A 1997 impact mitigation study found that the expansion of Sea-Tac International Airport, including a proposed Third Runway, would impose significant costs on surrounding communities — with Burien and Des Moines alone accounting for nearly 80% of an estimated $2.95 billion in mitigation needs. The study examined 26 specific environmental impacts across areas such as noise, air quality, and water quality, and recommended establishing a permanent noise monitoring program to ensure projected noise contours are not exceeded. It also called for a comprehensive South King County planning effort to balance the needs of communities, schools, hospitals, and the airport.Open full document
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A 1997 study prepared for surrounding communities examining the potential impacts of the proposed Third Runway project at Sea-Tac International Airport. The study estimates $2.95 billion in potential mitigation costs, with approximately 80% attributed to Burien and Des Moines alone, covering noise, traffic congestion, and socioeconomic impacts. The report recommends an overall planning approach for Southern King County and proposes a permanent noise monitoring program to verify EIS projections are not exceeded.