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V <br /> A . <br /> it <br /> I <br /> { <br /> l <br /> I <br /> E. MW2. Benzene (0.020),toluene (0.022 ppm), ethylbenzene (G.0050 ppm) and xylenes (0.027 <br /> ppm)were detected in soils from SBI. Benzene(0.010 ppm)was detected in the soils collected <br /> from SB2, and xylenes(0.026 ppm)were detected in soils collected from SB8. Chromium (41 <br /> ppm),lead(8.4 ppm)and zinc(67 ppm)were detected in the soils collected from the soil boring <br /> E . <br /> drilled near the waste oil tank pit (SB11). No other petroleum hydrocarbon analytes were <br /> ' detected above method reporting limits (Table 1). <br /> 5.2 Groundwater <br /> ]Prior to development, purging and sampling, depth to water data was collected (Table 2). <br /> Subjequently a groundwater grdient map was created {Figure 4}. The gradient magnitude is <br /> 0.006 ft/ft or 30 ft/mile in a northeasterly direction. This gradient direction and magnitude is <br /> consistent with other Tracy area sites. Groundwater monitoring and purging data is presented <br /> • in Appendix III. <br /> The wells were purged-and developed bY pumping, with a bladder pump,a minimum of 3 well <br /> and casing volumes from each well. Groundwater samples were collected after EC, pH and <br /> temperature had stabilzLed. Groundwater samples were analyzed for BTEX, TPHG and 17PHD <br /> by EPA methods 8020 and modified 8015, respectively. <br /> Moderate to high levels of dissolved petroleum hydrocarbr i analytes were detected in wells <br /> _ MWI apd MW2(Table 3). No analytes were present in MW3. Detection limits were increased <br /> during sample analysis in samples collected from MWI'and MW2 due to the high levels of <br /> constituents in the samples. <br /> 6.0 CONCLUSIONS <br /> i r 6>� Soil Impact <br /> ------=— ------'---- - ----"----- ------,----_d_ _. . . ----- --- - - — -- = <br /> i aboratoryanalysis of soil samples indicates that the extent petroleum hydrocarbon <br /> cOntamination in the soil has been defined. The lateral extent is confined to a narrow zone <br /> i <br /> beneath the former product lines, beneath the former waste oil tank (TP2), and around the <br /> R-017792.LF <br /> >es <br /> 11WIrg"IMMEME, Wain., <br /> EI „ <br /> E <br /> y. _ <br />