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Soil Boring and Monitoring Well Installation Report Page 3 Ranch Market Riverbank CA September 6 2000 • of each soil sample The drill cuttings were placed on visqueen, and stored at the Site pending characterization and removal The auger steam cleaning water was retained and stored in 55- gallon drums pending offsite disposal 4.2 Soil Sampling Soil samples were collected from the 4 GeoprobeTM borings and from SB-1, S13-2, MW-6, MW-8, and MW-9 at 5-foot intervals, beginning at 5 feet bgs to total depth Samples were collected from the GeoprobeTM borings using a lined 18-inch long, 1-inch O D direct-push sampler Samples were collected from the HSA borings using a 2 5-inch O D split-spoon sampler, lined with three 2-inch-diameter by 6-inch-long brass sample tubes The split-spoon sampler was driven 18 inches ahead of the augers at each sample point At the continuous core borings (SB-1 and SB-2) samples were collected into 2-inch-diameter by 6-inch-long brass sleeves directly from the continuous core barrel The continuous core barrel was pushed approximately 6-inches ahead of the augers during drilling at five foot increments Selected soil samples were field screened for hydrocarbon vapors using a PID Soil was logged using the Unified Soil Classification System by a SECOR field geologist working under the supervision of a California registered geologist (Appendix B) One four point composite soil sample was collected from the stockpiled drill cuttings in 2-inch-diameter by 6-inch-long brass sample tubes for use in profiling the soil for offsite disposal A copy of the field notes have been included in Appendix C . Selected samples were sealed, labeled and placed on ice in an insulated container for transport under chain-of-custody manifest to Kiff Analytical LLC, a California state-certified analytical laboratory located in Davis, CA Soil samples submitted for laboratory analysis were chosen on the basis of PID readings, hthology, historical analytical results, and depth to groundwater observed in each boring Selected samples were analyzed using U S Environmental Protection Agency(EPA) method 8260B for BTEX, TPHg, and MtBE Refer to Table 4 for a summary of samples submitted for analysis by boring location 4.3 Lithology Based on the description of the soil samples collected from the soil borings, the lithology at the Site consists mainly of sands and silts with varying degrees of gravel in the upper 75 feet bgs The hthology generally coarsens downward from sandy silt towards the groundwater surface to gravelly sand found at depth Figures 4, 5, and 6 show the layout of the two geologic cross-sections through the Site, geologic cross-section A to A', and geologic cross- section B to B', respectively No obvious low permeability confining layer of clay or silty clay were observed the two continuous cores collected from soil bonngs SB-1 and SB-2 Boring logs of all thirteen bonngs drilled during this assessment and boring logs from previously drilled MW-1 through MW-4 are included in Appendix B i File R-Wellinstall&M&S rpt doe SECOR International Incorporated