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The rate of mine water discharge from West Elk's underground <br /> workings ranges from 0 to 2,000 gpm. The average over a year <br /> has been approximately 100 gpm. Water discharged from the <br /> mine has met NPDES criteria with periodic excursions of high <br /> alkalinity and iron. The high alkalinity caused some WET test <br /> failures in past years. MCC has worked with the WQCD and the <br /> Division to develop a solution for eliminating the alkalinity <br /> problem. As of October 8, 2008, Colorado Water Quality Control <br /> Division is reviewing past exceedances of discharge limitations <br /> for iron(potentially dissolved and total recoverable) at outfall <br /> 017. MCC has ceased mine water pumping at Outfall 017 and is <br /> investigating potential corrective measures to ensure future <br /> discharges at Outfall 017 comply with effluent limitations <br /> specified in CDPS Permit No. CO-0038776. <br /> In 1998, Mountain Coal Company performed an extensive study <br /> of the springs in the vicinity of the West Elk Mine. The study <br /> showed that nearly all the springs tapped shallow meteoric <br /> groundwater in the colluvial deposits, rather than bedrock <br /> sources. As a result of the study, a revision was made in the <br /> monitoring program, with the eighteen springs monitored to <br /> include all decreed springs and those which might have some <br /> bedrock groundwater component. Springs are also monitored <br /> three times a year for pH, conductivity, temperature, total <br /> dissolved solids, total suspended solids, total iron and total <br /> manganese. The springs, to date, show no significant trends or <br /> changes which can be associated with mining activity. Most <br /> springs are responsive to spring runoff, but flow rates are <br /> sporadic and many times do not correlate well with other seasonal <br /> parameters such as snowpack, precipitation, or streamflow. <br /> b. Surface Water Effects <br /> The West Elk Mine has installed a system of ditches and ponds for <br /> controlling sediment eroded from areas disturbed by mining activities. <br /> Drainage from undisturbed land is diverted around the site. Almost all <br /> drainage from disturbed areas is collected in ponds and treated on-site. <br /> There are several small, isolated areas where drainage is not routed to a <br /> sediment pond; in these areas, alternative sediment control methods (silt <br /> fences, mulch, etc.) are used for controlling sediment. <br /> A system of lined and unlined ditches convey water from the disturbed <br /> areas to six sedimentation ponds that have been constructed for the <br /> surface facilities area. These are: <br /> MB-3 Small lower pond <br /> MB-4 Train loadout pond <br /> MB-5E Bear pond <br /> 46 <br />