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h10V 18 '94 11~38HP~ UI'd:19INEFNL~~.~=Ei~L~:n;I P.~i3 <br />• • <br />Tom Gillis <br />-2- November 18, 1994 <br />groundwater quality, <br />The ore analysis provided is not acceptable as it does not accurately simulate the <br />conditions under which the ore will be processed and reclaimed. The operator will <br />need to have representative samples of each ore body to be mined sent to a reputable <br />laboratory and analyzed for metals leachability using a standard method, such as the <br />Nevada/New York Meteoric Water Mobility procedure. It will also be necessary to <br />have the operator estimate the anticipated volumes of each ore type to be mined. <br />Existing acid base accounting results are valuable; however, we also need an accurate <br />measure of the percent of sulfide present in each ore type. <br />4. The method proposed for disposal of spent ore seems plausible. However, there <br />appears to be potential for degradation of surface and groundwater, The ore analysis <br />presented suggests the prt;sence of arsenic in high concentrations. Accordingly, the <br />operator should demonstrate methods to be used, such as a clay cap, w minimize air <br />and water movement into the respnead spent ore doting fmal reclamation. Surface <br />water diversions may also be helpful, especially where spent ore is exposed above <br />ground. <br />Use of water from Little Deadwood Gulch for process water should be evaluated and <br />approved by a qualified representative of the State Engineer's Office. The operator <br />may be required by the SBO to demonstrate adequate water rights for this particular <br />operation. <br />6. The operator has proposed a zero discharge facility. Tt should be noted that any <br />discharge of excess process water back to Little Deadwood Gulch will require an <br />NPDBS water discharge permit by the Colorado Department of Health, water t~uality <br />Control Division. <br />7. The operator has proposed a disposal method for processed are (fdter cake) to be <br />placed in the open cuts and mine openings of the disturbed area while at a moisture <br />content of approximately 25 percent. Thus, seepage of moisture from the filter cake <br />into the surrounding strata will constitute a discharge to groundwater. Therefore, the <br />operator should state what measures will be taken to comply with the provisions of <br />Rule 3.1.7 for protection of groundwater, <br />M:\09SWyy\meao\p~.L~ <br />