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3 <br /> DRILLING, WELL CONSTRUCTION AND SAMPLING PROTOCOL <br /> 'r <br /> DRILLING <br /> Prior to any drilling or excavation activities, <br /> Underground Service Alert (USA) wi-11 be contacted to mark all <br /> underground utility lines in the vicinity of the proposed <br /> work. All necessary permits will be obtained and 48 hour <br /> notification to the lead agency will be given prier to' the <br /> commencement of drilling. <br /> Borings will be drilled using hollow-stern auger with no <br /> less than 3 1/4-inch diameter ( ID) and 6 3/4 outside diameter <br /> (OD) . All drilling equipment will be thoroughly steam; <br /> cleaned before drilling begins to prevent the introduction of <br /> contamination from off-site, and between borings to prevent <br /> cross-cont am i nat i or,. <br /> All borings will be logged by a qualified geologist <br /> using the Unified Soil Classification System. The color, <br /> texture, moisture, plasticity ( if applicable) , consistency, <br /> pertinent soils or bedrock characteristics, and any evidence <br /> of contamination will be noted on the logs. All water,- <br /> bearing zones and the depths at which they were encountered <br /> will be noted on the legs. All logs will be reviewed by a <br /> California State Registered Cavil Engineer and verified <br /> correct. A sample of the material logged is to be collected <br /> and retained for further analysis and verification. <br /> The borings will be drilled in such a manner as to <br /> prevent cross-contarilination between strata. Exploratory soil <br /> borings will be backfilled with a neat cement/5% bentonite or <br /> nine sack sand cement slurry. Soil borings that encounter <br /> groundwater will be abandoned by first placing a one foot <br /> layer of bentonite fit the bottom of the boring and thea <br /> backfilling as stated above.44, <br /> If a deeper aquifer is to be investigated, conductor <br /> casing will first be grouted into place to seal off they upper <br /> aquifer (s) , in series if necessary, and drilling will proceed <br /> through the conductor casing after the grout has been allowed <br /> to set properly. If evidence of contamination is noted <br /> during drilling, the drilling will be halted until thee, <br /> responsible professional determines the advisability of <br /> deeper drilling. <br /> Upon termination, borings into the saturated zone,fwill <br /> either be completed as monitoring or extract ion/inject ion <br /> wells, or backfilled with bent cars ite/cement or cement slurry <br /> as described above. Soil borings greater than ten feet in <br /> depth will be backfilled by trernmying the material. All <br /> borings for wells will be of a diameter at least 4 iricties <br /> greater than the inside diameter of the well casing to'� be <br />