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08 September 2009 AGE -NC Project No. 03-1055 Page 17 of 19 concentration of 460 mg/kg (STCK-4). MTBE was reported in soil stockpile sample STC K -L at a concentration of 0.025 mg/kg. One or more BTEX compounds were reported in three soil stockpile samples at maximum concentrations of 0.010 mg/kg benzene, 0.066 mg/kg toluene, 0.022 mg/kg ethylbenzene, and 0.122 mg/kg xylenes in sample STCK-1. Lead was reported in six soil stockpile samples at concentrations ranging between 13 mg/kg and 22 mg/kg. No other analytes were reported at or above detection limits in the stockpile soil samples. One ground water sample WS -5 was collected following the UST removal. TPH-g and TPH-d were reported in the ground water sample at concentrations of 2,400 µg11 and 0.92 µg/1, respectively. BTEX compounds, ethylbenzene and xylenes, were reported at concentrations of 14 µg11 and 15.1 µg/1, respectively_ MTBE was reported at a concentration of 5.6 µg/1. Based on the average hydrocarbon concentration ofTPH-g in excavation soil samples, UST removal soil samples and soil boring samples, an estimated 71 gallons or 201 kg of gasoline were removed from the site during both the UST removal and soil excavation procedures (October and November 2003). In addition to 13 gallons or 64 kg of gasoline were removed during the October 2000 excavation. The procedures and results of the October and November 2003 soil excavations are presented in the AGE -prepared report entitled Well Destruction and Excavation Sampling Report, dated 23 March 2004. 7.0. DISCUSSION AND CONCLUSIONS Based on data collected during site assessment and ground water monitoring events at the former Tracy Diner site, AGE concludes: • Ground water flow direction is generally inferred to be towards the north-northeast under hydraulic gradients between 0.001 ft/fl and 0.006 ft/ft; ground water levels recorded at the site, averaged 10.74 feet btoc_ • TPH-g has been established as the contaminant of concern at the site. • Laboratory analyses of soil samples indicate the source of petroleum hydrocarbon -impact to soil on-site are the former 500 -gallon UST and northernmost dispenser. • Boring MW 11 exhibited the only `deep' (beyond 15 feet bsg) soil contamination throughout all subsurface investigations; contamination encountered in this boring is likely from the former Chevron site. • The impacted soil in the center of Adams Street in the vicinity of borings B13, B 14 and B 15 is likely the result of the former Chevron release as evidenced by the following: 1) the borings are located down -gradient of the former Chevron UST areas and significantly Advanced GeoEnvlronmentsl, Inc