2008-09-29_PERMIT FILE - C1981019A (29)

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RULE 2 PERMITS Topsoil Removal Soils information for the area to be mined has, in the past, been gathered by the Soil Conservation Service and the Bureau of Land Management. Information supplied by these two agencies has provided sufficient information concerning the soil resources available for reclamation at Colowyo. This information has been confirmed by reclamation personnel at the mine who have been closely monitoring topsoil removal operations since the initiation of mining in the fall of 1976. Therefore, the amount of soil sampling and mapping is considered quite adequate for determining topsoil volume estimates. Any additional mapping and sampling would have no beneficial effect on topsoil volume estimates or reclamation operations at Colowyo. The sequence of topsoil removal at the Colowyo Mine is shown on the Topsoil Handling Map (Map 28) and explained in detail in section 2.05.3 and 2.05.4. Overall, topsoil removal will include all of the A horizon and B horizon material available which is not the heavy clay with the hard columnar structure and sticky, plastic properties less suitable for revegetation. Based on the topsoil volume calculations, and 12+ years of topsoil experience, we have confirmed that there is a sufficient quantity of more desirable horizons with loam and clay loam textures making it unnecessary to remove undesirable heavy clay horizons. In addition, there are areas of rock outcrops or shallow and stoney soils where little or no suitable topsoil is available for removal. The shale or sandstone outcrops within the Work and Burnette mapping units comprise an insignificant area within these two units. Therefore, topsoil volume projections for these areas would not be affected to any significant amount. After lengthy discussion with the Division during the initial permit application, Colowyo had committed to a topsoil monitoring plan as summarized in the ColoMo Findings and Proposed Decision to Approve Permit File No C-019-81, September 28, 1982. "'Colowyo has committed, within the application, to include information in an annual report verifying that enough topsoil is being salvaged each year to replace a sufficient amount of soil on regraded areas. The monitoring program will serve to refine or verify the accuracy of topsoil volume estimates by providing accurate yearly topsoil balance assessments. If, in the future, the Division determines that the monitoring has established, that sufficient topsoil is available throughout the life-of-the-mine to allow successful reclamation given the present topsoil salvage plan, the monitoring requirement may be suspended."' The information had been collected and is found summarized in the 1983, 1984, 1985 and 1986 Annual reports. Overall, Colowyo demonstrated that there is sufficient topsoil available throughout the life of the mine to allow for successful reclamation. Colowyo had requested in the 1986 Annual Report that this monitoring requirement be suspended. This request was subsequently approved. During 2005, Colowyo modified the topsoil redistribution depth based on a volumetric analysis. This determination is provided in Rule 2.05 and the revised distribution depth is discussed in Rule 4.06. Rule 2 Permits 2.04.9-8 Revision Date: 6/23/08 Revision No.: MR-91