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22 October 2009 AGE-NC Project No. 00-0697 Page 8 of 10 and February 2006).TPH-g and benzene concentrations have only been detected once since sampling began in ground water samples collected from wells MW-1,MW-2,and MW-5;TPH-g and BTEX have never been detected above laboratory reporting limits from wells MW-4 and MW-6. Historically,MTBE has been detected once from well MW-2 at a concentration of 85 11g/1(August 2005)and twice from well MW-4 at concentrations as high as 14 pg/l(August 2005). TAME was detected during three sampling events from well MW-3 at concentrations as high as 17 µg/1 (November 2005) and 1,2-DCA was detected during two sampling events from well MW-3 at concentrations as high as 6.7 µg/1 (November 2005). Ground water analytical data is summarized in Table 5. TPH-g and BTEX have not been detected from wells on-site since May 2008 and February 2008, respectively. MTBE has not been detected in ground water samples collected from the site since November 2005;TAME and 1,2-DCA concentrations have not been detected from site wells since May 2006.Presently,the lateral and vertical extent of petroleum hydrocarbon-impacted ground water is defined. Based on a plot of TPH-g and benzene versus time(Appendix E),a definitive trend of decreasing dissolved concentrations has been evident at the site from impacted well MW-3. Based on the last two sampling event performed in July and October 2008,TPH-g,BTEX,and the remaining analytes are all at non-detect levels. 7.0. DISCUSSION AND CONCLUSIONS Based on data collected during site assessment and ground water monitoring events at the Terminous Market,AGE concludes: • Since initiation of the ground water monitoring program, ground water elevations have ranged from 16 feet to 21 feet below NAVD and depths to ground water have ranged between 2 feet and 7 feet btoc. Ground water elevation data is summarized in Table 4. Ground water elevation figures depicting ground water flow directions and gradients from November 2004 to October 2008 are presented in Appendix D. • Petroleum hydrocarbon-impacted soil extends from the former leaded UST towards the east encompassing an area 40 feet by 45 feet(Figure 2).The vertical extent of TPH-g impacted soil extends to a depth of 15 feet bsg across most of the site; in the area of well MW-6, TPH-g impacted soil extends to a depth of 20 feet bsg(MW6-20).Benzene was not detected below 10 feet bsg in any of the soil samples analyzed. • AGE estimates 57.16 pounds,or 9.15 gallons total petroleum hydrocarbons appear to remain in soil at the site.The assumptions for the calculation of Hydrocarbon mass remaining in soil Adwnced GeoEmAronowntal,lwe.