2013-05-01_REVISION - M2002004 - Laserfiche WebLink

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topsoil. Reclamation of active roadways along which conveyor belts are located, will be performed when the conveyors and roadways are no longer required for mining activities and either relocated or permanently removed. GCC is proposing two topsoil /subsoil removal options. The first option is utilized when topsoil and subsoil materials are being directly hauled from the pit in advance of reclamation. The second option is utilized when topsoil and subsoil materials are being stockpiled for later redistribution. The baseline Soil Volume Summary contained in Exhibit I — Soils Information, contains a listing of soil types and recommended salvage depths. The salvage depths are based on critical review of the soil laboratory analyses contained in Appendix B - SOILS DOCUMENTATION, the baseline soil surveys and the NRCS Soil Survey for Pueblo County (SCS, 1979). While these topsoil and subsoil salvage depths average 6 and 12- inches respectively, soil salvage depths will be determined by actual soil depths that are determined generally by topographic position. Deep topsoil is usually located in draws and valley floors while ridge tops have generally very shallow topsoil. Shallow ridge topsoil usually covers unweathered overburden that may not be favorable for final reclamation. The suitability of the native topsoil and subsoil materials to sustain several native plant communities will be determined as described in Exhibit I — Soils Information. Direct Haul Topsoil/Subsoil Salvage Option. Salvaged topsoil and subsoil materials will be directly hauled and placed on final graded backfill whenever possible. The advantages of direct -haul topsoil are discussed further in Appendix G — RECLAMATION PLAN SUPPORT DOCUMENTATION. The following topsoil/subsoil removal option will be utilized when the salvaged soil is being directly hauled and placed on final graded backfill: 1. To minimize compaction and destruction of soil structure, soil removal activities should be scheduled when soil moisture levels are sufficient to minimize dust yet dry enough to minimize soil mucking. Ideal soil moisture conditions for soil salvage are above the wilting point and below field capacity. 2. As with all mine related activities, dust emissions resulting from topsoil activities need to be kept to a minimum. 3. Topsoil (A and E- horizons) will be removed as a separate layer from the area to be disturbed. This salvaged topsoil will be directly hauled and placed on final graded subsoil and backfill materials. 4. Stripping of topsoil from the bottom of drainages should be given first priority to prevent contamination of topsoil by disturbed runoff. It may be necessary to strip drainage corridors to establish proper drainage prior to additional topsoil removal. 5. Upon completion of topsoil salvage activities, all topsoil removal areas will be bladed to collect any additional topsoil not salvaged by scrapers. 6. If the native topsoil is less than 6- inches thick, the topsoil will be removed and the unconsolidated AC and /or B- horizon material immediately below the topsoil and treat the entire 6 inch mixture as topsoil. Suitable AC and /or B- horizon subsoil will be managed as subsoil to be removed and placed directly on regraded spoil prior to the placement of the salvaged topsoil materials. 7. The topsoil removal crew will be provided with a detailed map showing the projected stripping depths, and a qualified individual will ensure that soil is removed consistent with this plan. Technical Rev No. 4 April 26, 2013 D -5