Notes
Memorandum dated November 27, 2000 from Dave Garland, NWRO Water Quality Program, Washington State Department of Ecology, to Ann Kenny (Shorelands and Environmental Assessment Program) and Kevin Fitzpatrick (Water Quality Program). Subject is wetland hydrology impacts from Port Of Seattle’s proposed excavation of Borrow Area 3 sand and gravel fill for the Sea-Tac Third Runway embankment. References Pacific Groundwater Group (PGG, 2000) Sea-Tac Runway Fill Hydrologic Studies Report finding that excavation ‘would likely have substantial impacts to wetland water flows, and possibly biota.’ Seven wetlands in Borrow Area 3 (including wetlands 29 and 30) at risk from interception of perched aquifer zone. Proposes drainage swale along northwest pit margin, HDPE liner, flow control weir, and minimum 50-foot undisturbed buffer. Cites Hart Crowser 2000a and 2000b reports. Relates to Section 401 Water Quality Certification, AR 033691–033693, ECY00017857–17859, Exhibit 2097.