2007-06-29_PERMIT FILE - C1981022A (2)

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Section - 2.05.3 F. Substation No. 4 and Powerline -Anew substation will be established to provide power • for both the mine power system and ancillary support equipment including mine fans, pumps, and conveyor drives. The substation, to be located in the upper portion of the Elk Creek Mine portal bench azea, will consist of a concrete slab foundation, grounding field, control building, support structures, transformers, control and switching equipment, and a chain-link security fence with locking access gate. A power distribution line tying to the main Delta-Montrose Electric transmission line will run up the west side of Ells Creek Canyon to supply power to the new substation. G. Mine Dewatering Wells and Underground Sump - A series of mine dewatering wells will be drilled fzom the surface prior to initiation of mine development work to allow dewatering of the D Coal Seam ahead of development and to provide for future discharge from a mine water collection sump. It is currently anticipated that four wells will be required ranging in depth from 15 to 200 feet in depth. The wells will be located along a line extending from south of the portal azea to the northeast corner of the Elk Creek portal bench, near the stratigraphic low point of the future D Seam Mine Dewatering Sump. The wells will be completed as 6- to 8-inch cased boreholes with perforated casing in and immediately above and below the D Seam with high-capacity submersible pumps. Initially, the pumps will draw directly from the D Seam and dischazge directly to Elk Creek, since water recovered directly from the D Coal Seam should meet applicable effluent standazds without further treatment. During mine development, four entries will be driven to the north in the coal seam to create a underground sump for mine water inflows. The sump will allow collection and temporary storage of mine water to allow suspended solids to settle out prior to recycling or dischazge. H. Water Storage and Head Tank - A water storage and head tank will be constructed in the upper portion of the Elk Creek Mine portal bench to both supply both water to meet mine operational requirements and as a storage tank for mine dewatering flows. The tank will be apre-fabricated steel tank mounted on a reinforced concrete slab foundation. The tank will be filled by pipelines from either the main water storage tank, located neaz the Somerset Cemetery, of the Elk Creek Mine dewatering wells or sump. In conjunction with tank construction, a pipeline with booster pump(s) will be constructed along the Elk Creek conveyor alignment from the main water storage tank. The tank will also be equipped with water level sensors, discharge valves, and an automatic overflow protection cutoff valve on the tank fill lines. A pipeline from the first dischazge valve will be routed through one of the mine ventilation shafts or a borehole to supply the mine water system. A pipeline from the second dischazge valve will empty to a short ripped channel segment adjacent to the Elk Creek channel providing energy dissipation and erosion control for the dischazge of any excess mine dewatering flows. The dischazge from the tank to Elk Creek is permitted as a CPDES discharge point subject to monitoring when discharge occurs. I. Foreman's Office and Lamp House -Two portable trailers will be utilized as a foreman's office and lamp house facility for the Elk Creek Mine. The two trailers will be located on the portal bench north of the mine portals and will be connected to Substation No. 4 for electrical power. Similaz to the existing lamp house facility, the lamp house will be used Eor miner check-in and check-out, as a waiting area Eor shift-change, and will house a miner's lamp service and repair azea, • TR-49 2.05-23 Revised]anuary 2005