2024-09-05_PERMIT FILE - C1980007 (2)

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West Elk Mine 2.05-9 Rev. 11/04- PR11; 03/06- PR10; 07/15- MR413; 07/18- PR15, 01/24-TR152, 04/24-TR154 separate bleeders were utilized). During secondary mining, partial or full pillar extraction was completed, depending on conditions in the panel. Longwall Mining Methods MCC uses longwall mining technology to mine the B and E Seams. Longwall panel layouts consist of gate-roads driven by continuous miners, a longwall face about 1,100 foot wide, and necessary ventilation and conveyor entries, and barrier pillars. After the ventilation and gate-road entries are completed, a longwall set-up or start room is driven at the far end of the panel. Longwall equipment is moved in and assembled. Once equipment is ready, the longwall system mines the panel in a retreat fashion until it reaches the main entry barrier pillar. The equipment is then disassembled and moved to another panel. Longwall Gate-Roads Room and pillar methods are used to develop gate-road entries for the longwall mining equipment. Generally, two to five parallel entries are driven on 100 to 200 foot centers. A three- entry yield abutment design has typically been used. The size and configuration of longwall gate pillars is based on the regional geology, and depth of cover. Longwall panel barrier pillars are left to protect main entries and bleeder entries. Bleeder Entries Bleeder entries were developed to ventilate active and previously mined longwall areas until those areas were permanently sealed. Bleeder entries were connected to the main return air ventilation system. In November 2009, the main mine ventilation system for the E seam and southern B seam was converted to a blowing system that includes a “bleederless” ventilation system resulting in each panel being progressively and/or completely sealed upon completion of mining of that panel. Barrier Pillars A barrier pillar is a large block of solid coal left in place to protect active mine workings. Barrier pillars are left between longwall panels and main entries, between submains and longwall panels, or in other areas, as needed. Barrier pillars vary in size, and designs are based primarily on life- expectancy and degree of protection required for the barrier. Design criteria include depth of overburden, horizontal stresses, etc. In all cases, the dimensions of barrier pillars will be adjusted for prevailing conditions, to provide the protection for which they are intended. Mining Under Restricted Areas No major buildings, major structures, occupied dwellings, cemeteries, parks, railroads, or highways overlie the coal planned for extraction at West Elk Mine. Although two reservoirs are within the coal lease area controlled by MCC, the reserves in the E and B Seams under these reservoirs have been legally severed from the lease. As such, no mining is planned beneath any