2020-06-25_REVISION - C1981019 (6)

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RULE 2 PERMITS Total Percentage of each criteria for Truck Shovel Sequence: SAR=47.9 feet/326.8 feet= 15% Se =0.3 feet/326.8 feet=0% B =N/A Sat=N/A Mo=22.7 feet/326.8 feet= 7% Suitability analysis for Drill Hole 83-D3-12 shows all criteria within the suitable range. Drill Hole 83-D3-14 Unsuitability range in feet of Truck Shovel Sequence: SAR> 15 =N/A Se > 0.3 =N/A B >5.0=22.5 feet Sat<25 or>80=N/A Mo> 1.0=6.0 feet Total Depth from surface to Bottom of Truck Shovel Sequence (176) =212.0 feet Total Percentage of each criteria for Truck Shovel Sequence: SAR=N/A Se =N/A B =22.5 feet/212.0 feet= 11% Sat=N/A Mo=6.0 feet/212.0 feet=3% 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 24B) 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- South Taylor/Lower Wilson—Rule 2,Page 69 Revision Date: 6/22/20 Revision No.: MR-220