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euve-e0-680188 nsenrnl Cherwerl:e0wr e{ hwrf sea in rx AP112016 of. (1) 15 it lips or (2) auger refusal. 'I he 15 it borehole depth wave selected to allow sampling both within the trendies(C) to 10 ft) and the vadom zone(10 to 15 it) beneath the trenches. A drilling geologist, present during the drilling of the boreboles, logged the cuttings to Provide information on the lithology and any meml or other debris that was encountered during drilling, and b verify the depth of the debris burial trench. Table I presents a summary of the Nuclides drilled including rota) depth, presence 0f debris and/or soil sminin& depth at which bedmck was enwuntered, and other noteworthy conditions encountered during drilling. Debris, including metal shavings, rusted metal, woe, and Imgenents of glass and ceramic, encounteredwas in six of the 13 borcholes. As shown on Figure 10, borehole located In Tost Pits 3, 4, and 5 contained debris (W-EOSA-3028, -3029f3029A, -3031, -3033, and A034). Photographs showing the type of debris encountered in borcholes are presented in Figure I1. All debris, where encoutme d, was located within the upper 10 fat of the borcholes. Soil staining was uonly associated with the debris. Every occurrence of stained to soil adjacent metal debris wv sampled for SVNYPAN and I'CB analyses. No debris was encountered in the borebnles located in 'I est Pits I M EGSA-3032) and 2 (E-EGSA-3027), in the borcholes located on the road adjacent to IM1e omrtlow pond (W-EGSA-3036, -3037, and -3038h or in bureholes W-EGSA-3030 and -1035. Depending 0n sawamal and annual rainfall, ground water depth beneath the Eastern USA debris burial trench ores varies from 10 and 20 0 bgs. Ground water was not encountered during drilling ofany ofthe borcholes, therefore the depth to ground water was not recorded. rings from each borehole committed a maximum volume of about 3 cubic feet, before subtracting any soil collected far chemical analysis. Auger cuttings were placed on plastic sheering adjacent to the borehole during drilling and sampling maivitiv. Upon reaching the total depth of the borebole or auger refusal and after soil sampling was completed, the bomboles were backfilled with cuttings 0forigin and tine surface topped with hydrated bentonhe. 3.2. Soil and Ground Water Sampling Methods used to collect soil samples from the borcholes including any deviations from the Work Plan made during field sampling, arc discussed in Section 3.2.1. When PCJU were detected in some soil samples collected from the boreboles, DOE/LLNL collected ground water samples fmm existing monitor wells located in the vicinity of the debris burial perches for PCB analysis Ground water sampling methods are discussed in Section 3.21. 31.1. Soil Sampling Soil samples were collected in each of the 13 borcholes in accordance with the prs cedures specified in the LLNL borehole soil sampling-rclated SOP 1.2 (Goodrich and Lorega, 2012) and with the EPA's "Guidance on Systematic Planning Using the DUO Process" (EPA, 2006). Within each of IM1e 13 borcholes, a hammered split-spoon soil sampler was driven to collect soil samples. Where possible, samples were collected at the three depths specified in the Work Plan: 5 4, 10 it and 15 it below ground surface (bgs). Sample collection depths were selected to obtain data: (I) within the debris burial bench (5 ft bps), (2) at the bottom or the debris burial trenches 00 ft him), and (3) fmm the varbow rune beneath the debris burial Irenches (15 it bps).