TagEnvironmental Impact Statement(400)

This document outlines the federal (NEPA) and state (SEPA) environmental review processes related to Sea-Tac Airport, tracing key milestones from initial scoping in 2018 through the issuance of a Finding of No Significant Impact (FONSI) in September 2025 and a subsequent court appeal filed in November 2025. The NEPA process involved public comment periods, city council presentations, and a 4-city interlocal agreement, while the SEPA process determined the project required a full Environmental Impact Statement (EIS), with a Draft EIS expected in Q1 2026. Together, these timelines reflect years of coordinated efforts by multiple cities to formally challenge and scrutinize the environmental impacts of airport operations and expansion.

A report by the Washington State Department of Ecology’s Air Quality Program examining overburdened communities that are highly impacted by air pollution. The document includes publication information, contact details for regional offices, and ADA accessibility information.

This is a legal filing in the U.S. Court of Appeals for the D.C. Circuit in which the U.S. Environmental Protection Agency asks the court to vacate its own previously issued air quality standard, arguing that EPA lacked the statutory authority to revise the standard without completing a full review process. The case centers on National Ambient Air Quality Standards (NAAQS) under the Clean Air Act, not airport noise policy. This document does not contain information relevant to Sea-Tac Airport noise policy.

The cities of Burien, Des Moines, and SeaTac are joining forces under a formal Interlocal Agreement to coordinate their review of and legal response to the Port of Seattle's Sea-Tac Airport Sustainable Airport Master Plan (SAMP), which could bring significant noise and environmental impacts to surrounding communities. The agreement, considered by Des Moines City Council on November 13, 2025, allows the three cities to jointly hire environmental consultants and legal counsel to analyze and formally challenge the airport expansion's environmental review under both federal (NEPA) and state (SEPA) law. A Draft Environmental Impact Statement from the Port is expected in early 2026, with the overall process estimated to conclude by December 31, 2028.

The cities of Burien, Des Moines, and SeaTac have entered into a formal agreement to coordinate their review of, and potential legal challenges to, the Port of Seattle's Sustainable Airport Master Plan, which could significantly impact surrounding communities over the next 20 years. The three cities agreed to share costs proportionally based on population, jointly hire environmental consultants and legal counsel, and issue unified comment letters during the NEPA and SEPA environmental review processes. Key provisions require unanimous agreement to file a joint appeal and a two-city majority to continue litigation at each subsequent stage.