COMMISSION 
AGENDA MEMORANDUM                        Item No.          11b 
BRIEFING ITEM                            Date of Meeting      October 25, 2022 
DATE:    October 5, 2022 
TO:        Stephen P. Metruck, Executive Director 
FROM:    Stan Shepherd, Sr Manager, Airport Noise Programs
Tom Fagerstrom, Airport Noise Programs Coordinator 
Sarah Cox, Director, Aviation Environment & Sustainability 
SUBJECT:  Briefing on the SEA Part 150 Noise and Land Use Compatibility Study Update 
EXECUTIVE SUMMARY
A Part 150 Noise and Land Use Compatibility Study is required by the Federal Aviation
Administration (FAA) to update airport noise compatibility programs and establish eligibility for
Airport Improvement Program (AIP) grant funds. SEA’s last Part 150 update was completed and
approved by the FAA in 2014.
In 1985 the Port completed the first Part 150 Study at SEA.  Since that time there have been
three other updates to the Study in 1993, 2002, and 2014.  Through our Part 150 noise
mitigation programs, flight tracking, noise monitoring, and airline outreach incentive programs,
the Port has been a national leader in both sound mitigation and noise abatement. To date we
have spent over $400  million on total mitigation programs including home and school
insulation, and property acquisition and relocations associated with the Third Runway project.
Noise Abatement programs have encouraged airline usage of newer and quieter aircraft,
promoted high FAA compliance levels with noise abatement flight paths and procedures, and
deployed a comprehensive flight tracking and noise monitoring system. 
A Part 150 Study is a multi-year effort that assesses current and future aircraft noise levels and
their associated effects within impacted areas of the surrounding communities.  The study
establishes land use guidelines and identifies areas of significant aircraft noise and incompatible
land uses. Part 150 regulation establishes that an area is considered impacted by aircraft noise
when located within a 65 DNL noise contour. DNL is an annual average of aircraft noise and is
the FAA required noise metric to be used in Part 150 studies.  The study process includes
extensive community involvement, including the scheduling of multiple public meetings.
A consulting team will be chosen to lead the study and will typically consist of professionals in
land use planning, public relations, aviation noise, and environmental issues.  In addition to
consultants, Port employees will participate in the update in the areas of land use planning, GIS
applications, community outreach, environmental evaluations, and noise. The work that will be

Template revised April 12, 2018.

             COMMISSION AGENDA – Briefing Item No. 11b                                 Page 2 of 4
Meeting Date: October 25, 2022 
performed by the consulting team is highly technical and must be consistent with federal
regulations and address a wide array of community interests.

JUSTIFICATION
Since the completion of the previous Part 150 update in 2014, many changes have taken place
in the airport’s noise environment. Airline fleets have changed due to the introduction of many 
newer generation aircraft. Regional population growth has led to steadily increasing passenger
demands on SEA. Aircraft operations (takeoffs and landings) have increased, and associated
noise is a concern for local communities.
DETAILS 
Scope of Work 
The major focus of the Part 150 Noise and Land Use Compatibility Study update will be to
determine and analyze any changes in the 65 DNL noise environment compatibility since the
completion of the previous update in 2014 to determine if any additional sound insulation
programs could be eligible. Other areas of focus will include analysis of SEA’s noise abatement
programs, noise monitoring locations and possible opportunities for improved deployment.
Once a consultant is hired, a detailed full project scope of work will be developed using their
expertise in the prescriptive Part 150 process outlined in the regulation and will be discussed
with the commission before finalizing.
Elements of a Part 150 process typically include: 
•   Developing a Public Involvement Plan 
•   Developing an inventory of existing conditions 
•   Preparing (or evaluating existing) Aviation Demand Forecasts 
•   Evaluating the need for additional noise measurements 
•   Preparing an existing conditions DNL noise contour 
•   Preparing a future 5-year conditions DNL noise contour 
•   Evaluating land use and community noise impacts based on prepared contours 
•   Evaluating noise abatement procedure alternatives
•    Preparing a final Noise Compatibility Plan (NCP) 
Schedule 
Part 150 studies are multi-year efforts that include extensive community outreach and
involvement.  An initial schedule of milestones leading to project kickoff is included in this
section.  Staff will return to the Commission in November for project authorization and to
contract for the consultant team.  Commission will be briefed multiple times throughout the

Template revised September 22, 2016.

             COMMISSION AGENDA – Briefing Item No. 11b                                 Page 3 of 4
Meeting Date: October 25, 2022 
Part 150 study to provide updates  on the progress, associated costs, and community
involvement.
Activity                                       Timeframe 
Commission authorization to contract            2022 Quarter 4 
Consultant Advertisement                       2022 Quarter 4 
Consultant selection                              2023 Quarter 2 
Project scope agreement & data collection        2023 Quarter 3 
Full project kickoff/public outreach                2024 Quarter 1 
Estimated Cost Breakdown 
To be Authorized     Total Project Estimate 
Project Cost                                                $6,000,000                $7,000,000 
Total                                                        $6,000,000                 $7,000,000 
*Previous authorization of $1M was included with the April 12, 2022, legal settlement
agreement (see Previous Commission Actions listed below) 
Annual Budget Status and Source of Funds 
This project will be included in the Noise Programs department operating expense budget on an
annual basis during the project. The Port anticipates it will be reimbursed approximately 80%
through the FAA’s Airport Improvement Program (AIP) grant with the remaining 20% being
funded by the Airport Development Funds (ADF). The spending cashflow is anticipated to be
approximately $500K in 2023, $2M in 2024, $2M in 2025 and $2.5M in 2026.
ENVIRONMENTAL SUSTAINABILITY/COMMUNITY BENEFITS 
This update will enable the Airport to evaluate any operational changes, and associated noise
effects, as a result of increased operations and airline fleet changes. Prior noise contours will
be compared with current contours to determine if greater or lesser noise impacts exist. If
greater impacts exist, that information will be useful to planning future Port and FAA noise
mitigation efforts for the community.
ATTACHMENTS TO THIS BRIEFING 
(1) P art 150 Study Update Resolution No. 3683
(2) Presentation slides



Template revised September 22, 2016.

             COMMISSION AGENDA – Briefing Item No. 11b                                 Page 4 of 4
Meeting Date: October 25, 2022 
PREVIOUS COMMISSION ACTIONS OR BRIEFINGS 
April 12, 2022 – The Commission authorized a legal settlement agreement that included a
commitment to engage a consultant to conduct a full Part 150 update for SEA Airport
which will include noise contours for the airport and to make a budget commitment in
2023 for funding commencement of the update. This action also included the
authorization of $1M to begin the Part 150 Study Update. 
October 22, 2013 – The Commission approved Resolution No. 3683, which updated the Part
150 program by adding operational and land use elements to the Airport’s Noise
Compatibility Plan, which was formally approved by the FAA in 2014.
December 12, 2000 – The Commission approved Resolution 3443, which updated the Part
150 program by adding operational and land use elements to the Airports Noise
Compatibility Plan, which was formally approved by the FAA in 2002. 
July 13, 1993 – The Commission adopted Resolution No. 3144 which Amended the Part 150
program to include additional operational and land use elements to the Airports Noise
Compatibility Plan. 
January 8, 1985 – The Commission adopted Resolution No. 2943; creating the first Seattle-
Tacoma International Airport Part 150 program which established the Port’s Noise
Acquisition and Insulation programs. 









Template revised September 22, 2016.