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Previously, during evaluation of the refuse pile, as permitted under TR 15, a chemical analysis of the processed waste material was completed, with the results presented as Table 20A, Waste Material Analysis. Based upon this analysis, it appears the refuse materials aze not potentially toxic or acid-generating. The previously referenced CTL/Thompson report addressing the refuse pile design and geotechnical evaluation includes a conservative estimate of the maximum quantity of water projected to drain from within the pile (see Exhibit 26A, page 17). The estimate is based upon the assumption that 3 inches of water infiltrates into and dischazges from the pile on an annual basis. The analysis further assumes that dischazge from the pile occurs during aone-month time period. Under these conditions, the average calculated flow from the drain is 0.2 cfs fot the month drainage occurs. The discharge from the refuse pile rock drain will be routed to Pond D. Given the very limited volume of rock drain dischazge relative to the surface water runoff contributions typically received by Pond D, no adverse water quality impacts are anticipated as a result of construction of the waste pile. Pond D will continue to be monitored for the applicable NPDES dischazge pemvt parameters as required. The permanent diversion ditches on and azound the perimeter of the Coal Refuse Pile (see Map 24 and Exhibit 26A, Appendix D) were established prior to constructing the refuse pile. The uppermost portion of the west side diversion ditch segment RDA-lb, however, was temporarily aligned slightly to the east of the location depicted on Map 24 in order to avoid the established topsoil stockpile (SF-6) in this azea (see Exhibit 26A, Figure 2). Topsoil stockpile SF-6 remained in its original location and is utilized as the initial topsoil source for reclamation of the refuse pile benches. In the event topsoil pile SF-6 has not been utilized to the degree necessary to allow the final configuration of ditch RDA-lb once the pile is developed to this elevation, the remainder of topsoil pile SF-6 conflicting with the final ditch alignment will be relocated and the permanent diversion ditch will be established between the existing sections. TCC does not intend to riprap the temporarily located portion of ditch RDA-lb until the fmal alignment is established. In order to facilitate the establishment of vegetation in permanent diversion ditch RDA-2, temporary rock check dams will be installed in selected segments of the ditch. The design of these rock check dams can be found in Exhibit 26-a(1), Refuse Pile, Rock Check Dam design. It should be noted that these dams will not exceed one foot in height, and extend across the 8' wide ditch bottom. The 12-foot rock dams will extend up the sideslope of the flow line. The rock check dams will be placed according to the following spacing interval: slope 1 percent or less - every 100 feet, 2 percent slope -every 50 feet, 3 percent slope - 3 dams per 100-foot segment of ditch, 4 percent slope - 4 dams per 100-foot segment of ditch, 5 percent slope - 5 dams per 100-foot segment of ditch, and 8 percent slope - 8 dams per 100-foot segment of ditch. Temporary diversion ditches designed to convey the 100-year, 24-hour storm runoff will be cut in approximately 50 feet upslope from the working area of the waste pile as pile construction progesses. The temporary ditches will be established in azeas stripped of topsoil, and aze intended to divert surface runoff away from the exposed coal waste materials during construction of the pile. TCC estimates a maximum of six temporary ditches will be established throughout the life of the pile. Refuse Pile Modification The refuse pile construction sequence is planned for modification as shown in Exhibit 26A-1. The modification of the construction sequence, as presented in Exhibit 26A-1, will result in a stable refuse pile configuration in accordance with the requirement of the DMG regulations. The bench ditch design is presented in Exhibit 8M. It should be noted the bench design is adequate to pass run-off from the 100-yeaz, 24-hour event. All of the provisions provided in Exhibit 26 will continue to be followed by TCC, except as modified by Exhibit 26A-1. The modification presented in Exhibit 26A-1 can be summarized as follows: 1) Seemented Construction- the requirement to place and compact the fill in 24-inch lifts will be followed, with testing of every other lift to verify compaction requirements are met. The entire footprint of the pile can be used for stockpiling of refuse material to allow for water to drain from the refuse prior to placement and compaction. The pile will be constructed in 50-foot benches as originally planned and drainage established off of these piles as presented in Exhibit 26A. Use of the entire footprint will accommodate having to stockpile refuse material during inclement weather, which typically extends from mid-October to late May. As presented in Exhibit 26A-1, this sequencing will not impact the stability of the pile; 2) Vertical Construction -this segment has been clarified to remove the requirement to TR 05-46 2.05-97 Revised -January 2005