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05 January 2004 <br /> • AGE-NC Project No. 95-0137 <br /> Page 5 of 8 <br /> 3.0. FINDINGS <br /> 1 <br /> AGE determined the approximate mass of hydrocarbons removed,based on the SVE flow rate and <br />' average TPH-g concentration from laboratory analysis collected at the SVE remediation system <br /> between late September and December 2003. Ground water elevation, flow direction and gradient <br /> were determined from field data collected on 04 November 2003;the contaminant impact to ground <br /> water was' quantifiedfrom the ground water laboratory data. SVE system efficiency and remediation progress was assesslrom the approximate remaining petroleum hydrocarbon concentrations in soil <br /> samples collected and analyzed. <br /> 3.1. SOIL VAPOR EXTRACTION <br /> - <br /> The SVE system operated continuously during the period between 10 September and.22 December <br /> 2003 at an average extraction flow rate of 136 cubic feet per minute (cfm). An induced vacuum <br />,t (negative pressure)of approximately 30 to 34 inches of water were measured in the,piping between <br /> the blower and extraction wells.Utilizing a photo ionization meter(PID),hydrocarbon concentrations <br /> were measured at between 5 and 12 parts per million volume (ppmv) at the SVE intake during this <br /> period. The field measurements are summarized in Table 1. <br /> ' 3.2. ANALYTICAL.RESULTS OF SOIL VAPOR SAMPLES <br /> TPH-g was detected from all influent vapor samples at concentration of 54 microgram per liter(gg/l), <br /> ' 36 ti and 34 ug/l (27 October to 22 December),respectively.BTEX compounds and MTBE were <br /> not detected in the influent vapor samples. <br /> ' The analytical results of the soil vapor samples are summarized on Table 2. The laboratory reports <br /> (MAI Sample Numbers:0309191,0310446,0311266 and 0312468),Quality Assurance and Quality <br /> Control (QA/QC) reports and chain-of-custody forms are included in Appendix C. <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/m3) <br /> Q = extraction flow rate (1113113r) <br /> t = operational period, in hours <br /> 10k <br /> Advanced G Environmental,Inc. <br />