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No adverse impact would be anticipated with respect to arsenic, <br />boron, cadmium, chloride, manganese, nitrate, lead, selenium <br />and zinc since concentrations of these parameters in the leaching <br />tests were well below [he stream standards on the North Fork <br />Gunnison River. Furthermore, no adverse impact would be <br />anticipated with respect to total and dissolved iron, sulfate, TDS <br />and SAR. <br />Concerns were raised by the Division regarding surface water <br />effects of the lower waste pile leachate reaching the North Fork <br />Gunnison River after the waste pile sediment pond is removed <br />and the [nine site has been permanently reclaimed. In response, <br />MCC provided an analysis of the worst case effects to the North <br />Fork of the Gunnison from leachate generated by the lower <br />waste pile. For the analysis, MCC assumed a 10-year 7-day low <br />flow in the river, maximum leachate production, and that all of <br />the leachate would reach the river undispersed and undiluted. <br />The results of the analysis showed that the discharge would not <br />jeopardize any receiving stream standards. The amount of <br />discharge is so low in relation to the stream flow that there will <br />be no adverse effects to the hydrologic balance outside the <br />permit area. <br />Upper Refuse Disposal Area -Potential impact to local surface <br />water hydrology will be similar to that of the Lower Pile and <br />Refuse Pile Expansion areas and is discussed above. However, <br />[he upper pile has not yet been constructed and construction is <br />not planned for this permit term. <br />ii. Mitigation of Surface Water Impacts - <br />Impacts to surface water during the five-year permit term are <br />expected to be minimal. The operator predicts [hat no <br />degradation of water quality in surface streams is expected. <br />Drainage from the waste pile, mine water, and runoff from all <br />disturbed areas will be passed through a sediment pond or <br />alternate sediment control prior to discharge to the North Fork <br />of the Gunnison River. <br />The West Elk Mine has an extensive water monitoring plan to <br />monitor surface water quality and quantity. West Elk is <br />currently monitoring seventeen stations. Seasonal (three times <br />per year) water samples are taken at all surface water <br />monitoring stations. Parameters measured include pH, <br />conductivity, temperature, total dissolved solids, total suspended <br />45 <br />