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West E!k Mine • 2.04.9 Soils Resource Information History of Soil Surveys at the West Elk Mine During the summer of 1976, the soils of the Nest Elk Mine study azea (Map 3) were mapped. Throughout the soil survey, mapping units were used to chazacterize the soils in the mine azea. These survey mapping units were combinations of Soil Families or selected Great Groups and Sub- groups according to the system of soil taxonomy used in the National Soil Program of the United States (USDA 1976). Subsequent to the 1976 mapping, the Soil Conservation Service mapped the soil on private, state, and BLM lands (SCS 1981) providing soil descriptions based on soil series, soil associations, and soil complexes. During the summer of 1993, the soils of the Gunnison National Forest (including the existing mine permit area, the Jumbo Mountain lease tract, and the Box Canyon lease tract) were mapped following criteria and descriptions contained in the Soil Conservation Service soil survey of the Paonia, Colorado area (SUDA-SCS, 1981). Any discrepancies in soil mapping units can be attributed to the change in soil classification nomenclature during the time between the mapping efforts. The 1976 survey was a general reconnaissance of study area soils. The mapping units were broad in concept and the level of cartographic detail represented in the original mapping was designed with regard for the rough, mountainous topography of the survey area. A baseline soils study was conducted in October 1995 for the Refuse Pile Expansion (RPE) area. Soil sampling was performed in accordance with Rules 2.04.9 and 4.06, and current recommended soil sampling methods. This report is included in Exhibit 70, Appendix M. The current soil survey presents general mapping of soil series and associations based on aerial photography, vegetation types, and field reconnaissance. The maps provide a general overview of the soils in and adjacent to the permit area. Characteristics of soil series which occurred or may occur in the disturbed areas are discussed in detail below. In 1980, a 1" Order soil survey was conducted on the affected area. The West Elk Mine site 1" Order soil survey was based on a 3`' Order survey of the Paonia area performed by the SCS in 1974. A representation of the SCS mapping of the West Elk Mine surface facilities area and the upper refuse disposal area is shown on Figure 15. It is most probable that the SCS delineation of mapping unit boundaries is based orily on vegetation cover and gross topographic changes and does not reflect the intensive field checking that was performed during the 1" Order survey described below. • 2.04-125 Revised lw. 1995 PR06; 11/96 PR07,~Revised Jan. 79977879