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' 26 December 2001 <br />' AGE-NC Project No 97-0290 <br /> Page 6of8 <br />' 16 April 2001 TPH-g was detected at 7,300 ug/l, benzene at 10yg/l toluene at 44 µg/l, <br /> ethylbenzene at 33 4g/I and total xylenes at 200 4g/1 <br />' The analytical results are summarized on Table 5 The laboratory reports (MAI Sample Numbers for <br /> influent samples 56708, 58604, 60632 , 63391, 64866 and 65625) Quality Assurance and Quality <br />' Control (QAJQC) reports and chain-of-custody forms are included in Appendix C <br /> Hydrocarbon concentrations measured in samples from the effluent stream indicated a mimmum 95- <br /> percent rate of destruction while operation of the Thermal Oxidation SVE system, and the carbon <br /> vessels after in April 2001 However, during the sampling of the carbon SVE in March 2001, almost <br />' no adsorption was indicted, then requiring the April exchange of carbon vessels <br />' 3 4 MASS OF RECOVERED HYDROCARBONS <br /> The hydrocarbon mass (TPH-g) removed during the operating period was calculated using the <br />'. following equation M = C•Q•t <br /> where M =cumulative mass recovered (kg) <br /> C — soil-vapor concentration (kg/m') <br /> Q = extraction flow rate (m'/hr) <br /> t =operational period, in hours <br /> The operational time was divided into at least three time periods The calculated mass of <br /> hydrocarbons removed was based on laboratory analysis of soil-vapor samples The mass of <br /> extracted hydrocarbons was calculated for each time period using average hydrocarbon <br /> concentrations of influent soil-vapor samples collected and average air flow rates Total of 1,652 <br /> gallons of gasoline (TPH-g and BTEX) were removed between 27 November 2000 and 16 April <br /> 2001 The volume/mass calculations are attached in Appendix D <br /> i3 5 TN-SITU ATR SPARGING <br /> Elevated concentrations of dissolved oxygen were detected in monitoring wells MW-1, MW-4 and <br /> MW-5, which were used as observation wells outside the IAS network on the site Dissolved oxygen <br /> concentrations in the other, down gradient wells showed smaller changes A small change in <br /> dissolved oxygen was observed in well MW-2 samples within the sparging well network The <br /> Ile dissolved oxygen data for each well measured is summarized in Table 5 <br /> f <br /> Advanced GeoEnvironmental,Inc <br />