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23 March 2001 AGE-NC Project No 97-0301 ' Page 8of11 concentrations as high as 67,000 micrograms per liter (µg11), however AGE suspects that TPH-g detected at wells MW-2 and MW-3 were due to sampling MW-7 first(TPH-g value equal to 67,000 ggll) and therefore cross-contamination occurred despite equipment decontamination TPH-d was ' detected in water samples collected from wells MW-1,MW-4,MW-5 and MW-7 at concentrations as high as 3,500 kigll, however the laboratory reported the TPH-d sample chromatograms to have significant gasoline range compounds TPH-k was detected in water samples collected from MWA, ' MW-4, MW-5 and MW-7 at concentrations as high as 2,800 gg/l BTEX compounds were detected in the ground water samples collected from wells MW-1 through MW-7 at concentrations ranging as lugh as 14,000µg/1(MW-7, benzene), however, AGE suspects that BTEX detected in samples collected from monitoring wells MW-2 and MW-3 were due to sampling MW-7 first (BTEX value equal to 14,000 ,ug/l) and therefore cross-contamination may ' have occurred despite equipment decontamination MTBE was detected in the water sample collected from MW-1 utilizing EPA Method 8260M at a ' concentration of 7 6µg/l, 1,2-DCA was detected in samples collected from wells MW-1,MW-5 and MW-7 at concentrations as high as 1,200 gg/l No other fuel oxygenated or lead scavenger compounds were detected above the laboratory reporting limits Analytical results of the ground water samples are summarized in Tables 4 and 5 The laboratory reports (McCampbell Analytical Inc I D No 57077 through 57083) and chain-of-custody forms are presented in Appendix H i 1 6.0. SUMMARY AND CONCLUSIONS ' The findings of the December 2000 drilling and well installation Investigation results are as follows ' Generally,medium dense to dense, silty fine sand was encountered at depths between 15 to 25 feet bsg, 35 to 40 feet bsg and 50 to 55 feet bsg, generally, a very stiff to hard, fine sandy, clayey silt was encountered between 5 to 15 feet bsg, 30 to 35 feet bsg,40 to 50 feet bsg and ' 55 to 100 feet bsg General lithology beneath the site in cross-sectional views A -A',B-B' and C- C'is depicted in Figures 3, 4 and 5 ' Field observations,including odor and PID readings, suggest that hydrocarbons were present in soil samples recovered from borings MW-5 at depths between 25 to 45 feet bsg and 85 feet bsg and from MW-7 at a depth of 30 feet bsg ' Saturated soil was generally observed In MW-5, MW-6 and MW-7 soil sample duplicates from 35 feet to 45 feet bsg, ground water levels were measured at approximately 29 feet bsg utilizing a Solinst water level meter ' TPH-g was detected by laboratory analysis of soil samples collected from boring MW-5, located near the northeast side of the former UST area at a depth of 70 feet bsg and from Adwnced GeoEnvironmental,Inc