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Coal was produced by bottom mining in 001 North Section until <br />• November of 1991. The rock slopes to the upthrown block of coal <br />through the east fault were completed. Coal was then mined from the <br />area east of the rock slopes during December. No water was <br />encountered while mining the rock slopes. <br />Mine Water Inflow / Dischartte <br />No water has been discharged from the mine end no flow into the mine <br />has been noted this year. Previous hydrologic reports have given <br />evidence 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 NPDB5 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 />Bast 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 0.60 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. Water is now being trucked to the mine. Table 1 gives <br />a month by month total of the water trucked to McClane Canyon. <br />As discussed in 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 Bast 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. The lower <br />elevation areas are undoubtedly still experiencing an inflow of <br />water. The volume of the sealed workings is now about 124 million <br />gallons. At the rate of inflow being experienced in 1990, 3.9 <br />gallons per minute, it would take about 60 years for the sealed area <br />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 1/29/93 <br />