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SOIL AND GROUNDWATER INVESTIGATION ' Utility Clearance Prior to drilling, Building Analytics personnel visited the site and marked the boring ' locations. USA and a private utility locating company were contacted to clear underground utilities at each boring location. ' Boring Permits and Business License Building Analytics applied to the SJCEHD for a well permit prior to advancing the borings ' and installing the monitoring wells. The well permit was issued on February 5, 1997. A copy of the permit is included in Appendix B. Drilling and Soil Sampling tOn February 11 and 12, 1997 Building Analytics conducted the subsurface drilling and soil sampling at the subject property. Borings were advanced using a hollow-stem auer drill- .1m rig supplied by Gregg Drilling and Testing of Martinez,California. Three borings, B-1, B-2 and B-3, were drilled to depths of 65 feet, 70 feet and 65 feet bgs respectively. Soil samples were collected 1.5 feet bgs and 5 feet bgs, then at five-foot ' intervals until groundwater was encountered. The sampler was driven by raising and lowering a 140-pound operated hammer that advanced the sampler approximately 18 to 24 inches. The blow counts for each six inches were counted, and these numbers were recorded on the boring logs. Soil samples were collected using a modified California sampler. Soil samples were collected in three six-inch long, two-inch diameter brass tubes inside the sampler. ' The soil in the middle sample tube was used to describe the soil lithology and to measure VOCs using a Photovac Microtip Model No. HL-200 photo ionization detector (PID). Approximately 112 of the soil was removed, placed in a plastic bag and sealed. The sample ' in the plastic bag was then agitated and set aside to allow organic vapors, if present, to accumulate in the void space (headspace) of the sample tube. The headspace was then evacuated with a PID equipped with a probe. The measurements were considered in the selection of soil samples for laboratory analyses. Two additional borings, P-6 and P-7, were advanced to 25 feet and 15 feet bgs respectively. Samples were collected at 5-foot intervals beginning at 5 feet bgs. P-7 was terminated at 15 feet bgs due to probe refusal. The PID readings were recorded on the boring logs along with soil descriptions and soil classifications according to the United Soil Classifications System (USCS). Coordination and supervision of drilling and soil sampling activities were performed by qualified Building Analytics personnel, under the supervision of a State of California Registered Geologist. Boring logs are enclosed as Appendix C. Following retrieval of the sampler, the bottom six-inch long tube was removed from the sampler, and its ends were covered with teflon tape and capped with polyvinyl chloride (PVC)end caps. The sample tube was labeled with the sample number,collection date and ' project number, and was placed in a cooler chilled to approximately 4° C (40° F) and retained for laboratory analyses. 6 197046a - Stockton