TagLandrum & Brown(15)

This chapter from Sea-Tac Airport's 2013 Part 150 Noise Compatibility Study explains how aircraft noise is measured and analyzed around Seattle-Tacoma International Airport. It covers the basic properties of sound—including loudness, pitch, and duration—and explains why noise is measured on the logarithmic decibel (dB) scale rather than a standard linear scale. The chapter also outlines how noise contour modeling was conducted to assess the real-world impact of aircraft operations on surrounding communities.

This chapter from the Seattle-Tacoma International Airport Part 150 Noise Compatibility Study presents aviation activity forecasts developed to support noise exposure planning through 2018 and beyond. It covers historical passenger enplanement trends showing growth from 8.2 million in 1990 to 15.6 million in 2009, as well as domestic and international air service patterns dominated by Alaska Airlines. The forecasts, approved by the FAA in August 2010, were used to project aircraft fleet mix and noise exposure contours for future planning purposes.

This appendix from Seattle-Tacoma International Airport's 2013 Part 150 Noise Compatibility Study presents supplemental noise analysis results using the FAA's Integrated Noise Model, covering metrics such as Time Above Level, Number of Events Above Level, and Sound Exposure Level. The analysis was prepared for informational purposes only and cannot be used to justify noise mitigation measures, but helps illustrate how aircraft noise affects daily activities like speech and sleep for communities surrounding Sea-Tac. Contour maps and grid point data show projected 2018 noise impacts on noise-sensitive facilities including schools, hospitals, libraries, and places of worship in nearby cities such as SeaTac, Burien, Des Moines, and Tukwila.

This document outlines the Future (2021) Noise Exposure Map and Noise Compatibility Program for Seattle-Tacoma International Airport, projecting noise levels for a typical day in 2021 assuming all recommended noise abatement measures are in place. Using the FAA's Integrated Noise Model, it forecasts 419,597 annual aircraft operations — a 15.4% increase over 2016 baseline levels — and maps noise contours at 65, 70, and 75 decibel DNL thresholds. The report details the fleet mix and runway usage data used in the modeling, with Boeing 737-800s representing the largest share of daily operations.

This exhibit from the Seattle-Tacoma International Airport 14 CFR Part 150 Study maps the existing 2013 baseline noise exposure contours around Sea-Tac Airport, showing DNL 65, 70, and 75 dBA noise zones across surrounding communities including SeaTac, Burien, Des Moines, and Tukwila. The DNL 65 dBA or greater contour covers approximately 5.9 square miles, encompassing an estimated 1,887 housing units and roughly 4,879 residents, along with 9 noise-sensitive facilities such as schools, churches, and hospitals. Notably, no housing units fall within the higher-impact DNL 70 dBA or above zones, though significant residential and commercial land uses exist within the broader 65 dBA contour area.