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.Open full document
Notes
This agenda item requests Des Moines City Council approval of an Interlocal Agreement (ILA) between Burien, Des Moines, and SeaTac to coordinate legal services, environmental review, and responses related to the Port of Seattle’s Sea-Tac Airport Sustainable Airport Master Plan (SAMP). The updated ILA restates the 2018 agreement, adds provisions for legal services, assigns fiscal management to SeaTac, and runs through December 31, 2028. The cities will work with outside legal counsel specializing in NEPA and SEPA to respond to the FAA’s environmental assessment and the Port’s upcoming Draft Environmental Impact Statement.
