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LEEDSNlLL-MEAXENNpPF. iNC, <br /> inserted down the center of the hollow-stem augers was used to collect the <br /> discrete samples from ten of the eleven borings (all except SBI) . The sampler <br /> was a California Modified (2.5- inch inside diameter) split-spoon sampler equipped <br /> with 6-inch long clean brass liners. The sampler was driven i8 inches into the <br /> undisturbed ground beyond the tip of the auger by a 140-pound hammer having a 30- <br /> inch drop. The sampler was then withdrawn from the auger and the liners removed. <br /> The other boring (SBI) was drilled with a 5-foot long split core barrel attached <br /> to drilling rods inserted down the center of the 6-inch hollow-stem augers and <br /> secured to the augers with a locking ring. Although the core barrel is 5 feet <br /> long, it was found that drilling 2.5-foot core segments produced the most optimal <br /> recovery of soil samples for this site' s conditions. As the augers advanced, a <br /> continuous sample filled the core barrel . The core barrel was then withdrawn <br /> from the auger and the continuous core sample removed. Discrete grab samples <br /> were selected from the continuous core for laboratory analysis by the field <br /> geologist. <br /> The split-spoon sampler and split core barrel were brushed and washed with a <br /> trisodium phosphate (TSP) solution and rinsed in clean water between each <br /> sampling interval . All sample liners and drilling equipment were thoroughly <br /> cleaned with high pressure, hot water prior to use to prevent potential cross- <br /> contamination between borings. The test borings were completely backfilled with <br /> a cement-bentonite grout mixture immediately after the samples were obtained. <br /> The drill cuttings produced from each of the boreholes were containerized in 55- <br /> gallon drums with lids and stored on-site to await disposal based on the results <br /> of the analytical testing. <br /> Once removed, all samples were capped, sealed, carefully marked, and identified. <br /> The samples were then carefully preserved for analysis in accordance with EPA and <br /> California Department of Health Services (OOHS) protocol . Before transport to <br /> the laboratory, samples were cooled to 4 Celsius at the site and maintained at <br /> that temperature until they were received at the laboratory. Prior to transport, <br /> the samples were logged onto a chain-of-custody form identifying the project <br /> number, sample type, container type, sample identification, type of analysis, <br /> sampler and date. The samples were picked up at LH' s office by a Superior <br /> Analytical Inc. representative, who signed the chain-of-custody form. <br /> All samples were obtained under the supervision of the field geologist. A <br /> • detailed boring log was kept at all times noting soil types encountered, using <br /> the Unified Soil Classification System (USCS) , and noting moisture conditions, <br /> location, and depth for each sample. Copies of the boring logs and the USCS are <br /> presented in Appendix B. <br /> A photoionization detector (HNU) was used to field monitor volatile organic <br /> vapors emitted from each sample and to assist the field engineer in determining <br /> whether or not background volatile organic vapors were present at the site. No <br /> ambient background volatile organic vapor concentrations were detected. The <br /> field-detected photoionization values for each sample are shown on the geologic <br /> j logs presented in Appendix B. These field instrumentation readings did not <br /> 1 replace the analytical laboratory testing. <br /> l 9 <br /> i <br />