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EXHIBIT 7, ITEM 14, PART R — EAST PIT RECLAMATION SEQUENCING <br />AND DITCH DESIGNS FOR PROSPECT DITCH, NORTH TRIBUTARY EAST <br />PIT DITCH AND FINAL EAST PIT DITCH <br />The East Pit area of the mine drains generally to the southeast, ultimately reporting to <br />Prospect Pond (Prospect Pond -007A) described in detail elsewhere (Exh. 7 -PP). The <br />drainage system is depicted in figures Fig. 7 -14R -1 and Fig. 7 -14R -2 included in this <br />Exh. 7 -14R. With respect to sediment pond performance, the drainage to Prospect Pond is <br />complicated by the fact that as mining progresses westerly, the watershed tributary to the <br />pond grows larger and continuously reflects changing surface conditions. This requires <br />the sediment pond design presented in Exh. 7 -PP to consider several time frames, notably <br />2010, 2012 and 2017. While the ditches that convey the runoff to the pond described in <br />Exh. 7 -14PP are the same ditches that are described in this section, only the final (post - <br />mining) time frame needs to be considered for the ditch design for this section. <br />Consequently, only the 419.1 acres of post -2017 watershed is included in this ditch <br />design section. These are the 250.3 from the North Tributary East Pit Ditch (hereafter <br />NTEP) and Final East Pit Ditch system and 153.3 from the Prospect Ditch. <br />The SEDCAD models for the entire stream system from their respective headwaters to <br />the down - gradient end of mining disturbance is included in the following pages. Because <br />the NTEP and Final East Pit Ditches join together at their respective lower ends, there are <br />two separate models; one for the Prospect drainage and the other for the NTEP /Final East <br />Pit system. Design parameters and flow conditions in all man -made channel components <br />presented in the attached SEDCAD output files are also incorporated into Table 1 in <br />Exh. 7 -14. <br />There are five "stock ponds" in the system. Dimensions and stage- storage curves for <br />these are taken from two sources. For the four stock ponds that have already been <br />constructed (PD -1, PD -2, NTEP -1 and EP -1), dimensions and stage- storage curves are <br />taken from as -built surveys performed in Fall 2011. For the other stock pond (EP -2), <br />dimensions are based on the November 2012 as -built survey. Some of these stock ponds <br />may be operated partly empty during the active mining time frame to assure compliance <br />with the sedimentation requirements. However, for this stream design evaluation they are <br />all conservatively assumed to be brim -full at the start of the design storm (10 yr, 24 hr). <br />That allows decisions regarding the post- mining fate of these stock ponds to be <br />independent of the ditch design or performance. <br />Depending on flow quantity, channel slope, and flow velocity, the channel linings vary <br />from vegetative liner where feasible, to rip -rap lined ditches where necessary. Suitability <br />of a vegetative lining is based on allowable velocities as presented in SEDCAD, as <br />discussed in more detail in the following section. <br />Exh. 7 -14R -1 Revision Date: 3/27/13 <br />Revision No. TR -97 <br />