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07 June 2004 AGE-NC Project No 02-0926 ' Page 9 of 1 I ' Selected soil samples were sent to Cooper Testing Laboratory(CTL)and analyzed for geotechnical properties The soil sample collected from MW-1 at 20 feet bsg is described as an olive brown clay with sand(very silty),with a porosity of 49 0%,an average permeability of 4 OX 10-7 centimeters per ' second (cm/sec) and a specific gravity of 2 74 cm/sec The hydraulic conductivity in sample MW 1-25 ranged from 5 5 X 10-7 cm/sec to3 7X 10 7 cm/sec,which,according to Robertson and others (1990), is consistent with soil behavior associated with sands and silty sands The soil sample collected from MW-1 at 50 feet bsg is described as an olive brown clay with sand (very silty), with a porosity of 39 8%, an average permeability of 4 OX 10-7 cm/sec and a specific ' gravity of 2 73 cm/sec The hydraulic conductivity in sample MW 1-50 ranged from 3 8X 10 7 cm/sec to 3 3x 10-7cm/sec, which is consistent with soil behavior associated with sands and silty sands The CTL laboratory report is included in Appendix F 43 ANALYTICAL RESULTS OF GRAB GROUND WATER SAMPLES Three'grab' grsamples ground water were taken from soil borings B4 through B6 and analyzed forthe p • constituents listed in section 3 1 1 TPH-g was detected in all three ground water samples at the following concentrations 1,200 micrograms per liter(µg/1)(B4),460,000,000 µg/1 (B5) and 12,000 µg/l (B6) TPH-d was detected ' in the samples from B4 and B5 at concentrations of 160 µg/1 and 14,000,000 µg/1, respectively BTEX compounds were detected in all three ground water samples analyzed The sample from B5 had the highest concentrations at'680,000 µg/1 benzene, 1,500,000 µg/1 toluene, 420,000 µg/1 ethylbenzene and 3,280,000 µg/1 total xylenes 1 MTBE and lead were detected in the ground water sample from B4 at 4 6 µg11 and 480 µg11, respectively No additional target analytes were detected at or above laboratory detection limits in ' the samples analyzed Analytical results of`grab' ground water samples are summarized in Table 3 ' The laboratory reports (MAI Work Order 0210339 and CTEL Project No CT214-0402106), QA/QC report and chain-of-custody forms are included in Appendix E 1 4 4 GROUND WATER GRADIENT AND FLOW DIRECTION ' At the time of the February 2004 sampling event, depths to ground water ranged from 42 61 feet to 43 11 feet below the tops of the well casings The average ground water elevation at the site was ' 24 11 feet below mean sea level(MSL) (Table 2) During this monitoring event, the ground water . levels in the wells were at least six feet below the tops of the well screens, indicating that the wells are screened properly to yield representative ground water samples ' Advanced GeoEnvironmental,Inc