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analysis. 2.8 GROUNDWATER MONITORING WELL INSTALLATION 2.8.1 MONITORING WELL LOCATIONS Should the results of the hydropunch sampling indicate that the groundwater beneath the Site is impacted, additional" shallow groundwater monitoring wells may be installed in Parcel 24, 3 and/or 4, at locations and depths based on the groundwater grab sample data. Current site data indicate that the probable locations for the monitoring wells are as follows: One (1) at the location of Borehole SB-5; One (1) at the location of Borehole SB-7; and Two (2) additional locations based on data collected, the locations are probable in the vicinity of Grids G9 and F17. 2.8.2 PILOT BOREHOLE SOIL SAMPLING A pilot borehole will be drilled to the desired total depth of the well using a hollow stem auger rig. During advancement of the pilot borehole, soil samples will be collected at 2, 5, 10, 15 and 20 feet bgs or to the depth of first encountered groundwater; soil samples will not be collected below the capillary fringe. Soil samples will be collected in three (3), 6-inch long stainless steel sleeves fitted within a split spoon-sampling tool, which is advanced into the subsurface soil to the target depth. To collect a sample, the hollow stem auger drill string is advanced to the target depth, and the sampling tool is driven approximately 18-inches into the soil ahead of the bottom of the auger using a slide hammer. The sampling tool is then extracted from the pilot hole and the three (3) stainless steel sleeves with soil are removed for sample description, field screening and laboratory analysis. Soil samples for volatile compounds such as TPHg and VOCs will be collected in accordance with the 5035-preparation method (EnCoreTM sampler). Upon sample retrieval, an EnCoreTM sampling device will be pushed into the exposed leading end of the first six (6) inch sleeve (closest to the leading end of the sampling tool). As the EnCoreTM device is pushed, an internal piston retracts allowing soil to fill a cylinder to a maximum capacity of either 5 g or 25 g of soil mass, thus preventing formation of head space above the soil within the sampling device. If, during sampling it is not possible to immediately collect soil using the EnCoreTM sampling device, the ends of the first stainless steel sleeve will be capped with Teflon sheets and plastic end caps to preserve the loss of volatiles. Once collected, the sample device will be capped with a locking cap with an "0-ring" seal to prevent loss of volatiles, and then placed into a previously labeled foil pouch and sealed. Prior to placing the EnCoreTM sampling device into the foil pouch, a self-adhesive labeled seal will be placed onto the locking mechanism to secure it from tampering, and to act as additional field QC of the sample. The secured sample will then be put into the insulated chest filled with ice pending transport to a California certified laboratory for analysis. "In addition to existing Wells MW-3 and MW-7 located in Parcel 24. Golden State Environmental, Inc. - 21 - Los Angeles, San Diego and Houston Revised Work Plan — Soil and GW Characterization July 2006