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samples taken in the Oliver Mine, that mine waters will not be toxic. <br /> This plan calls for the construction of a block wall at the portal and a <br /> four-inch PVC pipe to drain the collected mine waters. The second <br /> plan is contingent on the mine producing toxic mine waters. This plan <br /> calls for the construction of several engineered seals located within the <br /> mine designed to withstand pre-mining head pressures. <br /> MCC has conservatively estimated that the B Seam mine, including <br /> Jumbo Mountain, and the existing F Seam mine would flood and fill in <br /> 139.6 years. This estimate assumes no seepage or outflow and the <br /> worst case maximum steady inflow for the F Seam mine and the median <br /> of the 5-year and life-of-mine, worst case maximum steady inflows for <br /> the B Seam mine. <br /> Water moves downslope and discharges as seeps and springs. It also <br /> appears that mine inflows are controlled by the amount of precipitation <br /> (mostly snowmelt), depth of overburden and location and extent of <br /> fracture zones and not by the extent of the underground workings. <br /> Mountain Coal Company predicts that the West Elk Mine will have no <br /> significant impact on the quality and quantity of groundwater and <br /> springs. Representative water quality samples from wells located in the <br /> Lower Coal Member show that groundwater is suitable for discharge to <br /> the North Fork. <br /> The B Seam lies ten feet above the Rollins Sandstone unit. The <br /> operator states that based on data from the mining and reclamation plan <br /> and recent drilling, it is reasonable to assume that the North Fork of the <br /> Gunnison River recharges and receives discharge from the Rollins <br /> Sandstone in a small area on the northern edge of the West Elk <br /> property. It is evident from available data that the Rollins behaves <br /> similarly to the Barren Member and Coal members in the permit area <br /> except the extreme northern edge where it has an alluvial contact with <br /> the North Fork. <br /> The Rollins Sandstone is considered a marginal aquifer in terms of yield <br /> and water quality and, to the Division's knowledge, has no points of <br /> usage in the mine vicinity. Review of data for the region indicates that <br /> none of the other mines in the area have monitored the Rollins <br /> Sandstone. Since the Somerset Mine has been active since 1906, any <br /> potential for severe water quality impact would probably be evident by <br /> this time. The water quality data for R-1, a well completed in Rollins <br /> Sandstone and drilled by Mountain Coal Company in 1976, indicates <br /> total dissolved solids generally outside the range acceptable for drinking <br /> water. MCC has completed two wells in the Rollins Sandstone to <br /> monitor water levels and provide water quality data. Based on <br /> 38 <br />