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is the stock tanks fed by windmills which are used for <br /> livestock watering. Livestock utilize the area from June 1 to <br /> October 15 annually. No accurate records are available on <br /> completion depths of the windmills. Based on geologic logs in <br /> the vicinity of the windmills, coal seams at a depth of 100 to <br /> 150 feet supply water. The windmills do not enter the Apache, <br /> Allen or Maxwell Seam workings. Since predicted subsidence as <br /> a result of longwall mining will subside plastically rather <br /> than fracturing of inherent materials it is not likely <br /> instantaneous dewatering of overlying wells and springs will <br /> occur. The potential exists for zones presently producing <br /> water to be rendered non-functional because of settling. <br /> Assuming the worst case of dewatering of all windmills and <br /> springs, surface impoundments could be constructed capturing <br /> surface runoff or windmills could be redrilled after the <br /> subsidence effects have stabilized and a recharge zone <br /> reestablished. As previously discussed, it is Basin's intent <br /> to develop water to preserve the effective uses of rangeland <br />• and wildlife habitat. <br /> Loner-Term Impacts- Following mining, the mine workings <br /> will be flooded. Earlier in this section, it was anticipated <br /> that the maximum mine inflow within the projected mine plan <br /> would be 218.3 gpm from the coal face and roof, and at least <br /> 100 gpm from the fault. This is equivalent to 1.41 acft/day, <br /> or 514.7 acft/yr. The volume of the life-of-mine workings will <br /> be 14,302 acre feet, as acquired from an estimated area of <br /> mined out roof of 8.9 x 10' ftZ and a coal thickness of 7 feet. <br /> Thus, it will take approximately 27.8 years for the mine to <br /> flood completely. Prior to that, the mine will probably reach <br /> an equilibrium point where the water within the mine will begin <br /> to recharge the coal seam. The water levels in wells that have ~ <br /> been drawn down will rise, and seeps and springs that may have <br /> stopped flowing will begin to discharge again. <br /> The quality of the water in the mine will be comparable <br /> to the quality of water currently pumped from Golden Eagle. It <br />• will be a saline, slightly alkaline, sodium bicarbonate water <br /> of low hardness. The pH will average 8.4, the specific <br />2.05-47a (Revised oa/z7/9a) <br />