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Moab 2003 Energy Fuek Coalln~ - Southjrekl Mine * 2002AnnualHydrokgy Report ~ Page 4 2.0 GROUND WATER INFLOWS, USE, AND DISCHARGE 2.1 MINE INFLOWS As previously noted in Section 1.0, quarterly mine inflow monitoring was discontinued after September 2001 since access to monitoring sites was eliminated when the mine portals were sealed in December 2001. Mine inflows for 2001, as the last reporting period, were estimated at 5.2 acre-feet, as presented in Table 1, Mine Water Inflow Summary, for the monitoring locations shown on Figure 1, Mine Monitoring I,oratiora. These locations were monitored semi-annually during the spring and fall for each annual reporting period. The 2001 mine inflows represent a decrease from prior yeazs, possibly due to continuing drought conditions. Review of historic mine inflow water quality monitoring results from previous Annual Hydrology Reports indicates little vaziance in inflow water quality over time. 2.2 MINE WATER HANDLING, USE, CONSUMPTION, AND DISCHARGE During active operations, water handling systems in the mine captured most mine water inflows neaz their source. Within the mine, captured mine water was pumped to sumps located in Crosscut 32 or the 1st North Mains, or flowed by gravity to the mined-out and abandoned west azea of the mine. Water from the Crosscut 32 sump was pumped to the West Mains where it flowed by gravity to the abandoned west area of the mine. Prior to sealing of the mine, mine water handling activities were discontinued. Mine inflows will continue within the sealed mine workings and water will accumulate, initially in the lowest portions of the mine-out workings and gradually rising in other mined-out azeas until a dynamic equilibrium is reached between mine water inflows and dischazge to ground water systems. During the reporting period, consumptive water use was limited to water used for dust control and equipment wash-down during reclamation activities, minor quantities used for sanitary and domestic purposes, and limited pond evaporation. Total consumptive use for 2002 is estimated at 0.53 acre- feet as indicated on Table 2, IY/ater Balanee and Conrumptive Ure Summary. Use of the Corley Well as a water source was discontinued in late January 2001. Excluding pond evaporation, the source of water for minor consumptive uses was water trucked to the site from Florence or Rockvale. IC is anticipated that future consumptive water use will be limited to pond evaporation from the remaining sedimentation ponds (Ponds 4, 5, Ll, and LZ). The water balance compares water source withdrawals (previously included any excess mine water pumped from the mine as well as water withdrawn from well sources) with consumptive use and discharge quantities. No water was pumped from the mine or withdrawn from on-site wells during 2002. Consumptive use during the reporting period equaled the water quantity trucked to the site from outside sources and limited pond evaporation. No water was dischazged to azea streams. Given that there were no mine water discharges during 2002, the most recent water quality data (2001) for mine water axe summarized in Table 3, NPDES Dirrharge Summary. Historically, all dischazges were within NPDES permit limitations and all samples submitted for WET testing from Outfall 004 were in compliance. Given that future consumptive use is expected to be limited to pond evaporation, no future discharges of mine water are anticipated. MIGH * 1475 Pine Grove Road, Suite 109 * Steamboat Sprrngg CO 80487 * (970J 879-6260 LL":I [Tl EvD Fib/Xq] Nwd HN R°' /If/OlW