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analyzed for TPH as gasoline and BTE&X in accordance with EPA methods 8015m and <br /> 602, respectively. <br /> 4.0 FINDINGS <br /> 4.1 Groundwater Elevation and Gradient <br />' The elevation ofg roundwater in each well was calculated by subtracting the groundwater <br /> depth from the surveyed casing elevation (Table 1). The depth to groundwater ranges from <br /> r56.03 feet to 57.16 feet. Groundwater has risen an average of 3.49 feet since the October <br /> 1993 monitoring. <br />' The groundwater flow direction is towards the south-southwest (Figure 3). The flow <br /> direction and gradient are similar to that calculated for the October 1993 monitoring event. <br />' The anomalous mound noted during the October 1993 monitoring was not present during <br /> the April 1994 monitoring. <br />' 4.2 Laboratory Analyses Results <br /> TPH as gasoline, benzene, toluene, ethylbenzene and xylenes were detected in the sample <br /> from MW-1 at 69,000 ppb, 3,300 ppb, 4,600 ppb, 1,900 ppb and 6,500 ppb, respectively. TPH <br /> as gasoline, benzene, toluene, ethylbenzene and xylenes were detected in the sample from <br /> MW-4 at 570 ppb, 54 ppb, 7.2 ppb, 0.66 ppb and 5.6 ppb, respectively. Benzene and toluene <br /> were detected, just above the reporting limits, in MW-5 at 0.32 ppb and 0.38 ppb, <br /> respectively. No petroleum hydrocarbons were detected in MW-6, MW-7, or MW-8. The <br /> analytical results are summarized on Table 3. The laboratory report and chain-of-custody <br />' are included in Appendix A. <br />' 5.0 CONCLUSIONS & RECOMMENDATIONS <br /> Petroleum hydrocarbons in MW-1 have fluctuated greatly since October of 1992. TPH <br />' concentrations have been as low as 4,000 ppb and as great as 100,000 ppb. BTE&X <br /> concentrations have fluctuated similarly. The fluctuations seem to be seasonal, with the <br /> highest concentrations of petroleum hydrocarbons detected during the last quarter of each <br />' year, and the lowest detected during the first quarter of each year. MW-4 shows similar <br /> fluctuations of TPH and BTE&X concentrations. <br />' Benzene and toluene were detected just above the reporting limits (0.30 ppb), suggesting <br /> that MW-5 still defines the down-gradient portion of the contamination plume. <br />' GeoAudit recommends the next quarterly sampling be scheduled for June of 1994. However, <br /> since no petroleum hydrocarbons have ever been detected in MW-6, MW-7 and MW-8 <br /> An A M:b QFi3n-9H1AT <br />