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1 <br /> I • 21 February2003 <br /> AGE-NC Project No 96-0263 <br /> IPage 3 of 4 <br /> 3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES <br /> TPH-g was detected in water samples MW2,MW4,MW5,and MW7 at concentrations ranging from <br /> I400 micrograms per liter (µg/1) in MW4 to 36,000 Rg/l in MW7 <br /> Benzene was detected in water samples MW2, MW4, MW5 and MW7 at concentrations ranging <br /> Ifrom 6 9 Rg/l (MW5) to 530 µg/l (MW7) Toluene was detected in samples MW2 and MW7 at <br /> concentrations of 16 Rg/l and 1,100 Rg/l,respectively Ethylbenzene and total xylenes were detected <br /> I in samples MW2,MW4 and MW7 at concentrations ranging from 3 3 Rg/l(MW4)to 86 p.g/l(MW7) <br /> and 7 8 µg/l (MW4) to 250 Rg/l (MW7), respectively <br />' MTBE was detected in samples MW2, MW4, MW5 and MW7 at concentrations ranging frorn <br /> 180 µg/1 (MW4) to 21,000 Rg/1 (MW7) TAME was detected in sample MW7 at a concentration of <br /> 24 Rg/l TBA was detected in samples MW4 and MW7 at concentrations of 13 µg/l and 770 Rg/l, <br /> I respectively No other fuel additives were detected in the ground water samples collected from the <br /> site <br /> The current and past ground water sample analytical results are summarized on Table 2 Copies of <br /> the laboratory report(CTEL Laboratory IDs 0301-016-1 through 0301-016-11), QA/QC report and <br /> chain-of-custody form are in Appendix B <br /> I <br /> 4.0 SUMMARY ,AND CONCLUSIONS <br /> Based on the results of this investigation, AGE concludes that <br /> Depth to ground water ranged from 6 94 feet to 7 83 feet below the well casing tops The <br /> ground prevailingd water flow direction in Janus 2003 was inferred to be towards the <br /> January <br /> north-northwest at an average hydraulic gradient of 0 006 feet/feet <br /> • With the exception of the noticeable increase in TPH-g concentration in sample MW7, there <br /> was little change in contaminant concentrations between the third and fourth quarter <br /> Ianalytical results <br /> • The dissolved hydrocarbon plume extends northward from the former UST and dispenser <br /> areas,but not beyond the down-gradient monitoring wells (MW8, MW9 and MW10) The <br /> dissolved phase plume has been defined laterally in all directions Isoconcentration maps <br /> illustrating the approximate extent of TPH-g-,benzene- and MTBE-impacted ground water <br /> Iare depicted on Figures 4, 5 and 6 <br />