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' 18 May 2006 AGE-NC Project No 04-1239 Page 6 of 7 ' very fine- to medium-grained sand was encountered In boring M W 12 at 30 feet and 40 feet bsg, a soil sample was not recovered at 35 feet bsg In boring MW 13, advanced adjacent to MW 12, dark gray sandy silt was identified at the top of the 45-foot sample, with clayey silt - and silty clay identified to the total depth of the boring except for an approximately 6-inch thick lens of silty sand encountered near 55 feet bsg In boring MW14, silty clay was encountered from 45 feet to 55 feet bsg, underlain by sandy clay at 60 feet and 65 feet bsg ' A total of eleven soil samples were analyzed for the constituents listed in Section 2 1 1 , no petroleum hydrocarbon constituents were detected at or above laboratory detection limits In ' the soil samples analyzed • At the time of the March 2006 sampling event, depths to ground water ranged from 16 94 feet to 2105 feet below the tops of the well casings Ground water elevation in wells MW-9 through MW-I l ranged from 6 82 feet to 7 00 feet below MSL, and averaged approximately 6 89 feet below MSL, indicating an increase in average ground water elevation of 3 32 feet since the last monitoring event in November 2005 During this Imonitoring event, the ground water level was as high as 3 06 feet above the screened intervals in shallow wells MW-9 through MW-12 . • Ground water at the site was inferred to be flowing toward the west-southwest under a hydraulic gradient of approximately 0 004 ft/ft ' • TPH-g was detected In wells MW-9 and MW-14 at concentrations of 86,000 µg/l and 1,900 µg/l,respectively BTEX compounds were detected in wells MW-9 and MW-14 at the following maximum concentrations 31 µg/l benzene(MW-14),7,300µg/1 toluene(MW-9), 4,600 pg/i ethylbenzene (MW-9), and 28,900 pg/l total xylenes (MW-9) • The lateral extent of shallow petroleum hydrocarbon contamination is defined to the south by well MW-11, to the southwest by well MW-10, and to the north by well MW-12 The Ilater extent of deep contamination is defined to the north by well MW-13 S.Q. RECOMMENDATIONS Based on the findings of the environmental activities recounted in this report, AGE recommends • Continuation of quarterly monitoring events, the next event is scheduled for the second quarter 2006 • Installation of one additional shallow ground water monitoring well in the former UST area, as detailed in the AGE-prepared Additional Monitoring Well Installation Work Plan, dated 15 November 2005 • Advanced GeoEnvironmentab Inc I