Laserfiche WebLink
EFCI Southfield Mine — 2014Annual Hydrology Report February 12, 2014 <br />The 2001 mine inflow quantity represented a decrease from prior years possibly due to continuing <br />drought conditions at that time along with the elimination, from becoming inaccessible, of former <br />inflow or seep locations due to retreat mining Review of historic mine inflow water quality <br />monitoring results documented in previous AHR's indicates only minor variances in inflow water <br />quality over time. <br />Mine Water Handling. Consumptive Use. and Disch <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 were partially full of water from several storm events beginning in <br />mid -July, as described in Section 3.3, Surface Water Monitoring Results. Based on the size and <br />duration of pooled water in each pond, the total 2014 pond evaporation is estimated at 0.526 acre - <br />feet. This quantity is slightly higher as compared to previous years due to the ponds holding water <br />from more frequent rains during the third quarter of the reporting period. <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 2014, and it is anticipated that future consumptive water use will be limited to <br />pond evaporation from the two remaining sedimentation ponds at the mine site. Total consumptive <br />use for 2014 is based solely on pond evaporation estimated at 0.526 acre -feet, shown on Table 1, <br />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 2014. 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 />2014 AHR tBx AW Page 2 <br />