EXH AR023800: Email from Ann Kenny (Ecology) Re: Low Flow Draft Meeting Notes 7-9 — Septic Tank Impacts on Base Stream Flows

In a July 13, 2001 email, Ann Kenny of Washington State Department of Ecology urged the Port of Seattle to continue researching the water quantities contributed to base stream flows by septic tank systems slated for removal in the airport acquisition area. She noted that while eliminating septic tanks helps reduce fecal coliform contamination, it also removes water that recharges base flows — a water quality concern regulated under RCW 90.48. Kenny suggested the Port work to verify the accuracy of a 66,000-gallons-per-day estimate from its December 2000 Low Stream Flow Analysis by cross-referencing sewer authority and water supplier records.

Notes

Email dated July 13, 2001 from Ann Kenny of Washington State Department of Ecology to Kathryn Snider (Floyd Snider McCarthy), John Drabek, Kelly R. Whiting, Keith Smith, Paul Fendt, Charles ‘Pony’ Ellingson, Joe Brascher, and Rick Schaefer, cc’d to Raymond Hellwig and Kevin Fitzpatrick. Kenny responds to draft meeting notes from a July 9 low stream flow technical meeting regarding Port Of Seattle’s Third Runway EIS. She urges the Port to continue researching quantities of water contributed to base flows from septic tank systems, citing the Port’s December 2000 Low Stream Flow Analysis (Table 8, 66,000 gallons per day estimate). Kenny notes that septic tank removal, while beneficial for fecal coliform reduction, removes water from the system that recharges base flows. Ecology’s authority to regulate water quality is cited under RCW 90.48 and RCW 90.48.020. Suggests cross-referencing sewer authority connection records and local water supplier data to refine the estimate of homes on septic in the acquisition area. Administrative Record numbers AR023800–AR023801. Next meeting noted as Monday July 16, 2001, 9:00–12:00 at Westside office.

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