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EFCI Southfield Mine - 2013 Annual Hydrology Report August 1, 2014 <br />due to continuing drought conditions at that time along with the elimination, from becoming <br />inaccessible, of former inflow or seep locations due to retreat mining Review of historic mine <br />inflow water quality monitoring results documented in previous AHR's indicates only minor <br />variances in inflow water quality over time. <br />2.2 Mine M�der Handling, Consumptive Use, and DjmchaMt <br />During active operations, mine dewatering systems in the mine captured most mine water inflow <br />near their sources from where it was pumped downhill to the mined -out and abandoned west and <br />north areas of the mine. Dewatering activities were discontinued after September 2001. Mine <br />inflows are anticipated to continue within the sealed mine workings and water will accumulate in <br />the lowest portions of the mined -out workings, gradually rising into other mined -out areas, until a <br />dynamic equilibrium is reached between mine water inflows and recharge of localized groundwater <br />systems. Monitor well MW-NW was established in 2003, by approved conversion of a former mine <br />dewatering well into a monitoring well, in order to detect water accumulating in the Southfield <br />mine workings (see Section 3. 1, Groundwater monitoring results). No water has been observed at <br />this well through the period of this report. <br />During the period of this report, consumptive water use occurred only from pond evaporation. <br />Ponds 4 and 5 at the mine site, and Loadout Pond L -1, held limited water from storm events <br />beginning in August, as described in Section 3.3, Surface Water Monitoring Results. Based on the <br />size and duration of pooled water in each pond, the total 2013 pond evaporation is estimated at <br />0.340 acre -feet. This quantity is slightly higher as compared to previous years due to the ponds <br />holding water from more frequent rains during the reporting period, although there was a likely <br />decrease in surface runoff from reclaimed areas due to improved vegetation establishment. <br />The source of water for any intended consumptive uses would be obtained from the towns of <br />Florence or Rockvale, and hauled by truck. No water was trucked to the site or pumped from the <br />Corley Well during 2013, and it is anticipated that future consumptive water use will be limited to <br />pond evaporation from the remaining four sedimentation ponds (Mine Site ponds 4 and 5; Loadout <br />ponds L1 and L2). Total consumptive use for 2013 is based solely on pond evaporation estimated at <br />0.340 acre -feet, shown on Table 1, Water Balance and Consumptive Use Summary. <br />The water balance shown on Table 1 compares water source withdrawals (consumptive use) with <br />discharge quantities. Withdrawals previously included any excess mine water pumped from the <br />mine and all water withdrawn from wells. No water was pumped from the mine or withdrawn from <br />wells during 2013. Consumptive use during the reporting period was therefor only due to pond <br />evaporation. No pond water was discharged through the NPDES outfalls, shown on Table 2, to the <br />stream system during the reporting period. <br />2013AHR.doo Page 2 <br />