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4 0 CONCLUSIONS, RECOMMENDATIONS AND PROJECT STATUS <br /> Between June 2, and August 25, 2004, the groundwater surface beneath the site dropped an <br /> average of 3 85 feet The groundwater gradient configured using the shallow-constructed wells <br /> 1 increased from 0 00108 to 0 00256 foot/foot, and the gradient using the deep-constructed wells <br /> increased from 0 00253 to 0 00396 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 18 consecutive quarters <br /> Between June 2, and August 25, 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 detected <br /> in MW-8B for the first time in June 2004, was not detected in the August 2004 sampling event <br /> The total volume of groundwater extracted during the seven extraction events was approximately <br /> 16,710 gallons This translates to an average flow rate of approximately 4 97 gallons per minute <br /> Seven groundwater extraction events appeared to reduce the concentrations of MTBE and 1,2- <br /> DCA in groundwater Between December 18, 2003 and August 25, 2004, the concentration of <br /> MTBE increased from 92 to 100 µg/I in MW-5, and decreased from 390 to 100 µg/l in MW-7 In the <br /> ' same period, the concentration of 1,2-DCA decreased from 26 to 13 µg/l in MW-5, and decreased <br /> from 25 to 8 2 µg11 in MW-7 <br /> Based on these conclusions, Ramage Environmental recommends that groundwater extraction <br /> events be discontinued, until after the fourth quarter 2004 groundwater analytical data can be <br /> evaluated Following the next quarterly round of groundwater monitoring and sampling in <br /> December 2004, the possible continuation of groundwater extraction should be further evaluated, <br /> and/or the case should be re-considered for regulatory closure <br /> • 8 <br />