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• Name of specialist and date: Jeremy Casterson, 6/12/08 <br />NON-CRITICAL ELEMENTS <br />SOILS <br />Affected Environment: Soils are primarily derived from Lewis Shale and the Williams Fork <br />Formation although smaller areas of Twentymile and Kit-Trout Creek sandstones have also <br />contributed parent materials. Impass silty clay loam, 12 to 25 percent slopes; Impass silty <br />clay loam, 25 to 40 percent slopes; Elkhead clay loam, 0 to 5 percent slopes; Lintim loam, 3 <br />to 12 percent slopes; Impass silty clay loam, 3 to 12 percent slopes; and Phippsberg clay <br />loam, 25 to 65 percent slopes are the soils that are mapped overlying the federal coal estate. <br />All of the soils have deep soil profiles and high water holding capacities except for the <br />Phippsberg which typically has a depth of 20 to 33 inches over weathered shale bedrock and <br />a low water holding capacity. Permeability through the most restrictive soil layer of these <br />soils is moderately low and all but the Routt soils have a high shrink swell potential. These <br />soils have a moderately high to high runoff rate. <br />Environmental Consequences, Proposed Action: The soil resource overlying the zone of <br />subsidence is expected to remain intact with regards to important characteristics and <br />properties. Some fracturing or loosening of the soil profile may occur in areas where the <br />• surface is flexed from the irregular pattern of subsidence and to a lesser degree some <br />compression may result in and near the areas of maximum subsidence. These modifications <br />to the soil profile could result in increased percolation of water in areas that were flexed and <br />reduced percolation in areas which were compressed. These slight modifications to the soil <br />profile are not expected to cause appreciable changes to the characteristics or properties of <br />the soils, especially with regards to fertility or available soil moisture. <br />Environmental Consequences, No Action: Soils would not be affected. <br />Mitigative Measures: None <br />Name of specialist and date: Ole Olsen, 5/2/08 <br />UPLAND VEGETATION <br />Affected Environment: Upland vegetation in the area overlying the proposed mining are <br />composed of grassland, sagebrush-grass, and mountain shrub communities. <br />Environmental Consequences, both alternatives: There would be no direct impact to the <br />overall plant communities from either alternative. <br />Mitigative Measures: None <br />0