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III. Hydrologic Balance - Rule 4.05 <br /> A. Water Quality Standards and Effluent Limitations <br /> All discharges of water from the Yoast mine site from storm runoff, pit <br /> pumpage, water treatment facilities, and spoil springs will pass through a <br /> sediment pond designed to ensure that all discharges meet effluent limits in <br /> Seneca Coal Company's NPDES permit for the Yoast Mine. A storm water <br /> permit and spill prevention containment and control plan associated with the <br /> NPDES permit also dictate preventative and mitigation measures for ensuring <br /> that all water leaving the mine site meets applicable effluent limits. <br /> The Division proposes to grant a small area exemption from use of sediment <br /> ponds due to the limited size of the area and due to the fact that ponds and <br /> treatment facilities are not necessary for the drainage to meet the effluent <br /> limitations of Rule 4.05.2 and applicable State and Federal water quality <br /> standards for receiving streams and also due to the fact that no mixing of <br /> surface drainage with a discharge from underground workings will occur. <br /> The small area to be exempted is designated as Topsoil Pile L located on <br /> Exhibit 12-1. (4.05.2(3)(b)(i)). <br /> B. Diversions and Conveyance of Overland Flow <br /> Three collection ditches were planned for the first five year permit term. <br /> Diversion No. 1 was never built. Diversion No. 2 routes disturbed area <br /> runoff, from Topsoil Stockpile A, to Pond 10. Diversion No. 3 was designed <br /> to carry disturbed area runoff around the explosives storage area, through <br /> Annand Draw to Pond 10. Diversion No. 3 has been removed from the permit <br /> application package. Designs for Diversion No. 2 is located in Attachment <br /> 13-2 of the permit application package. <br /> Permanent drainages will be reconstructed in mined areas, to approximate the <br /> original drainage density. Drainages to be reconstructed are designed to <br /> safely pass runoff from the predicted 100-year, 24-hour precipitation event. <br /> Details of permanent drainage designs are located in Tab 13 and 20 of the <br /> permit application package. <br /> There are no variances from the requirements of the Rules and Regulations <br /> proposed at this time. Therefore, no specific findings regarding diversions <br /> have been made. <br /> Yo=Mine 22 October 19, 1999 <br />