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satisfy grade requirements were installed during this operation, with proper collection drains on the <br />downstream side leading to natural drainage basins. Headwalls of rock riprap were installed to prevent <br />erosion. Runoff calculations are discussed in another section of this permit application. <br />After the grading was completed, the drainage ditches were installed, surface of the roadway graveled <br />and cut and fill sections topsoiled with the material taken from the stockpile. During all the above <br />operations, the design engineer's construction inspectors monitored the work to assure compliance with <br />all regulatory agency requirements. Soils test for compaction and gradation were a part of the <br />inspection activity. Access and maintenance roads are maintained by periodic regrading of the gravel <br />surface and regraveling as required. Ditches and culverts are cleared periodically to assure proper <br />drainage. Since the maintenance road receives very little traffic, dust control is not used. The access <br />road surface is watered and treated as required for dust control. <br />Culverts and ditches were designed as discussed in Section IV.D.2. Drainage areas for culverts and <br />ditches are shown on Maps 23 and 86. Construction methods were similar to that discussed for the haul <br />road. Only authorized personnel use the road that serves as an access road to the explosives storage <br />area. <br />At the end of the mine life, culverts will be removed, the gravel surface scraped off and covered. These <br />areas will be regraded to approximate original contours, covered with topsoil and reseeded. <br />IV.I Grading Plan <br />Because of the nature of the terrain, a significant amount of grading work was required at the D Portal <br />Area to provide a flat area for buildings, workspace and parking tots. Grading requirements for <br />conveyors, the East Portal Area, and the Refuse Disposal Area were minimal. The B Seam ventilation <br />shaft site required a minimum amount of cutting into the valley slope to provide a firm foundation for the <br />shaft above the Scullion Gulch alluviallcolluvial deposits. Maps 151 and 152 show the site grading plan <br />for the B Seam ventilation shaft facility. <br />The first construction work was the portion of the haul road and plant access road between the existing <br />county road and the D Portal Area to provide access to that area. Grading for the facilities in the D <br />Portal Area then followed. Upon completion of this work, the grading for the rest of the haul road was <br />accomplished. No major grading was required in the disposal area. <br />During the first six months of construction, approximately 1 acre of ground was used as a temporary <br />construction trailer and parking site. This area was located near the junction of County Road 65 and the <br />haul road. Topsoil was stripped from this area, stockpiled, mulched and reseeded to minimize erosion. <br />The area was surfaced with approximately 4 inches of gravel. A cut off ditch above the trailer and <br />parking site and gravel surfacing was provided in lieu of a sediment pond since the area was small and <br />• Mine Permit Renewal #3 (Rev. 8199) IV-33 <br />