TagSustainable Airport Master Plan(237)

Seattle-Tacoma International Airport's Sustainable Airport Master Plan (SAMP), completed in 2018, outlines 31 near-term development projects and is currently undergoing a federal environmental review (NEPA) process, with a draft Environmental Assessment published in October 2024. The review evaluates potential impacts on air quality, water resources, noise, and other environmental factors before any projects move forward. Once the federal NEPA process concludes, a Washington State-level environmental review (SEPA) will follow.

The Port of Seattle announced the release of a draft Environmental Assessment (EA) for Seattle-Tacoma International Airport's Sustainable Airport Master Plan (SAMP) on October 21, 2024, covering 31 near-term development projects including a second terminal, elevated busway, and new cargo facilities. The plan addresses projected regional population growth of one million people by 2035. Members of the public were invited to submit comments on potential environmental impacts during an open comment period running from October 21 to December 5, 2024.

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.

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.

The Federal Aviation Administration (FAA) issued a Negative Determination in July 2024, concluding that planned near-term construction and equipment relocation projects at Seattle-Tacoma International Airport (SEA) are not reasonably likely to cause effects on Washington State's coastal zone. The 31 Near-Term Projects, which include taxiway extensions, blast pad expansions, and relocation of navigational aids, are part of the airport's Sustainable Airport Master Plan and are scheduled to begin construction in 2026. The FAA requested written concurrence from the Washington State Department of Ecology, while the Port of Seattle remains responsible for separate consistency certification for any projects requiring Clean Water Act permits.

The FAA issued a Negative Determination in July 2024, concluding that planned near-term construction and equipment-relocation projects at Seattle-Tacoma International Airport are not likely to cause effects on Washington State's coastal zone. The 31 Near-Term Projects—drawn from the airport's Sustainable Airport Master Plan—include taxiway extensions, blast pad expansions, and high-speed runway exits, with FAA involvement limited to relocating navigational aids and adjusting flight procedures on airport property. The Washington State Department of Ecology was asked to concur with this finding under the Coastal Zone Management Act.

The FAA issued a Negative Determination in July 2024, concluding that planned Near-Term Projects at Seattle-Tacoma International Airport (SEA) are not likely to cause coastal effects under the Coastal Zone Management Act. The projects include taxiway extensions, blast pad expansions, and relocation of navigational equipment across four airfield areas, with construction set to begin in 2026 over a six-year period. Because all FAA actions are confined to upland areas within the airport property, no significant impacts to Washington State's coastal zone resources were identified.

This technical report, prepared by Landrum & Brown for the Port of Seattle in June 2024, outlines the purpose and need for near-term construction and improvement projects identified in Sea-Tac Airport's Sustainable Airport Master Plan. It is part of a broader set of supporting documents that also covers alternatives analysis, terminal needs assessment, and air cargo facility requirements. The report provides the foundational justification for proposed airport development decisions and infrastructure changes.

This document is an Environmental Justice Protocol prepared by Landrum & Brown, Incorporated for the Federal Aviation Administration and the Port of Seattle in June 2024. It addresses socioeconomics, environmental justice, and children's health considerations related to Seattle-Tacoma International Airport. The protocol provides a framework for evaluating how airport-related impacts may affect minority, low-income, and other vulnerable populations in surrounding communities.