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• 3.0 CONCLUSIONS, RECOMMENDATIONS AND PROJECT STATUS ' Betweenu J ne 8, and September 18, 2001 groundwater levels dropped an average of 4 57 feet, and the groundwater flow direction and gradient remained relatively constant During the past five quarters of groundwater monitoring, the groundwater flow direction has remained north to northeast, at a relatively constant gradient ' Based on the results of previous subsurface investigation, sal and groundwater beneath the north ' end of the former middle UST are impacted by relatively low concentrations of gasoline hydrocarbons Most of the petroleum hydrocarbon mass remains concentrated in soil immediately below the north end of the former middle UST Vertically, the concentrations of gasoline ' hydrocarbons decrease rapidly with depth, and are defined between 65 and 80 feet bgs Based on the results from soil samples collected during the drilling of MWA, MW-2 and MW-3, the lateral ' extent of impacted soil appears to be defined to the area of the former USTs Impacts to groundwater at the water table appear to be limited to low concentrations of MTBE in ' MW-3 The monitoring well network does not include a well north-northeast (downgradient) of the former UST and dispenser system As such, the plume of impacted groundwater may not be fully ' delineated by the existing wells Based on these conclusions, on August 13, 2001, Ramage Environmental submitted to PHS/EHD ' a letter work plan, outlining the installation of one additional downgradient monitoring well On September 13, 2001, PHS/EHD approved the work plan The well installation is currently pending permit acquisition and contractor scheduling The well should be installed during the fourth quarter of 2001 Until the case is closed, groundwater should continue to be monitored and sampled on a quarterly basis, with the next event scheduled for December 2001 I 11 I