2014-07-11_REPORT - C1980007 - Laserfiche WebLink

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West Elk Mine 2013 Annual Hydrology Report 39 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 of the Gunnison River, and discharges of treated sanitary wastewater, sedimentation ponds, and mine water inflows. The individual components associated with the mine water balance are discussed below and illustrated in Figure 9. 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 2013 mine water balance (MCC, 2014) is summarized below and illustrated on Figure 9. Inflows (water entering the mine site and mine) include: • Raw water intake from North Fork of the Gunnison River diversion (including 19.5 ac -ft to the CPP and 247.6 to the 1.2 MG raw water tank into the mine): 314.2 ac -ft; • Mine Inflows (from faults, coal partings, roof, etc.): 35 ac -ft • Total Inflows = 349.2 ac -ft Outflows (water exiting the mine and mine site) include: • Water in mined coal and gob: 94.8 ac -ft • Water used in CPP: 19.5 ac -ft • Water used for surface operations (e.g. dust control and wash down): 50 ac -ft • Mine sump discharge via MWPF: 0 ac -ft • WWTP discharges: 10.7 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: 12.1 ac -ft • Runoff from surface operations \pond discharge: (0 +0 +0 +0 +0 +3.2) = 3.2 ac -ft • Total Outflows: 325.3 ac -ft The total inflows entering the mine and mine site during WY 2013 were 349.2 ac -ft versus total outflows of 325.3 ac -ft, resulting in a net difference of 23.9 ac -ft. For the most part, fault water inflows accumulated in the sealed sumps, including the B North Panels sealed sump. June 2014 HydroGeo, Inc.