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3. 0 PROCEDURES 3.1 Drilling On June 9, 1993 , one soil boring was drilled at the site. The boring was placed near the center of the former UST excavation and extended to a depth of 30 feet. It was advanced using a truck- mounted drilling rig equipped with 8-inch outside diameter hollow- stem augers. The Acker drill rig and two-man crew were supplied by West Hazmat Drilling. Auger returns were placed in a 55 gallon DOT drum and stored on site. The boring was backfilled using concrete- bentonite slurry for the entire depth. 3.2 Soil sampling .y Discrete soil samples were collected at 5 foot intervals ahead of the drill bit using a split-tube sampler loaded with three pre- cleaned 2 by 6-inch brass tubes. The sampler was driven into the soil with a 140-1b hammer, and the number of blows required to advance the sampler in 6-inch increments was recorded on the boring log (Figure 3) . To avoid cross contamination, the sampling equipment was washed in a tri-sodium phosphate (TSP) solution and rinsed twice with water prior to each sampling run. For each sample, both ends of the lead tube were then covered with aluminum sheets, capped and sealed with tape. The samples were labeled, logged on a chain of custody and stored on ice pending a transmission to WEST Laboratories in Davis. 3.3 Logging The soil was described in accordance with the Unified Soil Classification System (Figure 3) . The auger returns and soil sample duplicates were monitored for the presence of organic vapors using a photo-ionization detector (PID: Thermo Environmental 580A, 10. 0 eV, calibrated to isobutylene) . 4. 0 FINDINGS 4.1 Stratigraphy The boring penetrated predominately brown to orange-brown clayey silt and sandy silt. Slight hydrocarbon odors were observed only in soil samples B1-10 and B1-15. Volatile organic vapors were detected in all samples at concentrations of less than 10 parts per million (ppm) by the PID. 2