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A concrete saw will be used to core 12" diameter holes in the sidewalk to facilitate access to the subsurface. Boreholes will be initially advanced using a decontaminated hand auger to approximately three feet below grade, to avoid potential contact with mismarked utility lines. Each day, prior to field work, the field geologist or IT site representative will conduct a tailgate safety meeting to ensure proper site safety precautions are identified and also to conform to the IT site specific Health and Safety Plan (Appendix A). ' The borings will be drilled by a subcontractor with a current C-57 license. All drilling will be performed using a steam cleaned, 8 inch O.D. hollow stem auger drilling rig. Before advancing to another drill site, the downhole drilling equipment will be steam cleaned to ' prevent cross-contamination between boreholes. All rinsate generated by steam cleaning will be containerized in marked 55-gallon drums, and securely stored at a documented location. Soil cuttings, soils generated during the initial hand augering phase, and concrete cores removed, will be containerized for 55-gallon drums as generated. These drums will be stored with those containing equipment decontamination waters, pending future disposal. The field geologist will determine the depth of the borehole and any special procedures necessary to manage any unusual. or anomalous conditions (i.e., flowing sands). Boreholes are anticipated to be 30 feet in depth. i2.2 Soil Sampling All subsurface materials will be described using the visual method of the Unified Soil Classification Systems (USCS) as described in the United States Bureau of Reclamation Document No. 5005-86. Samples will be collected utilizing a split spoon sampler advanced using a 140 lb. hammer. The sampler will contain brass tubes for collection of undisturbed samples. The sampler and brass tubes will be decontaminated by scrubbing with a non- phosphate detergent, triple rinsing with tap water, rinsing with methanol followed by a distilled water rinse. Soil samples will be collected every five feet beginning at 20 feet below grade (upper 20 feet consists of clean imported fill material). All vadose zone samples collected, will be submitted for laboratory analysis in order to provide a vertical hydrocarbon distribution profile beneath the former tank excavation. Each soil sample will be promptly sealed with aluminum foil, plastic end caps and tape. The samples will then be placed in a "ziplock" bag, sealed with security tape and delivered to a M2105-19-94JUST/940062.nbr 2-2