2019-11-27_PERMIT FILE - M2019058 (10)

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D-3 The plant facilities are to be situated in a high-elevational area (nominal elevation of approximately 4,850 ft.amsl)in the extreme northwest portion of the Permit Area. All drainage run-off from this area will be directed toward the pit floor depression(nominal 30-ft. mining depth),where drainage will be dispersed through natural infiltration into the underlying sand and/or silt materials which will comprise the pit floor. Thus, there will be neither drainage-related impoundments nor active "impounding" of drainage flow. Potential up gradient run-on from the area of concentration to the west of the Permit Area is diverted and/or limited by the presence of Weld County Road 59,which extends south to north at this location. Potential run-on from the area of concentration to the south is naturally precluded or otherwise diverted by a series of topographic highs, and the intervening presence of an unnamed draw that is tributary to Ennis Draw. Thus,any run-on contributions from the south are effectively diverted into the Ennis Draw topographic low. Areas to north and east are generally lower elevation areas, and therefore, largely downgradient. Thus,drainage considerations within the confines of the defined mineable blocks(areas) within the overall Permit Area are generally limited to footprint precipitation accumulations, again subject to rapid and high infiltration, given the characteristics of the eolian sand deposit within which mining operations will be carried out. Accordingly, the Keenesburg Project will function as a"zero- discharge" facility. All operational areas will be incorporated into the facility's Storm Water Management Plan (SWMP), as a component of the required Colorado Discharge Permit System (CDPS) Storm Water General Permit. (d) The size of area(s)to be worked at any one time; The typical annual mine block is anticipated to be on the order of 100 to 110 acres in areal extent (annual mine blocks range from 91 to 132 acres under current mine planning parameters). However, the actual active mining area(face area)will encompass only a fraction of that annual area. Generally, the active face area will be on the order of 20 to 30 acres in areal extent, sufficient to allow routine operational flexibility in excavating, loading, and hauling activities, while minimizing overall actual disturbance. At any given time, the maximum area of disturbance will include: the active face area, up to the full extent of a typical annual mining block(for which CSC has conservatively estimated to be a nominal 125 acres in area); the previously mined out blocks, consisting of(up to) five(mine block)years, the Keenesburg No. 2 Mine_112 Reclamation Operation—November 22, 2019