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! A 4 . 0 DRILLING CPT SOIL BORINGS AND COLLECTING SAMPLES Prior to drilling, ASE obtained a drilling permit from the San Joaquin County PHS-EHD. A copy of this permit is located in Appendix B. Underground Service Alert (USA) was notified to have underground public utilities marked in. the site vicinity. On October 4, 2000, Gregg In-situ of Martinez, California drilled soil borings CPT-1 and CPT-2 at the site using a CPT direct push drill rig (Figure 3). The drilling was directed by ASE associate geologist Ian Reed. Soil boring CPT-1 was advanced to a depth of 60-feet bgs. Pore pressure dissipation tests were performed at depths of approximately 38-feet bgs and 58-feet bgs. Soil boring CPT-2 was advanced to a depth of 70-feet bgs and a pore pressure dissipation test was performed at a depth of approximately 15-feet bgs. A report explaining the CPT procedures and presenting the CPT logs and test results is included as Appendix C. A second boring was drilled approximately 3-feet from the initial borings drilled for lithology for the collection of soil and groundwater samples. Undisturbed soil samples were collected from boring CPT-1 at 7 and 41 - feet bgs. Undisturbed soil samples were collected from boring CPT-2 at 7 .. and 37-feet bgs. All soil samples were collected with a split-barrel drive sampler lined with acetate tubes. The liners were removed from the sampler, trimmed, sealed with Teflon tape, plastic end caps and duct tape, labeled, sealed in a plastic bag, and stored on ice for transport to Kiff Analytical, LLC under chain of custody. Groundwater samples were collected from boring CPT-1 at 41-feet bgs and CPT-2 at 37-feet bgs using a SimulProbe sampler. The SimulProbe sampler was advanced to the preferred sampling depth while being back- pressurized with nitrogen gas. At the preferred sampling depth, t h e nitrogen gas was released, allowing a discrete groundwater sample to flow into the sampler. The sampler was then extracted from the ground. Groundwater samples were contained in 40-m1 volatile organic analysis (VOA) vials, pre-preserved with hydrochloric acid. The samples were then labeled, sealed without headspace, and cooled on ice for transport to Kiff Analytical, LLC under chain of custody. Due to the low permeability of the water-bearing zone, no sample could be collected during t h e sampling attempt from the 55-foot depth in CPT-1. 574 West Grant Line Road Report — October 2000 -4-