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NMD (Panels 12 -Right through 16- Right, PR 99 -05) <br /> The geology description provided in PR -03 is also applicable for the NMD. One item to note is that TCC <br /> discontinued pumping from the Fish Creek Borehole for a period of approximately 18 months. When pumping <br /> recommenced the total recoverable iron and total dissolved solids concentrations increased to approximately 17 <br /> mg /1 and 7,200 mg /1 respectively. TCC is applying caustic soda to reduce the total recoverable iron concentration <br /> as per its CDPHE discharge permit. TCC believes the elevated concentrations are the results of the water <br /> stagnating in the underground sump. Once this pool of water is discharged, TCC believes the concentration will <br /> return to levels previously reported for the Fish Creek Borehole. TCC will continue to monitor the concentration, <br /> and anticipates the concentration to return to historic levels by late summer, 2000 or 2001. <br /> In regards to future impacts, TCC will not discontinue pumping of the underground sump for extended periods of <br /> time. This will eliminate the potential for the above situation to occur in the future. Once mining is completed at <br /> the facility, no further discharging will occur. Based upon this, there should be no impact to the postmining land <br /> use. <br /> Coal Refuse Disposal Area (CRDA, TR92 - 15, TR95 - 21, MR08 - 233, TR09 - 67) <br /> The original Coal Refuse Disposal Area (CRDA), located to the southwest of the Area 1 Pit, as shown on Map 24, <br /> Surface Facilities, has been designed to hold approximately 3,000,000 cubic yards of material. The CRDA is <br /> designed to accommodate temporary placement and permanent disposal of coal refuse materials generated from the <br /> preparation plant, excess coal development waste material from the mine, or a combination of preparation plant and <br /> mine waste material. This material or combination of materials will be hauled to the pile using either TCC's <br /> existing mobile equipment fleet or contractor equipment. The original design of the CRDA was contracted to <br /> CTL /Thompson. The design was revised and updated to reduce the overall footprint and address operational <br /> placement and final grading concerns, by Northwest Colorado Consultants. Both the original design and revisions <br /> are documented in Exhibits 26A, 26A -1, and 26A -2. Within 30 days of start-up of the preparation plant, a sample <br /> of the waste material generated from the preparation plant was obtained and analyzed to verify the assumptions <br /> used for the pile design presented in Exhibit 26A. TCC forwarded results of this analysis to the Division along with <br /> a certified statement from a registered P.E. summarizing the results of the analyses as compared to the original <br /> design assumptions. The surface runoff/diversion system design for the pile was developed in -house by TCC and is <br /> presented as Appendix D to the CTL /Thompson Report. The locations of the CRDA and associated drainage <br /> features are shown on Map 24, Surface Facilities. <br /> As shown on Exhibit 26A, Figure 1, the CRDA is constructed west of the reclaimed valley to the west of the Area 1 <br /> Pit. Prior to construction, approximately 18 inches of topsoil from within the pile footprint were removed and <br /> placed in topsoil stockpile SF -12 (see Map 29). During reclamation of completed pile benches, suitable cover <br /> materials and topsoil will be redistributed over the face of the pile. Direct placement of topsoil will occur to the <br /> extent possible during the bench reclamation/pile extension process. It is anticipated that topsoil replacement will <br /> stay one bench below the active working zone of the pile. During construction of the CRDA, inactive portions of <br /> topsoil stockpile SF -12 will be seeded with the topsoil stabilization seed mixture at the first appropriate opportunity <br /> following stockpiling operations. Table 49A, Topsoil Stockpile Summary, has been revised to show the potential <br /> modification to the existing stockpile SF -12 resulting from the construction of the refuse pile. Also, the table <br /> presents information for all other Twentymile topsoil stockpiles. The stockpile identification numbers in the table <br /> correlate with the stockpile designations presented on Map 29. <br /> Spoil/subsoil material will be used as suitable, non -toxic cover, to be placed over completed refuse benches prior to <br /> topsoil replacement. During development of the refuse pile, spoil /subsoil material will be selectively removed from <br /> within the footprint of the pile. The spoil/subsoil will normally be hauled directly to an active reclamation area and <br /> spread over the completed refuse bench. In cases where direct placement is not operationally feasible, cover <br /> - materials may be temporarily stockpiled within the pile footprint or in adjacent areas. After placement of the <br /> spoil /subsoil material, the area will be topsoiled, as previously described. Redistributed topsoil will be seeded with <br /> the pastureland seed mixture. <br /> TR09 -67 2.05 -96 06/16/09 <br />