Laserfiche WebLink
a <br /> PpUlry <br /> za THOMAS R. FLINN _�/�, P.O.BOX 1810-1810 E.HAZELTON AVENUE <br /> . � DIRECTOR �Cw` a STOCKTON,CALIFORNIA 95201-3018 <br /> (209)468-3000 FAX(209)468-2999 <br /> www.co.san-joaquin.ca.us <br /> THOMAS M.GAU L/>r <br /> DEPUTY DIRECTOR <br /> MANUEL SOLORIO worldug for YOU <br /> DEPUTY DIRECTOR <br /> STEVEN WINKLER <br /> DEPUTY DIRECTOR <br /> April 4 2006 <br /> ROGER JANES <br /> BUSINESS ADMINISTRATOR <br /> Mr. Todd Del Frate,PG <br /> Central Valley Regional Water Quality Control Board <br /> 11020 Sun Center Drive#200 <br /> Rancho Cordova,California 95670-6114 <br /> SUBJECT: RESULTS OF EXPLORATION TO ASSESS SOURCE OF GROUNDWATER IMPACT AT <br /> THE CLOSED CORRAL HOLLOW LANDFILL <br /> Dear Mr. Del Frate:� <br /> e <br /> Attached please find the Results of Phase 1 Investigation to Evaluate Potential Impacts to Groundwater at the <br /> Corral Hollow Sanitary Landfill. This investigation was performed in accordance with the Plan to Evaluate <br /> Impacts to Groundwater as Part of Corrective Action,submitted February 10,2005. <br /> In summary,we found refuse at three exploratory trenches across the drainage ditch west of the eastern landfill <br /> access road. The closure cap was apparent at only one of these locations. Refuse was not found east of that <br /> road. Directing rainwater to the drainage ditch,where it flows over refuse which sometimes is without closure <br /> cap, is probably responsible for the apparent impact to the shallow aquifer as indicated at groundwater <br /> monitoring well MW-5. <br /> A likely corrective action would be to extend the closure cap from its present edge to include the drainage <br /> ditch and a portion of the access road. Such cap extension is best accomplished by the installation of GCL. <br /> Phase 2 exploration, proposed in this report,would determine the edge of the closure cap west of the road, and <br /> the area over which the closure cap would be extended. <br /> Although not initially proposed as corrective action,regrading the drainage ditch to eliminate ponding in <br /> December 2003 seems to have reduced infiltration sufficiently to allow dissipation of the impact seen at MW- <br /> 5. <br /> If you have any questions, please call me at(209)468-8504. <br /> Sincerely, <br /> W. MICHAEL CARROLL, PE <br /> Senior Civil Engineer <br /> WMC:1j <br /> N:\ICorral Hollow\PlanToEvalImpactToGW\TDelFrateOI-Phase IInvestigResults.doc <br /> Enclosure <br /> c: R. McClellon, Environmental Health Department <br /> LA 21850 <br />