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Mr. Robert McClellon July 1, 2004 Page 3 of 5 will be placed near the southern boundary of the property. The estimated boring locations are shown on Figure 4. Drilling Methods The borings will be advanced to a depth of approximately 30 feet bgs or until shallow groundwater is encountered. A drilling company licensed in the State of California will advance the borings using a truck mounted Geoprobe direct push drilling rig (Fisch Environmental, C57-683865). Soil samples will be collected for logging and identification purposes at 5-foot depth intervals. Samples will be collected using a 2-inch diameter core sampler lined with clear acetate sleeves. A portion of a soil sample selected for laboratory analyses will be immediately capped and preserved in an iced cooler at a temperature of approximately 4° Centigrade. No cuttings requiring disposal will be produced using the direct push drilling method. Borings will be backfilled to the ground surface with neat cement grout. We expect to submit soil samples collected from each boring at depths of approximately 10 and 20 feet bgs to a State-certified laboratory for analysis of total petroleum hydrocarbons as oil (TPHo) using EPA method 8015 modified, CAM17 metals, and soluble lead. In addition, one discrete groundwater sample will also be collected from each boring and analyzed for the constituents listed above. The groundwater samples will also be analyzed for the presence of volatile organic constituents (VOCs) using EPA 8260. Groundwater samples will be collected through a sampler driven the to the desired depth and retracted to expose the screen to the formation, or through a temporary PVC casing installed in the borehole. The sample will be collected using a length of polytetrafloroethylene (PTFE) tubing equipped with a stainless steel bottom check valve. The tubing will be inserted into the probe rods/temporary casing and pushed to the screened interval at the desired depth. The groundwater sample will be brought to the surface by gripping the top of the tubing and rapidly moving the tubing up and down creating a positive displacement effect, thereby forcing the water sample to the surface where it will be collected directly into the sample containers. All sampling and drilling equipment will be washed thoroughly with laboratory-grade detergent and water between uses to minimize the potential for cross contamination. General Site Safety Practices The CIWMB previously identified a number of potential chemical and physical hazards that may be encountered at the site. A summary of potential hazards at the site is presented below. Potential Chemical Hazards Heavy Metals Burn ash sample analysis obtained from previous waste characterization investigations from other sites indicate that non-hazardous household or municipal waste contains various heavy metals. Test G:\GROUNDZE\Palomino\wpjorings.doc