EXH 236A: NHC Letter to Army Corps & Ecology — Stormwater Mgmt Plan Approval Process, STIA Third Runway

In a July 31, 2000 letter to the U.S. Army Corps of Engineers and Washington State Department of Ecology, Northwest Hydraulic Consultants raised concerns about unresolved technical problems with the Stormwater Management Plan (SMP) for the proposed third runway at Seattle-Tacoma International Airport. Independent reviews had found serious flaws in the hydrologic modeling that could result in undersized facilities failing to meet flow control requirements. The firm requested full public disclosure of ongoing SMP discussions and a meaningful comment period before any regulatory approval of the runway project.

Notes

Exhibit 236A (AR018958–AR018959). Letter dated July 31, 2000 from Northwest Hydraulic Consultants (NHC), signed by William A. Rozeboom P.E. and K. Malcolm Leytham Ph.D. P.E., addressed to Jonathan Freedman (U.S. Army Corps of Engineers Regulatory Branch) and Tom R. Luster (Washington State Department of Ecology Permit and Coordination Unit), on behalf of the Airport Communities Coalition (ACC). Raises unresolved concerns about the Stormwater Management Plan (SMP) for the Sea-Tac Airport Master Plan Update Improvements third runway development. References prior NHC comment letters dated November 24, 1999 and May 3, 2000; Pacific Groundwater Group review (June 19, 2000) finding fundamental questions in hydrologic modeling; King County review identifying numerous technical problems; and HSPF model calibration issues. Requests full public disclosure and comment period before regulatory certification or approval of the proposed third runway project. Filed in PCHB Third Runway EIS docket.

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