EXH0593023827

PCHBPollution Control Hearings Board of the State of Washington

These final draft meeting notes have been prepared by Kate Snider, Floyd & Snider Inc. ATTENDEES Ann Kenny, Dept. of Ecology John Drabeck, Dept. of Ecology Kelly Whiting, King County Keith Smith, Port of Seattle Paul Fendt, Parametrix Charles Ellingson, Pacific Groundwater Group f - MEETING SCOPE AND AGENDA This meeting was scheduled as a status meeting regarding Low Stream Flow related tasks. Previous meetings regarding low stream flow evaluation were held on April 25 and May 8. The agenda of the meeting included: 1) Modeling status 2) Modeling deliverab!es regarding low stream flow impact • Non-hydrologic effects • Response to public comment related to low stream flow 3) Mitigation and Operational Plan 4) Schedule and process expectations MODELING STATUS 1. HSPF and embankment seepage modelers have agreed on the area that will be modeled for embankment see._age and treated differently in HSPS (per the 5/9 meeting notes). Mapping has been prepared that shows the area and configuration of impervious within the area. 2. Hydrus modeling has been completed. 10 and 20' thicknesses were included in the Hydrus modeling effort to better define areas of thin fill. AR 023827 C.'COCUME- t_,i_e_e,6__LOCAL$-_'_Ter_,,L o,_owT e FINAL DRAFT c_ 06/26/01 PaCe t of A 401 Permit Decision-Making. Sea-Tac Airport Third Runway - Floyd & Smder z.¢. June 13, 2001 3. Slice cross-sections have been developed and digitized, slice modeling is beginning. 4. Since the 5/9 Low Flow meeting, it was agreed that precipitation would occur on HSPF, net directly to Hydrus. Initial HSPF…
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