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31 March 2008 AGE-NC Project No. 98-0500 Page 9 of 10 3.4. SOIL VAPOR EXTRACTION PIPING NETWORK A network oftwo-inch diameter,schedule 40 PVC piping will be installed in 6-inch wide by 12-inch deep trenches at the site. The PVC piping will be routed from each SVE well head to a vapor-moisture dropout drum; the vapor dropout drum will be directly connected to the vapor extraction system. A PVC ball valve will be installed at each SVE well head so that vapors can be drawn from each well independently.The plan of the proposed piping system will include each well location. 3.5. SOIL VAPOR EXTRACTION SYSTEM DESIGN The current catalytic destruction process utilizing an gas-heated catalytic oxidizer soil vapor extraction (SVE )system is proposed for extracted continued hydrocarbon vapors and IAS vapor from the subsurface. The SVE is able to operate between 200 and 350 cubic feet per minute(cfm). Soil vapors will be extracted from the proposed configuration of extraction wells using a vacuum blower and routed to the catalytic oxidizer. 3.5.1. Soil Vapor Extraction Monitoring Activities During the initial"start-up"period for the SVE system(approximately one week),the VES unit will be monitored daily using a Dwyer DS-200 flow sensor and a photo-ionization detector(PID). The Dwyer DS-200 flow sensor will monitor operational parameters(air flow,combustion temperature, volume of processed vapor, oxygen level and the lower explosive limits) to ensure optimal destruction of recovered hydrocarbon vapors. The PID will monitor the concentrations of hydrocarbon vapors from the influent and effluent ends of the VES unit to record before and after catalytic destruction. In addition,vapor samples will be collected on a daily basis from the influent and effluent ends of the VES utilizing the vacuum pump on a Model 580b organic vapor meter (Thermo Environmental Instruments Inc.); the samples will be collected in Tedlar bags, placed in a chilled container and transported under chain-of-custody procedure to a DHS-certified laboratory for analysis. After start-up,the VES unit will be monitored weekly using the PID and Dwyer DS-200 flow sensor to ensure optimal destruction of recovered hydrocarbon vapors and to monitor cleanup progress. Vapor samples will be collected from the influent and effluent ends of the VES on a monthly basis; the vapor samples will be collected in Tedlar bags and transported in a chilled container under chain- of-custody procedure to a DHS-certified laboratory for analysis. Advanced GeoEnvironmental,Inc.