TagCEQ(27)

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.

The U.S. Supreme Court ruled in May 2025 that federal agencies have broad discretion in determining the scope of environmental reviews required under the National Environmental Policy Act (NEPA). The case involved a proposed 88-mile railroad in Utah, where the Court held that agencies do not need to analyze the environmental effects of separate upstream or downstream projects — such as oil drilling or refining — when reviewing a specific infrastructure project. Courts must give substantial deference to agency decisions about what to include in environmental impact statements, rather than imposing their own judgment about what details are required.

This Congressional Research Service report explains how President Trump's 2025 executive orders revoked earlier Clinton and Biden administration environmental justice policies and directed federal agencies, including the EPA, to close environmental justice offices and end related programs. The report outlines which specific EPA programs and activities may be affected, such as grant programs, screening tools, and interagency councils. It also notes that while the executive orders change agency priorities, they do not override existing federal pollution control laws that Congress has established.

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.

In May 2024, the Council on Environmental Quality published major updates to the rules governing how federal agencies must review environmental impacts of projects, affecting everything from public participation to project timelines. The changes place new emphasis on environmental justice, requiring agencies to meaningfully engage communities facing disproportionate environmental burdens, and remove previous rules that limited who could challenge agency decisions in court. While some updates are designed to speed up the review process, others may add new requirements for agencies and project sponsors seeking federal permits or funding.