2002-03-04_REVISION - M1986015 (8)

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SOILS INFORMATION Exhibit I Soils Information The soils of this site are generally of an alluvial origin and exhibit properties ranging from sandy looms to clay looms. As expected, the more coarse soils are closer to the river while the more silty and clay soils are found further from the river. The clay materials probably come from more upland areas and through erosion and deposition become mixed with the silts and sands deposited by the river. The Soil Conservation Service (now, the Natural Resources Conservation Service) soil surveys of this area extensively describe the soils o£ the site. The various properties of the soils are described later in a summary format. These descriptions are followed by diagrams that represent the typical cross-sections of the soils. A separate section discusses potentially problematic soils. In addition to the descriptions, a separate section describes the area of each soil type and the estimated volume of salvageable soil present within the area to be mined. These areas and volumes are derived from the soil map in Exhibit C-5. Exhibit J, Vegetation Information, provides not only a description of the vegetation found on the site but the relationships that exist between the vegetation and soils. In most cases the correlation between soil and vegetation is rather poor, except for those areas still dominated by natural vegetation units. Where various human influences occur (farming, grazing, timber removal, etc.) the vegetation and the soils exhibit very little relationship. For a description of how the soils will be utilized in the reclamation of the site, please refer to the Reclamation Plan, Exhibit F. Soil Areas and Volumes Within the area to be affected in Phase 1, the following table shows the estimated volume of each soil that is potentially salvageable. These volumes only include the upper horizons of the soil and not necessarily any of the lower horizons. In actual practice, some mixing of the horizons will occur simply because, in some cases, the boundary between horizons is vague at best, This does not necessarily represent the amount of soil that will be replaced in the reclamation. This is because much of the mined land will be converted to water surface in the form of a sealed reservoir. There is no need to topsoil the reservoir bottom. Soil salvaged below the nominal salvage depth will be considered overburden. The nominal salvage depth is estimated from the diagrammatic cross-sections of each soil. The Pueblo East Pit Amendment Exhibit I Page 1