TagEnvironmental Impact Statement(325)

This March 2024 technical report, prepared by Landrum & Brown for the Port of Seattle, assesses air quality and climate impacts associated with near-term construction and operational projects outlined in the Sustainable Airport Master Plan for Seattle-Tacoma International Airport. It analyzes emissions from sources including aircraft, ground support equipment, stationary and mobile sources, auxiliary power units, and construction activities. The report follows NEPA air quality and climate protocols to evaluate potential environmental effects of planned airport improvements.

This technical report, prepared by Parametrix for the Port of Seattle in February 2024, documents the wetlands and streams found at Seattle-Tacoma International Airport as part of the Sustainable Airport Master Plan (SAMP) Near Term Projects. It covers the delineation of wetland and stream boundaries, assesses potential impacts to these aquatic areas from planned airport improvements, and outlines mitigation measures and permitting approaches to address those impacts.

This technical report, prepared by Parametrix for the Port of Seattle in February 2024, documents the wetlands and streams found at Seattle-Tacoma International Airport as part of the Sustainable Airport Master Plan (SAMP) Near Term Projects. It covers the delineation of wetland and stream boundaries, assessments of potential impacts to these aquatic areas from planned airport projects, and proposed mitigation measures and permitting strategies to address those impacts.

This technical report, prepared by Parametrix for the Port of Seattle in February 2024, documents the wetlands and streams found within and around Seattle-Tacoma International Airport as part of the Sustainable Airport Master Plan (SAMP) Near Term Projects. It covers the delineation of aquatic critical areas, assessments of potential project impacts on wetlands and waterways, proposed mitigation measures, and the permitting approach needed to address those impacts. The report also includes analysis of impervious surface changes and Federal Flood Risk Management Standard (FFRMS) compliance worksheets.

This February 2024 technical report from the Port of Seattle documents the wetlands and streams located at and around Seattle-Tacoma International Airport as part of the Sustainable Airport Master Plan (SAMP). It includes mapped locations of wetlands surveyed across multiple years (2006, 2014, and 2017) along with stream corridors such as Miller Creek, Des Moines Creek, and Walker Creek. Field hydrology monitoring data from 2020 is also provided, recording groundwater depth and soil saturation measurements to assess wetland conditions across the airport property.

Washington Senate Bill 5990, introduced in January 2024, aims to reduce environmental health disparities by requiring assessment of cumulative pollution burdens on overburdened communities before approving new projects. The bill defines key terms such as 'disproportionate impact' and 'environmental justice impact statement,' and establishes a framework to evaluate stressors like air pollution, water quality, and public health risks. Note: this bill addresses broad environmental justice concerns statewide and does not specifically address Sea-Tac Airport noise policy.

This Land Use Technical Report, prepared for the Port of Seattle's Sustainable Airport Master Plan Near-Term Projects, examines how proposed improvements at Seattle-Tacoma International Airport align with land use plans and regulations in surrounding communities including SeaTac, Des Moines, Burien, and Tukwila. It reviews existing and planned land uses, relevant local and regional planning documents, and assesses potential land use impacts under three alternatives: No Action, Proposed Action, and a Hybrid Terminal Option. The report was originally prepared in January 2024 by Landrum & Brown and later updated in April 2026 by Parametrix for the SEPA Environmental Impact Statement.

This document contains scoping comments submitted to the Port of Seattle regarding the Sustainable Airport Master Plan (SAMP) environmental review process, compiled by the Quiet Skies Coalition. Community members raised concerns about the lack of long-term human health and environmental impact studies related to aircraft noise and emissions, questioning why the Port had not studied the effects of a four-year increase of 97,000 additional annual flights. The comments request comprehensive assessments covering neighborhoods such as Des Moines, Burien, Tukwila, and Normandy Park, and call for the Port to include worldwide scientific studies on the health effects of aircraft noise and pollution in its environmental review.

This U.S. Army Corps of Engineers Record of Decision evaluates a permit application from the Port of Seattle (case 1996-4-02325) for construction work in the Seattle area, assessing environmental impacts including effects on wetlands, fish habitat, water quality, air quality, and noise. The document reviews compliance with numerous federal and state laws—such as the Clean Water Act, Endangered Species Act, and National Environmental Policy Act—and addresses public and agency concerns, including those related to airport and aircraft safety. It ultimately documents the Corps' findings and determinations regarding whether to issue, conditionally issue, or deny the requested permit.