TagPart 150(262)

In September 2025, acoustical engineers tested 29 homes near Seattle-Tacoma International Airport to measure how much aircraft noise penetrates indoors. The study found that none of the homes exceeded the 45-decibel interior noise threshold required to qualify for federally funded soundproofing treatments, though 10 homes had at least one room above that level. The findings are part of SEA's Repair and Replacement Program, which evaluates whether previously soundproofed homes need updated windows and doors.

A presentation introducing the Part 150 Study process for Seattle-Tacoma International Airport. The document explains the federal regulatory framework for preparing Noise Exposure Maps and Noise Compatibility Programs, outlines the phases of the study process, and provides historical context of previous Part 150 studies conducted at SEA from 1985 to 2014.

The Highline Forum held its September 24, 2025 meeting at the City of Des Moines Police Training Room, with key agenda topics including an update on the Part 150 Noise Study for Seattle-Tacoma International Airport and the South King & Port Community Fund Environmental Improvement Program. The hybrid meeting, co-chaired by Councilmember Matt Mahoney, also featured presentations on the SEA Airport Aviation Director search and a StART update from Port of Seattle representatives. The forum meets bimonthly throughout 2025, rotating among local host cities including Federal Way, Burien, Des Moines, and SeaTac.

This document is the agenda and attendance record for the fourth meeting of the Part 150 Study Technical Review Committee, held on August 11, 2025, at Seattle-Tacoma International Airport. The meeting covered updates on Phase 1 Noise Exposure Mapping, a kickoff for Phase 2 Noise Compatibility Program planning, and a review of the project schedule. Representatives from neighboring cities, airlines, King County, the FAA, and the Port of Seattle participated as members or liaisons.

14 CFR Part 150 sets out the federal rules for airport noise compatibility planning, establishing how airports must measure noise, map affected areas, and develop programs to reduce conflicts between aircraft noise and nearby land uses. It defines key terms such as day-night average sound level (DNL), compatible and noncompatible land use, and noise exposure maps, and it outlines the process by which the FAA reviews and approves or disapproves airport noise compatibility programs. Importantly, FAA approval of such a program does not itself commit federal funding or authorize specific actions without further environmental review.