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VOK Ai4l� V Ioi` YV' The groundwater data from Borings B-2 and B-3 suggests that a minor amount of dissolved TPHG, TPHD and Ethanol is present about 50 feet downgradient of the existing tank pit The other volatile fuel components (BTEX and NIT$E and oxygenates) were not observed in any borehole soil or groundwater sample "The distribution of these contaminants in B-2 and B-3 suggests a west southwesterly local groundwater flow direction. The laboratory case nairattve reported that the patterns for both TPHG and TPHD did not match the chromatographic patterns for Gasoline and Died it is possible that these compounds do not represent these fuels or might be interferences form sampling in the borehole On the basis of the subsurface data, tank leakage of the dispenser appears to be limited since only very low concentrations of TPHG and TPHD that do not match the standards were revealed and volatile components were not detected 6.9 Conclusions and Recommendations Wright drilled and sampled four exploratory borings placed at lie SJC EHD approved locations near the existing underground tank and dispenser at Ace Tomato The borings revealed cemented sandy silt and clayey silt strata with some interbedded silty sand, Groundwater was encountered at depths of about 38 to 39 feet that entered boreholes slowly This is interpreted as the uppermost aquifer and limited groundwater measurements indicate the aquifer is unconfined. Groundwater data from the boreholes was insufficient to plot a groundwater flow direction Regional hydrogeologic studies show a westerly flow direction Chemical analysis of groundwater samples showed the presence of very low concentrations of TPHG, TPHD and Ethanol;volatile components BTEX, MTBE and TBA were not detected in any sample. The laboratory reported that the soil and groundwater TPHG and TPHD results did not match the typical chromatographic pattern for those fuels Soil excavation removed contaminated soil near the fill bucket and the subsurface data suggested that the release appeared]uruted in lateral and vertical extent. The limited amount of Ethanol present might be attributed to dispenser leakage While TPHD and TPHG were detected in apparent downgradient groundwater samples, the laboratory narrative indicates these may riot be petroleum compounds On the basis of the absence of BTEX, TBA and MTBE in soil and water samples, and lack of TPHG and TPHD petroleum compound confirmation by the laboratory it is our opinion that a minor groundwater release is indicated from this data Wnght recommends the following• • A review and discussion of the sample chemical data and chromatograms with Kiff may be warranted to confirm TPHG and TPHD If the laboratory review shows these are not petroleum compounds it would indicate that together with the absence of BTEX, TBA and MTBE in soil and groundwater, the dispenser leak was confined to the vadose zone area Wright excavated • A copy of this report should be forwarded to SJD PHD for theirreview and continent. i i Page 4 of 6