2015-07-01_REPORT - C1980007 - Laserfiche WebLink

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West Elk Mine 2014 Annual Hydrology Report 36 hourly data, and to ensure that the loggers are submerged and in the shade when possible. The temperature data loggers are downloaded to a laptop computer on a monthly basis, except when access is prevented by excessive ice or by dangerously high flows. 4.0 MINE WATER MANAGEMENT ACTIVITIES The mine water management activities (water balance) pertains to the water flows into and out of the mine and mine site, and include fresh water intake (appropriated diversions) from the North Fork, and discharges of treated sanitary wastewater, sedimentation ponds, and mine water inflows. The individual components associated with the mine water balance are discussed below. 4.1 Mine Water Balance The mine water balance was developed as a tool for management to quantify the water entering and leaving the mine and mine site. The WY 2014 mine water balance (MCC, 2015) is summarized below and illustrated on Figure 10. Inflows (water entering the mine site and mine) include: • Raw water intake from North Fork of the Gunnison River diversion (including 6.1 ac -ft to the CPP and 263.2 ac -ft to the 1.2 million gallon (MG) raw water tank into the mine): 315.8 ac -ft; • Mine Inflows (from faults, coal partings, roof, etc.): 30 ac -ft • Total Inflows = 345.8 ac -ft Outflows (water exiting the mine and mine site) include: • Water in mined coal and gob: 98 ac -ft • Water used in CPP: 6.1 ac -ft • Water used for surface operations (e.g. dust control and wash down): 70 ac -ft • Mine sump discharge via MWPF: 0 ac -ft • WWTP discharges: 8.8 ac -ft • Miscellaneous mine seepage and evaporation: 10 ac -ft • Evaporation from all ponds: 35 ac -ft • Moisture taken into ventilation air: 90 ac -ft • Treated water usage: 11.5 ac -ft • Runoff from surface operations\pond discharge: 0 ac -ft • Total Outflows: 329.4 ac -ft The total inflows entering the mine and mine site during WY 2014 were 345.8 ac -ft versus total outflows of 329.4 ac -ft, resulting in a net difference of 16.4 ac -ft. For the most part, fault water inflows accumulated in the sealed sumps, including the B North Panels sealed sump. June 2015 HydroGeo, Inc.