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Soil Survey Map and Soil Descriptions <br /> The following soil survey data have been included to document site-specific soil conditions <br /> relevant to reclamation and erosion control at the GEM Mine Reclamation Project. These soils <br /> correspond to those identified within the project boundary and surrounding slopes, as defined by <br /> the NRCS Web Soil Survey(Georgetown Area, CO, 2025). <br /> These soils correspond to NRCS Map Units 27 and 23 respectively, as detailed in the NRCS map <br /> unit descriptions attached in this exhibit. <br /> Existing Soil Data <br /> Data Sources: <br /> U.S. Department of Agriculture (NRCS)— Web Soil Survey, Georgetown Area, Colorado(2025). <br /> Supplemental source: Mountain Top Environmental field observations and site soil testing at the <br /> GEM Mine Reclamation Area. <br /> Summary of Soils Within the Limits of Construction: <br /> 1. Arents—Dumps, Mine Complex(5-80 % slopes): Highly disturbed mine spoils with <br /> very low organic content and acidic pH (5.0-6.2). Soils are well drained to somewhat <br /> excessively drained, with very low water holding capacity and severe erosion potential <br /> when unvegetated. Surface fragment content is>60%,primarily igneous and <br /> metamorphic rock fragments. Hydrologic Soil Group D. Runoff potential is very high. <br /> 2. Cathedral—Rock Outcrop Complex(5-30 % slopes): Thin mountain soils interspersed <br /> with bedrock outcrop. Depth to bedrock 10-20 inches(Cathedral series)to 0 inches <br /> (Rock Outcrop). Soils are well drained, with low available water capacity(—0.7 in.). <br /> Hydrologic Soil Group D; land capability class 6e—steep terrain and erosion limit use for <br /> cultivation. <br /> Erodibility and Runoff Risk: <br /> Both map units have high K-factors(>0.37), indicating strong susceptibility to sheet and rill <br /> erosion during rainfall events if not stabilized. Temporary and permanent erosion control BMPs <br /> will be implemented as outlined in the SWMP Section 4 and Section 8 to stabilize soils during <br /> and after construction. <br /> Reference Mapping: <br /> Figure E-1 —Soil Survey Map, GEM Mine Reclamation Area (USDA NRCS Web Soil Survey, <br /> Georgetown Area, CO 2025) is attached to this SWMP. <br /> The map delineates the extent of both soil units within the project boundary and adjacent <br /> undisturbed areas. <br />