SITE INFORMATION AND CORRESPONDENCE FILE 1

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i King Island Resort page 2 11530 W . Eight Mile Rd , Stockton . The construction specifications of the ART wells were not included in the CAP . Please submit exact well construction diagrams and narrative descriptions that clearly describe and show the dimensions of the ART wells. The screened interval of the casing , the diameter of the borehole, as well as all of the devices to be installed in the casing is to be included . Documentation (work plan approval letters or regulatory No Further Action letters) that ART has been successfully used in the Central Valley area should also be submitted . Although the CAP is not approved at this time , the concentration of MtBE in MW-5, MW-6 , and MW-7 indicate that the plume is unstable and continues to be a threat to the drinking water well located just over 100 feet from the plume . EHD requires you to conduct interim remediation to reduce the MtBE concentrations and threat to the well . Ozone injection may an effective interim remediation but the bench scale test proposed in the CAP is required to be conducted . In addition to the tests listed for the bench scale test in the CAP , EHD requires that a biological plate count analysis be added . Potentially, additional ' biologicals' from the septic tank could be in the shallow soils and ground water in this area . Competition for the additional oxygen provided by the ozone injection could reduce the efficacy and increase the costs of the ozone system . The plate count and bench scale test may provide data to support the conclusion that ozone injection is a viable remedial alternative . MW-6 is the most down gradient monitoring well for this site and had the highest MtBE ground water contamination detected at the site, 2900 ug/I in December 2005 . With a consistent northeast ground water gradient direction recorded for this site (to MW-6) , the lateral extent of the dissolved plume is not defined . Additionally, only the first ground water is being investigated by the current array of monitoring wells at the site . The dissolved MtBE plume is not vertically defined . In order to provide a better understanding of the nature of the dissolved plume, EHD requires you to submit a Site Conceptual Model (SCM) that includes calculations of the residual contaminant mass and pathways for plume migration by June 7 , 2006 . Please contact Michael Infurna at (209) 468-3454 if you have any questions . Donna Heran , REHS, Director Environmental Health Department Michael Infurna , Senior REHS Margaret Lagorio , UIC / Unit IV Supervising REHS c: CVRWQCB — Jim Barton , Sacramento c: ATC — Dave Ashcom , 1117 Lone Palm Ave #B , Modesto, 95351