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1 25 November 2002 <br /> • AGE-NC Project No 98-0448 <br />' Page 3 of 8 <br />' 3 1 SOIL VAPOR EXTRACTIONAN-SITU AIR SPARGE SYSTEM PROCEDURES <br /> The SVE system utilizes a model Fuji, 3-horsepower regenerative vacuum blower and two <br />' 100-gallon carbon canisters to extract and adsorb hydrocarbon vapor from the subsurface Two-inch <br /> diameter, schedule 80 PVC piping was installed underground from wells VW-1 through VW-5 to <br />' the inlet of the regenerative vacuum blower, the outlet from the vacuum blower was routed through <br /> two sequential 55-gallon carbon canisters A Magnehelic vacuum gauge was attached to the inlet of <br /> the blower, air flow was monitored-at the inlet using a Dwyer DS-200 flow sensor A flow rate was <br />' determined from the measured differential pressure and the piping diameter using a nomograph <br /> (Appendix B) <br />' In order to monitor the efficiency of hydrocarbon destruction, 1)the SVE air flow of the influent and <br /> effluent streams was monitored routinely for the presence of organic vapor using an organic vapor <br /> analyzer (OVA) equipped with a photo-ionization detector (PID Thermo Environmental 580A, <br />' 10 0 eV, calibrated to isobutylene) and 2)influent and effluent air flow vapor stream samples were <br /> collected from sampling ports installed upstream(influent)and downstream(effluent)of the vacuum <br /> blower and analyzed Field measurements were recorded at regular intervals and are summarized in <br />' Table 6 <br />' 3 2 COLLECTION AND ANALYSIS OF VAPOR EXTRACTION AIR FLOW SAMPLES <br /> A total of six extracted air flow vapor samples were collected on 17 July, 20 August and <br />' 11 September 2002 from the influent and effluent streams of the regenerative vacuum blower unit <br /> to measure concentrations of hydrocarbon vapor The samples were collected in Tedlar bags using <br /> a hand air-vacuum pump <br /> Following sample collection the samples were properly labeled, placed in a covered container and <br /> transported under chain-of-custody to a DHS-certified laboratory for analysis Each sample was <br /> analyzed within 72 hours of collection for TPH-g and BTEX in accordance with EPA Methods <br /> 8015C Modified and 8021B <br /> 4.0 FINDINGS <br /> AGE determined ground water flow direction and gradient from the field data collected on 20 <br /> August 2002, the contaminant impact to ground water was assessed from the laboratory data <br /> • <br /> Advanced GeoEnvironmental,Inc <br /> I <br />