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10 May 2007 AGE-NC Project No. 01-0839 Page 5 of 5 3.2. SOIL VAPOR EXTRACTION SYSTEM DESIGN The Solleco Ecat 250 SVE unit, consisting of a condensation separator, a vacuum blower, and an electrically heated catalytic oxidizer, is proposed for hydrocarbon vapor recovery at the site; the Solleco Ecat 250 should be able to extract soil vapor between 225 and 250 cubic feet per minute (cfm). The SVE unit will be connected through a manifold box to vapor recovery wells VW-2, VW-4, and VW-5; petroleum hydrocarbon vapors extracted from these wells will be sequentially routed through a 100-gallon steel condensation entrapment chamber and a vacuum blower before entering a catalytic oxidizer for final destruction. A diagram of a typical system is illustrated on Figure 4. Induced vacuum measurements will be collected utilizing a Magnehelic vacuum gauge attached near the inlet of the blower; SVE air flow will be monitored using a Dwyer DS-200 flow sensor. Following the start-up period, the SVE air flow along the influent and effluent lines will be monitored weekly for the presence of organic vapor using an organic vapor analyzer (OVA) equipped with a photo-ionization detector(PID:Thermo Environmental 580; 10.0 eV;calibrated to isobutylene). Sampling ports will be installed upstream of the vacuum blower inlet to recover SVE influent air-flow vapor stream samples,and downstream ofthe catalytic converter to recover effluent SVE air-flow samples to monitor the efficiency of hydrocarbon destruction. 3.3. SOIL VAPOR EXTRACTION MONITORING During the start-up period for the SVE system, organic vapor samples will be collected and operational parameters will be monitored on a daily basis. The anticipated start-up period will be approximately one week. Following the start-up period,the vapor extraction system will be monitored weekly using a PID and Dwyer DS-200 flow sensor to ensure optimal destruction of recovered hydrocarbon vapors and to monitor cleanup progress. The PID readings will be taken and recorded from the influent end of the vacuum blower unit and the effluent end of the catalytic oxidizer.Operational parameters(air flow, air vacuum, and volume of processed vapor) will be measured on a weekly basis to monitor and record soil-vapor volumes extracted and operational efficiency. Vapor samples will be collected on a monthly basis from the influent and effluent end of the vapor extraction system utilizing an electric vacuum pump.The samples will be collected into Tedlar bags and transported under chain of custody to a DHS-certified laboratory and analyzed for TPH-g, BTEX, and MTBE. Advanced GeoEnvironmentaI,Inc.