Though Sea-Tac International Airport is located within the City of SeaTac, the majority of the City is not significantly impacted by airplane noise. Noise contours provided by the Port of Seattle reflect the fact that airplane traffic is concentrated northbound and southbound, while the majority of land area in the City unencumbered by the Port of Seattle is east of the airport. Noise contours are measured in LDNs (day-night average noise level); LDN 65 and above is the federal standard defining significant levels of noise exposure.
The City of SeaTac noise contours map provides a visual reference.