Laserfiche WebLink
2.05.6(3) Protection of the Hydrologic Balance <br />• The Operator originally believed the source of the contaminants was the coal stockpile. <br />However, with the emergence of the spring which is near the location of AA1, it is probable <br />that the quality of water in alluvial well AA1 has been degraded by the spring water since <br />1986. <br />The mine portals were sealed on January 9, 1997. On November 17, 1997 the DMG was <br />notified of a slide that is located immediately west of the reclaimed Bear No. 3 Mine portals. <br />The slide became active on Saturday, November 15th. Debris from the slide flowed onto <br />the old coal stockpile pad (west of the the reclaimed stacking tube) and into the North Fork <br />of the Gunnison River south of the mine access bridge. Shortly after the slide occurred, <br />water started to flow from the east side of the slide scarp. <br />Some water could eventually accumulate in the mine workings and result in mine water flow <br />through the coal seams into the North Fork of the Gunnison River. Although the Operator <br />does not believe either the B-Seam or the C-Seam will become totally inundated with water, <br />a worst case analysis was prepared to estimate the seepage from the coal seams. Darcy's <br />Law was utilized to estimate the seepage from the coal seams as follows: <br /> Darc 's Law O=Kia <br />Floode K -cm/sec H- w -width h- L- I- O -GPM <br />d Head of coal Seam Outcro H/w <br />Workin pillar Heigh p <br /> t Len th <br />B 4 X 10-6 30 309 20 4223 0.1 0.5 <br />Seam <br />B 5 X 10-5 30 309 20 4223 0.1 6.0 <br />Seam <br />C- 4 X 10-6 75 159 8 3964 0.47 0.9 <br />Seam <br />C 5 X 10-5 75 159 8 3964 0.47 11.0 <br />Seam <br />Area=hxL <br />K is from MCC's TR-080 documents and provides a range of seepage rates. <br />The Operator's existing discharge permit provides for the discharge of water directly to the <br />North Fork of the Gunnison River through outfall 001. The spring water discharge initially <br />flowed at approximately 20 gpm. As of April 1998, the flow increased to about 35 gpm. <br />During 2001 the flow from the treatment pond averaged about 16 gallons permit minute with <br />2.05-55b Rev. 1/03 <br />/1t R-a5 <br />CRN-oy~ <br />/al /PRovED ri//ylo3 <br />