2020-03-24_PERMIT FILE - C1981019A (2)

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RULE 2 PERMITS Suitability analysis for Drill Hole 83-D3-14 shows all criteria within the suitable range. After removal of the overburden, the coal seams are exposed. As the coal seams are exposed, they are cleaned using auxiliary equipment, then either drilled and shot with explosives or ripped to prepare the coal for loading and removal. When explosives are needed, the drilling is performed by an auger drill. The drill hole pattern is generally spaced approximately 12 feet by 12 feet, but is dependent upon the actual coal seam thickness. Drill holes are loaded with either ANFO or a waterproof explosive, if the holes are wet. Once the coal has been prepared for loading by blasting or ripping, a rubber -tired front-end loader loads the coal into haulage trucks. Following loading, these haulage trucks transport the coal along in pit haulage routes to the primary crusher located just outside of the mining area as shown on the Existing Structures - South Map (Map 22). In order to visualize the overall mine plan, a range diagram was drawn. This diagram is found as Mining Range Diagram (Map 2413) and depicts operations by draglines in combination with shovels and trucks. Coal from the mining area is transported to a coal crushing facility as shown on the Existing Structures - South Map (Map 22). Details of the coal crushing and load -out facilities are included in Volume 1, Section 2.05.3 under the heading of Mine Facilities. After coal recovery by conventional truck/shovel and dragline methods has reached the maximum economical recovery limit, Colowyo has the potential of using a highwall miner when the conditions allow. The highwall miner can recover additional reserves left in the pit face that were deemed non- recoverable by conventional surface mining methods. This new highwall miner technology can recover coal up to 1600 feet in advance of the final pit walls with an approximate coal recovery ratio of 40% to 60%. Once the coal has been recovered and stockpiled in the pit, then the coal will be transported to the primary crusher and train loadout by coal haul trucks. Refer to Map 23A for the location of potential highwall mining areas. As soon as possible after the coal is removed from the mining area and sufficient room is available for back -filling, reclamation begins. In general, rough backfilling is completed by the over -burden trucks and bulldozers. As stated earlier, overburden material removed ahead of the operation is transported by truck around the active coal mining areas and deposited into the mined -out and stockpile areas. A dragline may also be utilized on the backfill material to assist in final spoil placement and in achievement of the planned final topography. Final grading for topsoil placement will be done in a manner that reduces erosion and provides a surface for topsoil that minimizes slippage. Prior to completion of topsoil replacement on 3:1 (horizontal to vertical) slopes, a dozer will construct a drainage control bench or furrow, where necessary, to slow water flow on the longer slopes and minimize erosion. The design Calculations for the benches and furrows are found in Exhibit 7, Hydrology Information. At the completion of the final grading, topsoil will be redistributed over the regraded spoil and revegetated in accordance with Volume 1, Section 2.05.4. Other surface treatments are also described in Volume 1, section 2.05.4. A list of the equipment used by Colowyo in order to perform the day-to-day operation of coal mining is shown in Volume 1, Table 2.05- 3. South Taylor/Lower Wilson — Rule 2, Page 71 Revision Date: 4/7/17 Revision No.: RN -07