2002-07-03_PERMIT FILE - M2002004

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Exhibit D soil/subsoil. This material will subsequently be utilized to reclaim the open areas of the Year-1 block at • the completion of mining, and for regrading and reclaiming the central conveyor slot at the completion of mining each panel. Alternatively, material for reclamation of the Year 1 block may come from the stockpile located up gradient of year 5. Refer to the generalized cross-sections A-A' through C-C' on Exhibit D-1, which illustrate the position of in-pit reclamation backfill and the conveyor corridor slot during active mining. An average of approximately 18,000 tons per year of Codell Sandstone that lies directly below the limestone will be removed. The sandstone will be moved to the plant via the same route as the limestone: from the crusher and enclosed conveyor belt to plant. The actual thickness of the material to be removed will vary between 2 and 6 feet depending upon quality of this unit. TOPSOIL & SUBSOIL SALVAGE As discussed in more detail in Exhibit I - Soils Information, A and E-horizon topsoil materials will be salvaged separately from AC or B-horizon subsoil materials. Topsoil and subsoil removal and replacement operations may be conducted with any of several combinations of equipment including a scraper, truck/shovel, truck/loader, backhoe, dozer, etc. Mobile equipment will be used to remove topsoil and subsoil materials that will be either directly hauled from the pit in advance of reclamation or placed in stockpile storage area shown on the mine plan, adjacent to each production panel for easy re-application to the mined area. It is proposed that each production block will be fully reclaimed by placing the overburden material from the adjacent panel on the floor of the pit and then reapplying the subsoil and 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. • Rio Grande 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 Rio Grande 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 by using WDEQ/LQD Table I-4: Criteria to Establish Overburden Suitability (Wyoming DEQ, 1994) as described in Exhibit I - Soils Information. Suitability criteria will be met for pH, electrical conductivity, saturation percentage, texture, sodium adsorption ratio, selenium, boron and percent by volume of coarse fragments. If the topsoil and subsoil materials comply with WDEQ/LQD's criteria as "suitable" or "marginal" these materials will be acceptable for use as a plant growth substrate over the final graded backfill material. 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 1180-Mine Permit Exhibits (Jul.05.02)FINAL.doe D-5 July 8, 2002