TagPart 150(263)

This January 2025 technical report, prepared by Environmental Science Associates for the Port of Seattle, documents a pilot program assessing the condition and effectiveness of sound insulation previously installed in homes near Seattle-Tacoma International Airport. The report covers resident surveys, research into the expected useful life of sound insulation building materials, acoustic testing methods, and test results from selected homes. It aims to inform future decisions about repairing or replacing aging noise-reduction treatments in affected neighborhoods.

This document is Chapter One of the Seattle-Tacoma International Airport (Sea-Tac) Part 150 Noise Compatibility Study, finalized in October 2013. It provides an overview of the airport's size, ownership by the Port of Seattle, and its role as the Pacific Northwest's primary commercial hub, while explaining the federal regulations (14 CFR Part 150) that guide airport noise compatibility planning. The study was undertaken to update a 2002 noise plan, accounting for major changes such as the opening of a third parallel runway in 2008, with the goal of reducing noise impacts on surrounding communities.

A King County motion to adopt the King County International Airport’s Federal Aviation Regulation Part 150 Noise and Land Use Compatibility Study and to accept federal grants for implementing recommended programs. The motion outlines the airport’s economic importance and various noise mitigation strategies including sound insulation programs, flight restrictions, and a Ground Run-up enclosure.

This document presents evidence that the Port of Seattle violated Federal Grant Assurance C.6 and Washington State law RCW 53.54.020 in connection with its FAR Part 150 Noise Compatibility Program at Seattle-Tacoma International Airport. It compiles 17 items of supporting evidence, including a 1998 congressional request for a GAO audit, state auditor correspondence, findings by Deloitte & Touche identifying violations from 1990 to 1994, and records showing the Port received over $100 million in federal funds tied to noise mitigation commitments it allegedly failed to honor. The materials illustrate the consequences for surrounding communities and governments that held land-use authority under the noise compatibility planning process.