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' 20 September 2000 AGE-NC Project No 97-0333 ' Page 8of11 ' 3 4 2 LABORATORY RESULTS OF GROUND WATER SAMPLES TPH-g was detected in water samples collected from wells MW-1, MW-2, MW-3 and MW-4 at concentrations as high as 140,000 micrograms per liter (ptg/l), the laboratory reported the sample chromatograms as unmodified or weakly modified gasoline ' BTEX compounds were detected in water samples collected from MW-1,MW-2, MW-3 and MW-4 at concentrations as high as 28,000 µg/1 (MW-2, toluene), the greatest benzene concentration was detected from MW-2 at a concentration of 13,000µg/1 ' MTBE was detected in water samples collected from MW-1, MW-2 and MW-3 at concentrations as high as 980,000 ,ug/1 TAME was detected in the water sample collected from MW-1 at a ' concentration of 580 µg/1 No other petroleum hydrocarbon constituents or fuel oxygenated compounds were detected during ' the laboratory analysis Analytical results of the ground water samples are summarized in Table 4 The laboratory reports(McCampbell Analytical Inc I D 42574 through 42578)and chain-of-custody ' forms are presented in Appendix H ' 40 SUMMARY AND CONCLUSIONS The findings of the lune and July 2000 drilling and well installation investigation results arc as follows • Generally, a fine sand was encountered at depths of 5 and 10 feet bsg underlain by a sandy, ' clayey silt at a depth of 15 feet bsg underlain by a silty fine sand to fine sand at 20, 25 and 30 feet bsg General lithology beneath the site in cross-sectional views A - A and B - B' is depicted in Figures 3 and 4 ' • Field observations, including odor and PID readings, suggest that hydrocarbons were present in soil samples recovered from borings MW-1, MW-2, MW-3 and MW--4, particularly ' between 15 and 30 feet bsg • Saturated soil was generally obser,,ed in soil sample duplicates at 20 feet bsg, ground water levels were measured at approximately 17 feet bsg utilizing a Solinst water level metes ' . TPH-g was pnmanly detected in samples from borings MW-1 and MW-2 located on the north and south sides of the fanner UST excavation and from boring MW-4, located ea"t of ' the fuel dispensLr area The highest TPH-g concentrations occurred at 15 feet bsg in bonngs 'v9W-i and MW-? and at 25 feet hs.,; in honing Mih-4 in general, the �crticai extent of f P[j- • ' idtan4,df-ttA11vttonnuniti int