TagFAA(793)

A 1992 water quality study of Des Moines Creek, prepared by Parametrix, Inc. for the FAA and Port of Seattle, assessed the health of the creek during storm runoff events. The creek, which originates near Sea-Tac International Airport and flows to Puget Sound, had its aquatic ecosystem severely damaged by jet fuel spills in 1985 and 1986. The study sampled seven locations along the creek and three tributaries to identify water quality problems and determine whether stormwater pollution from airport operations was causing toxic conditions.

AR037747. Draft Final Report of the Puget Sound Air Transportation Committee’s Flight Plan Project, January 1992, sponsored by the Puget Sound Regional Council and Port Of Seattle with FAA grants. Study findings and draft recommendations for long-term air carrier system needs of the Puget Sound Region, including a Draft Programmatic Environmental Impact Statement. Committee chaired

These two Port of Seattle Flight Track Sample maps compare jet aircraft arrival and departure patterns at Seattle-Tacoma International Airport (SEA) under south flow conditions, one from March 22, 1989 (pre-4 Post) and one from March 31, 1991 (4 Post). Both charts plot all jet flight tracks between approximately 4:30–24:00 and 6:00–22:00 respectively, showing how flight paths over the Seattle region shifted between the two periods. The maps are annotated to highlight southbound departures and arrivals over Seattle, serving as visual evidence for noise impact analysis related to airport runway and procedure policy changes.

On April 2, 1990, the FAA announced it would implement the 'Four-Post Plan,' a set of air traffic control procedural changes at Seattle-Tacoma International Airport designed to reduce congestion, improve efficiency, and address worsening arrival delays. The plan, developed after nearly a year of public meetings, environmental review, and computer simulation of 13 alternatives, was determined to produce no significant noise impact on surrounding communities. The FAA cited a 30,000 increase in annual landings and takeoffs since 1988 and the failure of mediation talks to produce an agreed-upon flight path solution as key reasons for moving forward with the changes.

This 1990 document outlines a comprehensive package of noise abatement actions for Seattle-Tacoma International Airport, agreed upon by a Mediation Committee on March 31, 1990. It covers measures such as nighttime flight restrictions, soundproofing programs for nearby homes and public buildings, improved flight corridors, and a new noise management monitoring system. According to the technical consultant involved, full implementation of these agreements could reduce noise levels by approximately 50% for communities surrounding the airport.

This 1990 Final Environmental Assessment, prepared by the FAA's Air Traffic Division in Seattle, evaluates proposed changes to arrival and departure flight routes at Seattle-Tacoma International Airport. The document was signed by Air Traffic Division Manager Temple H. Johnson, Jr. on March 27, 1990, and examines the potential environmental impacts of rerouting aircraft traffic in and out of Sea-Tac. It serves as an official federal record relevant to noise and environmental policy affecting communities around the airport.

This 1990 FAA document explains why the Day Night Average Sound Level (DNL) was chosen as the standard metric for measuring airport noise. DNL averages noise exposure over a full 24-hour period, applying a penalty for nighttime flights, and has been adopted by multiple federal agencies—including the EPA, DOT, HUD, and DOD—as the most reliable way to assess how aircraft noise affects surrounding communities. The FAA formally incorporated DNL into federal regulation through FAR Part 150, Airport Noise Compatibility Planning, in 1981.