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however, be restricted by the undisturbed coal. The ground water <br />. would stagnate and react with fragmented roof, floor, coal, rock <br />dust, and other materials within the one cavity. Due to stagnation <br />in the mine workings, water quality would be of lower quality than <br />that currently pumped from the underground workings and similar to <br />the quality of water measured at the New Elk mine coal processing <br />waste pile. The total dissolved solids levels may equal or exceed <br />2600 mg/1. This mine water would spread as a plume of degraded <br />water down the dip of the rock strata which is, in this case, <br />downgradient. Based on the structural contours of the coal seam, <br />water passing through the flooded workings would move in a <br />northeasterly direction. It is anticipated that soluble materials <br />would be readily flushed, but the low permeabilities of the <br />affected rock strata downdip would slow the flow of water from the <br />mine, causing the flushing action to persist over a long time <br />period. Since the coal seam aquifer currently contains poor <br />quality water, 806 to 1100 mg/1 total dissolved solids, and is not <br />used as a water supply in the general area, the effects of mining <br />on this aquifer will not materially damage the quality of ground <br />water used off-site. <br />Post-mining effects on the water quality in the <br />stream/alluvial aquifer system would be expected to be less than <br />those occurring during operations because mine water would no <br />longer be discharged from the underground workings. <br />• 3. Migratory birds of high Federal Interest: <br />No birds of high Federal interest are known to nest in the <br />mine area. However, individual birds could be affected if <br />subsidence caused an undiscovered nest to be destroyed/disturbed. <br />Subsidence is expected to be minimal (about one foot) which is not <br />expected to appreciably affect nesting habitat. <br />4. Renewable resource/unique agricultural values: <br />Undermining of the Purgatoire River might be expected to <br />deplete flow in the stream/alluvial aquifer system. Calculations <br />indicate that 2.3 gpm of water would flow downward and enter the <br />mine workings. This small water loss from the stream/alluvial <br />aquifer system would have a minimal impact on Purgatoire River <br />flows or alluvial ground water levels. <br />5. Recreational resource values: <br />Impacts to recreational values would be subsidence-related and <br />negligible. <br />6. Social and economic values: <br />There are no social or economic values affected by the <br />proposal. <br />• ~ 11 <br />