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APPENDIX A EXPLORATORY BORING AND WELL INSTALLATION PROCEDURES The general procedures used in site assessments for drilling exploratory borings, collecting samples, and installing monitoring wells are described in this appendix. These general procedures are used to provide consistent and reproducible results; however, conditions may exist where variations of these procedures are applicable. The following procedures are supervised by a California state-registered geologist. Exploratory Soil Borings Exploratory soil boring will be drilled using 10-inch-diameter, continuous-flight, hollow-stem auger drilling equipment. Soil samples for logging will be obtained from auger-return materials and by advancing a modified California split-spoon sampler equipped with brass or stainless steel liners into undisturbed soil beyond the tip of the auger. Soils will be logged by an IT geologist according to the Unified Soil Classification System and standard geological techniques. The soil sampling equipment will be cleaned with a detergent water solution, rinsed with clean water, and equipped with clean liners between sampling intervals. Augers and samplers will be steam cleaned between each boring to reduce the possibility of cross contamination. Steam cleaning effluent will be contained in 55-gallon drums and temporarily stored on site. Drill cuttings generated during the drilling procedure will be stockpiled on site. Stockpiled drill cuttings will be placed on and covered with plastic sheeting. The stockpiled soil will be characterized by collecting and analyzing composite samples from the stockpile. Based upon the analytical results, the stockpiled soil will be transported to a designated facility. Soil samples for chemical analysis will be collected in brass or stainless steel liners, sealed with Teflon tape and plastic end caps, labeled, placed on ice, and delivered to a state-certified analytical laboratory, along with the appropriate chain-of-custody documentation. Soil samples selected for chemical analysis will be determined from a head-space analysis using a hand-held photoionization detector (PID). The soil will be placed in a plastic baggie, sealed, and placed in a warm atmosphere. After approximately 15 minutes, which is generally sufficient for volatiles to escape from the soil, the PID probe will be inserted into the plastic baggie. The total volatile hydrocarbons present are detected by the PID and reported in parts per million (ppm). The PID will be calibrated to an isobutylene standard. Sac1N:ICamPk\DataWchivc\Arco15469uieports15469p103.doc-95 ft:1 IT Corporation A-1 02/28/00