Draft Environmental Impact Statement for the Sustainable Airport Master Plan Near-Term Projects

The Port of Seattle has released a Draft Environmental Impact Statement (EIS) under Washington State's environmental review law for 31 near-term construction projects at Seattle-Tacoma International Airport (SEA). The projects, which include a new 19-gate terminal and an elevated busway system, are designed to handle up to 56 million passengers by 2032. While a prior federal review found no significant environmental impacts requiring mitigation except for surface transportation, this state-level review evaluates two action alternatives alongside a no-action scenario.

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Port of Seattle Draft Environmental Impact Statement (EIS) under Washington State Environmental Policy Act (SEPA), Chapter 43.21C RCW, for Seattle-Tacoma International Airport (SEA) Sustainable Airport Master Plan (SAMP) Near-Term Projects (NTPs). Covers 31 Near-Term Projects including a new terminal with 19 gates and an elevated busway with three stations connecting rental car facility, new terminal, and main terminal, designed to accommodate 56 million passengers and meet forecasted demand to 2032. Evaluates two action alternatives — Proposed Action Alternative and Hybrid Terminal Option — against a no-action alternative. FAA issued Finding of No Significant Impact/Record of Decision under NEPA in September 2025; surface transportation identified as the only category with potential significant impact. POS SEPA No. 2026-01. Prepared in accordance with WAC Chapter 197-11 and Port of Seattle Resolution No. 3650.

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