Laserfiche WebLink
10 April 2002 <br /> AGE-NC Project No 01-0827 <br /> Page 4 of 6 <br /> I32 ANALYTICAL RESULTS OF SOIL-GAS VAPOR SAMPLES <br /> TPH-g was detected from all influent SVE air flow samples at concentrations as high as 810 µg/1 <br /> TPH-g was detected in the 10 December 2001 effluent SVE air flow sample at a concentration of <br /> 710 µg/1, but was not detected in effluent samples collected in January and February 2002 <br /> BTEX compounds except benzene were detected in all influent SVE air flow samples at <br /> concentrations as high as 220 µg/l(xylene, 12 December 2001) Toluene, ethylbenzene and xylenes <br /> were detected only in the December 2001 effluent SVE air flow sample at concentrations of <br /> 0 92 µg/l, 5 8 µg/1 and 13 µg/1, respectively <br /> The analytical results of SVE air flow samples are summarized in Table 2 The laboratory reports <br /> (MAI Lab Numbers 85705,85706,88123,88124,90620 and 9062 1)Quality Assurance and Quality <br /> Control (QA/QC) reports and chain-of-custody forms are included in Appendix B <br /> I3 3 MASS OF RECOVERED HYDROCARBONS <br /> IThe 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 (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 mass of extracted hydrocarbons was calculated for <br /> the time period using average hydrocarbon concentrations of influent soil-vapor sample data, <br /> averaged air flow rates and duration of operation The operational results are summarized on Table I <br /> Approximately 279 2 kg or 98 4 gallons of hydrocarbons were extracted and destroyed by the SVE <br /> network between 05 November 2001 and 18 February 2002 The volume and mass calculations are <br /> attached in Appendix C <br /> 3 4 GROUND WATER GRADIENT AND FLOW DIRECTION <br />' The elevation of ground water in each well was calculated by subtracting the depth to ground water <br /> • from the surveyed well casing elevations (Table 3) <br /> IAdvanced GeoEnwronmental,Inc <br />