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16 3 0 CONCLUSIONS, RECOMMENDATIONS AND PROJECT STATUS Between August 22 and November 2 g 6, 2002, the groundwater surface beneath the site dropped an average of 1 12 feet The groundwater gradient configured using the shallow-constructed wells increased from 0 0018 to 0 0029 foot/foot, and the flow direction shifted approximately 20 degrees to the northeast The groundwater gradient configured using the deep-constructed wells decreased slightly from 0 0041 to 0 0038 foot/foot, and the flow direction shifted approximately 20 degrees to the north Currently, groundwater is at the lowest level since February 1998 Since May 1992, the groundwater surface has risen approximately 210 feet Groundwater from Irrigation Well #2 did not contain detectable concentrations of any of the gasoline constituent compounds analyzed This represents 11 consecutive quarters of no gasoline compounds in groundwater from Irrigation Well#2 Between August 22, and November 26, 2002, 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 (downgradrent) of the former UST As shown on an isoconcentration map (Figure 6), the plume of groundwater impacted by MTBE is defined to the Msouth at MW-2, and to the northeast (downgradrent) at MW-8A and MW-8B Groundwater in five of the monitoring wells continue to contain concentrations of MTBE As shown on the Chaffs of MTBE in Groundwater(Appendix B), concentrations of MTBE in the wells nearest the former UST source area (VW-2 and MW-3) have declined significantly, However, the MTBE concentration trends in the wells downgradrent of the source area (MW-5, MW-6 and MW-7) are increasing On October 31, 2002, Ramage Environmental met with EHD to discuss the possibility of closing the regulatory case, given the remaining concentrations of MTBE in groundwater Since the lateral and vertical extent of impacted groundwater had been delineated, the plume of impacted groundwater I appeared to be stable, and nearby sensitive receptors did not appear to be threatened, EHD agreed to consider the case for closure if the Fourth Quarter 2002 groundwater analytical results remained stable On December 11, 2002, Ramage Environmental verbally reported to EHD the Fourth Quarter 2002 groundwater analytical results, and that the concentrations of MTBE in the downgradrent wells (MW-5. MW-6 and MW-7) continued to show an increasing trend Based on this verbal report, EHD indicated that case closure could not be considered until the MTBE concentration trend could protect the natural attenuation of MTBE to below water quality goals 7