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I I22 February 1999 • AGE-NC Project No 96-0263 ' Page 6 of 8 ' hydrocarbon impacted ground water resides'in the area of the former dispenser (MW-7) BTEX compounds were detected in the water samples at concentrations of 4,700 ,ug/l, 7,200,ug/l, ' 1,500 µg/l and 5,600 ,ug/l, respectively MTBE was detected by EPA Method 8020 in the ground water sample from well MW7 at a concentration of 88,000µg/1 The same sample contained MTBE detected by EPA Method 8260 Modified at a concentration of 99,000µg/1 No other oxygenates were detected in the ground water samples Analytical results of water samples collected in December 1999 are summarized on Table 3, The laboratory report (MAI Sample ID Nos 26729-26736), QA/QC report and chain-of-custody form are included in Appendix F Figure 8 depicts an approximate areal distribution of impacted ground water containing MTBE and benzene for 02 December 1999 The analytical results from the Jan sampling event are as follows Yt �"Y p g ITPH-g was detected in the water samples collected from monitoring wells MW2,and MW-4 through MW-8 at concentrations up to 18,000 micrograms per liter (1,ig/1) The highest concentration of I. hydrocarbon-impacted ground water is in the area of the former dispenser (MW-7) and the down- gradient well MW-5 BTEX compounds were detected in the water samples at concentrations as high as 1,400,ug/l, 1,100 ug/l, 270µg/l (MW-7) and 3,200,ug/1 (MW-5), respectively MTBE was detected by EPA Method 8020 in the ground water sample from well MW7 at a concentration of 43,000 µg/l The same I sample contained MTBE detected by EPA Method 8260 Modified at a concentration of 31,000,ug/I The only other fuel oxygenate detected was TBA at a concentration of 9 3 ug/l in MW-8 ' Analytical results of water samples collected in January 2000 are summarized on Table 3, The laboratory report (MAI Sample ID Nos 29177-29184), QA/QC report and chain-of-custody form are included in Appendix F Figure 9 depicts an approximate areal distribution of impacted ground ' water containing MTBE and benzene for 13 January 2000 4.0. SUMMARY AND CONCLUSIONS The following conclusions were drawn from the results of this investigation ISaturated soil samples were encountered at approximately 10 feet bsg The static water level was determined to be approximately 7 5 feet below the well casing tops The prevailing ground water flow direction in December in this area was toward the north and somewhat northeast The prevailing ground water flow direction in January in this area was toward the Advanced GeoEnvironmental,Inc I