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' 19 February 2002 AGE-NC Project No 95-0109 ' Page 4of6 Hydrologic Unit 3`(HU3)extends from 99 to 140 feet bsg on-site and vanes from 96 to 140 feet bsg ' off-site (CPT-3), the bottom of the unit is not well defined The soil consists predominantly of fine grained soil with laterally discontinuous sand intervals, pore pressures vary from moderate to high, but exhibit limited lateral continuity of specific high or low pressure intervals, pore pressures W ' become more variable at CPT-3, varying from low to high W 3 3 LABORATORY RESULTS OF "GRAB" GROUND WATER SAMPLES A total of nine grab ground water samples were collected from CPT-1, CPT-2 and CPT-3 and submitted for laboratory analysis for the above mentioned constituents Ground water samples were collected from CPT-1 and CPT-2 at 72 feet to 76 feet bsg (HU2), 92 feet to 96 feet bsg(HU2) and ' 110 feet to 114 feet bsg (HU3), from CPT-1 at 130 feet to 134 feet bsg(HU3), and from CPT-3 at 76 feet to 80 feet bsg (HU2) and 110 feet to 114 feet bsg (HU3) ' TPH-g was detected in water samples collected from HU2 and HU3 at concentrations as high as 500 micrograms per liter (µg/1) One or more BTEX compounds were detected in the water samples I • collected from CPT-2 at concentrations as high as 2 7 µg/1 benzene, 57 µg/1 toluene, 22 µg/1 ethylbenzene and 152µg/1 total xylenes (CPT2-72-76) Toluene was detected in the two CPT-3 samples at concentrations of 21 µg/1 and 4 4 µg11 N-Propyl- benzene was detected in the water samples collected from CPT-2 at 72 feet to 76 feet bsg (HU2) and 92 feet to 96 feet bsg(1-1U2) and isopropylbenzene, 1,3-dichlorobenzene and p-Isopropyltoluene were detected in the water sample collected from CPT-2 at 72 feet to 76 feet bsg (HU2) at concentrations as high as 5 9 µg/1 IOther volatile organic or fuel oxygenating compounds were not detected at or above laboratory reporting limits in the ground water samples analyzed The laboratory report (CTEL Lab I D I 0112-088-1 through 0112-088-7 and 0112-095-1 and 0112-095-2) QA/QC report and chain-of- custody form are included in Appendix B Analytical results of the CPT grab ground water samples are summarized in Table 1 4.0. SUMMARY AND CONCLUSIONS ' IBased on the findings from this investigation, AGE concludes I Generally,silty sand,sand to gravelly sand were encountered at depths between 5 and 20 feet bsg, 30 and 40 feet bsg, 45 and 55 feet bsg, 65 and 100 feet bsg, 120 and 125 feet bsg and 135 and 142 feet bsg Fine grained, sandy silt, clayey silt and silt were observed at all other depths Geologic cross section A-A' was generated from CPT data collected and depict • general ltthology beneath the site in cross sectional view (Figure 3) Advanced GeoEnvironmentai,Inc 1 1 3 w 1