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STEEPEN ROBERTSON 8 KIRSTEN <br />' Mr. Gary Dodson <br />Battle Mountain Gold Company <br />' November 23, 1988 <br />Page Two <br />' We anticipate that all of the coreholes will be advanced using HQ core <br />barrels, thereby allowing standpipe piezometers to be installed in fihe boreholes <br />' where appropriate and sufficiently large geotechnical samples to be obtained for <br />use in the proposed laboratory testing program. The coreholes will be advanced <br />through the Santa Fe Formation to the contact with the green clay. Tlne green clay <br />' and the underlying formations containing the confined aquifer ar•e not to be <br />penetrated as part of this program. <br />' ~ As the cores are retrieved from the coreholes, SRK proposes to classify <br />them in the field for geotechnical purposes and place them in c~oreboxes for <br />storage and eventual transport to our laboratory in Lakewood, Colorado. Detailed <br />lithologic logs will be developed based on evaluation of the core and the <br />' observations of the ease of coring. Hydrogeologic testing will be completed and <br />standpipe piezometers installed in the open coreholes. We anticipate that <br />Halepaska will specify their proposed hydrogeologic testing anc piezometer <br />' installation program in a separate document to be submitted to Battle Mountain <br />Gold (BMG). <br />The completed coreholes will either be converted to standpipe piezometers <br />' or will be backfilled to the grout surface. We anticipate that back Filling with <br />a cement bentonite ground will be required as sufficient amounts of cuttings <br />are not anticipated to be generated for use as backfill during the coring <br />' operations. <br />The proposed geotechnical laboratory testing program will address the <br />' ~ following items: <br />The primary permeability of the material. This is the permeability <br />that is due solely to the material itself and riot due to <br />discontinuities. The secondary permeability, which is diue to water <br />flow through joints/faults, can then be estimated by comparison with <br />the overall permeabilities determined in the drill program. The <br />' purpose is to assess whether the Santa Fe Formation is a homogeneous <br />or heterogeneous hydrological unit with seepage controlled by either <br />primary or secondary permeability. This will influence the location <br />and placing of the horizontal drain program that will be implemented <br />' as the south wall is being exposed. The drains must intercept the <br />water conduits and if the secondary permeability is determined to <br />be critical then the location of the fracture/fault zoroes must be <br />' delineated. If the Santa Fe is a more homogeneous unit then the <br />spacing of the drains and the location is governed by water flow <br />through the pores separating the individual sand/clay particles; <br />' The porosity and moisture content of the Santa Fe. This coupled with <br />the drill program will establish the level of saturation; <br />1 <br />CJ <br />