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C A M g R A November Lori Duncan 18,2005 Work Tasks Permit: Cambria will obtain an appropriate permit for drilling from SJCEHD. Site Health and Safety Plan: Cambria will prepare a site safety plan for field work. Utility Clearance: Cambria will mark the proposed drilling locations, and the locations will be cleared through Underground Service Alert prior to drilling. In addition, Cambria will retain a private utility locator to clear the locations. Site Investigation: Five DPE wells (VEW-3 through VEW-7) are proposed at the locations © shown on Figure 4. The exploratory borings will be drilled using hollow-stem auger equipment and will be converted to DPE wells. The wells will be located near the former USTs and the northwestern dispenser islands. A Cambria geologist will supervise the drilling and describe encountered soils using the Unified Soil Classification System. Cambria will collect soil samples from the borings at 5-foot intervals for soil description, possible chemical analyses, and organic vapor screening with a photo- ionization detector (PID). Cambria will prepare a boring log for each well and record PID measurements on the boring logs. Soil samples designated for chemical analyses will be retained in stainless steel or brass sample tubes. Cambria will cover the tubes on both ends with Teflon sheets and plastic end caps, label the soil samples,enter them onto a chain-of-custody record, and place them into a cooler with ice for transport to a State-of-California-certified laboratory for analyses. We will request a standard 2-week turn-around time for laboratory results. DPE Well Installation: Well borings VEW-3 through VEW-7 will be drilled to approximately 45 fbg. Based on the third quarter 2005 monitoring data, first-encountered groundwater is approximately 37 to 39 fbg. The wells will be constructed using 4-inch-diameter Schedule 40 PVC casing with 0.020-inch Circumslot screen. The well screen intervals will be from approximately 20 to 45 fbg. The sand pack in each well will be placed from the bottom of the well screen up to 2 feet above the top of the well screen and followed by a 2-foot-thick bentonite seal and cement grout to grade. Actual well construction details will be based on soil types and PID readings during drilling. Each well will be secured with a locking cap under a traffic-rated well box. Well Development and Sampling: Blaine Tech Services, Inc. (Blaine) of San Jose, California will develop the new DPE wells prior to sampling. After well development, Blaine will sample the site groundwater monitoring and DPE wells according to the existing sampling schedule and submit the samples to a State-of-California-certified laboratory for chemical analyses. 6