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4.0 CONCLUSIONS, RECOMMENDATIONS AND PROJECT STATUS Between September 17, 2003 and March 25, 2004, the groundwater surface beneath the site rose an average of 3 85 feet The groundwater gradient configured using the shallow-constructed wells decreased from 0 00240 to 0 00106 foot/foot, and the gradient using the deep-constructed wells decreased from 0 00450 to 0 00187 foot/foot The groundwater flow direction remained relatively consistent toward the northeast Groundwater from Irrigation Well #2 did not contain detectable concentrations of any of the gasoline compounds analyzed Groundwater collected from Irrigation Well #2 has been free of gasoline compounds for 16 consecutive quarters Between September 17, 2003 and March 25, 2004 the concentrations of gasoline compounds in the groundwater monitoring wells remained relatively consistent MTBE in groundwater appears to be limited to the groundwater table to the northeast (downgradient) of the former UST As shown on the isoconcentration maps (Figures 8 and 9), the plume of groundwater impacted by MTBE is defined to the south by VW-1, to the east by MW-4, and to the northeast (downgradient) by MW-8A ' and MW-813 During the three groundwater extraction events, a total of 6,850 gallons of groundwater were removed from MW-5 and MW-7 This translates to an average flow rate of approximately 4 75 gallons per minute Groundwater extraction appears to be reducing the concentrations of MTBE and 1,2-DCA in groundwater Between December 18, 2003 and March 25, 2004, the concentrations of MTBE and 1,2-DCA have remained relatively stable in MW-5, and have declined an average of 44% in MW-7 Based on these conclusions, Ramage Environmental recommends that the monthly groundwater extraction events continue for at least another quarter Following the next quarterly round of groundwater monitoring and sampling in June 2004, the effectiveness of groundwater extraction will be further evaluated 1 0 8