Notes
Paper by Scott A. Tobiason (Port Of Seattle) and Linda R. J. Logan (Parametrix Incorporated) documenting stormwater whole effluent toxicity (WET) testing at Seattle-Tacoma International Airport (STIA) during 1998-99 across four NPDES permit outfalls. WET tests used Daphnia pulex and Pimephales promelas (fathead minnow); outfall SDN1 draining 6 hectares of rooftops and roadways failed Washington State Department of Ecology performance standards in 7 of 9 tests. Source tracing via EDTA metals chelation identified zinc from approximately 0.8 hectare of zinc-galvanized metal rooftop on two Transiplex air cargo buildings as the principal toxicant, with 50%+ dissolved zinc in runoff. Synthetic rooftop spray tests confirmed zinc toxicity. Document references NPDES permit, SWPPP, Miller Creek, Des Moines Creek, Puget Sound, Industrial Waste Treatment Plant (IWTP), and EPA Method 1669.