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before construction can begin. The upper pile will not be covered in this document; <br /> however, specific information is contained within Exhibit 50 of the permit <br /> application. The lower pile is currently in use and specifics regarding the design are <br /> located in Exhibit 51 of the permit application. <br /> The lower waste pile is located adjacent to Highway 133, at the west side of the <br /> mouth of Sylvester Gulch. MCC initially proposed the disposal of waste rock within <br /> two waste piles in the original permit application. One pile, the "initial waste rock <br /> pile," would contain approximately 1.25 million cubic yards and would be located on <br /> the lower facilities bench (the current location of the shop). Subsequent to permit <br /> approval, this initial waste rock pile was deleted from MCC's permit. The second <br /> waste pile, the "upper waste pile," would be significantly larger and be located on <br /> the bench above the portal area, and as previously mentioned will not be constructed <br /> during this permit term. <br /> In the fall of 1985, Mountain Coal Company submitted a permit revision application <br /> requesting approval of a permanent lower waste pile to be located adjoining the <br /> mouth of Sylvester Gulch. This application originally requested approval to <br /> permanently dispose of 1.77 million tons of coal processing waste within the <br /> proposed structure. The original design phased the refuse pile into five specific <br /> design layouts (Phases I through V), including recompaction and reconfiguration of <br /> temporarily stored waste material. The pile was constructed according to this <br /> original phased design until the Phase IV configuration. A revision application was <br /> submitted in November 1992, which eliminated Phase V and reduced the pile to 1.2 <br /> million tons. The proposed storage volume represents a 15.7 year life. The <br /> proposal included the combination of a 28,500 cubic yard topsoil pile during <br /> Phases I through III and a maximum of 45,000 cubic yards of non-toxic soil cover <br /> (subsoil) stockpile. Topsoil removed for Phase IV will be stored on the 50-foot <br /> bench constructed in Phase III. In addition, an access road was constructed in Phase <br /> Three and a portion of the Sylvester Gulch access road to the main fan portal was <br /> relocated. Underdrains have been constructed beneath the pile. Piezometric ground <br /> water monitoring will be conducted. Slopes of the pile will be maintained at <br /> 2.5H:1V. <br /> The permit revision application included a thorough slope stability analysis <br /> performed in accordance with the prudent state-of-the-art slope analysis for the <br /> original design in 1985, and for the redesigned pile in 1992. Material strength <br /> values were derived from on-site sample testing and nearby previously reported test <br /> results. Piezometer observations, falling head parameter tests and analytical <br /> projections were completed in order to predict appropriate phreatic surfaces within <br /> the proposed waste structure. Data for the 1992 analysis utilized data collected for <br /> the 1985 analysis. <br /> The applicant has committed to the installation and quarterly monitoring of three sets <br /> of survey monuments to monitor slope stability of the waste structure. One row of <br /> monuments has been installed parallel to the state highway adjoining the toe of the <br /> waste pile on 100-foot intervals. Two additional rows of monuments have been <br /> installed perpendicular to the highway on the facial slope of the pile at 50-foot <br /> 41 <br />