Notes
Memorandum dated September 20, 1999 from Parametrix consultants Ken Ludwa, Paul Fendt, and Linda Logan to Scott Tobiason reviewing the first draft of the 1999 Annual Stormwater Report for Seattle-Tacoma International Airport (STIA). Document AR024773 raises issues including: consistency of water quality comparators between years and parameters (instream Bellevue samples vs. Portland NPDES outfall study for copper); statistical validity of ‘trimmed’ data sets; confounding factors affecting TSS and turbidity reductions beyond construction wheel wash (grass germination, new SDS pipes, roadway sediment flushing); mixing zone determination for NPDES permit compliance; replacement of ‘receiving water criteria’ with ‘water quality standards’; and NPDES Permit Section S12.B.2 BMP implementation timelines for noncapital and capital BMPs. References SDS1, SDN2, taxiway construction, SWPPP updates, and WET limits. Filed in PCHB Third Runway EIS administrative record.