2022-04-29_PERMIT FILE - C2010089 (17)

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Section 2.05.4(2)(d) Page 5 December 2021 (RN-02) Topsoil Stripping Before any area at the NHN Mine site other than a topsoil stockpile, light use access road, shallow drainage ditches, power line corridors and other small area exemption areas are disturbed, the suitable topsoil material was be removed. Suitable topsoil was salvaged from all significant disturbance areas including sediment ponds (includes pond area, embankment and spillway), mining activities, spoil stockpiles, haul roads, access roads, mining areas, facilities area and diversion ditches, which extended below the depth of salvageable topsoil. Prior to topsoil removal, vegetation which was too large for incorporation into the topsoil was scraped away, placed in the pit, or utilized on Dryland Pasture reclamation areas as habitat. The remaining vegetation was incorporated into the topsoil to help increase organic matter levels. Since the topsoil map is an estimation based on field data and the salvage depths vary according to the actual topsoil depths observed during topsoil stripping, all topsoil was salvaged to maximize postmining vegetation production. Structural damage can occur to topsoil if they are salvaged while saturated. Therefore, topsoil salvage equipment was generally limited to the drier areas. Wet areas were dewatered and allowed to dry prior to salvage. During the preparation of the initial boxcut area, the existing topsoil materials were salvaged in a single lift and hauled to a designated topsoil. During the normal mining sequence as operations advance and there is sufficient graded area behind the pit for reclamation, topsoil was removed and direct hauled from the advanced stripping areas to the graded areas behind the pit. On the Garvey property, the Irrigated Pasture/Cropland (IPC) areas corresponding to the more productive Progresso topsoil and REC topsoil were salvaged separately and stockpiled separately. With respect to the ERMR-Meehan property south of Meehan Draw, all of the topsoil materials which are largely Progresso with inclusions of Pinon topsoil were salvaged and stockpiled together. Topsoil Storage Stockpiled topsoil was selectively placed on a stable surface area within the permit area and are protected from wind and water erosion. The protection measures will be accomplished by an effective cover of non-noxious, quick growing annual and perennial vegetation. A self-contained ditch or berm will be constructed around the perimeter of the stockpile to prevent loss of the topsoil resource. As soon as practical after topsoil is no longer being moved to or from a stockpile, NHN will seed the pile with Seedmix #3 as presented in Section 2.05.4(2)(e): Revegetation. A topsoil sign will be placed at the toe of the pile as required by rule.