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AM FIELD METHODS Site Safely Plan Field work performed by RESNA at the site was conducted in accordance with RESNA's Site Safety Plan. This plan described the safety requirements for drilling soil borings at the site. The Site Safety Plan was applicable to personnel and subcontractors of RESNA. RESNA's personnel and subcontractors scheduled to perform work at the site were briefed ti. on the contents of the Site Safety Plan before work began. A copy of the Site Safety Plan was available for reference by appropriate parties during the work. The onsite Staff Geologist of RESNA acted as the Site Safety Officer. Soil Bodp s Soil borings were started by hand-angering to a depth of approximately 5 feet below grade to attempt to locate underground structures. The borings were drilled with a Mobile B-57 drill rig equipped with 8-inch-diameter, hollow-stem augers. The drillers steam-cleaned the augers before drilling each boring to minimize the possibility of cross-contamination. Soil Sampling in Borings Soil samples were collected at approximately 5-foot intervals from the ground surface to the full depth of the borings. The soil samples were collected by advancing the boring to a point immediately above the sampling depth and then driving a California-modified, split- spoon sampler containing brass sleeves through the hollow center of the auger into the soil. The sampler and brass sleeves were laboratory-cleaned, steam-cleaned, or washed thoroughly with a laboratory-grade, non-phosphatic detergent and water before each use. The sampler was driven 18 inches with a standard 140-pound hammer repeatedly dropped 30 inches. The number of blows to drive the sampler each successive 6 inches was counted 6- and recorded to evaluate the relative consistency of the soil. During sampling, the geologist used a field photoionization detector (PID) to characterize +- the relative levels of hydrocarbons. Field instruments such as the PID are useful for indicating relative levels of hydrocarbon vapors, but do not detect concentration of hydrocarbons with the same precision as laboratory analyses. One of the samples in brass sleeves not selected for laboratory analysis at each sampling interval was tested in the field using a PID. This testing was performed by placing the soil sample in a resealable polyethylene bag, sealing the bag and manually breaking up the soil in the bag, and allowing the contents to warm in sunlight for approximately 1 hour and then placing the intake probe of the PID into the bag and recording the readings on the Logs of Boring. 0316kear 86102-7 16W - 6W