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1./ \1 02 May 2013 AGE-NC Project No. 04-1168 Page 3 of 10 from the overlying tank pit. Boring B2 was advanced as a continuation of B1, located 10 feet north of 131 just outside the tank pit. Samples were collected in boring B2 starting at 35 feet bsg to a total depth of 45 feet bsg. Boring B3 was advanced in the former dispenser location to a total depth of 20 feet bsg. Total petroleum hydrocarbon quantified as gasoline(TPH-g)was detected in soil samples collected from borings B1 and B2 at a maximum concentration of 500 milligrams per kilogram (mg/kg) in boring 131 at 25 feet bsg. Toluene, ethylbenzene and xylenes were detected in borings B1 and B2 at maximum concentrations of 0.017 mg/kg toluene(B2-45),0.017 mg/kg ethylbenzene(132-45)and 6.3 mg/kg xylenes(132-35). EDB was detected in one soil sample at a concentration of 0.045 mg/kg (132-35). • July 2005 - Three soil borings were advanced at the site for collection of soil samples and installation of three groundwater monitoring wells (MW-1 through MW-3)TPH-g was detected in soil samples collected from borings MW-1 and MW-2 at concentrations of 1.5 mg/kg (MW1-35) and 1.0 mg/kg (MW2-50). Total xylenes were detected in soil samples collected from borings MW-1, MW-2 and MW-3 at concentrations of 0.086 mg/kg (MW1-35), 0.052 mg/kg (MW1-45), 0.046 mg/kg (MW2-50) and 0.014 mg/kg (MW3-50 feet bsg). General site stratigraphy is illustrated in Figure 3. The lateral and vertical extent of adsorbed TPH-g in soil are illustrated in Figures 4 and 5; the lateral of dissolved TPH-g in groundwater is illustrated in Figures 6. Historical soil analytical data is summarized in Table 1. Groundwater elevation data, and groundwater monitoring data are summarized in Tables 2 and 3. Boring logs are included in Appendix C. 2.4. GROUNDWATER MONITORING PROGRAM Between August 2005 and December 2012, a total of seven groundwater monitoring events have been conducted at the site to monitor dissolved petroleum hydrocarbon concentrations in groundwaterand to characterize groundwater flow direction and gradient at the site. 2.4.1. Groundwater Levels Since initiation of the groundwater monitoring program (November 1999), groundwater elevations ranged between approximately 18 and 35 feet below the North American Vertical Datum 88 (NAVD88); depths to groundwater ranged from approximately 42 to 58 feet below the tops of the well casings (btoc). Advanced GeoEnvironmental,Inc.