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t 1 07 December 2004 • 'AGE-NC Project No 98-0448 Page 4 of 9 Schedule 80 PVC piping was previously Installed underground from wells VW-1 through VW-6'to ' a vapor moisture knockout drum and to the Inlet of the regenerative vacuum blower,the outlet from the vacuum blower was routed through two-400 pound carbon canisters A PVC ball-valve was installed at each SVE well-head for added controls and so that the SVE network could be reconfigured when appropriate ' A Magnehelic vacuum gauge was attached to the inlet of the blower, air flow was monitored at the Inlet using a Dwyer DS-200 flow sensor A flow rate was determined from the measured differential pressure and the piping diameter using a nomograph (Appendix B) ' In order to monitor the efficiency of hydrocarbon removal, 1) the SVE air flow of the influent stream was monitored routinely utilizing an organic vapor analyzer(OVA) equipped with a photo- ionization detector(PID Thermo Environmental 580B, 10 0 eV, calibrated to Isobutylene), and 2) influent air flow vapor stream sample was collected from sampling ports Installed upstream (influent)ofthe vacuum blower and analyzed Field measurements were recorded at regular intervals ' and are summarized in Table 6 3 2 IN-SITU AIR SPARGING SYSTEM PROCEDURES Between April 2001 and September 2004,the IAS system utilized a 5 horsepower, Speedaire(model no 517229B)electric air compressor to inject air beneath the water table,however,due to a crack that was discovered at the top of the Speedaire compressor air tank, a 7'/z horsepower,Westward(model 5Z639)air compressor was installed at the site on 23 September 2004 to replace the Specdaire From the outlet of the air compressor, a manifold network of one-inch diameter, schedule 80 PVC piping was installed underground to the well heads at IAS wells AW-1 through AW-4(screened 25-30 feet), AW-5 (30-35 feet) and IAS well MW-4B (screened 45-50 feet) A Wilkerson oil filter(model no M18) and Wilkerson air pressure regulator (model no R28) are Installed at the outlet of the air compressor for added controls, Wilkerson air pressure regulators (model no R18) are installed at each 1AS well-head to enable independent control over the varying pressures required to displace water within each air sparge well casing, resulting in continuous air sparging in the IAS network system Generally,air pressure was discharged at shallow screened IAS wells AW-1 through AW-5 between 5 and 8 pounds per square inch(psi), and to deeper screened well MW-4B between 13,and 15 psi A liquid-filled, air-guage was installed at each of the above well heads to monitor air pressure r s Advaxced GeoEnvironmental,Inc r n