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31 January 2013 AGE-NC Project No. 02-0926 Page 6 of 21 4.1. ADSORBED PETROLEUM-IMPACT: 5'-30' BSG Based on soil samples collected at the site between 5 and 30 feet bsg (generally slightly above first encountered groundwater), AGE has modeled the estimated lateral extent of adsorbed hydrocarbon impact within the above sampling interval, prior to any remediation that has been performed at the site. Based on these sampling results the adsorbed soil plume appears to be highly impacted directly surrounding the former tank pit area near borings B5 and MW5. Utilizing VW-1 as a midpoint the plume extends approximately twelve feet to the north, eight feet to the east, seven feet to the south and twenty-six feet to the west. The most significant TPH-g impact in the 5 to 30 foot interval was encountered directly beneath the north end of the former underground storage tank area (boring B5) at a maximum concentration of 15,000 mg/kg (B5-18); maximum TPH-d impact was detected at the B5-18 sampling location at a concentration of 11,000 mg/kg. Significant BTEX constituent impact has been encountered in the 5 to 30 foot interval and at maximum concentrations of 8.2 mg/kg benzene (B5-25), 1,800 mg/kg toluene (B5-18), 2,100 ethylbenzene (B5-18) and 3,690 mg/kg xylenes (B5-18). Analytical results of soil samples collected from 5 to 30 feet bsg are summarized in Table 1. The estimated area of impact within the above zone is illustrated in cross sectional view in Figures 5 and 6, and the lateral maximum extent is illustrated in Figure 7. 4.2. ADSORBED PETROLEUM-IMPACT: 30'-60' BSG Based on soil samples collected at the site between 30 and 60 feet bsg (within the historic saturated zone), AGE has modeled the estimated lateral extent of adsorbed hydrocarbon impact within the above sampling interval, prior to any remediation that has been performed at the site. Based on these sampling results the adsorbed soil plume appears to be highly impacted directly surrounding the former tank pit area near borings B5 and MW5 and highly impacted soil extends to the north near deep monitoring well MW-6. Slightly less impacted soils appear to extend to the south near boring B4, likely a result of historic groundwater flow direction to the south of the former tank pit. Utilizing VW-1 as a midpoint the plume extends approximately seventeen feet to the north, eight feet to the east, thirty feet to the south/southeast and sixteen feet to the west. The most significant TPH-g impact in the 30 to 60 foot interval was generally encountered directly beneath the north end and appears to have migrated slightly north towards MW-6; TPH-g has been reported at a maximum concentration of 16,000 mg/kg (B5-33) within the interval; maximum TPH-d impact was detected at the B5-33 sampling location at a concentration of 6,900 mg/kg. Significant BTEX constituent impact has been encountered Advanced GeoEnvironmental, Inc.