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2012 AHR <br />McClane & Munger Canyon Mines <br />Page 4 <br />Future Water Inflow <br />When mining resumes development will be to the south where the coal seam is <br />relatively dry. Since most of the water generated in the mine comes from the <br />sealed areas in the north the water inflow should be relatively constant or slowly <br />decreasing. <br />As shown on Figure 4.2 -3, the saturated strata appear to outcrop in the valley <br />formed by the north split of Munger Canyon. Since the strata in the area dip at <br />four percent to the northeast, water may be infiltrating the seam along the valley <br />bottom. Any water infiltrating the strata at this location will flow down dip until the <br />aquifer is totally saturated unless there is an area where water may escape. The <br />elevation of the saturated zone would approximate the elevation of the outcrop <br />(5,600 ft) if no water flows out of the strata at a lower elevation. There are no <br />known springs or seeps that would allow escape of the water from the zone of <br />saturation so it can be expected the coal seam will be saturated near the outcrop <br />elevation. <br />Munger Canyon Mine <br />The Munger Mine has been sealed and the disturbed areas were graded and <br />seeded in 2007. There was no water encountered in mine; therefore, there has <br />been no effect on the hydrologic regime of the area. The current mine workings <br />are shown on Figure 4. <br />Precipitation <br />Based upon Bureau of Land Management records from a rain gage in Ashford <br />Canyon, the 2012 water year experienced 9.52 inches of precipitation compared <br />to average precipitation of 17.42 inches. Water year 2012 was an extreme <br />drought year for the grand valley and the state of Colorado. The rain gage is not <br />located at the mine but about 3.5 miles north at an elevation of 5895 feet <br />compared with 5610 at the portals. Figure 2 presents a graphical comparison of <br />the 2012 water year total monthly precipitation and the average monthly <br />precipitation for the period 1977 through 2012. Precipitation data are obtained <br />from the BLM (NDieteri @blm.gov). <br />Effect of the Mine on the East Salt Creek Regime <br />Surface Water <br />Due to the limited disturbance of the mines there is little chance any significant <br />effect on the quantity or quality of the surface waters near either mine sites has <br />occurred. As the Division notes in its approval package for the Munger Canyon <br />Mine, the total area that will be disturbed by both mine sites amounts to 0.12 <br />percent of the area of the East Salt Creek drainage basin above the mines. <br />Surface water samples from East Salt Creek were obtained all four quarters <br />during the water year at monitoring station SW -1 and SW -8. The results from all <br />water samples collected during the water year are presented in Table 4. Due to <br />