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�V1 it . 17 January 1997 AGE-NC Project No 95-0121 Page 3 of 5 3 2 LABORATORY RESULTS OF GROUND WATER SAMPLES TPH-g was detected in water samples collected from wells MW-1 through MW-9 at concentrations as high as 35,000µgA (micrograms per liter or parts per billion ppb) TPH-d was detected in water samples collected from MW-1 through MW-9 at concentrations as high as 11,000 ppb BTE&X constituents were detected in water samples from wells MW-1 through MW-9 at concentrations as high as 9,600 ppb (benzene, MW-2) MTBE was detected in samples from MW-1, MW-2 and MW-7 at concentrations up to 210 ppb The analytical results for ground water samples are summarized in Table 2 -Analytical Results of Ground Water Samples The laboratory report (CAL Laboratory Batch No 952) and chain-of- custody forms are included in Appendix B 4.0 CONCLUSIONS & RECOMMENDATIONS 41 CONCLUSIONS Based upon data collected during the November 1996 monitoring, AGE has the following conclusions • Ground water flow direction has remained relatively constant at the site (northeast) over the past two years Monitoring wells MW-6 and MW-9 continue to be up-gradient of the former UST area, MW-8 continues to serve as the down-gradient well • Concentrations of some dissolved petroleum hydrocarbon constituents increased in six of nine wells at the site Concentrations of all dissolved hydrocarbons slightly decreased only in wells MW-2, MW-3 and MW-4 • The greatest concentrations of dissolved petroleum hydrocarbons continues to be in the area of wells MW-I through MW-4, near the "core" of hydrocarbon-impacted soil • Concentrations of benzene detected in wells MW-I through MW-9 were above the State of California Maximum Contaminant Levels (MCLs) for drinking water of 1 0µg/1 • Concentrations of toluene detected in wells MW-i through MW-3 and MW-7 were above MCLs for drinking water of 150µg/1 • Concentrations of xylenes detected in well MW-1 were above MCLs for drinking water of 1,750µg/1 • Concentrations of MTBE in wells MW-1, MW-2 and MW-7 are above the State of California Drinking Water AL of 35 ppb