TagSea-Tac Airport(1835)

This October 2024 Draft Environmental Assessment, prepared by Landrum & Brown for the Port of Seattle and the FAA, evaluates the environmental impacts of near-term construction projects at Seattle-Tacoma International Airport as part of its Sustainable Airport Master Plan. The assessment covers a wide range of environmental topics—including noise and noise-compatible land use, air quality, water resources, and environmental justice—for proposed improvements to passenger terminals, cargo facilities, airfield design, taxiways, and fuel storage. It is intended to support FAA decision-making under the National Environmental Policy Act (NEPA) and addresses the airport's ability to accommodate a projected 56 million annual passengers.

The FAA submitted a Biological Evaluation to support an informal consultation under the Endangered Species Act for near-term construction projects at Seattle-Tacoma International Airport, all expected to be completed by 2032. The projects aim to expand passenger and cargo capacity, upgrade taxiway layouts, and increase fuel storage including sustainable aviation fuel. The evaluation assessed potential impacts on 14 species, determining that several—including Chinook salmon, bull trout, and killer whales—may be affected but not likely adversely, while the remaining species, such as the marbled murrelet and North American wolverine, would face no effect.

The Port of Seattle's Sustainable Airport Master Plan (SAMP) outlines 31 near-term construction projects at Seattle-Tacoma International Airport, including a second terminal with 19 gates, new cargo facilities, and roadway changes, all aimed at serving up to 56 million passengers annually by 2050. A federal environmental review (NEPA) is underway to assess potential impacts, with a 45-day public comment period opening October 21, 2024, allowing community members to submit feedback online, by mail, or at public libraries in Burien, Des Moines, and SeaTac. A separate state-level environmental review (SEPA) will follow once the federal process is complete.

This report analyzes existing traffic conditions around Seattle-Tacoma International Airport as part of the Sustainable Airport Master Plan (SAMP) Near-Term Projects Environmental Review. It examines 108 intersections—including 63 signalized, 41 stop-controlled, and 4 uncontrolled—along key routes connecting the airport to surrounding communities, focusing on the weekday PM peak hour (4–6 p.m.). Freeway segments of SR 518 and I-5 were also evaluated at WSDOT's request to provide a comprehensive picture of surface transportation conditions in the airport study area.

This technical report analyzes existing surface transportation and traffic conditions around Seattle-Tacoma International Airport as part of the Sustainable Airport Master Plan (SAMP) Near-Term Projects Environmental Review. It examines 108 intersections — including signalized, stop-controlled, and uncontrolled locations — along key travel routes connecting the airport to surrounding communities, focusing on weekday PM peak-hour traffic volumes. The study also includes freeway analysis of SR 518 and I-5 ramps and segments at the request of WSDOT.