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to a discussion of stabilization materials (e.g., <br />vegetation or other means). <br />The applicant shall submit details of road embank- <br />ments, including specifications for slopes, embankment <br />material (rock fragment dimensions, presence of acid <br />forming, organic materials, etc.), construction meth- <br />odology (leveling, compaction), removal of vegetation <br />and topsoil, and temporary erosion control measures. <br />Drainage <br />The applicant has supplied in-mine drainage ditch and cul- <br />vert sizing data and calculations in Figure 2, Appendix C, <br />and Addendum II. The main in-mine haul roads will be <br />crowned to facilitate drainage. Figure 2 of. the permit <br />application indicates that two 18-inch corrugated culverts <br />are planned for Ditch D near the shop area, and a 36-inch <br />culvert is proposed for the North Fork under the haul road <br />between Pit 1 and Pit 2. The existing 24-inc;h culvert in <br />Bush Draw will not be replaced and should be adequate to <br />safely pass runoff from the 10-year, 24-hour storm event. <br />As discussed in detail in the Surface Water Section of <br />this TEA, the Manning's Equation used by the applicant to <br />determine culvert size is inappropriate for the short cul- <br />verts that will be installed in the permit area drainages. <br />The applicant is hereby referred to the discussion of cul- <br />verts and the accompanying stipulation presented in that <br />Section of this TEA. <br />Surfacing <br />The applicant has provided a description of road surfacing <br />material in Addendum II (p.8). The applicant intends to surface <br />roads with the massive light-gray sandstone found above the coal, <br />-69- <br />