Laserfiche WebLink
Section - 2.05.3 <br />F. Substation No. 4 and Powerline - A new substation will be established to provide power <br />for both the mine power system and ancillary support equipment including mine fans, <br />pumps, and conveyor drives. The substation, to be located in the upper portion of the Elk <br />Creek Mine portal bench area, will consist of a concrete slab foundation, grounding field, <br />control building, support structures, transformers, control and switching equipment, and a <br />chain -link security fence with locking access gate. A power distribution line tying to the <br />main Delta- Montrose Electric transmission line will run up the west side of Elk Creek <br />Canyon to supply power to the new substation. <br />G. Mine Dewatering Wells and Underground Sump - A series of mine dewatering wells will be <br />drilled from the surface prior to initiation of mine development work to allow dewatering <br />of the D Coal Seam ahead of development and to provide for future discharge from a mine <br />water collection sump. It is currently anticipated that four wells will be required ranging in <br />depth from 15 to 200 feet in depth. The wells will be located along a line extending from <br />south of the portal area to the northeast corner of the Elk Creek portal bench, near the <br />stratigraphic low point of the future D Seam Mine Dewatering Sump. The wells will be <br />completed as 6- to 8 -inch cased boreholes with perforated casing in and immediately above <br />and below the D Seam with high- capacity submersible pumps. Initially, the pumps will <br />draw directly from the D Seam and discharge directly to Elk Creek, since water recovered <br />directly from the D Coal Seam should meet applicable effluent standards without further <br />treatment. <br />During mine development, four entries will be driven to the north in the coal seam to <br />create a underground sump for mine water inflows. The sump will allow collection and <br />temporary storage of mine water to allow suspended solids to settle out prior to recycling <br />or discharge. <br />H. Water Storage and Head Tank - A water storage and head tank will be constructed in the <br />upper portion of the Elk Creek Mine portal bench to both supply both water to meet mine <br />operational requirements and as a storage tank for mine dewatering flows. The tank will be <br />a pre- fabricated steel tank mounted on a reinforced concrete slab foundation. The tank <br />will be filled by pipelines from either the main water storage tank, located near the <br />Somerset Cemetery, or the Elk Creek Mine dewatering wells or sump. <br />In conjunction with tank construction, a pipeline with booster pump(s) will be constructed <br />along the Elk Creek conveyor alignment from the main water storage tank. The tank will <br />also be equipped with water level sensors, discharge valves, and an automatic overflow <br />protection cutoff valve on the tank fill lines. A pipeline from the first discharge valve will <br />be routed through one of the mine ventilation shafts or a borehole to supply the mine <br />water system. A pipeline from the second discharge valve will empty to a short ripped <br />channel segment adjacent to the Elk Creek channel providing energy dissipation and <br />erosion control for the discharge of any excess mine dewatering flows. <br />Foreman's Office and Lamp House — The two story pre - engineered steel building <br />Foreman's Office and Lamp House is located on the portal bench north of the mine <br />portals and is connected to Substation No. 4 for electrical power. The facility will be used <br />for miner check -in and check -out, as a waiting area for shift - change, houses a miner's lamp <br />service and repair area and foremen's offices. <br />TR -68 2.05 -23a Rev. April 2010 <br />