Tagenvironmental assessment(30)
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2025-09-24Final Environmental Assessment for the Sustainable Airport Master Plan Near-Term Projects: Seattle-Tacoma International Airport
★ 33The Federal Aviation Administration (FAA) released a Final Environmental Assessment (EA) in September 2025 for near-term construction and development projects at Seattle-Tacoma International Airport, prepared on behalf of the Port of Seattle. The Final EA was updated from an earlier Draft EA to reflect public and agency comments, correct errors, and remove sections on climate change, environmental justice, and cumulative impacts following changes to federal executive orders, regulations, and a 2025 Supreme Court ruling. These regulatory shifts meant the FAA was no longer required to analyze how the proposed projects might affect vulnerable communities or contribute to broader environmental trends. -
2025-10-14Final EA Impact Classification Chart
A slide titled 'In the FINAL EA, A Few Items Changed' presents a tiered matrix of environmental impact categories ranging from 'Significant impacts requiring mitigation' down to 'Not present.' Notable changes shown include 'Climate' being struck through and replaced with 'Greenhouse Gas Emissions,' and 'Environmental Justice' similarly struck through within the Socioeconomic category, indicating terminology revisions between draft and final Environmental Assessment versions. -
2025-09-01Environmental Assessment for the Sustainable Airport Master Plan Near-Term Projects: Chapter 4 — Environmental Consequences
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. -
2025-09-01Sustainable Airport Master Plan Environmental Assessment: Chapter 3 – Affected Environment
This section of the Seattle-Tacoma International Airport (SEA) Environmental Assessment describes the airport's physical setting and surrounding communities as they existed in 2022, serving as the baseline for evaluating potential impacts from near-term expansion projects. SEA occupies approximately 2,800 acres in the City of SeaTac, bordered by state routes and residential neighborhoods in cities including Burien, Des Moines, and Tukwila. The assessment defines a General Study Area of 3,692 acres where direct or indirect impacts from proposed actions may reasonably be expected to occur. -
2024-12-03Seattle-Tacoma International Airport (SEA) Sustainable Airport Master Plan environmental assessment: EA highlights and public comment
The Port of Seattle held a public meeting on December 3, 2024 in Des Moines, WA to present highlights from the Environmental Assessment (EA) for Seattle-Tacoma International Airport's Sustainable Airport Master Plan (SAMP). The SAMP outlines a wide range of near-term construction and expansion projects across the airport, including airside, landside, terminal, cargo, and support facilities. The meeting provided an opportunity for community members to learn about the plan's environmental findings and submit public comments. -
2024-10-01SAMP Exhibit 3-3 Area of Potential Effects (APE) Water
Exhibit 3-3 from the Seattle-Tacoma International Airport Environmental Assessment for the Sustainable Airport Master Plan (SAMP) Near-Term Projects, prepared by Landrum & Brown, dated October 2024 (Draft). The map depicts the Biological Resources ESA Study Area boundary (shown in blue dashed line) surrounding the airport property, extending to Puget Sound to the west and encompassing nearby waterways including Miller Creek and Walker Creek. -
2024-10-01Appendix O: Agency & Public Engagement — Seattle-Tacoma International Airport Environmental Assessment for the Sustainable Airport Master Plan Near-Term Projects
This appendix summarizes the public and agency engagement activities conducted as part of the Environmental Assessment (EA) for Seattle-Tacoma International Airport's Sustainable Airport Master Plan Near-Term Projects. Outreach included scoping meetings held in 2018 with seven agencies and four public sessions in surrounding cities, as well as advertisement in multiple languages across newspapers, email, and social media. Public meetings were scheduled in November 2024 at locations in Federal Way, Des Moines, Burien, and SeaTac, with a comment deadline of December 5, 2024. -
2024-10-01Seattle-Tacoma International Airport Environmental Assessment for the Sustainable Airport Master Plan Near-Term Projects: Chapter 6 — List of Preparers
This section of the Seattle-Tacoma International Airport Environmental Assessment lists the individuals and organizations responsible for preparing the document, including staff from the FAA, Port of Seattle, and several consulting firms. The team covered a wide range of technical areas, with specialists handling noise analysis, air quality, surface transportation, wetlands, cultural resources, and public engagement. The assessment was produced in October 2024 as a draft under the airport's Sustainable Airport Master Plan for near-term projects. -
2024-10-01Seattle-Tacoma International Airport Environmental Assessment for the SAMP Near-Term Projects: Chapter 5 — Cumulative Impacts
This section of the Seattle-Tacoma International Airport Environmental Assessment examines cumulative impacts from past, present, and reasonably foreseeable future development projects at and around SEA airport, covering the period from 2017 through 2032. It reviews actions by the Port of Seattle and surrounding cities and agencies — including hotel construction, terminal expansions, and flight procedure changes — to assess how their combined environmental effects, such as noise, emissions, and land use changes, may affect nearby communities. Projects beyond 2032 or those in the long-term vision phase are excluded from detailed analysis due to insufficient specificity. -
2024-10-01Seattle-Tacoma International Airport Environmental Assessment for the SAMP Near-Term Projects: Chapter 4 — Environmental Consequences
This October 2024 draft Environmental Assessment evaluates the potential environmental impacts of near-term construction and operational projects at Seattle-Tacoma International Airport under three alternatives: No Action, a Proposed Action, and a Hybrid Terminal Option. The analysis covers impacts through 2032 and an out-year of 2037, finding that increases in air quality emissions and effects on biological resources are not considered significant, with mitigation measures proposed for stormwater management and migratory bird nesting. Farmlands and Wild and Scenic Rivers were determined to have no presence in the study area and required no further analysis.