TagDes Moines(304)

A Des Moines, WA resident and airport advisory committee member submitted this public comment to challenge the noise analysis in the Sea-Tac Airport (SEA) expansion environmental review, arguing that the standard Day-Night Average Sound Level (DNL) metric fails to capture how frequently aircraft noise actually occurs in nearby neighborhoods. Using direct measurements from five Port of Seattle noise monitors, the analysis found that some community locations currently experience roughly 529 aircraft noise events per day with a median quiet gap of only 1.5 minutes between them—conditions the commenter projects will worsen by 2032. The submission calls on the Port of Seattle to supplement its environmental review with event-based noise metrics that reflect real community exposure, including nighttime event counts and inter-event recovery time, as required under Washington State's environmental review law (SEPA).

A Des Moines, WA resident and airport advisory committee member submitted this public comment challenging the noise analysis in the Sea-Tac Airport (SEA) expansion environmental review, arguing that the standard Day-Night Average Sound Level (DNL) metric used by the Port of Seattle fails to capture the true burden of aircraft noise on nearby communities. Using direct measurements from Port noise monitors, the analysis found that some locations currently experience around 529 noise events per day with a median gap of only 1.5 minutes between events, conditions projected to worsen significantly under the airport's own growth forecasts. The comment calls on the Port to supplement its environmental review with event-based noise metrics—such as event frequency, quiet-period gaps, and nighttime disturbances—that research links more directly to health impacts like sleep disruption and cardiovascular disease.

A Des Moines resident submitted a formal comment arguing that the Seattle-Area Metroplex Environmental Impact Statement (SAMP EIS) significantly underestimates the health risks of aviation noise by omitting key peer-reviewed studies linking aircraft noise to cardiovascular disease, heart structural changes, and sleep disruption. The commenter contends that the EIS relies on outdated and methodologically flawed research, particularly FICAN studies using extrapolated rather than measured data, while ignoring more recent findings from the WHO, the HYENA Project, and a 2025 cardiac MRI study. The comment calls on the FAA to conduct a proper cumulative health effects analysis and require additional noise mitigation measures beyond the current DNL 65 dB contour threshold.

A Des Moines resident's formal comment argues that the Seattle-Area Metroplex Environmental Impact Statement's noise analysis is legally inadequate because it relies solely on a federal FAA noise threshold rather than Washington State's own multi-factor significance standard. The comment contends that the standard noise metric used (DNL) masks the real impact of roughly 96 additional daily flights projected by 2037, since it averages out individual disturbance events rather than counting them. The commenter calls for supplemental analysis using alternative metrics—such as single-event sound levels and nighttime averages—supported by peer-reviewed health studies linking aircraft noise to sleep disruption and cardiovascular harm.