Notes
AR019516. Section 4.2.2 of the Seattle-Tacoma International Airport (STIA) Comprehensive Stormwater Management Plan (SMP), December 2000, filed in the PCHB Third Runway EIS administrative record. Describes the Industrial Wastewater System (IWS) at STIA, originally constructed in 1963 to collect runoff from terminal aprons, taxiways, hangars, terminal rooftop, parking garage, toll plaza, and aircraft/vehicle maintenance areas. Covers IWS spill-control BMP function, contamination sources including fuel spills, de-icing chemicals, and aircraft washwater; Kennedy/Jenks 1995 engineering evaluation; IWS conveyance system divided into air cargo/runway and terminal drainage areas; Industrial Wastewater Treatment Plant (IWTP); three lagoons (Lagoons 1, 2, 3) in southwest corner of STIA; NPDES Permit WA-002465-1; Midway Wastewater Treatment Plant marine outfall to Puget Sound; KCRTS (King County Regional Time Series) simulation; 25-year design storm sizing; five pump stations overflowing to Surface Drainage System (SDS); AKART determination; IWS storage capacity Table 4-2 for 2006 configuration.