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I <br />' 25 February 2004 <br /> AGE-NC Project No 95-0130 <br />' Page 5 of 7 <br /> from EW-2 at depths between 30 and 55 feet bsg at concentrations as high as 497 parts per million <br />' (ppm) Organic vapor field measurements are recorded on the boring logs contained in Appendix A <br />' 3 3 ANALYTICAL RESULTS OF SOIL SAMPLES <br />' A total of ten soil samples were submitted to a DHS-certified laboratory for analysis of TPH-g, <br /> BTEX, fuel oxygenates, 1,2-DCA and EDB TPH-g was detected in soil samples collected from <br /> EW-1 at 40, 50 and 55 feet bsg and from EW-2 at 55 feet bsg at concentrations as high as 280 <br />' milligrams per kilogram (mg/kg) BTEX compounds were detected in the same samples at <br /> concentrations ranging as high as 12 mg/kg xylenes in the 55 foot sample collected from EW-2 <br />' MTBE was detected in the 40-foot, 50-foot and 55-foot soil samples collected from EW-1 and the <br /> 55-foot soil sample from EW-2 at concentrations ranging as high as 0 22 mg/kg(EW 1-40) 1,2-DCA <br /> was detected in the 55-foot soil samples at EW-1 and EW-2 at concentrations of 0 022 mg/kg and <br />' 0 019 mg/kg, respectively No other fuel oxygenates were detected by laboratory analysis The <br /> analytical results of the selected soil samples are summarized In Table 1 The laboratory reports <br /> (Castle Analytical Laboratory Reference No 2813 and McCampbell Analytical Inc Lab I D No <br /> 5923 and 5924) and chain-of-custody forms are included in Appendix D <br />' 4.0. DISCUSSION AND CONCLUSIONS <br />' The following conclusions were drawn from the results of this investigation <br /> • Saturated soil at the site was encountered at approximately 45 feet bsg The static water level <br /> was measured at approximately 43 feet below the tops of the monitoring well casings <br /> • The lithology underlying the site is dominated by fine sandy silt and clayey silt from surface <br /> grade to approximately 35 feet bsg, and silty fine sand, fine sand and fine to medium sand <br />' between 35 feet and 55 feet bsg(Hydrologic Unit 1) The modeled site stratigraphy is shown <br /> in Figures 3 and 4 <br />' • From previous investigation, the deepest soil horizon found to be impacted by petroleum <br /> hydrocarbons and/or oxygenated fuel additives was at 86 feet bsg (CPT-2A and MW-6) <br /> Based on the current data collected from MW-8, EW-1 and EW-2, impacted soil was <br />' encountered from EW-1 and EW-2 at depths ranging from 35 feet bsg to the total depth of <br /> the borings at 55 feet bsg This distribution of contaminants, in conjunction with the site <br /> stratigraphy as described above, suggests a narrow, vertical plume of impacted soil <br />' descending from the former UST area,at the north edge of the site,that spread laterally upon <br /> encountering the ground water table at 50 feet bsg The vertical extent of impacted soil near <br />' Advanced GeoEnvironmental,Inc <br />