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Samples below 35 feet consisted of poorly sorted, medium-grained <br /> sand. During drilling, water was encountered at a depth of <br /> approximately 28 feet in each boring (see Boring Logs) . <br />' 4.2 Relative Groundwater Elevation and Gradient <br />' Table 1 shows the relative piezometric levels on April 14 , 1993 . <br /> These data yield a gradient to the north-northeast (N 180E) . The <br /> gradient is 0. 0025 ft/ft. The flow direction is illustrated on <br /> Figure 3 . <br />' 4 .3 Field and Laboratory Results <br /> Hydrocarbon odors were observed in soil samples from Boring #4 . <br /> Volatile organic vapors were detected by the PID in samples and <br /> auger returns from Borings #4 at levels as high as 4 , 675 ppm. No <br /> hydrocarbon odors or volatile organic vapors were detected in <br /> Borings #1 through #3 . <br /> All soil samples were reported as non-detect for total petroleum <br /> hydrocarbons. BTE&X compounds were detected only in the sample from <br /> Boring #4 at a depth of 20 feet (B4-20: benzene, 0 . 22 ppm; toluene, <br /> 0. 055 ppm; ethylbenzene, 0. 0065 ppm; xylenes, 0. 33 ppm) . Total lead <br /> was detected in sample B4-20 at 3 .9 ppm. The analytical results are <br /> summarized in Table 3 . <br /> I Toluene was the only analyte that was detected in any of the water <br /> samples. A concentration of 0. 39 µg/L (ppb) was reported in the <br /> water sample from MW-3 (MW-3/4-14-93) . The water sample analysis <br /> are summarized in Table 4 . <br /> 5. 0 CONCLUSIONS & RECOMMENDATIONS <br /> 5. 1 Soil Contamination <br /> The analytical results of the soil samples indicate that <br /> contaminated soil is limited to the vicinity of Boring #4 . Minor <br /> concentrations of BTE&X are present at a depth of 20 feet in this <br /> area. No contamination was detected in samples collected at greater <br /> depths (25 and 28 feet) . The remaining soil contamination can <br /> probably be removed by re-excavation. GeoAudit estimates removing <br /> approximately 50 to 100 cubic yards of soil. <br />' 5.2 Groundwater Contamination <br /> Slightly contaminated groundwater is present in the vicinity of MW- <br /> 3 . In the absence of other volatile aromatics or petroleum <br /> hydrocarbons, the detection of a low concentration of toluene is <br /> rather surprising. GeoAudi.t recommends that all monitoring wells be <br /> I re-sampled within 90 days to confirm the results of the April 1993 <br /> sampling. <br /> 4 <br />