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4 <br /> 13 May 2004 <br /> iAGE-NC Project No 97-0290 <br /> Page 4of5 <br /> 3 2 ANALYTICAL RESULTS OF SOIL VAPOR SAMPLES <br /> The carbon-SVE unit operated continually,24 hours a day,during the observation period Extraction <br /> flow rates were calculated to have been as high as 49 scfm An Induced vacuum (negative pressure) <br /> of up to 26 Inches of water was measured in the piping between the SVE blower and extraction wells <br /> (Table 5) <br /> Hydrocarbon concentrations detected in soil-vapor samples are as reported below <br /> • The Influent soil-vapor sample collected on 27 October contained detectable concentrations <br /> of TPH-g (1,100 µg/1) and the BTEX compounds benzene (0 83 4g/1), toluene (2 0 4g/1), <br /> ethylbenzene (0 60 µg/1) and total xylenes (20 4g/1) <br /> • The Influent soil-vapor sample collected on 18 November contained detectable <br /> concentrations of TPH-g(810 4g/1) and the BTEX compounds benzene(0 64 µg/1),toluene <br /> (6 7 µg/1) and total xylenes (22 µg/1) <br /> • The Influent soil-vapor sample collected on 30 December contained detectable <br /> concentrations of TPH-g(660 µg/l) and the BTEX compounds benzene (0 41 µg/1), toluene <br /> (0 94 µg/1), ethylbenzene (0 43 µg/1) and total xylenes (15 µg/1) <br /> No additional target analytes were detected The analytical results are summarized on Table 4 The <br /> laboratory reports(MAI Work Orders 0310445, 0311251, 0312542)QA/QC reports and chain-of- <br /> custody forms are included In Appendix C <br /> 3 3 SOIL VAPOR EXTRACTION <br /> The carbon-based SVE system operated between 27 October and 30 December 2003, during the <br /> fourth quarter The hydrocarbon mass(TPH-g)removed during the operating period was calculated <br /> using the following equation M= C•Q•t where <br /> M =cumulative mass recovered (kg) <br /> C =soil-vapor concentration (kg/rn) <br /> Q =extraction flow rate (M3/hr) <br /> t=operational period, in hours <br /> The calculated mass of hydrocarbons removed was based on laboratory analysis of soil-vapor <br /> samples The mass of extracted hydrocarbons was calculated using average hydrocarbon <br /> concentrations of influent soil-vapor sample collected between 27 October and 30 December 2003 <br /> and the average air flow rates at the dates A calculated total of 528 lbs of gasoline (TPH-g) and <br /> 0 388 lbs of benzene were removed between October and December Operational parameters are <br /> presented on Table 5 The volume/mass calculations are attached in Appendix D <br /> Advanced GeoEnvtronmental,Inc <br />