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Ms Lori Duncan <br /> . Page 4 of 5 <br /> Analytical Results — Soil Samples <br /> The soil samples collected from the depths of 25 and 30 feet were analyzed for total petroleum <br /> hydrocarbons as gasoline (TPHg) using EPA method 8015; total oil and grease (TOG) using <br /> method 552013; benzene, toluene, ethylbenzene and xylenes (BTEX) using EPA method 8020; <br /> and volatile organic compounds (VOC's) including gasoline oxygenate additives using EPA <br /> method 8260. <br /> No target analytes were detected in either soil sample. Analytical results for soil samples are <br /> summarized in Table 2. Laboratory data sheets and chain of custody documentation are included <br /> in Attachment B. <br /> Analytical Results — Groundwater Samples <br /> The groundwater sample was analyzed for TPHg, BTEX, TOG , VOCs and oxygenated fuel <br /> additives by the methods listed above. <br /> No detectable concentrations of TPHg, BTEX or TOG were present in the groundwater sample. <br /> Methyl-tert-butyl ether (MTBE) was reported in the sample at a concentration of 46 parts per <br /> billion (ppb). The following VOCs were also detected in the sample: 1,1-dichloroethane (1,1- <br /> DCA) at a concentration of 17 ppb; 1,1-dichloroethane (1,1-DCE) at 3.6 ppb; cis-1,2- <br /> . dichloroethene (cis-1,2-DCE) at 10 ppb; tetrachloroethene (PCE) at 4.4 ppb and 1,1,1- <br /> trichloroethane (TCA) at a concentration of 16 ppb. <br /> Analytical results are summarized in Table 4. Laboratory data sheets and chain of custody <br /> documentation are included in Attachment B. <br /> SUMMARY <br /> Soil boring SB1A was drilled to a depth of 36 feet in the middle of the former UST <br /> excavation. Groundwater was encountered at a depth of 32.5 feet. Soil samples collected at <br /> 25 and 30 feet below grade did not contain detectable concentrations of any contaminants of <br /> concern. A grab groundwater sample from the boring was found to contain detectable levels <br /> of MTBE and several chlorinated hydrocarbons. <br /> CONCLUSIONS <br /> The current data support the previous conclusion that no residual soil contamination remains at <br /> the site. <br /> The groundwater results suggest that trace quantities of TCA and PCE may have migrated from <br /> the pre-existing contaminated soil mass to groundwater. Neither of these compounds was <br /> detected at a concentration above the State of California Primary Maximum Contaminant Level <br /> (MCL). <br /> 'is'uto/reports/addsubsurfsti m,doc <br />