TagSea-Tac Airport(1855)

This document is the References section of the Environmental Assessment for Seattle-Tacoma International Airport's Sustainable Airport Master Plan Near-Term Projects, finalized in September 2025. It lists all sources cited across the assessment's chapters, including federal regulations, FAA advisory circulars, technical memoranda, city comprehensive plans, and environmental studies used to evaluate the airport's proposed development projects. The referenced materials cover topics such as air quality, facility requirements, stormwater management, land use, and aviation activity forecasting.

The Final Environmental Assessment for Seattle-Tacoma International Airport's Sustainable Airport Master Plan near-term projects explains that cumulative impact analysis has been removed from the document. This change reflects recent legal developments, including the revocation of CEQ regulations implementing NEPA and a May 2025 Supreme Court ruling, which together mean federal agencies are no longer required to assess the combined environmental effects of separate but related projects. As a result, the section that previously contained cumulative impacts data and analysis is now absent from this final report.

This September 2025 Environmental Assessment evaluates three alternatives for near-term development projects at Seattle-Tacoma International Airport, comparing a No Action scenario against a Proposed Action and a Hybrid Terminal Option through analysis years 2032 and 2037. The study finds that while both action alternatives would increase aircraft operations to approximately 475,655 by 2032 and 509,892 by 2037, resulting in higher emissions and some biological resource impacts, none of the increases are considered significant. Mitigation measures, where warranted, include post-construction stormwater controls and nest protection protocols during construction activities.

The Port of Seattle has issued a Determination of Non-Significance (DNS) under Washington's State Environmental Policy Act (SEPA) for its Flight Corridor Management Program at Seattle-Tacoma International Airport. The program, conducted approximately every five years, identifies and removes trees and other obstructions near the airport's runways that could interfere with flight paths, while also requiring ongoing ecological monitoring and tree replacement. A 15-day public comment period ran through September 11, 2025, after which the Port planned to formally adopt the determination, with any appeals required to be filed in King County Superior Court within 21 days of formal adoption.

The Port of Seattle's Flight Corridor Management Program is an ongoing effort to identify and remove trees near Seattle-Tacoma International Airport (SEA) that obstruct the flight paths of its three parallel runways, as required by FAA regulations. Approximately every five years, the Port surveys the area, removes obstructing trees, and replants replacements, with each cycle documented in publicly available Implementation Plans and Regulatory Memoranda. This 2025 programmatic environmental review under Washington's State Environmental Policy Act (SEPA) covers the long-term program rather than individual removal projects.