TagThird Runway(201)

A 1997 study examined the unequal distribution of costs and benefits generated by Seattle-Tacoma International Airport, finding that while the airport's economic benefits (jobs, income, and travel services) spread across the broader Puget Sound region, its harms—including noise, traffic, and reduced property values—fell disproportionately on a small number of nearby cities: Burien, Des Moines, Federal Way, Normandy Park, and Tukwila. Data from a 1991 passenger survey showed that these five heavily impacted communities accounted for only 5.9% of home-originating enplanements, while King County as a whole contributed 57.2%. The study concluded that mitigation measures were needed to redirect some of the airport's regional benefits back to the communities bearing the greatest burden of its operations.

This document outlines a Neighborhood Impact Matrices framework used to assess environmental, transportation, and socio-economic effects of a proposed airport-related project on communities surrounding Seattle-Tacoma International Airport, including cities such as Burien, Des Moines, Federal Way, Normandy Park, and Tukwila. Each matrix evaluates impacts across four columns — Measure, Impact, Mitigation, and Cost — covering issues such as aircraft noise (DNL and SEL contours), air quality, surface and groundwater quality, wetlands, and floodplains. Proposed mitigations range from neighborhood buyouts at $760,000 per acre for areas within the 65 DNL contour to easement and insulation programs, stormwater management plans, and flight track modifications.

In July 1996, the Puget Sound Regional Council adopted Resolution A-96-02, amending the region's Metropolitan Transportation Plan to include plans for a third runway at Seattle-Tacoma International Airport, paired with additional noise reduction measures. The decision followed years of study, including an Expert Panel finding that neither demand management strategies nor high-speed rail could eliminate the need for expanded capacity. Final approval of the runway remained contingent on environmental review by the Port of Seattle, Federal Aviation Administration permitting, and completion of required noise mitigation steps.

This 1996 Puget Sound Regional Council document summarizes the multi-year planning process that led to amending the regional transportation plan to include a third runway at Seattle-Tacoma International Airport. It traces decisions from the 1988 Regional Airport System Plan through the Flight Plan Project and environmental studies, explaining how planners concluded that no feasible alternative airport site existed and that measures like high-speed rail or congestion pricing could not substitute for added runway capacity. The plan also required implementation of additional noise reduction measures as a condition of approving the new runway.

This document summarizes the Puget Sound Regional Council’s planning process for amending the Metropolitan Transportation Plan to include a third runway at Sea-Tac International Airport. It covers the history of regional aviation planning from the 1988 Regional Airport System Plan through the Flight Plan Project, Sea-Tac Master Plan, and Expert Arbitration Panel findings on noise