2010-12-30_PERMIT FILE - P2010026 (4)

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3.2.1 SOIL DESCRIPTIONS Soil descriptions for the five major soils in the study area, Forelle, Piceance, Redcreek, • Rentsac, Yamac, as well as the minor map units, Disturbed Land and Reclaimed Land, are discussed below. Soils are listed alphabetically and grouped by map unit. Forelle loam (Map Unit 33) is a very deep, well drained soil found on upland hillslopes. Forelle soils formed in alluvium and slope alluvium derived from sedimentary rocks. The native vegetation on these soils consists of mainly shrubs and mixed grasses. Forelle is classified as a "Fine-loamy, mixed, superactive, frigid Ustic Haplargids". Forelle loam comprises approximately 85 percent of map unit 33 (Soil Survey Staff 2009b). Other soils series that may occur within this map unit include the Patent, Piceance, Work, Yamac, and Zoltay series. Approximately 21 acres of Forelle soils were mapped in the study area (14% of total). The representative Forelle loam sample site was located approximately 1,227 feet east, 1,598 feet south of the NW corner of Section 4, T2S, R98W. The landscape at the sample site was a 2% slope with a northwest aspect. Vegetation included big sagebrush, rubber rabbitbrush, and a variety of mixed grasses. The surface was stable with no visible evidence of disturbance or erosion. Forelle typically has an "A" horizon surface layer that is brown loam or sandy loam approximately 4 inches thick. The upper 8 inches of "B" horizon subsoil is brown loam, and the lower 10 inches is highly calcareous loam. The "C" horizon substratum, encountered at a depth of approximately 45 inches, is a light olive brown loam. Shale, interbedded with sandstone and siltstone bedrock, is below 60 inches. Permeability of Forelle is moderate or moderately slow, runoff is slow to medium, and the available water holding capacity is moderate to high. The effective rooting depth is 60 inches or more. The hazard of water erosion is slight to moderate. Forelle is not considered Highly Erodible Land (HEL). Piceance fine sandy loam (in Map Unit 64 and 75) is a moderately deep and well drained soil on broad upland ridges and sideslopes. Piceance soils formed in material weathered from calcareous sandstone. Vegetation is mainly native sagebrush shrub and mixed grasses. Piceance is classified as a "Fine-loamy, mixed, frigid Ustic Haplocambids". Piceance soils comprise approximately 85% of map unit 64. However, Piceance occurs as a minor component of the Rentsac-Piceance complex in map unit 75, comprising approximately 30% of the soils in the Rentsac-Piceance complex (Soil Survey Staff 2009c). Other soils series that may occur within these map units include Forelle, Redcreek, Rentsac, Yamac and Rock outcrop. By using these percentage estimates, we can assume that approximately 46.61 acres of Piceance soils occur in map units 64 and 75 within the study area. is 5