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

Home Browse Search

RULE 2 PERMITS Typically the surface layer is a light gray silty clay loam about 1 inch thick. The underlying material is a light brownish gray gravelly, silty clay loam and overlies soft Mancos shale at a depth of 17 inches. 105 - Kemmerer-Moyerson Silty Clay Loams Permeability is slow and available water capacity is low. Surface runoff is rapid and erosion hazard is high. Most of this unit is native range and used for grazing. Present and potential productivity is poor. X110-Kemmerer-Yamac complex A small area (about 5 acres) of this soil complex was disturbed during construction of the access road and the Colowyo administration building. No additional disturbance is anticipated in areas of this soil complex, and no detailed chemical or physical data have been collected. The Yamac soil is a deep, well drained soil forming in loess and sandstone residiuum at a depth of 20 to 60 inches. Typically the surface layer is pale brown loam about 5 inches thick. The subsoil is a pale brown loam about 10 inches thick. The substratum is calcareous, very pale brown loam or light clay loam. The Yamac soil has moderate permeability and the available water capacity is high. The effective rooting depth is 60 inches or more. Surface runoff is moderately low, and erosion hazard is slight from wind and moderate from water. Most of this complex is native range and used for grazing. Present and potential productivity is poor. RL-Rock Outcrop About 70 percent of the surface consists of barren rock exposures. Weakly developed coarse or medium textured soils and talus slopes make up the remaining 30 percent. The major portion of the unit is sandstone. A small area of this series has been disturbed as a source for road surfacing material near the north edge of the lease. No additional disturbance is anticipated, and no detailed chemical or physical data have been collected for this series. Present and potential productivity is poor. Topsoil Suitability Table 2.04.9-1, Suitable Topsoil Available for Reclamation, contains a Summary of the approximate depth of topsoil to be removed for each of the soil series. Table 2.04.9-2, Suitability as a Plant Growth Media of Soils by Horizon in the Area to be Mined, provides an approximate suitability by horizon for the major soils to be disturbed by mining. The chemical and physical data for soils to be disturbed at the Colowyo mine site are shown in Table 2.04.9-3, Chemical and Physical Data for Soils Colowyo Mine. Soil sample locations are shown on the Soils - South Map (Map 6). The information was supplied by the Bureau of Reclamation Lab in Denver, Colorado. Rule 2 Permits 2.04.9-7 Revision Date: 6/23/08 Revision No.: MR-91