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2001 AHR McClane & Munger Canyon Mines Page 3 <br />Source of Water Inflow <br />As detailed in previous reports, the water flowing into the mine seems to be a mix of <br />water infiltrating the graben along the faults and water in the coal seam. The zone of <br />saturation of the coal seam was initially estimated using the results of exploration <br />drilling. The drilling indicated that holes in the McClane graben were dry; specifically, <br />holes 7-15-3 and 7-21-1. <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 />As the mine extends farther to the east and then north as shown in Figure 2.1.1 of the <br />permit application, it is proven that water will be encountered. Figure 4.2-3, of the <br />permit application, shows the saturated strata may again be encountered approximately <br />400 feet ahead of where mining stopped in 1997. During 2000 this saturated strata was <br />encountered about 600 feet ahead of where mining stopped in 1997. This location is <br />near the eastern edge of Figure 3, Mine Map, at about cross-cut 32 in the Main East <br />Entries. The mine plans are to develop to the east and then to the north during 2002 so <br />additional mine inflows/seeps may be encountered. <br />As shown on Figure 4.2-3, the saturated strata appear to outcrop in the valley formed <br />by the north split of Munger Canyon. Since the strata in the area dip at four percent to <br />the 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. The elevation of the existing faces is approximately 5610 ft. <br />There are no known springs or seeps that would allow escape of the water from the <br />zone of saturation so it can be expected the coal seam will be saturated near the <br />outcrop elevation. <br />MONGER CANYON MINE <br />The Munger Mine has been sealed and it is not expected to be reopened. There was <br />no water encountered in mine; therefore, there has been no effect on the hydrologic <br />regime of the area. The current mine workings are shown on Figure 4. Table I <br />documents that water was used at the mine this year for dust control. <br />