Notes
Letter dated June 5, 2000 from Amanda Azous of Azous Environmental Sciences to Gail Terzi and Jonathan Freedman, US Army Corps of Engineers, Regulatory Section, Seattle District, on behalf of Airport Communities Coalition (ACC). Reviews Wetland 44a in relation to the proposed temporary SR509 interchange at S. 176th Street in the City of SeaTac. Finds significant discrepancy between HNTB Corporation project plans (signed February 24, 2000) and actual field conditions observed June 1, 2000: Wetland 44a may be 20–40 feet closer to SR509 than shown, with depression located within the SR509 right-of-way rather than east of it. Cites Parametrix Memorandum dated May 3, 2000 (‘Analysis of indirect impacts to wetlands from the temporary SR-509 interchange- Seattle Tacoma Airport’). Identifies Walker Creek, Miller Creek, Wetland 43, Wetland 44a, and Manhole AC-5 as hydraulically connected systems subject to sedimentary discharge impacts from interchange construction. References GP-2 Grading Plan, HNTB hydraulic report (April 12, 2000), and Southwest Suburban Sewer District 1984 sewer line map.