Notes
Exhibit AR021219. Letter dated August 6, 2001 from Water Resources Consulting L.L.C. (Peter Willing, Ph.D.) to U.S. Army Corps of Engineers (Muffy Walker, Gail Terzi) and Washington State Department of Ecology (Ann Kenny), on behalf of the Airport Communities Coalition (ACC), commenting on the Port Of Seattle’s ‘Low Flow Analysis – Flow Impact Offset Facility Proposal’ by Parametrix (July 2001), submitted in support of Department of the Army Section 404 permit application for Sea-Tac Airport (Reference: 1996-4-02325). Letter criticizes the document as incomplete (missing figures, appendices, unfinished sections), argues the proposed 46 acre-feet of stormwater storage across Miller Creek (18.8 ac-ft), Walker Creek (15 ac-ft), and Des Moines Creek (12.2 ac-ft) watersheds is unallocated and undesigned, challenges reliance on grassed swales and biofiltration BMPs for nutrient and metals removal, disputes Port’s treatment of non-hydrologic impacts on low streamflows, raises water quality concerns about propylene glycol deicing discharges (407 mg/L at SDS3), dissolved oxygen, copper, zinc, cadmium, and nitrogen/phosphorus removal performance, and argues that references to ‘adaptive management strategy’ and future plans do not constitute reasonable assurance for 401 certification. Clean Water Act Section 401/404, NPDES, stormwater vaults, microbubble diffusers, and biofiltration swales are specifically discussed.