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a , 27 January 2006 AGE-NC Project No 98-0500 Page 2 of 10 Two deep-screened (145 feet to 150 feet bsg) depth-discrete wells located in the former underground storage tank (UST) area and the former dispenser area, MW-34, MW-36, MW-39,MW-42,MW-44,MW-46,and MW-48 are screened In the sixth hydrogeologic unit (HU6), • Deep-screened well MW-37 (195 feet to 200 feet bsg) is screened in the seventh hydrogeologic unit(HU7), and • Deep-screened well MW-35 (225 feet to 245 feet bsg) is screened across the seventh and eighth hydrogeologic units (HU7 and HU8, respectively) A brief summary of background information and a basic site conceptual model is included in Appendix A Field work was performed in accordance with guidelines established by the CVRWQCB for subsurface investigation of contaminated sites The monitoring well designations were reassigned during the final quarter of 2003 in a sequential order, the renumbered wells are presented in Table 3 and on Figure 2 • 2.0. SOIL-VAPOR EXTRACTION OPERATION AND MONITORING RESULTS A catalytic oxidizer soil-vapor extraction(SVE)unit is connected to a total of twenty-six extraction wells on the eastern and western portions of the site A total of nineteen individual SVE wells (VW-6A through VW-1513) and monitoring well MW-1 are located on the eastern side of the site and are connected aboveground to the SVE unit using 2-inch diameter, Schedule 40 polyvinylchloride (PVC)piping and 2-inch ball valves to control flow from individual wells Four SVE wells(VW-lA through VW-213) and two monitoring wells (MW-15 and MW-16)are located on the western edge of the site and are connected below grade near the wells and then above grade through the building to the SVE unit using 2-inch diameter, Schedule 40 PVC piping However,due to pipe damage and excessive vapor collection within the site, the western wells were not utilized this quarter The piping (influent line) was routed through 3-inch diameter, Schedule 40 PVC piping manifold and then through a moisture knockout vessel to a 20-horsepower,maximum 500 standard cubic feet per minute (scfm) blower Sampling ports were installed upstream of the vacuum blower inlet to recover influent soil-gas vapor stream samples,and downstream of the catalytic converter to recover effluent stream samples to monitor the efficiency of hydrocarbon destruction A Magnehelic vacuum gauge was attached to the inlet of the SVE unit to measure the inlet potential pressure Field measurements, recorded at regular intervals, are summarized in Table 1 SVE-system operations are in accordance with San Joaquin Unified Air Pollution Control District (APCD) permit-5861-1-0 Advanced GeoEnvironmental,Inc