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4A All drilling equipment and sampling tools were cleaned prior to arriving, between each borehole 10 and before leaving the site The probe was advanced collecting continuous cores of soil in borehole B-1 and interval sampling in the remaining boreholes The sampler was retrieved and dissembled, and the soil filled acetate liner was sealed with Teflon paper or foil and plastic endcaps, labeled, logged onto chain-of-custody forms and place in a chilled ice chest on crushed ice Soil sample intervals retained for chemical analysis were cut from the liners at depths of suspected contaminant presence The boreholes were logged using the Unified Soil Classification System under the supervision of a registered geologist Additional lithologic information was collected to describe the subsurface geology Soil samples were field screened for petroleum soil vapor using a photoionization vapor meter calibrated to the manufacturers specifications Interval samples were collected at five-foot intervals, at intervals of obvious contamination and at stratigraphic features of interest Upon completion of the borehole drilling and collection of water samples, all boreholes were backfilled with grout, placed from the bottom to top of the borehole and a PHS EHD representative witnessed that process Groundwater Sampling Each exploratory boring was sampled. The ground water samples collected from the boreholes were used for a reconnaissance of the site groundwater contamination A brief summary of the sampling procedures follows Each borehole was advanced into the aquifer and temporarily cased for sampling Depth to groundwater measurements were made in some boreholes to the . nearest one-one hundredth of one foot to surface grade, and also checked for the presence of separate phase product The water entering the borehole was sampled using a clean bailer, and carefully poured into the appropriate laboratory prepared container with minimum cavitation Each water sample was labeled, logged onto a chain-of-custody form, and placed in a chilled ice chest for transport to the Iaboratory Subsurface Conditions Six borings were advanced on the site Boreholes B-1 and B-2 were advanced through the former tank pits in the sidewalk These two borings showed sandy clay fill to depths of about 1 I feet Push refusal was encountered in boreholes B-1 and B-2 at about 20 feet The remaining borings (B-3 through B-6) revealed sandy clay and clayey gravel to depths of about 11 feet Sand strata underlie the sandy clay at depths of I1 to about 15 feet The sand contained some local gravel lenses and flowed in the boreholes This sand laterally grades to a clayey sand and sandy clay to the north across 110' Street Sandy clay and silty clay underlie the sandy strata below depths of about 20 feet to 26 feet (see Figures 1 and 2) 0 Page 2 of 7