2015-03-12_PERMIT FILE - C1981014A (6)

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EFCI controls mine inflows by utilizing a series of sumps, high capacity submersible pumps, and water lines to transfer water from active workings to abandoned mine areas. The primary areas where significant underground mine inflows are currently occurring are the 2-North Mains and the abandoned 1-North section. EFCI has also experienced large volume inflows in the south submain area. However, inflows occurred over a limited period of time and have not been persistent. Inflow sources for the above mine areas appear to be abandoned old workings above and/or up-dip of the Southfield Mine, and other limited perched aquifers. The 1-North section has been utilized as an underground sump since 1984, receiving pumped dewatering flows and local groundwater inflow, with subsequent discharge to the surface via the North Dewatering Well. Water discharged by the North Dewatering Well has reported to Clean Water Pond No. 3, then into EFCI's surface water handling system described in Section 2.05.6. As a result of water rights issues pertaining to consumptive use of water pumped from within the Southfield Mine, EFCI ceased use of the North Dewatering Well in 1994 and subsequently transferred all mine inflows to abandoned downgradient workings in the westend of the mine. EFCI eliminated use of the North Dewatering Well by curtailing pumped inflows into the 1-North Section and creating a hydraulic connection between 2-North Mains and the lower end of 1-North. Water drained from 1-North into the 2- North Mains, as described above, and flowed to the north and west, filling abandoned mine workings. When the water level rose into the active working areas of the 2-North Mains, existing high capacity pumps discharged the excess water through water lines installed from 2-North into the Main Entries, where it flowed downgradient into abandoned areas of the West Mains. MR-50 2.05.3-12 Revised -June 2003