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1 <br /> 0 The bacterial populations will migrate to areas where food <br /> sources exist effectively seeking out pockets of <br />' contamination. <br /> 6.2 Contaminated Soil Remediation <br />' Bioremediation of hydrocarbon-contaminated soil has been documented <br /> to be effective and the techniques proposed are at the forefront of <br /> the development of the technology. GeoAudit concludes that in-situ <br />' bioremediation can potentially remediate the soil at the site at a <br /> fraction of the cost of other methods, with no significant risk to <br /> the subsurface environment, and with minimal disruption to site <br />' activities. Methods of implementation are presented below. <br /> i <br /> 6.2 . 1 Equipment and Design <br />' Inoculation of the hydrocarbon consuming bacteria will take place <br /> in vadose zone wells VW--1 through VW-4 as well as dry monitoring <br /> wells MW-1, MW-3 , MW-4 and MW-5 . For inoculation purposes, up to <br />' three additional 4-inch diameter vadose zone wells are being <br /> considered for installation. One vadose zone well will be <br /> installed between VW-4 and MW-1 (proposed VW-5) and one zone vadose <br /> well will be installed west of VW-1 (proposed VW-6) . An additional <br /> vadose zone well will be installed east of MW-14 (VW-7) if <br /> significant soil contamination is indicated northeast of VW-5 <br />' during installation. <br /> 6.2 .2 Permitting <br />' Since the inoculation of the vadose zone wells will not have an <br /> adverse effect upon the groundwater, GeoAudit does not believe that <br /> any special permits will be required for the in-situ bioremediation <br /> of the contaminated soil. <br /> Drilling permits for the installation of additional vadose zone <br /> wells will have to be obtained from the PHS/EHD. <br /> 6.2 . 3 Progress/Confirmation Soil Sampling <br /> GeoAudit proposes to drill one or two soil borings on a biannual <br /> basis, to monitor the progress of the in-situ bioremediation. The <br /> depth and location of the borings will vary, but all borings will <br /> be placed within the known contaminated plume (see Figures 8 <br /> through 15) . Prior to each drilling event, the CVRWQCB and PHS/EHD <br /> will be notified of the locations and depths of the borings. <br /> The soil borings will be sampled every five feet and will be <br /> monitored in the field using a PID. Selected soil samples will be <br /> analyzed for TPH as gasoline and BTE&X. The results will be <br /> compared to baseline samples. <br /> 11 <br />