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r 3.0 PROCEDURES V& W Drilling mobilized a truck-mounted hollow-stem anger drilling rig to the site on At gust 24, 1999 and drilled four soil borings under the supervision of Upgradient Environmental. the first boring (B-•1 in Figure 2)was drilled near the southwestern corner of the former UST excavation, and was sampled at 5-foot intervals starting at a depth of 1S feet(close to the',ase of the UST excavation)using a split-spoon sample barrel loaded with clean brass sample h.bes. The soil was moist at a depth of 40 feet, suggesting that the capillary fringe had been react --d, but groundwater did not enter the boring and drilling was terminated at this depth. After steam-cleaning the augers, V&W drilled four more borings(Figure 2.) Samples we-e collected at 5-foot intervals, beginning at either 5 or 10 feet. These borings were terminate i at 30 feet and were plugged with cement-bentonite •out. The auger returns were placed on plastic sheeting east of the investigation area and covered, pending laboratory analysis of tl.e soil samples. After all borings were drilled, they were backfilled with cement-bentonite grc it. A geologist from Upgradient examined the samples and prepared a boring log (see App radix A). The number of percussion hammer blows needed to drive the sampler 18 inches int) the native soil was recorded on the boring log, along with a description of the sample. One tube from each sample was capped, sealed, labeled, and placed in a cooled ice chest pri')r to shipment to McCampbell Analytical in Pacheco, California. The chain-of-custody fo;m is included in Appendix B. 4.0 RESULTS The site is underlain at shallow depths by beds of silt and fine-grained sand that vary in thickness and extent (Figure 3). The uppermost unit is a silt bed whose color and thicknes., are variable. This bed is missing in the UST excavation area. East of the excavation, the silt be i overlies a relatively thin sand bed that is fine grained to silty. Below the sand is a thick laye of relatively consolidated (compacted) silt that contains leaf impressions, root holes, and othe evidence of soil formation. Below the silt bed is another sand bed that coarsens downward but its base was not reached during drilling. The contact between the silt bed and this lower sa id bed varies from a depth of 24 feet in B 1 to approximately 28 feet in B2 and B5. It was not encountered in B4. Strong to moderate hydrocarbon odors were detected in the upper silt bed in B 1, and a sli;;ht odor was noted in the uppermost sand sample(25 feet) from this boring. No evidence of contamination was noted in any of the other soil samples or in the auger cuttings. Boring B3 was located within a few feet of the first locomotive fueling track, in a slight depression between the first locomotive fueling track and the location of the former UST cavity. This boring encountered water at a depth of less than 2 feet, and petroleum sheen -as observed on the water, The driller suspended drilling to determine whether a subsurface w iter line had been breached. Personnel from SME inspected the location and informed Upgra{ ient 2