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ri CAMBRIA Well Installation: One soil boring (VE-3) is proposed at the location shown on Figure 2. This boring will be drilled using hollow-stem auger equipment and will be converted to a soil vapor extraction well. The proposed well is placed adjacent to well MW-5 and near the northwestern dispenser. A Cambria geologist will supervise the drilling and describe encountered soils in the borings using the Unified Soil Classification System and Munsell Soil Color Charts. Soil samples will be collected at five-foot intervals for describing soil, possible chemical analyses, and organic vapor screening with a photo-ionization detector (PID). PID readings will be recorded on the boring log for each boring. Soil samples will be retained in stainless steel or brass sample tubes and will be covered on both ends with Teflon sheets and plastic end caps. The samples will be labeled, entered onto a chain- of-custody record, and placed into a cooler with ice for transport to a State of California certified laboratory for analyses. The soil vapor extraction well will be completed using 4-inch diameter Schedule 40 PVC casing. The well will be screened from 35 to 45 feet below grade. The sandpack will be placed along the entire screened interval and two feet above the top of the well screen followed by a two-foot thick bentonite seal and cement grout to grade. The well will be secured with a locking cap under a 12-inch diameter traffic-rated well box. SVE Pilot Tests: Following the SVE well installation, and depending on soil concentration results, Cambria will perform a second 5-day SVE test using one or more of the three SVE wells. Cambria will begin the test by performing a series of short-term SVE tests. Each test will consist of a minimum of three steps (varied operating parameters) to determine the optimal extraction rate. The optimal extraction rate is defined as the vacuum that produces the maximum sustained flow rate. Once it is established, Cambria will conduct the remainder of the 5-day SVE test at the optimal extraction rate. To assess whether any rebound is occurring, Cambria may conduct one or more additional SVE tests approximately two to six weeks after the second SVE test described above. E The tests will be performed with a pneumatic positive displacement blower with carbon filtration. Cambria will measure the vapor extraction airflow rate, the applied vacuum at the wellhead, vapor stream and the vacuum influence in nearby wells periodically during the long- term tests. Temperature will be measured at the wells to determine if short-circuiting is taking place. 1346 2