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4 0 CONCLUSIONS, RECOMMENDATIONS AND PROJECT STATUS <br /> Between March 25, and June 2, 2004, the groundwater surface beneath the site dropped an <br /> average of 0 85 feet The groundwater gradient configured using the shallow-constructed wells <br /> increased from 0 00106 to 0 00108 foottfoot, and the gradient using the deep-constructed wells <br /> increased from 0 00187 to 0 00253 foot/foot The groundwater flow direction remained relatively <br /> consistent toward the northeast <br /> Groundwater from Irrigation Well #2 did not contain detectable concentrations of any of the <br /> gasoline compounds analyzed Groundwater collected from Irrigation Well#2 has been free of <br /> gasoline compounds for 17 consecutive quarters <br /> Between March 25, and June 2, 2004 the concentrations of gasoline compounds in the <br /> groundwater monitoring wells remained relatively consistent MTBE in groundwater appears to be <br /> limited to the groundwater table to the northeast (downgradient) of the former UST MTBE was <br /> detected in MW-81B for the first time, since the well was installed in March 2002 <br /> During the three groundwater extraction events conducted during the second quarter, a total of <br /> 7,310 gallons of groundwater were removed from MW-5 and MW-7 The total volume extracted <br /> during the first and second quarters was 14,160 gallons This translates to an average flow rate of <br /> approximately 4 92 gallons per minute <br /> Groundwater extraction appears to be reducing the concentrations of MTBE and 1,2-DCA in <br /> groundwater Between December 18, 2003 and June 2, 2004, the concentration of MTBE has <br /> increased from 92 to 110 µg11 in MW-5, and decreased from 390 to 110 µg11 in MW-7 In the same <br /> period, the concentration of 1,2-DCA has decreased from 26 to 16 µg/l in MW-5, and decreased <br /> from 25 to 8 0 µg11 in MW-7 <br /> Based on these conclusions, Ramage Environmental recommends that the monthly groundwater <br /> extraction events be discontinued For the third quarter of 2004, one groundwater extraction event <br /> should be completed, and the monitoring well network should be sampled Following the next <br /> quarterly round of groundwater monitoring and sampling in September 2004, the effectiveness of <br /> groundwater extraction should be further evaluated <br /> 8 <br />