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"`. Table 3). The average depth to the water table has risen 0.01-foot since July 7, 1995 when the <br /> f _ f average depth to the water table was 15.73 feet utilizing depths sounded in all five monitoring <br /> wells. <br /> :i <br /> J <br /> Table 4 lists clock times of soundings for monitoring activities performed since September 19, <br /> 1994, with Stockton-corrected times and heights of highest&lowest tides. Using the three-point <br /> method, the calculated local ground-water flow direction on October 18, 1995 was approximately <br /> S87°E along a gradient of 0.014 foot/foot. Between July 7 and October 18, the flow direction <br /> has shifted 16° to the south, but has remained easterly (see the Ground-Water Gradient Map, <br /> Figure 3). <br /> f:= Ground-Water Sampling <br /> Ground-water samples collected from the five wells for the fourth quarter of 1995 were received <br /> jat Sherwood Labs on October 19, 1995. The analytical results revealed continuing nondetectable <br /> concentrations of TPH-g and BTEX in samples collected from wells MW-4, MW-5, and MW-7. <br /> _.� The results of the analyses of the samples collected from MW-6 indicate that the ground-water <br /> underlying that vicinity remains impacted with TPH-g and benzene analytes above the Maximum <br /> Contaminant Levels (MCLs) set by the California DoHS; the analyses were less prevalent, <br /> however. With the exceptions of benzene, detected at 0.4 ggli, and xylenes, detected at Just <br /> 0.6 gglE, the sample collected from MW-8 revealed nondetectable analytes; these results are <br /> slightly higher than the laboratory detection limit of 0.3 µglf. Laboratory analytical results for <br /> ground water are summarized in Table 5. <br /> -_A� NATURE AND EXTENT OF HYDROCARBON D"ACTION <br /> Based on analytical results of ground-water samples collected on September 21, 1995, given <br /> respective concentrations of TPH-g and BTEX, gasoline hydrocarbon impaction appears to have <br /> I:j occurred in the vicinity of monitoring well MW-6, and Hydropunches''''HP-1, HP-2, HP-3, and <br /> HP-9. Soil samples with concentrations exceeding the target cleanup level (10 mg/Kg of TPH-g <br /> and 0.3 mg/Kg of benzene) were collected during the drilling of monitoring well MW-6 at <br /> !_J depths of 15 and 20 feet bsg, and in the location of the overexcavation. <br /> =i <br /> i <br /> W.W. Irwin, Inc. <br /> Project No. 33016.07 <br /> December 1995 5 <br /> I <br />