Laserfiche WebLink
24 November 1997 <br /> AGE-NC-95-0103 <br /> ' Page 5 of 6 <br /> ' One set of extracted soil gas samples was analyzed for TPH-g, BTE&X and other volatile organic <br /> compounds by EPA 8260 TPH-g was detected in the 22 September 1997 sample collected from <br /> influent vapor stream at concentrations of 2,600 ppb BTE&X were detected at concentrations as <br /> ' high as 80 ppb (xylene) Petroleum hydrocarbons as TPH-g were detected at 82 ppb in the sample <br /> collected from the effluent stream on 22 Septembei The analytical results of air samples are <br /> summarized on Table 4 The laboratory report(MAI Lab No 81027), Quality Assurance and Qualrt} <br /> Control (QA/QC) reports and chain-of-custody forms are included in Appendix D <br /> Concentrations of extracted volatile organic compounds measured with the organic vapor meter <br /> ' equipped with a photo ionization (PID) correspond to approximately one-fifth of the analytical <br /> results obtained from the influent stream samples Analytical data collected before the catalytic <br /> oxidizer and the effluent stream indicate a 97 percent late of destruction <br /> 3 4 , MASS OF RECOVERED H I DROC ARSONS <br /> ' <br /> The hydrocarbon mass removed during the operating period was calculated using the following <br /> equation M = C•Q•t <br /> where M= cumulative mass recovered (kg) <br /> ' C = vapor concentration (kg/m3) <br /> Q =extraction flow rate (m3/hr) <br /> t w operational period, in hours <br /> The operational tirne over the Iast quarter was estirnated to be 45 full days The mass of <br /> hydrocarbons removed was based on laboratory analysis of the single soil gas sample collected The <br /> mass of extracted hydrocarbons was calculated for the period using hydrocarbon concentrations of <br /> the influent vapor sample collected and the average air flow rate <br /> An estimated total of 87 gallons of hydrocarbons were removed from the site The mass calculations <br /> are attached in Appendix E <br /> t <br /> ' 4 0 SUMMARY/CONCLUSIONS <br /> Based upon data collected from the site, AGE concludes the following <br /> 1 • The greatest concentrations of petroleum hydrocarbons were detected in samples collected <br /> from well MW-4 near the former USTs location Hydrocarbons were also detected at lesser <br /> concentrations in wells MWA, MW-3 and MW-5 Detectable concentrations of target <br />