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I<ivrs U0 L ,. <br /> I <br />' 30 December 1999 <br /> AGE-NC Project No 95-0104 <br />' Page 3 of 7 <br />' The SVE pilot test utilized a regenerative vacuum blower and two carbon canisters (55-gallons <br /> each) Two-inch diameter, schedule 40 PVC piping was installed aboveground from the well-head <br /> at VW-1 to the inlet of the regenerative vacuum blower, the outlet from the vacuum blower was <br />' routed through two sequential 55-gallon carbon canisters A Magnehelic vacuum gauge was attached <br /> to the inlet of the blower The air flow was monitored using a Dwyer DS-200 flow sensor The flow <br /> rate was determined from the measured differential pressure and the piping diameter using a <br />' nomograph (Appendix B) The air stream from VW-1 was monitored for the presence of organic <br /> vapor using an organic vapor analyzer (OVA) equipped with a photo-]onizat>on detector (PID <br />' Thermo Environmental 580A, 10 0 eV, calibrated to isobutylene) Sampling ports were installed <br /> upstream the vacuum blower inlet to recover influent soil gas stream samples, and downstream of <br /> both carbon canisters to recover effluent stream samples to monitor the efficiency of hydrocarbon <br />' filtration Field measurements were recorded at regular Intervals throughout the pilot test and are <br /> summarized in Table 4 <br />' As noted In the Revised Corr ective Action Plan - January 1997, dated 18 February 1997, the <br /> theoretical radius of influence of VW-1 Is approximately 20 feet, and all of the known impacted soil <br /> lies within 15 feet of VW-1, VW-1 is adequately screened and placed to address all known impacted <br />'. soil <br />' 32 COLLECTION AND ANALYSIS OF SOIL GAS SAMPLES <br /> A total of ten extracted soil gas samples were collected from the inlet of the regenerative vacuum <br />' blower unit to measure concentrations of hydrocarbon vapor The samples were collected In Tedlar <br /> bags using an organic vapor analyzer as an air pump <br />' Following sample collection, the samples were placed in a covered container and transported under <br /> chain-of-custody to Precision Enviro-Tech Analytical Laboratory (PEAL) In Stockton, California <br />' Each sample was analyzed within 72 hours of collection for TPH-g and BTE&X 2n accordance with <br /> EPA Method TO-14 <br /> 40 FINDINGS <br />' From ground water monitoring data, AGE was able to determine a ground water flow direction <br /> towards the northeast at a gradient of 0 002 ft/ft Laboratory analysis of four ground water samples <br /> detected TPH-g in one ground water sample and BTEX compounds in two ground water samples <br /> IFrom laboratory analysis of ten gas samples collected during operation of the SVE pilot test between <br /> • 31 August 1999 and 14 December 1999, AGE was able to estimate the removal of 59 15 gallons of <br /> petroleum extracted from well VW-1 <br /> Advanced CeoEn-,ironmental,Inc <br /> I <br />