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i <br /> 5.4 ANALYTICAL RESULTS AND DISCUSSION <br /> 5.1 Soil Samples <br /> Soil samples collected from each of the soil borings were evaluated for total petroleum <br /> hydrocarbon compounds in the gasohne range and volatile aromatic compounds including <br /> BTEX The laboratory results are summarized and presented in Table 1 Complete <br /> analytical reports are located in Appendix 4 <br /> ' The analytical results show that minor gasoline contamination is present in several of the <br /> soil samples collected from the five soil borings Only one of the borings however, <br /> ' (MW-1), displayed evidence of BTEX contamination in excess of federal or state levels for <br /> soil The presence of contamination in soil samples collected from the 18-f0ot depth would <br /> ' suggest that contamination is present in the groundwater at this location A comparison <br /> of these results with the water analyses presented in Table 2, substantiates this premise <br /> Soil contamination (BTEX) is found in the soil samples collected from a depth of 18 feet <br /> in both MW-1 and MW-3, but not in MW-2 or MW-4 Both MW-2 and MW-4 appear to <br /> ' be located outside the zone of both the zone of strong soil contamination as well as the <br /> Plume of contaminated groundwater <br /> ' It is therefore difficult to explain the minorwell below regulatory( g story limits) gasoline <br /> contamination found at a depth of 10 feet in MW-4 The depth is too great to be <br /> attributed to localized spills, and is to far removed from either the former <br /> pump island <br /> or the former tanks to be related to surface spillage The only possible conclusion for the <br /> presence of trace amounts of BTEX in the 10-foot sample collected from MW-4 is cross <br /> contamination as a result of the drilling process itself, i e incomplete cleaning of drilling <br /> equipment or perhaps a sample tube <br /> iThe absence of BTEX constituents in the soil sample collected from a depth of 15 feet <br /> in MW-3, while present in the samples collected from 10 and 18 feet, is more readily <br /> explained Although closer to the former underground tanks than MW-4, the location of <br /> 12 <br />