Notes
Memorandum dated July 1, 1998 from Ken Ludwa (Parametrix, Inc.) to Paul Fendt describing results of a Reasonable Potential Analysis (RPA) conducted for the Seattle-Tacoma International Airport (STIA) Third Runway area. Analysis used outfall 005 (SDS-3) stormwater runoff data with 1996 deicing sampling events removed; geometric 95th percentile calculated per RPA methods. Water quality criteria determined for Miller Creek (hardness 23 ppm) and Des Moines Creek (hardness 35.6 ppm) per STIA 1998 NPDES Permit Fact Sheet. Pollutants evaluated include copper, fecal coliform, turbidity, and metals. Attendees included Lisa Zinner (Ecology), Lori Terry (Preston Gates and Ellis), Tom Hubbard (POS), John Rogers (CH2M Hill), Bill Taylor (Taylor and Assoc.). Copper concentrations after BMP treatment (bioswales, sand filters, wet ponds/vaults) exceeded criteria. NPDES, stormwater, PCHB administrative record AR024691.