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�a <br /> initially encountered at approximately 86.5 feet. <br /> see Figure 2 for well location information, ApVendix E <br /> for boring logs, and monitoring well construction diagrams, <br /> Figures 8, 9, & 10- <br /> 3.2 WELL CONSTRUCTION <br /> All the materials used in the construction of Monitoring <br /> Wells 1, 2, and 3 were thoroughly cleaned prior to <br /> introduction into the boring. A 2-inch OD well casing (PVC) <br /> with a threaded end cap, and O.C20-inch factory slotting for <br /> placement into One saturated zone, was placed in the borings. <br /> A #3 Monterey sand was used for the filter pack. The annular <br /> seals in each well consist of hydrated bentonite pellets. <br /> MW-1, MW-2 and MW-3 were each advanced to depths of 101. <br /> feet. Blank casing extends to 75 feet with slotted casing <br /> extending from 75 to 100 fermi: in each well. The filter packs <br /> in 73 to <br /> 100the feet. The bentonite seals lar saces of t'ie hextend ree lfrom ls x68ntofm <br /> 73 feet. <br /> The filter packs and well seals were tremmied through <br /> the auger. The bentonite seals were hydrated with 5 gallons <br /> of distilled water, and a 5% bentonite slurry was pumped into <br /> the remaining annular space, up to 0.5 foot below grade in <br /> each well. Mr. Mike Infurna of the SJCEHD observed grouting <br /> proceedings. <br /> J <br /> Locking caps were placed on top of the well casings <br /> inside water-tight street boxes cemented into place. <br /> 3.3 DRILLING <br /> Prior to the start of drilling operations, Underground <br /> u Service Alert (USA) marked the locations of underground <br /> utility lines in the vicinities of the proposed borings, so <br /> that the lines could be avoided when the borings proceeded. <br /> A permit for the installation of the three monitoring <br /> wells was obtained, and work began on July 29, 1991. See <br /> Appendix G for associated permits. <br /> The three borings were drilled using a hollow-stem auger <br /> with a 8-inch outer diameter (OD) . All drilling equipment <br /> was thoroughly steam-cleaned before drilling began to prevent <br /> the introduction of contamination from off-site sources, and <br /> between borings to prevent cross-contamination. <br /> Soil samples from all borings were logged by a qualified <br /> geologist using the Unified soil Classification System. The <br /> color, texture, moisture, plasticity, consistency, pertinent <br /> -ET5-ENVIRONMRNTAL.._.&-ASSOC _. .---..--- ------- -:------- <br /> PROJECT 305, PAGE 5 <br />