Notes
Letter dated November 26, 2001, from Northwest Hydraulic Consultants (on behalf of ACC, Airport Communities Coalition) to Colonel Ralph H. Graves, Ms. Muffy Walker, and Ms. Gail Terzi of U.S. Army Corps of Engineers, Seattle District, Corps Ref. No. 1996-4-02325. Identifies serious flaws in Port Of Seattle’s low flow mitigation analysis for Miller Creek, Walker Creek, and Des Moines Creek related to Sea-Tac Airport Third Runway construction. Critiques Pacific Groundwater Group August 2001 embankment fill modeling report, Earth Tech December 2000 Low Streamflow Analysis, and Hydrocomp HSPF modeling by Norm Crawford. Argues runway secondary recharge volumes are overstated, stream low flow impacts understated, and reserve storage mitigation volumes undersized. Criticizes use of hourly time step in HSPF modeling and filter strip infiltration assumptions. References 401 certification conditions, King County comments, and Ecology 45-day review period. Exhibit No. 444, M. Green, dated 12-20-01.