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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 the 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 mine 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 /> the 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 that 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 prior to <br /> discharge to the North Fork 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 eleven stations. Seasonal (three times per <br /> year) water samples are taken at all surface water monitoring <br /> stations. Parameters measured include pH, conductivity, <br /> temperature, total dissolved solids, total suspended solids, total <br /> iron and total manganese. More specific details regarding <br /> 47 <br />