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West Elk Mine <br />MB-1 and FW-1, for the clay material embankment, the consolidated undrained stability was <br />critical, while for MB-2, the consolidated drained condition was critical. <br />Both a static analysis and a seismic analysis were performed for each dam embankment. For <br />the static analysis a fully saturated embankment was assumed. The seismic (or dynamic) <br />analyses, assuming the same condition, in combination, are summarized in Exhibit 44. The <br />final run for each analysis is included as a supplement to Exhibit 44. <br />Hydrologic Protection During Construction <br />Early in construction, prior to the disturbance of any area for surface construction, <br />sedimentation ponds were constructed, and diversion channels to collect undisturbed surface <br />runoff were constructed to meet specific design requirements. These channels were <br />constructed coincidentally with the initial access road, and divert the runoff away from the <br />disturbed areas. These structures were designed per Exhibit 44. Runoff is released from the <br />sedimentation ponds only after sufficient settlement of suspended solids and satisfaction of the <br />effluent standards has been achieved. Disturbance of the adjacent areas was held to a <br />minimum. The NPDES permits were secured prior to discharging. See Exhibit 7 to this <br />Mining and Reclamation Plan. Construction practices are geared to minimize erosion in all <br />disturbed areas (Exhibit 43). <br />During construction of the ST-4 crushed coal stack-tube and storage area, drainage in the area <br />was diverted into the enlarged MB-3 pond so that the former ponds MB-2 and MB-6 could be <br />dried in preparation for the construction of pond MB-2R and the coal storage area. <br />Best Management Practices (BMP) were utilized during road construction associated with the <br />Sylvester Gulch Facilities Area (PR07). BMPs were also utilized as the substation was <br />constructed. Prior to the construction of the shafts site benches, aclear-water diversion ditch, <br />designed to handle the peak flow from a 100-year, 24-hour storm event, was constructed. In <br />addition, prior to removing vegetation and stripping topsoil at the shafts site benches, sediment <br />pond SG-1 was constructed. The shafts site will naturally drain to the sediment pond, so life- <br />of-mine sediment ditches may not be constructed immediately, but will be established as the <br />site is developed. <br />Sediment contributions from drill sites constructed by MCC within the permit area will be <br />minimized by clearing the smallest area possible, containing drilling water and cuttings in an <br />appropriately-sized pit and reclaiming the site promptly upon completion. Reclamation would <br />include grading the site, redistributing topsoil, scattering vegetative slash, seeding, and <br />mulching, if necessary. <br />2.05-36 Revised June 2005 PR10; Rev. January 2006; Rev. March 1006; Rev. Apri12006 PR10, May 2006 PR10; Rev. January 2009 MR-350 <br />