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08 Julie 2001 • AGE-NC Project No 95-0137 Page 6 of 9 ' Organic vapor was detected in most soil pilot boring samples at concentrations as high as 477 ppm at 20 feet bsg PID data is included on the boring logs (Appendix A) 32 ANALYTICAL RESULTS OF SOIL SAMPLES ' A total of fourteen soil samples were analyzed for the constituents liste in Section 2 4 • TPH-g was detected in each of the samples analyzed at concentrations as high as ' 990 milligrams per kilogram (mg/kg) (VW7-10) TPH-d was also detected in each sample analyzed at concentrations as high as 1,500 mg/kg (VW6-18) • BTEX compounds were detected in each sample analyzed Benzene was detected at concentrations as high as 0 64 mg/kg at a depth of 18 feet bsg(VW3B-18) ' • The only fuel additive detected was 1,2 DCA, at which was detected at concentrations up to 20 micrograms per kilogram(,ug/kg) (VW11-15) ' Analytical results of soil samples are surr manzed on Tables 1 and 2 The laboratory reports (MAT Lab I D No 36881 to 36894), quality assurance and quality control (QA/QC) report and chain-of- custody forms are included in Appendix D 33 SOIL-VAPOR EXTRACTION The SVE unit operated at varying rates during the observation period Extraction flow rates were ' initially calculated to range from 40 cfin up to 150 cfm The startup flow rate was low,automatically diluted with ambient air by the SVE unit, due to the presence of free product or high hydrocarbon concentrations levels introduced into the SVE system The high concentrations cause the SVE unit to automatically open the inlet dilution metering valve to stabilize the operating temperature below 1150 ° F (degrees Fahrenheit) ' An induced vacuum (negative pressure) of approximately 14 to 30 inches of water was measured in the piping between the blower and extraction wells An induced vacuum of approximately 0 2 inches and 0 015 inches was measured at well MW-1 and MW-4, a distance of 10 feet and 45 feet, ' respectively, from the extraction wells The SVE unit operation was continuous over the quarter The analytical results are summarized on Table 3 The laboratory reports (MAI Sample Numbers 55106, 55107, 56077, 56078, 56598, 56599, 57301, 57302,58597, 58598, 60948, 60949, 65177 and 65178) Quality Assurance and Quality Control (QA/QC) reports and chain-of-custody forms are included in Appendix E Extracted organic vapor concentrations measured with the OVM were low compared to the analytical results from the soil-vapor samples The highest concentration of organic vapor measured with the OVM was 495 ppm Advanced GeoEnvironmental,Inc