EXH2111033722

Tom: I take issuewith GregWingard'sstatementthat Ecology'sNWRO hasadmittedthat the third lagoonexpansion is to accommodatethe proposed Third Runway. I am not aware of any such documentor statementfrom staff here at the NWROto that effect. What I do know about the third lagoon expansion is that it isbeing undertakento accommodate the impacts of a larger continuous flow monitoringstorm events for the IWS and to provide capacity to meter flow into the King CountySewer interceptor from the IWS. This expansion will also prevent untreatedoverflow events from the IWSto Des MoinesCreek. I am presently checking with Port of Seattle environmental personnel to see if there is any part of the proposedThird Runwaythat would tie-in with the IWS and so far their initial reviewreported backthat there is no direct tie- in to the IWSfrom the proposedThird Runway. As to the increase in impervious surface and resulting impacts to recharge of base flows to surroundingwetlands and Des Moines Creek, I am assuming that Greg Wingard is referring to the increase of impervious surfacethat will result with the lining of the third lagoonwith a synthetic liner. I do not know if such an evaluation of recharge was ever conducted. I suspectthat itwas not conducted because any recharge to surfacewaters, whether to the surrounding wetland or to Des MoinesCreek, from the lagoon would be consideredvery minor andvirtually non-existent. The lagoon presentlyhasa clay linerwith very low hydraulicconductivity which reduces its current rechargevalue. The decisionto requirea synthetic liner in the third lagoonwas to eliminate a pathway of pollutantsfrom the IWS to…

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PSCAA Advisory Council Meeting Agenda
Add to CalendarMWednesday Mar 11, 9:00am - 11:35am
1904 3rd Avenue, Suite 105, Seattle, WA 98101
Call to order – Roll Call – Quorum Established – Land Acknowledgement We would like to acknowledge that our Agency operates in four present-day counties, which are the traditional lands of the Coast Salish people, past and present. This acknowledgement does not take the place of authentic relationships with indigenous communities in our jurisdiction and [...]