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lVervivealING and sampling operations. A copy of the signed Health and Safety Attendance Form is included as Appendix C. 2.5 Drilling Procedures Four boreholes were drilled by pushing a two-inch diameter drilling rod utilizing a truck- mounted Geoprobe 5400 drilling rig. This drilling method was selected over the use of hollow- stem augers to minimize the volume of soil cuttings generated. A sampler attached to the end of the drilling rod was used to collect an undisturbed soil sample in polyethylene tubing inside the sampler. The drilling rod and sampler were then removed from the borehole, the sampler removed and replaced with a clean sampler, and the drilling rod was pushed down the existing hole to the next desired sampling depth. Boring logs are presented in Appendix D. Subsurface conditions consisted of poorly-sorted, moderate-brown silty sand from just below the asphalt pavement to the maximum depth explored of approximately 26 feet below ground surface (bgs). Stabilized groundwater levels were recorded at approximately 18 feet bgs during the investigation on May 16, 1997. 2.6 Soil Sampling and Analytical Results During the drilling activities, soil samples were collected at five-foot intervals beginning at five feet bgs and continuing until groundwater was encountered. A portion of the sample was retained for headspace analysis and descriptive logging according to the Unified Soil Classification System (ASTM D-2487). The locations of the boreholes are shown in Figure 2. Three soil samples were collected from each of the four boreholes. Soil samples were collected from depths of 5.5, 10.5, and 15.5 feet bgs from each borehole. One soil sample from each borehole was submitted to McCampbell Analytical Laboratories (California Department of Health Services Certification No. 1644) for analysis for total petroleum hydrocarbons as gasoline (TPH-G); TPH as diesel (TPH-D); benzene, toluene, ethylbenzene, and total xylenes (BTEX); oil and grease; and Leaking Underground Fuel Tank(LUFT) metals (cadmium, chromium, lead, nickel, and zinc). Total metals were reported in soil results. The soil samples submitted for analysis were collected from a depth of 15.5 feet bgs from each borehole, corresponding to the approximate depth of the soil groundwater interface (capillary fringe). The soil samples analyzed did not contain TPH-D, TPH-G, BTEX, lead, or oil and grease at or above the laboratory's reporting limit for each test method. Concentrations of chromium, nickel, and zinc were detected in the soil samples analyzed from the Site. These levels are consistent with the USGS's published background levels for this area. The analytical results for the soil samples are summarized in Table 1, and a complete copy of the laboratory analytical results and project chain-of-custody documents are included in Appendix E. 4583-97/3622-500/1un30'97 3