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APPENDIX A <br /> EXPLORATORY BORING AND WELL INSTALLATION <br /> PROCEDURES <br /> The general procedures used in site assessments for drilling exploratory borings, collecting <br /> samples, and installing monitoring wells are described in this appendix. These general <br /> procedures are used to provide consistent and reproducible results; however, conditions may <br /> exist where variations of these procedures are applicable. The following procedures are <br /> supervised by a California state-registered geologist. <br /> Exploratory Soil Borings <br /> Exploratory soil borings for sites characterized by relatively shallow ( less than 100 feet deep ) <br /> groundwater are generally drilled using 8 - to 12- inch-diameter, continuous-flight, hollow-stem <br /> auger drilling equipment. The drilling method for sites in which depth to groundwater is greater <br /> than 100 feet is determined on a case- by-case basis. Soil samples for logging will be obtained <br /> from auger-return materials and by advancing a modified California split-spoon sampler <br /> equipped with brass or stainless steel liners into undisturbed soil beyond the tip of the auger. <br /> Soils will be logged by an EMCON Associates ( EMCON) geologist according to the Unified <br /> Soil Classification System and standard geological techniques. Exploratory soil borings not <br /> used for monitoring well installation will be backfilled to the surface with a bentonite-cement <br /> slurry pumped into the boring through a tremie pipe . <br /> The soil sampling equipment will be cleaned with a detergent water solution, rinsed with clean <br /> water, and equipped with clean liners between sampling intervals. Augers and samplers will be <br /> steam cleaned between each boring to reduce the possibility of cross contamination. Steam <br /> cleaning effluent will be contained in 55 - gallon drums and temporarily stored on site. The <br /> disposal of the effluent will be the responsibility of the client. <br /> Drill cuttings generated during the drilling procedure will be stockpiled on site. Stockpiled drill <br /> cuttings will be placed on and covered with plastic sheeting. The stockpiled soil is typically <br /> characterized by collecting and analyzing composite samples from the stockpile. EMCON will <br /> recommend an appropriate method for disposition of the cuttings based on the analytical <br /> results. The client will be responsible for disposal of the drill cuttings. <br /> Soil samples for chemical analysis will be collected in brass or stainless steel liners, sealed with <br /> Teflon`9 tape and plastic end caps, labeled , placed on ice, and delivered to a state-certified <br /> SAC/pjUD117V 170530.4MM-94/pas:5 A- 1 Rev. 0, 11 /30/94 <br />