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In the first three soil sampling events, a hand-held drive sampler was used to collect soil samples from the tank excavation at depths ranging from 2.8 to 12.1 ft. In the fourth event, four boreholes were mechanically advanced from the south side of the tank excavation; two boreholes were angled toward the tank excavation at bearings of N300E, and the other two were vertical. Boreholes U850-DlUl-13 and U850-DlU1-14 were slant-drilled at 23 and 13 degrees from vertical, respectively. The steep slope on the north side of the tank excavation prevents the use of a drill rig there. In the fifth event, soil samples were collected from the excavated soil pile at the southwest corner of the tank excavation. Drill cuttings produced during the first four soil sampling events were spread along the floor of the tank excavation. Drill cuttings produced during Event Three were field-screened with a Thermo Environmental Organic Vapor Meter (OVM) and yielded a maximum total petroleum hydrocarbons (TPH) concentration of 53.0 ppmv/v. Event Four drill cuttings yielded a TPH maximum concentration of 4.0 ppmv/V as measured on a Foxboro Organic Vapor Analyzer (OVA). Drill cuttings produced during Event Five were left on the soil pile. The handling of drill cuttings was consistent with ERD Standard Operating Procedures (SOPs), Procedure 1.10 (Rice et al., 1990). Boreholes advanced with the drill rig were grouted to the surface with portland cement and bentonite. To preserve soil sample integrity and to minimize the potential for cross-contamination and the volatilization of VOCs prior to chemical analysis, soil samples were collected using thin-wall stainless-steel tubes in the drive samplers. The samplers were driven with either a hand-held slide hammer or a Mobile B-53 drill rig. Hand-driven soil samples were 1.5-in. in diameter and were driven after hand auguring had reached the desired depth with a 4.5-in.-o.d. auger. Mechanically driven soil samples were 2.0-in. in diameter and were collected using a 3.0-in.-o.d. split-barrel sampler advanced by a 140-ib hammer falling 30 in. through 6.25-in.-o.d. hollow-stem augers. All mechanized drilling equipment was decontaminated between boreholes by steam cleaning to minimize the potential for cross-contamination. Between sample runs, the drive samplers were washed and rinsed with Site 300 tap water. The stainless steel-tubes were steam cleaned and air dried prior to use. Immediately following collection, the tubes were sealed with Teflon sheets and plastic caps. The samples were stored on ice in an ice chest and were later transferred to a refrigerator. Samples were transported to a state-certified analytical laboratory in ice chests and were typically delivered to the laboratory within 24 hr of collection. For each soil sampling event, a chain-of-custody record was filled out in triplicate with the sample identification number, date of collection, and the desired analysis and turnaround time. The records accompanied the samples to the analytical laboratory and document the change of hands, times, and dates of relinquishment. Upon arrival, a log number was assigned to each sample for additional tracking. A copy of each completed chain-of-custody record was returned to LLNL, where it is kept on file. Nineteen soil samples were collected using a hand-held drive sampler. As measured from the floor of the tank excavation, the bedrock contact is 12.1 ft and 3.0 ft beneath the east and west ends of the excavation, respectively (Figs. 5 and 6) (Fig. 7 shows the location of cross sections.) The bedrock contact represented the refusal limit of the hand-held drive sampler. Twenty-four soil and bedrock samples were collected at 5-ft intervals using the drill rig, with the total depths of the boreholes ranging from 31 to 45 ft. Blow counts were high for all four mechanically 8