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i 15 February 2002 AGE-NC Project No 96-0229 Page 3of12 collected from MW-1, MW-3 and MW-6 at concentrations as high as 1,500 mg/kg and BTEX compounds as high as 140 mg/kg TPH-g was detected in water samples collected from all wells at concentrations as high as 150,000 µg/l and BTEX compounds as high as 2 1,000,ug/l, MTBE was detected in ground water samples collected from MW-1 and MW-2 at concentrations as high as 1,800 4g/1, TBA was detected in ground water samples from MW-1 and MW-6 at concentrations as high as 320µg/1 Analytical results of soil and ground water samples collected during the November 1997 investigation are summarized in Tables 2 and 4, respectively • In October 1998, five ground water monitoring wells (MW-7,MW-8, MW-9, MW-I OA and MW-10B) were installed off-site, TPH-g was not detected from any of the soil samples selected for analysis BTEX compounds were detected in MW-7 soil samples at concentrations as high as 0 052 mg/kg and MTBE was detected from MW-8 at a concentration of 0 0053 mg/kg Initial TPH-g-impact was detected in water samples collected from wells MW-7, MW-8, MW-IOA and MW-10B at concentrations as high as 2,000µg/1 and BTEX compounds from MW-7,MW-I OA and MW-1 OB as high as 120µg/1 MTBE was detected in water samples collected from wells MW-7, MW-8, MW-10A and MW-IOB at concentrations as high as 66µg/l,TAME was detected in a ground water sample from MW-8 . at a concentration of 2 9 µg/1 TBA was detected in the sample collected from MW-7 at a concentration of 40µg/1 Analytical results of soil and ground water samples collected during the October 1998 investigation are summarized in Tables 2 and 4, respectively • In December 2001, AGE advanced six cone penetrometer testing (CPT) soil borings to depths of approximately 100 feet bsg on- and off-site to assess the vertical extent of petroleum-impact and identify potential hydrogeologic units Based on CPT data, AGE interpreted the CPT data to identify three potential hydrogeologic units informally identified as "First Water Zone" ground water located between 20 and 45 feet bsg), "Second Water Zone" ground water located between 60 and 80 feet bsg and "Third Water Zone" ground water located between 90 and 100+feet bsg Geologic cross section B-B'was generated from CPT data collected at P-10, P-11 and P-12 and depicts the informal hydrogeologic units and petroleum hydrocarbon concentrations beneath the site in cross sectional view (Figure 3) • Between November 1997 and December 2001, sixteen quarterly ground water monitoring events were performed at the site Generally, TPH-g was detected in water samples collected -F�. . ....11� ASIXT 1 N 1V-7 11/f�IT_Z MAXT_� �"rl T1/f`xT_7 at rnnrPntratinnc nc hioh nc 170 000 11Vlll YY VIla 1Vl VV-1, 11A V -, —II ✓, 111 II V i.._111 1I ! VVaav via�a u�l vaa� baa ,vvv µg/l and BTEX compounds as high as 34,000µg/1 Generally, MTBE was detected in water samples collected from wells MW-1, MW-2,MW-6,MW-7 and MW-8 at concentrations as high as 1,800µg/1, low concentrations of DIPE, TAME and TBA were detected from wells MW-1,MW-4,MW-5,MW-6,MW-7,MW-8 and MW-9 on isolated occurrences Analytical results of ground water sampling events performed at the site are summarized in Tables 4 • Advanced GcoEnvirontnental,Inc