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III. Hydrologic Balance -Rule 4.05 <br />A. Water Quality Standards and Effluent Limitations <br />Storm runoff from all disturbed areas (except some topsoil stockpiles), pit <br />pumpage, water treatment facilities, and spoil springs will pass through a sediment <br />pond designed [o ensure that all discharges meet effluent limits in Seneca Coal <br />Company's NPDES permit for the Seneca II-W Mine. A storm water permit and <br />spill prevention containment and control plan associated with the NPDES permit <br />also dictate preventative and mitigation measures for ensuring that all water leaving <br />the mine site meets applicable effluent limits. <br />Disturbed areas, as defined by Rule 1.04(36), are delineated on permit area map <br />Exhibit 12-2. Disturbed areas drain into approved sedimentation ponds, with the <br />exception of certain haul road and access road segments that are located outside <br />approved sedimentation pond collection areas, as allowed by Rule 4.03, and with <br />the further exception of certain small area exemption locations as discussed in the <br />following paragraph. <br />The Division has granted a small area exemption from use of sediment ponds due <br />to the limited size of the area and due to the fact that ponds and treatment facilities <br />are not necessary for the drainage to meet the effluent limitations of Rule 4.05.2 <br />and applicable State and Federal water quality standards for receiving streams, and <br />also due to the fact that no mixing of surface drainage with a discharge from <br />underground workings will occur. The small areas to be exempted are the topsoil <br />stockpiles listed on Table 13-8-1 and shown on Exhibits 13-2, and 13-3. <br />(4.05.2(3)(b)(i)). <br />B. Diversions and Conveyance of Overland Flow <br />All major drainages that are [o be disturbed by mining will be reclaimed to <br />approximate the premining configuration and to blend with the undisturbed drainage <br />above and below the area to be reclaimed. Table 20-2 provides the pre-and <br />postmine drainage channel summary. The reclaimed drainages are located on <br />Exhibit 20-2. <br />The average postmining stream gradients will have concave longitudinal profiles <br />which approximate the premining slopes. The premining and postmining drainage <br />areas of the reclaimed channels are similar in acreage and slope. After the <br />watershed has been graded and the location of the drainage channel determined, the <br />channel will be constructed to the required shape. Permanent channel construction <br />including riprap installation (where specified) will be comopleted within one year of <br />completion of the final grading of adjacent backfill slopes, and prior to topsoiling <br />Seneca II-W Findings Document 26 July 3, 2006 <br />Permit Renewal No. 5 <br />