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2009 AHR McClane & Munger Canyon Mines Page 3 <br />Additionally, a piezometer installed down dip from the mine outside of the graben has <br />not realized water to date. Since the piezometer is down-dip and is dry it is apparent <br />water flowing into the mine is from a perched aquifer in the area of the coal mine. <br />The water within the perched aquifer flowing into the mine probably comes from surface <br />water infiltration along the faults east and west of the mine. Both faults have ephemeral <br />drainages crossing their surface trace. These faults may be one source of recharge to <br />the perched aquifer. The water then infiltrates the coal seam which has become <br />saturated over time. This assumption is supported by the previously documented <br />cyclical nature of water inflow corresponding with periods of precipitation. <br />Future Water Inflow <br />All future mine development is currently projected to the south where the coal seam is <br />relatively dry. Since most of the water generated in the mine comes from the sealed <br />areas in the north the water inflow should be relatively constant or slowly decreasing. <br />As shown on Figure 4.2-3, the saturated strata appear to outcrop in the valley formed by <br />the north split of Munger Canyon. Since the strata in the area dip at four percent to the <br />northeast, water may be infiltrating the seam along the valley bottom. Any water <br />infiltrating the strata at this location will flow down dip until the aquifer is totally saturated <br />unless there is an area where water may escape. The elevation of the saturated zone <br />would approximate the elevation of the outcrop (5,600 ft) if no water flows out of the <br />strata at a lower elevation. There are no known springs or seeps that would allow <br />escape of the water from the zone of saturation so it can be expected the coal seam will <br />be saturated near the outcrop elevation. <br />Munger Canyon Mine <br />The Munger Mine has been sealed and the disturbed areas were graded and seeded in <br />2007. There was no water encountered in mine; therefore, there has been no effect on <br />the hydrologic regime of the area. The current mine workings are shown on Figure 4. <br />Precipitation <br />Based upon Bureau of Land Management records from a rain gage in Ashford Canyon, <br />the 2009 water year experienced 9.18 inches of precipitation compared to average <br />precipitation of 17.61 inches. The rain gage is not located at the mine but about 3.5 <br />miles north at an elevation of 5895 feet compared with 5610 at the portals. The daily <br />rainfall record is detailed on Table 2. The greatest 24 hour precipitation event during the <br />water year, 0.95 inches, occurred on December 25'. Figure 2 presents a graphical <br />comparison of the 2009 water year total monthly precipitation and the average monthly <br />precipitation for the period 1977 through 2009. Precipitation data are obtained from the <br />BLM (Nathan_Dieterich@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 effect on <br />the quantity or quality of the surface waters near either mine sites has occurred. As the <br />Division notes in its approval package for the Munger Canyon Mine, the total area that