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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, <br /> collecting samples, and installing monitoring wells are described in this appendix. These <br /> general procedures are used to provide consistent and reproducible results; however, <br /> conditions may exist where variations of these procedures are applicable. A California <br /> state-registered geologist supervised the following procedures. <br /> Exploratory Soil Borings <br /> Exploratory soil borings were drilled using 8-inch-diameter, hollow-stem auger drilling <br /> equipment. Soil samples for logging were obtained from auger-return materials and by <br /> advancing a modified California split-spoon sampler equipped with brass or stainless <br /> steel liners into undisturbed soil beyond the tip of the auger. Soils were logged by an IT <br /> geologist according to the Unified Soil Classification System and standard geological <br /> techniques. <br /> The soil sampling equipment was cleaned with a detergent water solution, rinsed with <br /> clean water, and equipped with clean liners between sampling intervals. Augers and <br /> samplers were steam cleaned between each boring to reduce the possibility of cross <br /> contamination. Steam cleaning effluent was disposed of on-site. <br /> Drill cuttings generated during the drilling procedure were considered to be clean and <br /> disposed of on-site. <br /> Soil samples for chemical analysis were collected in brass or stainless steel liners, sealed <br /> with Teflon® tape and plastic end caps, labeled, placed on ice, and delivered to a <br /> state-certified analytical laboratory, along with the appropriate chain-of-custody <br /> documentation. Soil samples selected for chemical analysis were determined from a <br /> head-space analysis using a hand-held photoionization detector (PID). The soil was <br /> placed in a plastic zip-lock type baggie, sealed, and placed in a warm atmosphere. After <br /> approximately 15 minutes, which is generally sufficient for volatiles to escape from the <br /> soil, the PID probe was inserted into the plastic baggie. The total volatile hydrocarbons <br /> present are detected by the PID and reported in parts per million (ppm). The PID was <br /> calibrated to an isobutylene standard. Additionally, soil samples were analyzed for lower <br /> explosive limits using an explosive gas meter. <br /> R CORMSfimn <br /> SAC:\N:\Consulting\data\Shared\Projects\PJ8\809251.aa.doc-00\ta:1 <br /> 809251 <br />