Laserfiche WebLink
4.0 FINDINGS <br /> 4.1 Relative Groundwater EIevation and Gradient <br /> ' The relative elevation of groundwater in each well was calculated by subtracting the depth <br /> to groundwater from the surveyed relative casing elevation(Table 1) Groundwater dropped <br /> an average of 142 feet since the May 1994 monitonng event The gradient was calculated <br /> to be 0 0037 ft/ft directed N 54° E (Figure 3). Tlus is consistent with data from the <br /> November 1993 and May 1994 monitoring events The flow direction is also consistant with <br /> data from the USA Gasoline site, located southeast of the Pacific Gas property across <br /> tFarmington Road <br /> ' 4.2 Laboratory Evidence of Groundwater Contamination <br /> TPH as diesel was detected in water samples from MW-1, MW-2 and MW-3 at <br /> concentrations of 290 ppb, 170 ppb, and 400 ppb respectively. TPH as gasoline was detected <br /> in MW-3 at a concentration of 63 ppb No benzene, toluene, ethylbenzene or xylenes were <br /> detected in the water samples The analytical results of the samples are listed in Table 2 <br /> ' The laboratory report and chain-of-custody are included in Appendix B <br /> ' TABLE 2 <br /> ANALYTICAL RESULTS OF WATER SAMPLES <br /> Pacific Gas <br /> 2088 Mariposa Road, Stockton, CA <br /> (µ91L) <br /> ' Sample TPH as TPH as Ethyl- <br /> ID Gasoline Diesel Benzene Toluene benzene Xylene <br /> MW-1/11-10-93 ND 260 ND 199 ND ND <br /> ' MW-1/5-27-94 ND 90 ND ND ND ND <br /> MW-119-26-94 ND 290 ND ND ND ND <br /> ' MW-2/11-10-93 ND 390 ND ND ND ND <br /> MW-2/5-27-94 ND 100 ND ND ND ND <br /> MW-2/9-26-94 ND 170 ND ND ND ND <br /> 1 MW-3111-10-93 53 140 ND 24 ND ND <br /> MW-3/5-27-94 ND 110 ND ND ND ND <br /> ' MW-319-26-94 63 400 ND ND ND ND <br /> A91L parts per Whon <br /> ND = Not Detected <br /> 1 <br /> 07 jopwt Am&Scry 1. 6 <br /> Ra6c 6.•R>uA 9U632 S <br /> 1 <br /> I i♦r r i <br />