2012-01-06_PERMIT FILE - C1982057 (16)

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Soils of lesser areal extent occurring within the mine study area include stratified soils forming • on colluvium, alluvial fans, and lower terraces along intermittent drainages (Chapterton, Silas, and Venablel. These soils consist of sandy loam, loam, sandy clay loam, silty clay loam, clay loam, silty clay, and clay to depths greater than 60 inches. Soils with fine textures occur along the tie across haul road corridor. The surface and substratum of these soils (Abor, Bulkley, and Morapos) consist of clay loam, silty clay loam, and clay. Slopes range from 0 to 30 percent. The hillside slopes and benches are farmed and cropped to wheat. The alluvial fan drainages have agrassland-shrub vegetation cover. The Spicerton Variant soil which exists in the drainages has a very saline and sodic subsoil and substratum. Soil Laboratory Data. The results of laboratory analysis of all soil samples collected during the 1979, 1989, 7990, and 1997 soil surveys are provided in Appendix 9-4, Soil Laboratory Data. The soils are dominantly moderately acidic to moderately alkaline, non-sodic, and non-saline, although one saline-sodic soil was encountered in a lowland area along the tie across haul road corridor. With exception of this soil, analytical data indicate acceptable values for conductivity (EC1, sodium adsorption ratio (SARI, soil reaction IpHI, boron, selenium, and trace metals. The limiting factors for use of these soils as a topdressing medium are clayey and rocky subsoils. • Saturation percentage values typically reflect soil texture, organic matter levels, and clay mineralogy. Saturation percentage values range from 25 to 35 percent for the coarse-loamy soils, 35 to 55 percent for the fine-loamy soils, and 55 to 99 percent for the fine or clayey soils. Soil reaction ranges from strongly acid (pH 5.11 to moderately alkaline IpH 8.21 with the majority of the soils being slightly acid to neutral (pH 6.1 to 7.31. The lowest pH levels. associated with subsurface soil horizons, are attributable to leaching of bases. The highest pH levels are associated with the accumulation of sodium and magnesium salts in subsurface horizons. Very few soils had lime accumulations in subsoil or substratum horizons. The clayey soils which have developed on soft shales had slight accumulations of lime and/or gypsum in their substratum. The amount and composition of water soluble cations also influences soil suitability for use in reclamation. Most soils within the study area have suitable quantities and ratios of cations. Salinity and sodicity values are very low, typically less than 1.0 mmhos/cm and 2, respectively. Calcium is the dominant water soluble cation, followed by magnesium, and then sodium for most soils within the study area. Only one soil exceeded the recommended limit for EC and • SAR. This soil (Spicerton variant) is associated with the saline-sodic alluvial lowlands of the tie across haul road corridor. 25 Revised 9/96