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A S S 8 C I A T E S I N C ISoil boring SB 10 was advanced approximately seven feet north of the northwestern edge of the chiller unit at an angle of 35 degrees from vertical Approximately 16 6 feet of augers were advanced bgs, at which point three 18-inch long California modified split spoon samplers ' containing brass sleeves were driven in succession to collect soil samples Soil boimg SB1 O was advanced until approximately 27 6 feet of augers were below the ground surface, at which point three California inodified split spoon samplers containing brass sleeves were driven in tsuccession to collect soil samples Soil boring SB 10 was advanced further until approximately 38 6 feet of augers were below the ground surface, and three California modified split spoon samplers containing brass sleeves were driven in succession to collect soil samples Following collection of soil samples from the third depth Interval, the measured angle of the augers was 30 degrees with respect to vertical, indicating auger migration of 5 degrees in the vertical direction ' as a result of gravitational influence Assuming drilling angles of 35 degrees, 32 5 degrees, and 30 degrees with respect to vertical, and using trigonometric ftlnct>ons, the first, second, and thud sampling Intervals, with respect to vertical, were calculated to be approximately 13 6 --- 17 3 Leet ' bgs, 23 3 --27 1 feet bgs, and 33 4 — 37 3 feet bgs, respectively Soil boring SBI1 was advanced vertically in the vicinity of MW-7 to an approximate depth of 39 5 feet bgs, to collect soil samples from beyond the known extent of CrVI impacted soil SBI I is located hydraulically crossgradient with respect to Vault 8 and the chiller unit CrVI was not detected in soil samples collected from the borehole of MW-7 at depths of 40 and 50 feet bgs when this well was installed in September 2002 Soil samples were collected from SB 11 by driving three California modified split spoon samplers containing brass sleeves in succession at vertical depth intervals of 15 — 19 5 feet bgs, 25 — 29 5 feet bgs, and 35 — 39 5 feet bgs The soil samples collected from SBI I were observed to ensure time lithology was smmilai to that of the samples collected from SBIO The purpose of soil sample collection frons SBI I was to provide non-impacted control samples or samples representative of backgi ound concentrations for baseline characterization and bench scale testing The soil encountered in SB 10 and SB 11 was similar and generally consisted of brown sandy clay ' All drill cuttings were stored on site in 55-gallon drums pending proper disposal Desciiptions of soil types encountered, field observations, and sample collection intervals aie piesented on the soil boring logs contained in Appendix A ' 22 Groundwater Sample Collection Activities ' On October 19, 2004, groundwater samples weie collected from MW-1 through MW-9 as part of the fourth quarter sampling event The groundwater samples were collected after purging each well of three well casing volumes Ten gallons of groundwater collected from MW-3 and five gallons of site tap water were submitted to PRIMA to be utilized in the bench scale treatability study The gioundwater samples collected from MW-I through MW-9 were submitted to PRIMA for baseline analyses and characterization, and to Excelchem Environmental Labs for analyses 1 associated with the quarterly monitoring program ti k.nvironin ntn11G25831rLportslbeuch test rpt doc 4