2012-02-28_REVISION - M1980244 (97)

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Baseline Technical Report ARCADES Report for Soils and Biological Resources, MLE2 Project Area 2.1.9 SI. Ivywild- Catamount complex, 30 to 70 percent slopes Within the Cresson Project area, these soils are found on north - facing mountainsides in association with the dense conifer - dominated woodland vegetation type, and some areas of transitional aspens. Both unit components have formed from colluvium and residuum derived from granite. Both soils are somewhat excessively drained, shallow, and consist of gravelly sandy loam or loamy coarse sand. This soil unit is not present within the survey area. 2.1.10 Sz. Seitz very gravelly loam, 20 to 50 percent slopes Seitz series soils are found on mountainsides with the dense conifer - dominated woodland vegetation type and in some areas of transitional aspen forests. Typically, these soils consist of very gravelly loams and clay loams to a depth of approximately 24 inches, which overlie a subsoil composed of very angular cobbles. A thin surface layer composed of decomposing conifer needles (duff) is often present within the survey area. Approximately 24 percent of the survey area (103 acres) is comprised of this soil unit. Portions of the northern Cresson Project area previously mapped as Seitz series soils have been disturbed by timbering and land- clearing operations. 2.2 Growth Medium Resources As part of the ongoing mining operations at the Cresson Project, CC &V salvages soil that is suitable for assisting with revegetation. Soil recovered for use during reclamation is termed growth medium. The soils information presented in Table 2 -3 is generally representative of growth medium within the District. However, the depth figures for these soil map units are not representative of the depths that can be salvaged. The volume of growth medium that can be salvaged from areas proposed for disturbance is based primarily on the depth of the upper soil horizons, but also is influenced by slope, surface rock, areal extent, and vegetative cover. Regardless of these factors, depths of less than 6 inches are typically considered to be unsalvageable due to the large size of the equipment used to recover soil for reclamation purposes. Growth medium depths vary greatly depending on their position on the terrain, with the shallowest soil on the upper slopes and deepest at the toe of the slope. The presence of rock outcrops in some areas renders salvage operations unmanageable. By removing large roots and stumps and pushing slash, unavoidable mixing of the soil horizons occurs. Many soils within the project area are very to extremely cobbly at shallow depths, which may limit their usefulness as growth medium during reclamation. Field tests of soil pH did not indicate any additional limitations to use of project area soils as secondary growth medium. CCV Baseline Soils Biology Resource Report (11- 17- 11).doc 9