2011-06-06_REVISION - M1981185 (56)

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Geochemistry and Water Quality Review Adequacy Response Wildcat May Day; DRMS File No. M-1981-185 Conversion Application CN-1 Adequacy Issue #17 A. The Division does not agree that "dry stack underground tailings mitigates all potential surface and ground water quality mining impacts." The mine site is located in an area of relatively high precipitation and even if the proposed tailings deposition area is above the water table in the unsaturated zone and currently dry, that is no guarantee that it will always be so and there may be a risk of periodic wetting due to ground water infiltration. Fine-grained tailings located where they may undergo repeated wetting and drying is an ideal scenario for weathering that can leach contaminants and generate acid-rock drainage. The Applicant proposes "appropriate ground water and surface water monitoring." The Applicant will need to develop a rigorous testing and monitoring program, and depending on conditions in the mine, measures may be needed to isolate the tailings from current and future infiltrating ground water. B. It is not entirely clear what information is intended to be conveyed in Figure D-1B Dry Stack Tailings Disposal Sites. The Applicant should clarify whether both the red dots and thick red line intended to depict tailings disposal areas. Response 17 A and B: Wildcat Mining has committed to disposing the dry stacked tails (caked-unsaturated) in a dry environment. An aggressive leaching study completed by the Company coupled with a chemical fate analysis has demonstrated leachate (if generated) will not adversely affect surface or groundwater. Multiple monitoring points have been or will be established to monitor if underground dry stacked disposal continues to reflect there are no hydrogeological impacts and that the dry stacked disposal site is functioning as designed. In addition, future water and static and kinetic whole rock testing and monitoring will be used to determine if changes have or could occur. If changes have or could occur, corrective actions will be implemented to mitigate concerns. Wildcat Mining, as previously discussed, will conduct mine rock static tests on run of mine rock after each 5,000 tons of materials mined to determine if the rock is acid or toxic producing. C. Exhibit D, Mining Plan page 4. The mining plan states that "wet-submerged tailing disposal will be researched and implemented upon demonstration the underground disposal sites are suitable and that the tails will not induce environmental impacts." The Applicant should describe the research and testing that will be done to evaluate the suitability of wet-submerged tailings disposal and to demonstrate that the tails will not induce adverse environmental impacts. Response 17 C: The Company has proposed submerged tailings disposal as future research option at the suggestion of DRMS. Wildcat Mining will not dispose tailings beneath the water table 6/6/11