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I19 December 2005 <br /> AGE-NC Project No 99-0645 <br />' Page 7 of 8 <br /> Icontamination <br /> AGE calculated that approximately 1,204 lbs,or 192 gallons,of gasoline were extracted by the SVE <br />' system since start-up on 05 October 2004 A chart illustrating the contaminant concentration trends <br /> of influent soil vapor samples collected between October 2004 and July 2005 is provided in <br /> Appendix B <br /> I <br /> 4.0. PETROLEUM HYDROCARBON DISTRIBUTION IN SOIL <br /> tThe majority of petroleum hydrocarbon-impacted soil appeared to be limited to the west and, to a <br /> lesser extent,the north ends of the former UST area(Figure 2) The highest petroleum hydrocarbon <br />' concentrations in soil,namely TPH-g, were detected in samples T1-N-15 (17,000 mg/kg)and WW <br /> (23,000 mg/kg), collected in May 1999 and March 2000, respectively (Table 2) <br />' The concentrations of petroleum hydrocarbons in soil vapor samples extracted from well VW 1 B, <br /> installed in the area of greatest adsorbed petroleum hydrocarbon contamination,have declined below <br /> laboratory detection limits between initiation of SVE remediation in October 2004 and the present <br /> I � <br /> 5.0. PETROLEUM HYDROCARBON IMPACT TO GROUNDWATER <br /> Historically, low concentrations of petroleum hydrocarbon constituents were detected sporadically <br /> in monitoring well MW-1 before its destruction in September 2002 MTBE was detected in MW-1 R <br /> Iduring its initial ground water monitoring in October 2003 at a concentration of 120 pg/l,TPH-g was <br /> detected in well MW-2 during its second ground water monitoring in April 2002 at a concentration <br /> of 130 µg/l Monitoring well MW-3 has remained uncontaminated <br /> The concentrations of etroleum hydrocarbon contaminants in wells MW-1R and MW-2 have <br /> p <br /> declined below detection limits between the initiation of groundwater monitoring in November 2001 <br /> or October 2003, respectively, and the present (Table 3) <br /> 6.0. SUMMARY AND CONCLUSIONS <br /> IBased upon a review of site assessment activities to date, AGE concludes <br /> • The majority of petroleum hydrocarbon-impacted soil appeared to be limited to the west end <br /> I and, to a lesser extent, the north end of the former UST area The highest petroleum <br /> hydrocarbon concentrations in soil, namely TPH-g, were detected in samples T1-N-15 and <br /> • WW, collected in May 1999 and March 2000, respectively <br /> Advanced GeoEnvironmental,Inc <br /> I <br />