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' 31 October 2003 <br /> • AGE-NC Project No 95-0137 <br /> ' Page 4 of 6 <br /> ' vacuum(negative pressure)of approximately 30 inches ofwaterwas measured in the piping between <br /> the blower and extraction wells Utilizing a photo ionization meter (PID), hydrocarbon <br /> concentrations were measured at between 12 and 40 parts per million volume (ppmv) at the SVE <br /> ' intake during this period The field measurements are summarized in Table 1 , <br /> No significant changes were detected in dissolved oxygen concentrations measured in the monitoring <br /> ' wells,the highest dissolved oxygen value was measured in well MW-2 at 12 3% Dissolved oxygen <br /> measurements are presented in Table 3 <br /> ' <br /> 32 ANALYTICAL RESULTS OF SOIL VAPOR SAMPLES <br /> TPH-g was detected from all influent vapor samples at concentration of 240 microgram per liter <br /> (gg/l), 82 gg/l, 61 gg/l, 53 pg/l and 64 µg11 (May to September), respectively Various BTEX <br /> compounds were detected at low concentrations in two influent vapor samples, the highest <br /> concentration was detected in the June 0 49 gg/l of xylenes Benzene and MTBE were not detected <br /> in any of the samples analyzed The analytical results of the soil vapor samples are summarized on <br /> Table 2 The laboratory reports (MAI Sample Numbers 0305205,0306427, 0307438,0308232 and <br /> ' • 0309191),Quality Assurance and Quality Control(QA/QC)reports and chain-of-custody forms are <br /> included in Appendix B <br /> 1 <br /> 3 3 MASS OF RECOVERED HYDROCARBONS <br /> The hydrocarbon mass (TPH-g) removed during the operating period was calculated using the <br /> equation M=C•Q•t <br /> ' where M= cumulative mass recovered (kg) <br /> C = soil-vapor concentration (kg/m 3) <br /> Q =extraction flow rate (m3/hr) <br /> ' t= operational period, in hours <br /> The estimated mass of hydrocarbons removed was based on laboratory analysis of soil-vapor <br /> ' samples, the flow rate and operational time, the operational results are summarized on Table 1 A <br /> total of 97 7 kg(215 3 lbs),or 34 45 gallons of hydrocarbons as gasoline was removed between May <br /> and September 2002, the volume and mass calculations are attached in Appendix C A total of <br /> ' 2095 5 kg(4,169 7 lbs),or a volume of 739 gallons hydrocarbons as gasoline was removed between <br /> December 2000 and September 2003 <br /> 1 <br /> Advanced GeoEnvironmental,Inc <br />