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the faults of the graben. During the mid 1980's, a clear picture of mine water inflows was <br />obtained because water that collected in the faces was regularly pumped to NPDES point <br />OU2 and discharged. The quantity of water discharged was recorded on a meter and a <br />correlation with precipitation was made. The steady decrease in the amount of water <br />pumped from the mine during the idle years is evidence of the creation of a dewatered <br />zone in the saturated coal strata. This decrease also provides evidence that there is little <br />communication with the comparatively large aquifer within the East Salt Creek alluvium <br />across the west fault of the graben. <br />When mining resumed, additional area in the saturated portion of the graben was <br />exposed, increasing the flow of water into the mine. The inflow of water went from a <br />low of 0.80 gpm in 1988 to a high of 3.87 gpm in 1990. Water Flowing down dip into the <br />faces was pumped to the sump and used in the mining process for dust control. On April <br />27, 1990, Section 001 was abandoned and sealed. <br />A small amount of water was trucked to the mine for supply road dust suppression <br />starting in October 1999 prior to production. When production resumed in February <br />2000 the demand increased to approximately 373,000 gallons per month. In April 2000 <br />water started flowing from the mining faces developing to the East. To keep up with <br />production demands, a sump was established and the section was moved to the south. <br />This inflow from the East faces is now pumped to the sump and again used in the mining <br />process for dust control thus not requiring any water to be trucked to the mine. The <br />inflow of water in the East faces is approximately 8.33 gpm based on the mine's demand <br />for water. Table I gives a month by month total of the water trucked to McClane <br />Canyon. Table 6 gives quality results of mine inflow. <br />As discussed in previous reports, the area in the mine that experienced an inflow of water <br />was sealed in 1990. In July of 1992 all areas to the north of the East Mains were sealed <br />and are now inaccessible. Figure 3, McClane Mine Map, shows the location of the seals; <br />as well as, the area of the mine that is not accessible. The sealed area is lower in <br />elevation than accessible areas of the mine but is undoubtedly still experiencing an inflow <br />of water. The volume of the portion of the mine behind the seals is equivalent to about <br />124 million gallons. At the rate of inflow being experienced in 1990, 3.9 gallons per <br />minute, it would take about 60 years for the sealed area to fill with water. Only then will <br />the mine realize a detectable inflow of water from the areas that had been making water <br />previously. <br />Source of Water Inflow <br />As detailed in previous reports, the tivater 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 />2 <br />