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Previously, during evaluation of the refuse pile, as permitted under TR 15, a chemical analysis of the processed <br />waste material was completed, with the results presented as Table 20A, Waste Material Analysis. Based upon this <br />analysis, it appears the refuse materials are not potentially toxic-fomung or acid-generating. The previously <br />referenced CTL/Thompson report addressing the refuse pile design and geotechnical evaluation includes a <br />conservative estimate of the maximum quantity of water projected to drain from within the pile (see Exhibit 26A, <br />page 17). The estimate is based upon the assumption that 3 inches of water infiltrates into and dischazges from the <br />pile on an annual basis. The analysis further assumes that discharge from the pile occurs during cone-month time <br />period. Under these conditions, the average calculated flow from the drain is 0.2 cfs for the month drainage occurs. <br />The dischazge from the refuse pile rock drain will be routed to Pond D. Given the very limited volume of rock <br />drain dischazge relative to the surface water runoff contributions typically received by Pond D, no adverse water <br />quality impacts are anticipated as a result of construction of the waste pile. Pond D will continue to be monitored <br />for the applicable NPDES discharge permit parameters as required. <br />The permanent diversion ditches on and around the perimeter of the Coal Refuse Pile (see Map 24 and Exhibit 26A, <br />Appendix D) were established prior to constructing the refuse pile. The uppermost portion of the west side <br />diversion ditch segment RDA-]b, however, was temporarily aligned slightly to the east of the location depicted on <br />Map 24 in order to avoid the established topsoil stockpile (SF-6) in this area (see Exhibit 26A, Figure 2). Topsoil <br />Stockpile SF-6 remained in its original location and will be utilized as the initial topsoil source for reclamation of <br />the refuse pile benches. In the event Topsoil Stockpile SF-6 has not been reduced through topsoil replacement to <br />the degree necessary to allow construction of the final configuration of ditch RDA-lb once the pile is developed to <br />this elevation, any portion of Topsoil Stockpile SF-6 conflicting with the final ditch alignment will be relocated and <br />the permanent diversion ditch will be established between the existing sections. TCC does not intend to riprap the <br />temporarily located portion of Ditch RDA-lb, but will riprap the ditch when the final alignment is established. <br />In order to facilitate the establishment of vegetation in permanent diversion Ditch RDA-2, temporary rock check- <br />dams will be installed in selected segments of the ditch. The design of these rock check-dams can be found in <br />Exhibit 26-a(1), Refuse Pile, Rock Check-Dam design. It should be noted that these dams will not exceed one foot <br />. in height, and extend across the 8-foot wide ditch bottom. The 12-foot rock dams will extend up the ditch <br />sideslopes to the flow-line. The rock check-dams will be placed according to the following spacing interval: Slopes <br />I percent or less -every 100 feet, 2 percent slope -every 50 feet, 3 percent slope - 3 dams per 100-foot segment of <br />ditch, 4 percent slope - 4 dams per 100-foot segment of ditch, 5 percent slope - 5 dams per 100-foot segment of <br />ditch, and 8 percent slope - 8 dams per 100-foot segment of ditch. <br />Temporary diversion ditches designed to convey the 100-year, 24-hour storm runoff will be cut-in approximately <br />50 feet upslope from the working area of the waste pile as pile construction progresses. The temporary ditches will <br />be established in areas stripped of topsoil, and aze intended to divert surface runoff away from [he exposed coal <br />waste materials during construction of the pile. TCC estimates a maximum of six temporary ditches will be <br />established throughout the life of the pile. <br />Refuse Pile Modification <br />The refuse pile construction sequence is planned for modification as shown in Exhibit 26A-1. The modification of <br />the construction sequence, as presented in Exhibit 26A-1, will result in a stable refuse pile configuration in <br />accordance with the requirement of the DMG regulations. The bench ditch design is presented in Exhibit 8M. It <br />should be noted the bench design is adequate to pass runoff from the ] 00-year, 24-hour event. <br />All of the provisions provided in Exhibit 26 will continue to be followed by TCC, except as modified by Exhibit <br />26A-1. The modification presented in Exhibit 26A-1 can be summarized as follows: <br />1) Seemented Construction -The requirement to place and compact the fill in 24-inch lifts will be followed, with <br />testing of every other lift to verify compaction requirements aze met. The southern portion of the refuse pile will be <br />the primary temporary stockpiling area, although the entire footprint of the pile can be used for temporary <br />stockpiling of refuse material to allow for temporary storage of material during the winter, when adequate <br />compaction may not be feasible, and to allow water to drain from the refuse prior to placement and compaction. <br />TROS-49 2.05-97 Revised -May 2005 <br />