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Mine Water Inflow / Discharge <br />No water has been discharged from the mine and no flow into the mine <br />has been noted this year. Previous hydrologic reports have shown <br />that the inflow of water to the mine can be attributed to <br />dewatering of a perched aquifer as well as surface water <br />infiltration along the faults of the graben. During idle years a <br />clear picture of mine water inflows was obtained because water that <br />collected in the faces was regularly pumped to NPDES point 002 and <br />discharged. The quantity of water discharged was recorded on a <br />meter and a correlation with precipitation was made. The steady <br />decrease in the amount of water pumped from the mine during the idle <br />years is evidence of the creation of a dewatered zone in the <br />saturated coal strata. The decrease is also evidence that there is <br />little communication with the comparatively large aquifer within the <br />East Salt Creek alluvium across the west fault of the graben. <br />When mining resumed, additional area in the saturated portion of the <br />graben was opened, increasing the flow of water into the mine. The <br />inflow of water went from a low of 0.80 gpm in 1988 to a high of <br />3.87 gpm in 1990. Water flowing downdip into the faces was pumped <br />to the sump and used. On April 27, 1990 Section 001 was abandoned <br />and sealed. Since then all water necessary for operations has been <br />trucked to the mine. Table 1 gives a month by month total of the <br />water trucked to McClane Canyon. Since no production occurred in <br />1993, there was only 10,000 gallons of water imported for use at <br />the mine. Additionally, 4,500 gallons of potable water was trucked <br />to the site for the mine offices. <br />As discussed is previous reports, the area in the mine that created <br />water was sealed in 1990 and no water has been produced in other <br />areas of the mine since then. In July of 1992 all areas to the <br />north of the East Mains were sealed and are now inaccessible. <br />Figure 1, McClane Mine Map, shows the location of the seals; as well <br />as, the area of the mine that is not accessible. These areas are <br />lower in elevation than active areas are undoubtedly still <br />experiencing an inflow of water. The volume of the sealed workings <br />is now about 124 million gallons. At the rate of inflow being <br />experienced in 1990, 3.9 gallons per minute, it would take about 60 <br />years for the sealed area to fill with water. <br />Only then will the mine realize a detectable inflow of water from <br />the areas that had been making water previously. It is possible <br />that water will be encountered as the mine extends farther to the <br />east and then north as shown in Figure 2.1.1 of the permit <br />application. Additional water may be infiltrating the seam in the <br />valley formed by the north split of Munger Canyon. If water is once <br />again encountered, its existence will be documented and detailed in <br />future reports. <br /> <br />Page - 2 1/19/94 <br />