TagSustainable Airport Master Plan(237)

This appendix outlines the traffic mitigation measures required for the Seattle-Tacoma International Airport Sustainable Airport Master Plan Near-Term Projects, as mandated by the FAA's Record of Decision and the Port of Seattle's State Environmental Policy Act Environmental Impact Statement. It details specific intersection improvements across multiple jurisdictions—including the City of SeaTac, City of Burien, City of Des Moines, and WSDOT—such as new traffic signals, roundabouts, and turn lane additions, along with proportionate-share cost contributions where full mitigation is not required. The measures are designed to address projected traffic impacts through 2037 and maintain acceptable levels of service at affected intersections near the airport.

Meeting agenda for April 13, 2026 Des Moines Airport Advisory Committee meeting and minutes from the March 9, 2026 meeting. Agenda includes discussion of SAMP updates, StART meeting updates, committee workplan amendments, and support for city response to SAMP Draft EIS.

Vashon Island Fair Skies (VIFS), a Washington nonprofit representing residents affected by aircraft noise, has filed a petition in the Ninth Circuit Court of Appeals challenging a September 2025 FAA decision approving near-term expansion projects at Seattle-Tacoma International Airport. The group argues that the FAA's environmental review failed to adequately address the significant noise impacts on Vashon and Maury Islands resulting from concentrated, low-altitude flight paths introduced under the FAA's NextGen navigation program. VIFS has been actively opposing these flight path changes since 2018, when new Performance-Based Navigation procedures began routing more aircraft directly over the islands at lower altitudes.

In November 2025, the law firm Ogden Murphy Wallace (OMW) agreed to jointly represent the cities of Burien, Des Moines, and SeaTac as special environmental counsel in matters related to the Port of Seattle's Sustainable Airport Master Plan. The firm's scope of work covers environmental review processes under federal (NEPA) and state (SEPA) law, as well as any potential litigation against the Port of Seattle or the Federal Aviation Administration. Attorneys are billed at hourly rates ranging from $300 to $535 depending on role and experience, with no advance fee deposit required.