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i . sampled for TPH and volatile organic compounds (VOC) by EPA methods 8015/8020 All sampling equipment was decontaminated prior to each sampling event using the three bucket wash system to minimize the potential for cross-contamination Procedures used for water sampling are presented in Appendix C Results indicated wells MW4, MW6, TBI, TB7, and TBS all contain greater than 10,000 ug/l TPH and greater than 1,000 ug/l benzene Wells MW3R and TB 10 contained significantly lower levels but had up to 59 ug/l dissolved benzene Well MW5 has consistently contained free product and therefore was not sampled Figure 5 depicts the distribution of dissolved benzene as indicated by the data Table 2 summarizes the groundwater sampling data Appendix E contains the laboratory data with chain of custody and method detection limit CONCLUSION The findings of this investigation indicate the soils beneath the site consist mostly of low permeability silty clay and clayey silt to the total depth investigated of 90 feet bgs A sand layer that occurs between 70 and 75 feet bgs was encountered in each deep well This layer is underlain by fine grained deposits typical of the upper section Groundwater occurs at approximately 60 feet bgs and flows to the northeast under a gradient of about 0 003 Groundwater was previously encountered at 50 feet bgs in 1988, and 80 feet below grade in 1992 The majority of hydrocarbon-affected soil appears to occur in three distinct areas at the site These areas all have soil samples with TPH concentrations greater than 1,000 mg/kg TPH A rough estimate of the hydrocarbon load in each area is presented in this report Based on this calculation, approximately 29,000 lbs of hydrocarbon is present in the soil The site is now equipped with vapor extraction wells and groundwater recovery wells in key areas across the site Underground piping has been installed to many of the wells so that a remediation Page 8