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EFCI Southfield Mine - 2009 Annual Hydrology Report March 10, 2010 <br />2.0 GROUNDWATER INFLOWS, WATER USE AND DISCHARGE <br />2.1 Mine Inflows <br />Mine inflow monitoring was discontinued after September 2001, immediately prior to permanently <br />sealing the mine in December 2001. Total mine inflows measured during 2001, as the last <br />reporting period, were estimated at 5.2 acre-feet as compared to 10.3 acre-feet during the 2000 <br />reporting period. Prior to 2001, mine inflow locations were monitored semi-annually during the <br />spring and fall for each annual reporting period. The 2001 mine inflows represented a decrease <br />from prior years possibly due to continuing drought conditions at that time along with the <br />elimination 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 little variance in <br />inflow water quality over time. <br />2.2 Mine Water Handling, Consumptive Use, and Discharge <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. <br />During the period of this report, consumptive water use occurred only from pond evaporation. Pond <br />4 and Pond 5 at the mine site intermittently held limited quantities of water from storm events <br />during the spring and summer months. Based on the size and duration of pooled water in each <br />pond, the total 2009 pond evaporation is estimated at 0.05 acre-feet. This quantity is significantly <br />less as compared to previous years. Lower water quantities were held in the mine ponds due to <br />small and infrequent storm events during the reporting period, and there was a likely decrease in <br />surface runoff from reclaimed areas having mature vegetation establishment. <br />The source of water for any intended consumptive uses would be from the towns of Florence or <br />Rockvale, hauled by truck. No water was trucked to the site or pumped from the Corley Well <br />during 2009, and it is anticipated that future consumptive water use will be limited to pond <br />evaporation from the remaining four sedimentation ponds (Ponds 4, 5, L1, and L2). Total <br />consumptive use for 2009 is therefore estimated at 0.05 acre-feet, as indicated on Table 1, Water <br />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 2009. Consumptive use during the reporting period was therefor only due to pond <br />evaporation. No pond water was discharged through any of the NPDES outfalls, shown on Table 2, <br />to the stream system during the reporting period. <br />2009 AHR.doc WP Page 2