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. and approximately 6 gallons were removed from that well The water was stored in 55-gallon drums on the south edge of the property Water samples were collected in disposable plastic bailers and placed in sterilized 40-m1 vials and 1-liter amber bottles A sample was also collected from the Gillies domestic well (G-1) at the tap The samples were placed in a plastic cooler, iced, and shipped to McCampbell Analytical in Pacheco, California for analysis All samples were analyzed for TPH-gasoline, TPH-diesel, BTEX Because gasoline and volatile aromatics have occasionally been detected in water samples but no samples had been previously analyzed for oxygenates, Mr Steve Sasson of PHS/EHD approved the analysis of three samples for gasoline oxygenates using method 8260 4.0 RESULTS 41< Groundwater Gradient and Flow Direction Depth-to-groundwater measurements and calculated groundwater elevations are presented in Table 1 Results from previous monitoring events are included for comparison On average, the static water level is about 62 5 feet below grade, or approximately 125 feet-sliallower than it was one year ago Three of the wells (GT-1, GT-2, and GT-3) are screened fr75 to 100 feet below grade, hence he water level in these wells is more than 12 feet above scree The other three wells are screened from o ee and the static water level is well within the screened interval • The present gradient closely resembles the gradient in October 1996 (Figure 3) The water table is not planar Rather, a prominent trough located along the southern property line indicates that groundwater flow is primarily linear from east to west The water table slopes rather steeply toward the axis of the trough from both sides The trough is oriented parallel to burred stream channel deposits that were mapped in 1996, suggesting that the trough is following the axis of one of these burred channels 4.2 Groundwater Contamination The laboratory results are summarized in Table 2 and the laboratory report is contained in Appendix B When interpreting the analytical results it is important to remember that the static water level in GT-1, GT-2, and GT-3 is several feet above the screened interval and the samples therefore probably represent less than the maximum concentrations that are likely to exist near the soil-water interface Overall, contamination levels are similar to those that were observed in December of last year, although close examination reveals minor differences Diesel concentrations rose slightly in GT-I and GT-6, declined in GT-5, and remained the same in GT-2 As last December, no diesel was detected in GT-9, G-1, or GT-3 (the well closest to the former UST cavity) No gasoline-range hydrocarbons (TPH-g) or volatile compounds (BTEX) were detected in any of . the wells Gasoline oxygenate compounds (MTBE, etc ) were also below detection limits 3