Draft EIS Summary: Seattle-Tacoma International Airport SEPA Environmental Impact Statement for the Sustainable Airport Master Plan Near-Term Projects

The Port of Seattle has released a Draft Environmental Impact Statement for its Sustainable Airport Master Plan (SAMP), outlining 31 near-term construction projects at Seattle-Tacoma International Airport aimed at handling a projected 56 million passengers by 2032. Key proposals include a second terminal with 19 new aircraft gates, an elevated busway connecting terminals, expanded cargo facilities, airfield safety upgrades, and new sustainable aviation fuel infrastructure. The plan addresses longstanding capacity shortfalls in parking, check-in, security, and gate areas that were already undersized as of 2018.

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Draft Environmental Impact Statement (EIS) summary prepared by the Port of Seattle under the State Environmental Policy Act (SEPA) for the Sustainable Airport Master Plan (SAMP) 31 Near-Term Projects (NTPs) at Seattle-Tacoma International Airport (SEA). Documents proposed expansion to accommodate 56 million projected annual passengers through 2032, including a second terminal and concourse with 19 additional aircraft gates, elevated busway linking rental car facility and terminals, cargo facilities, airfield taxiway updates (A01–A10), landside roadway realignment, Northeast Ground Transportation Center, employee parking structure, sustainable aviation fuel facilities, ARFF facilities, and airline support buildings. Exhibit S-1 maps all proposed NTP locations by category: Second Terminal Projects (T01, T02), Cargo Expansion (C01–C03), Airfield Operational and Safety/Standards Projects, and Sustainable Aviation Fuel Projects (S01). Filed May 2026 as part of the SAMP SEPA EIS process.

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