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SS No. 6348 , Tracy <br /> PIER, 1/31/92 <br /> In all borings, soil samples were collected at five <br /> foot intervals and immediately above the encountered water <br /> table, using a California modified split spoon sampler lined <br /> with brass sleeves driven by a 140-pound hammer falling 30 <br /> inches . Blow counts were recorded. One boring (MW-3 ) was <br /> continuously sampled. <br /> At each sampling interval , the contents of one <br /> six-inch sleeve was transferred into a zip-lock bag for testing <br /> with a photoionization detector (PID) . An adjacent six-inch <br /> sample, retained in its brass sleeve, was then prepared for <br /> laboratory analysis by wrapping the ends of the brass sleeve in <br /> teflon foil and covered them with plastic end caps. The sample <br /> was labeled, placed in a ziplock bag, and placed in a cooler <br /> with ice. Samples were selected for delivery to ChromaLab in <br /> San Ramon, California if PID readings and/or sample location <br /> determined it was from a point of interest. Chain-of-custody <br /> documentation accompanied the samples to the State-certified <br /> laboratory. <br /> The soil samples were classified lithologically in <br /> . accordance with the Unified Soil Classification System and <br /> standard geologic techniques. Copies of boring logs and well <br /> construction diagrams are attached as Appendix A. <br /> WELL CONSTRUCTION <br /> The wells were constructed using two-inch diameter <br /> PVC pipe with 15 feet of screened PVC (0. 020-inch slot) which <br /> was placed in the bottom of the borehole . Sand (#2 /12 <br /> Lonestar) was poured into the annular space surrounding the PVC <br /> pipe to a height of one-half foot above the top of the slotted <br /> interval . A two-foot thick layer of bentonite pellets was <br /> placed above the sand and hydrated. The remaining annular <br /> space was filled with neat cement to near the ground surface. <br /> The tops of the PVC were casing secured with locking plugs and <br /> enclosed in water-tight, locking vaults. <br /> The hollow stem augers were steam cleaned prior to <br /> use in each boring . All soil cuttings were placed on, and <br /> covered with, plastic sheeting. Steam cleaning rinseate <br /> generated during monitoring well installation was placed in <br /> 55-gallon DOT-approved drums and stored on site pending <br /> appropriate disposal. <br /> The wells were surveyed on July 11, 1991 to the top <br /> -4- <br />