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• • L I 1.0 mining, the B West Mains were advanced to the access to the 9th Northwest Headgate Section. This included the longwall recovery room development for the 9th Northwest Panel. The section was oriented to the north and the North Jumbo Mains were driven to completion at the Lone Pine ventilation portals. The 7th Northwest Panel was developed to and connected with the Lone Pine ventilation portals. Approximately 75% of the 8th Northwest Tailgate and 70% of the 8th Northwest Headgate were completed. Longwall mining included the 5th Northwest Panel (80%), the 6th Northwest Panel, and approximately 33 % of the 7th Northwest Panel. 1.6 WATER BALANCE An accounting of water use in the West Elk Mine is presented in Table 1.6-1. Sources of water introduced into the mine are the North Fork of the Gunnison River (at the Raw Water Intake Gallery) from which water is withdrawn and placed in fresh water pond FW-l; recycled water from ponds MB-1 and MB-2R into pond FW-1; and seepage into the mine workings. Not all of the water placed into pond FW-1 is pumped into the mine. Water is withdrawn from pond FW-1 to backwash the Raw Water Intake Gallery (returned to the River), for domestic use (returned to the River after being processed through the AHIt-93 :10/OS/ I S/96(I :78pm) Monirorvig Ani~~iritt sewage treatment plant), and for miscellaneous surface activities. This WY, some water was transferred from MB-1 and MB-2R to FW-1. Some amount of the water placed into pond FW-1 is lost due to seepage from the pond and evaporation from the water surface. Water is taken from the underground mine workings by pumping of excess free water, as added moisture to the coal product and waste (gob), as added moisture to exhaust ventilation air, and perhaps by some seepage (recharge) into the surrounding formations. Mine water is pumped from a sump that collects seepage into the mine and other excess inflows (if any), and discharged into pond MB-1, or MB-2R and, if not recycled back to FW-1, is released back into the North Fork of the Gunnison River upon meeting NPDES discharge requirements. 1.7 WATER QUALITY This WY, mine water was discharged into sedimentation ponds MB-1 and MB-2R during every quarter of the year. The MB-1 and MB-2R discharges are tested for pH, total suspended solids, total dissolved solids, total iron, and oil and grease if there is a visible sheen. Biomonitoring was performed quarterly. Table 1.7-1 characterizes the water quality of discharges from MB-1 and MB-2R. These ponds also treat surface water runoff. The water is saline with TDS ranging from 560-2040 mg/l, slightly alkaline with the pH ranging from 8.0-8.8, and has moderate levels of total iron (0.16-1mg/1). 12 REVISED 10/08/96