Notes
SEPA public comment submitted by Jeff Bogen, Des Moines resident and member of the Des Moines Airport Advisory Committee, on the SAMP SEPA Draft Environmental Impact Statement (DEIS) for Seattle-Tacoma International Airport (SEA). Analyzes aircraft noise cumulative exposure using Port Of Seattle noise monitor SEL event records from five community monitors (SEA12, SEA13, SEA17, SEA18, SEA19) spanning March 12–April 9, 2026, documenting event frequency, inter-event respite intervals, and nighttime exposure (22:00–07:00). Finds SEA18 records approximately 529 noise events per day with median inter-event gap of 1.5 minutes; 91.2% of intervals under 5 minutes; 89 nighttime events per night under current conditions, projected to increase to 111 under DEIS constrained 2032 scenario (+25.3% operations growth). Argues DNL metric fails to capture temporal noise structure and that DEIS violates WAC 197-11-330 and WAC 197-11-794 by omitting event-based cumulative impact analysis. Cites WHO Lnight guidelines (40 dB threshold), Basner et al. (2023), Neimann et al. (2013), and Baczalska et al. (2022) on cardiovascular and sleep health effects of repeated noise events.