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w - N [?' 09 April 2002 AGE-NC Project No. 97-0301 ' { Page 3 of 14 ground water samples collected during the December 1999 investigation are summarized in Tables 2 and 4, respectively; results of the December 1999 investigation were reported in Quarterly Report - First Quarter 2000, dated 20 March 2000. December 2000 - Monitoring wells MW-5, MW-6 and MW-7 were installed at the site as part of site assessment activities. TPH-g, TPH-d and TPH-k were detected in soil samples collected from MW-5 and MW-7 at concentrations as high as 7.6 mg/kg; BTEX compounds were detected in soil samples from MW-5 and MW-7 at concentrations as high as 1 . 1 mg/kg; and 1 ,2-DCA was detected in a soil sample from MW-7 at a concentration of 75 mg/kg. TPH-g; TPH-d and TPH-k were detected in water samples collected from wells MW- 1 through MW-7 at concentrations as high as 67,000 µg/1 and BTEX constituents detected as high as 14,000 µg/1; MTBE was detected in the water sample collected from MW- 1 at a concentration of 7.6 µg/1; and 1 ,2-DCAwas detected in samples collected from wells MW- 1 , MW-5 and MW-7 at concentrations as high as 1 ,200 gg/l. Analytical results of soil and ground water samples are summarized in Tables 2 and 4, respectively; results of the i December 2000 investigation were reported in Quarterly Report - First Quarter 2001 , dated J 20 March 2001 . • July 2001 - AGE advanced six cone penetrometer testing (CPT) soil borings (P-5, P-6, P-7, ( J P-8, P-9 and P40) to depths of approximately 125 feet bsg on- and off-site to assess the extent of petroleum-impact and to identify potential hydrologic units. Based on CPT data, AGE interpreted the CPT data to identify four potential hydrologic units informally identified as First Water Zone and located between 30 and 55 feet bsg), Second Water Zone located between 60 and 80 feet bsg, Third Water Zone located between 90 and 100 feet bsg and Fourth Water Zone located between 110 feet and at least 125 feet bsg. Geologic cross ,I sections D-D ' and E-E ' were generated from CPT data and depict the informal hydrologic units and petroleum hydrocarbon concentrations beneath the site in cross sectional view !' I (Figures 3 and 4, respectively). Analytical results of grab ground water samples are summarized in Table 3 ; results of the December 2001 investigation were reported in Cone Penetrometer Testing Site Investigation - Third Quarter 2001, dated 25 October 2001 . BetweenDecember-l999and Deeember�2001,-ninetwun&water-monitoring events were performed - at the site to monitor dissolved petroleum hydrocarbon concentrations in ground water and to characterize ground water flow direction and gradient on the site (Table 4). Generally, elevated TPH-g, TPH-d, TPH-k, BTEX and 1 ,2-DCA concentrations were detected in water samples collected I` from wells MW- 1 and MW-7; lesser concentrations were detected at wells MW-2 through MW-6 on isolated occurrences. Generally, low concentrations of MTBE and TBA were detected from MW- 1 . Analytical results of ground water sampling events performed at the site are summarized in _ ! Tables 4. The lateral and vertical extent of the dissolved petroleum hydrocarbon plume is not known toward Advanced GeoEnvironmentnl, Inc. i