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19 August 2003 <br /> AGE-NC Project No 96-0263 <br /> Page 3 of 4 <br /> I3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES <br /> TPH-g was detected in water samples MW2,MW4,MWS,and MW7 at concentrations ranging from <br /> 250 micrograms per liter (µg/1) in MW4 to 12,000 µg/1 in MW7 <br /> Benzene was detected in water samples MW2, MW4, MW5 and MW7 at concentrations ranging <br /> from 5 0 µg/1 (MW2 and MW4) to 230 µg/1 (MW7) Toluene was detected in sample MW7 at a <br /> concentration of 40µg/1 Ethylbenzene and total xylenes were detected in samples MW2,MW4 and <br /> MW7 at concentrations ranging from 2 0 µg/l(MW4)to 8 3 µg/1(MW7)and 2 0 µg/1(MW4)to 45 <br /> µg/1 (MW7), respectively <br /> MTBE was detected in samples MW2, MW4, MW5 and MW7 at concentrations ranging from <br />' 180 µg/1(MW4) to 15,000 µg/l(MW7) TAME was detected in sample MW7 at a concentration of <br /> 18 µg/1 TBA was detected in sample MW7 at a concentration of 18 µg/1 No other fuel additives <br /> were detected in the ground water samples collected from the site <br /> The current and past ground water sample analytical results are summarnzed on Table 2 Copies of <br /> the laboratoryreport(CTEL Project No CT214-0304007),QA/QC report and chain-of-custody form <br /> are in Appendix B <br /> 4.4. SUMMARY AND CONCLUSIONS <br /> Based on the results of this investigation, AGE concludes that <br /> • Depth to ground water ranged from 7 05 feet to 8 25 feet below the well casing tops The <br /> prevailing ground water flow direction in March 2003 was inferred to be towards the <br /> north-northwest at an average hydraulic gradient of 0 005 feet/feet <br /> • Contaminant concentrations between the fourth quarter 2002 and the first quarter 2003 <br /> remained relatively stable <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 Isoconcentratlon maps <br /> illustrating the approximate extent ofTPH-g--,benzene- and MTBE-impacted ground water <br /> Iare depicted on Figures 4, 5 and 6 <br /> I <br />