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A. Water Quality Standards and Effluent Limitations <br />All discharges of water from the Yoast mine site from storm runoff and spoil <br />springs will pass through a sediment pond designed to ensure that all discharges <br />meet effluent limits in Seneca Coal Company's NPDES permit for the Yoast Mine. <br />A storm water permit and Spill Prevention, Control and Countermeasure (SPCC) <br />plan associated with the NPDES permit also dictate preventative and mitigation <br />measures for ensuring that all water leaving the mine site meets applicable effluent <br />limits. <br />The Division previously granted 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 standards <br />for receiving streams and also due to the fact that no mixing of surface drainage <br />with a discharge from underground workings will occur. The small area exempted <br />was Topsoil Pile L depicted on 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. Diversion <br />No. 1 was never built. Diversion No. 2 routes disturbed area runoff from Topsoil <br />Stockpile A to Pond 10. Diversion No. 3 was designed to carry disturbed area <br />runoff around the explosives storage area, through Annand Draw to Pond 10. <br />Diversion No. 3 has been removed from the permit application package. Designs <br />for Diversion No. 2 are located in Attachment 13-2 of the permit application <br />package. <br />Permanent drainages have been reconstructed in mined areas to approximate the <br />original drainage density. Reconstructed drainages are designed to safely pass <br />runoff from the predicted 10 -year, 24-hour precipitation event. Details of <br />permanent drainage designs are located in Tab 13 and 20 of the permit application <br />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 have <br />been made. <br />C. Sedimentation Ponds <br />Sediment ponds to treat disturbed area runoff are Ponds 10, 11, 11a, 12, 13, <br />and 14. Ponds 10, 11, and 12 were constructed during the first permit term. <br />Ponds 11 a, 13, and 14 were constructed during the second permit term. Pond <br />10 treats disturbed area runoff from approximately 385 acres, in addition to <br />approximately 550 acres of undisturbed area. Pond 11 treats runoff from <br />approximately 78 disturbed acres. Runoff from roughly 64 undisturbed acres <br />19 <br />