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RESULTS OF QUARTERLY GROUNDWATER MONITORING GROUNDWATER GRADIENT AND FLOW DIRECTION Figure 4 shows the groundwater elevation gradient and flow direction determined from depth to water measurements at the five on-site monitor wells on September 8, 1999 The groundwater elevation has decreased by an average of 2 88 feet at the five monitor wells since the previous quarterly monitoring round on May 5, 1999 The general flow direction is to the west The overall gradient at the site is 0 002 feet/linear foot RESULTS OF CERTIFIED ANALYSIS OF GROUNDWATER SAMPLES The results of the certified analyses of groundwater samples collected from the five monitoi wells on September 8, 1999 are shown in Table 1 Copies of the labotatory reports ate included as Appendix C of this report TPH-G concentrations ranged front a maximum of 19000 ug/l at MWI to less than the laboratory detection limits of 50 ug/1 at monitor wells MW3, MW4, and MW5 Benzene concentrations ranged from a maximum of 2I00 ug/l at MWI to 0 8 uQ/l 1 at MN 4 MTBE concentrations ranged from a maximum of 65 ug/I at MWI to less than laboratory detection Iimits of 0 5 ug/I to MW2 Figure 5 shows the distribution of TPH-G, BTEX, and MTBE to groundwater as determined from groundwater samples collected on September 8, 1999 Monitor well MW5 closest to the former UST located at 1856 Country Club Blvd , continues to show traces of BTEX and MTBE Prior to the May 5, 1999 monitoring round, monitor well MW5 had not contained TPH-G or BTEX concentrations above laboratory detection limits since it was installed to 1994 RECOMMENDATIONS 1) Continue quarterly groundwater monitoring 2) Conduct records review of LUFT site located at 1856 Country Club Blvd Following pre-approval of costs by the UST Cleanup Fund 3) Install offsite monitor well west of MWI to define downgradtent extent of groundwater contamination plume 3 Sanchez QM 7-9 1999