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� y <br /> - 2.3.3 Drilling and Soil Sampling <br /> ISa soil 'borings)(B1 through B-6) were advanced using hollow-stem auger drilling and <br /> sampling equipment. Soil borings were located 'n accordance with Caltrans' Task Order <br /> No. 10-987901-MT and the final workplan (Shaw, 2003a). Figure 2 shows the boring locations. <br /> Boring locations presented in the workplan were based on an as-built diagram provided by <br /> Caltrans, which indicated a spacing of approximate) 3.7 meters (12 feet) between leach lines. <br /> Field observations during trenching indicated a spacing of 3 meters (10 feet). <br /> l .. <br /> The borings were advanced to approximately 3 me ers (10 feet) BGS. Discreet soil samples <br /> were collected at 1.5 meters (5 feet) and at 3 meters 00 feet) BGS, with the exception of boring <br /> B-2, where pea gravel extended to 2.1 meters (7 feet GS), and a single sample was collected at <br /> 3 meters (10 feet) BGS. Soil samples were collet ed using a split-spoon sampler lined with <br /> metal sample tubes. Soil samples were field screen d using a photo-ionization detector (PID). <br /> Groundwater was not encountered in the boreholes during drilling. <br /> Following sample collection, the borings were backfilled with bentonite-cement grout from the <br /> bottom of the borehole to ground surface. Drill cuttings were placed into a 208-liter (55-gallon) <br /> United Nations-approved drum. � <br /> u� } <br /> i. All drilling and sampling equipment was washed prior to use. In addition, to minimize <br /> cross-contamination between borings, all appropriate downhole drilling and sampling equipment <br /> was washed between borings. Decontamination wa er was placed into a 208-liter (55-gallon) <br /> United Nations-approved drum. <br /> A Shaw geologist logged the borings in general accordance with the United Soil Classification <br /> System. The boring logs were reviewed by a Califorin is Registered Geologist and are included in <br /> Appendix D. Drilling and sampling procedures are prpsented in Appendix E. <br /> 2.4 Waste Disposal <br /> Drill cuttings and wash water generated during the field investigation were contained for <br /> disposal in 208-liter (55-gallon) drums, approved by the United Nations for transport of liquid <br /> and solid wastes. The drums were stored at the site. The drums will be removed from the site <br /> for disposal within 90 days of initiation of the field investigation. <br /> 2.5 Laboratory Analyses <br /> Fourteen' soil samples were submitted to Twining Laboratories, Inc., of Fresno, California, a <br /> California-certified analytical laboratory, for analysis. The analyses were conducted on a normal <br /> t <br /> N.-1sacDP120031PgIB3035444.3ac.doc 2-3 <br />