1987-12-01_PERMIT FILE - C1981017 (185)

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Chapter IV b. Description of Renewable Resource Lands. Renewable resource lands that can be identified above underground workings, or within the areas of possible surface subsidence, consist of grazing lands and aquifer recharge areas. At elevations between 10,000 and 12,000 feet, and on unusually rugged mountainous surface terrain, there is limited grazing during the summer months which may qualify a portion of the surface area as renewable resource lands. It is estimated that only about 25% of the possible surface subsidence area contains grazing and browsing vegetation. The remainder is barren rock fields, rock cliffs and shale slides. There is no marketable timber or agriculture land due to the nature of the soils, the rugged topography and the climate at such high elevations. None of the U.S. Forest Service cattle grazing permits extend to the high elevations where possible surface subsidence could occur. One sheep grazing permit is granted in the Gunnison National Forest portion of the mining permit area. It lies above a small portion of the area that could possibly be affected by surface subsidence. A few elk and deer graze along the high rugged slopes and along the crest of Huntsman Ridge in early summer. They move to lower elevations in late summer, and none winter in the permit area. Hydrologic studies of the permit area show that the major aquifers lie in the Rollins Sandstone formation which is below the coal seams being mined. Sandstone lithologic units within the Mesaverde above the coal possess transmissivities and specific yields of such low values that regional hydrology would not be influenced significantly by underground mining activities. (See Section C -4 -b. Volume 4). During the adequacy review of this section by MLRD in 1981 -83, Mid - Continent's contention that underground mining activities would not significantly influence the regional hydrology was challenged. The following explanation was presented by Willard Owens consulting company on the protection of the hydrologic balance in Coal Basin: — "Our statements suggesting that the transmissivity and specific yields of the Mesaverde Formation are so low that the regional hydrology would not be significantly altered by mining activities are supported by the general conclusions of the 'West Central Colorado Coal Environmental Statement." In pursuing additional data on the transmissivity and specific yield of the Mesaverde Formation, we contacted personnel with the USGS office in Grand Junction. The USGS is currently undertaking a 3 to 5 year program to evaluate all groundwater aquifers in the area. However, the Mesaverde Formation is not a particularly significant aquifer in this study. As yet, the USGS personnel have collected no permeability data on the Mesaverde 27