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Whetstone' <br />Associates <br />Technical Memorandum <br />to accommodate 2 -inch PVC casing and meet the Division of Water Resources (DWR) requirements <br />for a 2 -inch annular space. Well completion specifications are provided in Section 7. <br />For wells drilled deeper than 300 ft depth, clean water with environmental -grade foam will be used <br />as the drilling fluid. The foam will be kept to the minimum required to suspend cuttings and clean <br />the hole, and the water -foam mixture will typically not exceed an injection rate of 2 to 5 gpm. The <br />borehole diameter will be a minimum of 8 inches to accommodate 3 -inch stainless steel casing and <br />meet the DWR requirements for a 2 -inch annular space. Well completion specifications are <br />provided in Section 7. <br />Drill cuttings will be contained in a pit. After drilling is complete, the water in the pit will be <br />allowed to evaporate and the pit and drill pad will be reclaimed in accordance with the Mine <br />Reclamation Plan. <br />3. GEOPHYSICAL LOGGING <br />Geophysical borehole logging will be performed on the deepest boreholes (Location L2, L4, and <br />L6). Borehole logging involves the lowering of sensors (or sondes) into the open borehole to <br />measure various physical properties of the formation around the boring. Multiple logs (called a <br />"suite ") will be recorded in each hole. <br />The following geophysical tools have been identified for downhole logging of the L2, L4, and L6 <br />locations: <br />• Caliper log <br />• Natural Gamma (aka direct gamma) <br />• Neutron density <br />Information gained from geologic logging will be used to identify fractured zones and aid in <br />selecting the placement of the pneumatic packers for hydraulic conductivity testing (Section 4) <br />placement of the well screen. <br />4. HYDRAULIC CONDUCTIVITY TESTING <br />4.1 Packer Testing Program <br />Packer permeability tests will be performed in the deepest borehole at each bedrock well site. Tests <br />will be performed in the open hole, prior to well completion, using a straddle packer assembly <br />(Figure 1) and an upstage testing method. <br />4109C.120309 3 <br />