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A. Water Quality Standards and Effluent Limitations <br />The Division granted a small area exemption (SAE) for the northwest corner of the <br />Morgan property. This allowed for the removal of Pond 11. The landowners asked for <br />the removal of Pond 11 so they could install permanent irrigation infrastructure to <br />support the post -mining land use and to manage their land as one continuous unit. See <br />Attachment 2.05.3(3)-7 and Map 2.05.3(3)-1 for further details, (4.05.2(3)(b)(i)). <br />B. Diversions and Conveyance of Overland Flow <br />ERMR uses various types of structures to control runoff from disturbed areas. In <br />addition, surface mining activities are planned and conducted to minimize disturbance <br />of the prevailing hydrologic balance in both the mine plan and adjacent areas in order <br />to prevent long-term adverse changes in the hydrologic balance. Sediment and runoff <br />control methods include diverting runoff through disturbed areas using stabilized earth <br />channels, culverts or pipes so as to prevent, to the extent possible, additional <br />contributions of sediment to stream flow or to runoff outside the permit area. ERMR <br />also uses straw dikes, silt fences, small V -ditches, riprap, mulches, check dams, <br />vegetative sediment filters, temporary cover crops and sediment traps that will reduce <br />overland flow velocity, reduce runoff volume, or trap sediment. Collection ditches, <br />culverts, and diversion design parameters are described in Section 2.05.3(3) Mine <br />Facilities and detailed design information is given in Attachment 2.05.3(3)-1. Map <br />2.05.3(3)-1 illustrates the topography, ponds, and ditches. <br />C. Stream Channel Diversions <br />There are no stream channel diversions proposed for the NHM. Calamity Draw flows <br />undisturbed parallel to the NHM southern boundary, while Tuttle Draw parallels the <br />northern boundary. <br />D. Sedimentation Ponds <br />ERMR uses sediment ponds to prevent additional contributions of sediment to <br />streamflow or runoff outside the permit area due to mining disturbances. Sediment pond <br />locations are shown on Map 2.05.3(3)-1. Sediment pond design, construction and <br />maintenance are described in Section 2.05.3(3) Mine Facilities. The pond designs and <br />runoff calculations for the permit area ponds are shown in the following attachments: <br />Pond 007 Attachment 2.05.3(3)-2, Pond 008 Attachment 2.05.3(3)-4, Pond 009 <br />Attachment 2.05.3(3)-5, Ponds 10 & 13 Attachment 2.05.3(3)-6, Pond 011 Attachment <br />2.05.3(3)-14, Pond 012 Attachment 2.05.3(3)-12 and 13, Pond 014 Attachment <br />2.05.3(3)-11, Pond 015 Attachment 2.05.3(3)-20, Pond 16 Attachment 2.05.3(3)-36 and <br />Pond 18 Attachment 2.05.3(3)-35. <br />Pond 010 has an approved design but this pond was never constructed. Ponds 007 and <br />008 are currently approved to remain as permanent impoundments after reclamation. <br />22 <br />