Laserfiche WebLink
• <br />West Elk Mine <br />Prior to 1996, all of this statement was true for the West Elk Mine. Because of fault system inflows <br />encountered in the eastern portion of the mine, MCC now adds: "Inflows associated with fractures <br />and faults may initially produce inflows of up to 8;000 gpm from more extensive fracture/fault <br />systems, which significantly reduce in inflow rate over time to one thought to be the constant <br />recharge rate." <br />5. "Generally, springs in the permit area seem to act independently of the bedrock water and <br />appear to be surface features related to weathered and fractured bedrock. Flows from these <br />springs tend to be highly ephemeral and only discharge during spring snowmelt. These springs <br />recharge and discharge in relatively small areas. Inflows from faults and fractures located <br />outside spring valleys generally dry up with time or flow intermittently at discrete points along <br />the fault or fracture." (p. 20-21). <br />Spring data from both the Apache Rocks and Box Canyon permit revision areas confirm this <br />statement. <br />6. "There are no immediate demands on groundwater in the vicinity of the West Elk Mine. <br />Domestic water for the mine will be supplied by surface water from the North Fork of the <br />Gunnison River." (p. 28). <br />This continues to be the case as of November 1998. Furthermore, given the local hydrogeology, <br />and with the exception of the alluvial aquifers along the North Fork and Minnesota Creek (including <br />the Dry Fork), groundwater could not realistically be utilized (due to lack of water and cost), or <br />unless a direct tap into either the B East Mains or 14SE Headgate faults occurs. As of the time of <br />this writing, MCC knows of no such use of this water. <br />7. "The permeability of the F and B -Seams and overlying strata is very low and the areal extent <br />and quantity of ;water stored in these units is small. (p. 28). MCC has conservatively estimated <br />that the B -Seam mine, including the Jumbo Mountain panels, and existing F -Seam mine would <br />fill in 139.6 years. This estimate assumes no seepage or outflow and the worst case maximum <br />steady inflow for the F -Seam mine and the median of the five-year and life of the mine worst <br />case maximum steady inflows for the B -Seam. mune." (p. 29). <br />Based on average inflows observed in 1997 resulting from fault system inflows in the eastern <br />portion of the mine (approximately 410 gpm), the same assumptions utilized for the Jumbo <br />Mountain permit revision (no outflow and steady, "worst case" inflow), MCC has determined that <br />an extremely conservative estimate for the time to fill the West Elk Mine, including the B and E - <br />Seams in the Apache Rocks mining area and the B -Seam in the Box Canyon mining area would be <br />approximately 52 years, or approximately 107 years at an average inflow rate of 200 Pin. The <br />basis for this computation is provided in Section 2.05.6. <br />"Reprrser_tati�,c water quality samples from ;yells located inn ti__ .rennber of the <br />Mesaverde. Fon nnlation show that groundwater is suitable for discharac to the North Fork." (p. <br />29). <br />2.05-178 Revised June 200.1 PRIG, January 1006, March 2006: Rev. Ala), 2006 PRIO, Alov. 2006 TRIO Sep. 2007 PR12:Feb 2008 PRI2 <br />