controlled break fuses system at IWS Lagoon 1 and Lagoon 2 and Stormwater
Pond M; 
(3)   Replace the netting system at Pond C, Pond D, Pond F and Pond G with unballasted
bird balls. 
Schedule 
Activity 
Design start                                       2018 Quarter 2 
Commission construction authorization          2019 Quarter 1 
Construction start                                2019 Quarter 3; 2020 Quarter 2 
In-use date                                       2019 Quarter 4; 2020 Quarter 3 
Cost Breakdown                                     This Request           Total Project 
Design                                                    $250,000             $1,648,000 
Construction                                                      0             $8,844,000 
Total                                                           $250,000             $10,492,000 
ALTERNATIVES AND IMPLICATIONS CONSIDERED 
Alternative 1  Do not upgrade or replace the damaged netting systems for stormwater ponds
or IWS ponds at the airport in the dry season of 2019 or 2020. 
Cost Implications: $150,000 annual expense cost 
Pros: 
(1)    No capital cost in 2019 or 2020, freeing up funds for other airport purposes. 
Cons: 
(1)    The  increased  habitual  use  of  ponds  on  or  near  the  airport  by  birds  is  well
documented. Doing nothing would result in an increasing potential risk of bird-aircraft
strikes. 

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

COMMISSION AGENDA  Action Item No. __6d__                              Page 4 of 6 
Meeting Date: June 12, 2018 
(2)    Risks of damage to pond netting system from future storms and not in compliance
with the airport WHMP. 
(3)   Not in compliance with FAR Part 139 requirements or FAA Advisory Circular 150/5200-
33B. 
(4)    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  in  2019  with  a
recommended alternative according to the feasibility study for all IWS and stormwater ponds at
the airport. 
Cost Implications: $9,467,000 
Pros: 
(1)   Accelerated reduced access of birds to the ponds on or near the airport and their 
presence 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. 
Cons: 
(1) No opportunity to evaluate the bird balls for  maintainability, performance, stability, 
and the environmental impacts at a pilot pond before implementing at other ponds. 
(2)   Risks of not completing all the ponds during dry season in 2019 and require work in
wet season with higher cost and possible delay to the dry season of 2020. 
This is not the recommended alternative. 
Alternative 3  Upgrade/Replace the existing pond netting system with the recommended
alternative according to the feasibility study over two construction seasons  for IWS and
stormwater ponds at the airport. 
Cost Implications: $10,492,000 
Pros: 
(1)    Reduces the access of birds to the ponds on or near the airport and their presence 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. 
(4)    Allows evaluation of bird balls one year after the installation at SDS4 and Pond F for
maintainability, performance, stability, and the environmental impacts such as water
quality before implementing them at other ponds. 
Cons: 
(1)    Delays full completion of improvements until 2020. 
This is the recommended alternative. 

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

COMMISSION AGENDA  Action Item No. __6d__                              Page 5 of 6 
Meeting Date: June 12, 2018 

FINANCIAL IMPLICATIONS 
Cost Estimate/Authorization Summary              Capital        Expense           Total 
COST ESTIMATE 
Original estimate                                $11,384,000               $0     $11,384,000 
Current change                                 $(892,000)               0      $(892,000) 
Revised estimate                               $10,492,000                0     $10,492,000 
AUTHORIZATION 
Previous authorizations                             $50,000                0         $50,000 
Current request for authorization                  $250,000                0        $250,000 
Total authorizations, including this request         $300,000                0        $300,000 
Remaining amount to be authorized           $10,192,000             $0    $10,192,000 
Annual Budget Status and Source of Funds 
The Stormwater Pond Bird Deterrent Improvements (CIP #C800980) is included in the 2018-
2022 capital budget and plan of finance with a budget of $11,384,000. The reduction in budget
was transferred to the Aeronautical Allowance CIP #C800753, which resulted in no net change
to the Airport capital budget. 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 was considered to be one of the important criteria and 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 

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

COMMISSION AGENDA  Action Item No. __6d__                              Page 6 of 6 
Meeting Date: June 12, 2018 

PREVIOUS COMMISSION ACTIONS OR BRIEFINGS 
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.