2018-07-09_PERMIT FILE - C1981019A (24)

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RULE 2 PERMITS deemed non-recoverable by conventional surface mining methods. This new highwall miner technology can recovery coal up to 1600 feet in advance of the final pit wall 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 23 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, scrapers, and bulldozers since the operation has reached a "steady state, " as shown on the Mining Range Diagram (Map 24). 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 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. Following the completion of mining, temporary overburden stockpiles will be removed and placed back into the open pit. Specifically, the top 75 feet of the temporary overburden stockpile known as "Hink's Peak" will follow this same removal and replacement within the north end of the West Pit. This will be performed by removing the Bucyrus 130OW Dragline (102) out of the West Pit Mining Sequence and walking it north into North Taylor draw and onto "Hink's Peak" via previously constructed lifts. Dozers will assist the dragline in grading this temporary overburden pile and the surrounding tail -dump areas of the West Pit. The final grade of the slopes will approximate the pre -mining topography (See Pre -mining Topography Map (Map 18), Post -mining Topography Map (Map 19) and Pre -mining and Post -mining Cross Sections (Map 20)). 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 Section 2.05.4. Other surface treatments are also described in 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 Table 2.05-3, Equipment List. Operation Description A detailed narrative description of the land to be affected within the permit area is provided' above under the heading Production Methods and Equipment. The mining plan is graphically portrayed on the Mine Plan Map (Map 23). The various acreages to be affected by the planned mine operation are shown in Section 2.03 on Table 2.03-1, Affected Areas for Mining and Reclamation. The details of these operations are shown on the Mining Range Diagram (Map 24). The lines on Map 23 refer to coal seam mining, the lines on Map 28, Topsoil Handling, refer to the anticipated overall disturbance that not only includes coal mining, but also associated perimeter disturbances as well. These disturbances include the upper truck/shovel cuts above the "X" seam, all ramps associated with the pit, and the yearly topsoil advance. Rule 2 Permits 2.05-5 Revision Date: 5/25/18 Revision No.: RN -07