Template revised April 12, 2018.
COMMISSION
AGENDA MEMORANDUM
Item No.
9b
BRIEFING ITEM
Date of Meeting
January 28, 2020
DATE: January 15, 2020
TO: Stephen P. Metruck, Executive Director
FROM: Arlyn Purcell, Director, Aviation Environment and Sustainability
Steve Rybolt, Sr. Environmental Program Manager, Aviation Environment and
Sustainability
SUBJECT: Sustainable Airport Master Plan (SAMP) Near-Term Projects (NTP) Environmental
Review Briefing –Forecast and Schedule Update
EXECUTIVE SUMMARY
This briefing will provide an overview of the results of the forecast update conducted for the
Sustainable Airport Master Plan (SAMP) Near-Term Projects environmental review and the
current schedule.
SUSTAINABLE AIRPORT MASTER PLAN NEAR-TERM PROJECTS ENVIRONMENTAL REVIEW
The Port of Seattle prepared the SAMP as a blueprint for changes at Seattle-Tacoma
International Airport (Sea-Tac Airport) to meet future demand. The SAMP planning process was
completed in 2018 and identified a set of Near-Term Projects (NTP) that are planned for
construction by 2027 as well as a Long-Term Vision. The NTP are the subject of this
environmental review and include more than 30 projects that would improve efficiency, safety,
access to the Airport, and support facilities for airlines and the Airport.
The Federal Aviation Administration (FAA) initiated a National Environmental Policy Act (NEPA)
Environmental Assessment (EA) and the Port of Seattle (Port) initiated a State Environmental
Policy Act (SEPA) Environmental Impact Statement (EIS) to evaluate and disclose the potential
environmental effects of the NTP.
Scoping, one of the first steps in the SAMP NTP environmental review, was completed on
September 28, 2018. Scoping is an early and open process for determining the scope of issues
that will be addressed in the environmental review document, soliciting input regarding the
NTP and reasonable alternatives, and identifying concerns regarding the potential
environmental effects of the NTP. The resulting comments provided valuable input that led to
several changes to the SAMP NTP environmental review scope.
One key outcome of the scoping process was a decision to review and update the forecast
originally developed in 2015 as part of the SAMP planning work.
COMMISSION AGENDA – Briefing Item No. 9b Page 2 of 3
Meeting Date: January 28, 2020
Template revised September 22, 2016.
FORECAST UPDATE
The SAMP forecasts for Sea-Tac Airport were completed in 2015 using 2014 as the base year.
Since then, strong economic growth, lower airfares, and airline competition drove passenger
traffic to rise faster than originally forecast. Passenger volume at SEA increased by 40 percent
between 2014-2018.
The updated demand forecast shows that the airport will reach the 2027 forecast activity levels
for operations by approximately 2022, five years sooner than originally projected, and for
passenger activity by 2023. However, this forecast only considers demand for services and
does not consider airport constraints such as the availability of gates and aircraft parking.
Gate and aircraft parking constraints will likely limit substantial activity increases at the airport
beyond 2023. In response, the Port, in collaboration with the FAA, developed estimates to
illustrate slower growth scenarios based on facility constraints. There are separate scenarios for
activity with and without the proposed NTP.
This constrained operating growth scenarios will be used as the basis for the SAMP NTP
environmental review analysis.
The FAA approved the updated 2019 demand forecast and concurred with the constrained
operating growth scenarios on January 10, 2020.
2027
2032
Passengers
(millions)
Aircraft
Operations
Passengers
(millions)
SAMP Demand
Forecast (2015)
56.0
527,000
63.0
SAMP Updated
Demand
Forecast (2019)
61.1
557,000
68.2
No Action
Constrained
Scenario
58.1
506,000
60.7
Proposed Action
Constrained
Scenario
59.2
524,000
63.1
Table 1 – SAMP Demand Forecasts and Constrained Scenarios
The table above shows both forecast activity demand and constrained growth scenarios. The
SAMP Demand Forecast [2015] and SAMP Updated Demand Forecast [2019] are based on
market demand and do not assume specific assumptions about physical, regulatory,
environmental or other impediments to aviation activity growth. Conversely, the constrained
growth scenarios represent known barriers to growth at Sea-Tac Airport.
COMMISSION AGENDA – Briefing Item No. 9b Page 3 of 3
Meeting Date: January 28, 2020
Template revised September 22, 2016.
EXTENDED SCHEDULE
The forecast update and other scope changes have resulted in an extension of the schedule:
• Update to the demand forecast and development of constrained operating growth
scenarios
• Continued advanced planning coordination
• Additional technical environmental analysis, in response to scoping comments
• Separation of the NEPA and SEPA documents and processes
• Continued extensive stakeholder engagement and community outreach
Key milestones include:
Oct. 2020 NEPA EA draft document released for agency and public review
Nov. 2020 NEPA EA agency and public review complete
Apr. 2021 NEPA EA final document and decision
May 2021 SEPA EIS draft document released for agency and public review
Jul. 2021 SEPA EIS agency and public review complete
Sep. 2021 SEPA EIS final document
ATTACHMENTS TO THIS BRIEFING
(1) Sustainable Airport Master Plan (SAMP) Near-Term Projects (NTP) Environmental
Review Briefing – Updated Forecast and Schedule PowerPoint presentation
PREVIOUS COMMISSION ACTIONS OR BRIEFINGS
February 26, 2019 – Commission Briefing: “Sustainable Airport Master Plan (SAMP) Near-
Term Projects (NTP) Environmental Review Briefing – Scoping Report”
May 8, 2018 – Commission Briefing: “Sustainable Airport Master Plan (SAMP) Planning and
Environmental Update”
February 13, 2018 - Commission Briefing: "Sustainable Airport Master Plan (SAMP) Planning
Update"
November 10, 2015 – Commission Action: “Environmental Review (National Environmental
Policy Act and State Environmental Policy Act) Personal Services Agreement for the
Sustainable Airport Master Plan”