Notes
Letter dated August 6, 2001 from J. Strand of Columbia Biological Assessments (Richland, WA), submitted on behalf of the Airport Communities Coalition (ACC), to U.S. Army Corps of Engineers (Muffy Walker, Gail Terzi) and Washington State Department of Ecology (Ann Kenny), evaluating the Port Of Seattle’s Low Flow Analysis/Flow Impact Offset Facility Proposal (Parametrix, Inc., July 2001). Document AR023128 critiques the Port’s plan to use detained stormwater to augment summer low flows in Miller Creek, Walker Creek, and Des Moines Creek near Seattle-Tacoma International Airport (STIA). Key concerns include: violations of Washington Water Quality Criteria for copper and zinc in stormwater discharged from STIA; anoxic conditions in detention vaults potentially increasing dissolved metals bioavailability and toxicity; fecal coliforms of human origin from airplane wastewater in Des Moines Creek posing human pathogen risk; lack of sediment management procedures for metals-enriched and pathogen-contaminated vault sediments; and an incomplete monitoring plan lacking Benthic Index of Biotic Integrity frequency detail and failing to notify WDFW. References Parametrix 2000 Whole Effluent Testing (WET) showing SDN1 daphnia survival as low as 10 percent and fathead minnow mean survival of 60 percent. Cites Cooke et al. 1993 on redox chemistry of metal partitioning under anoxic conditions.