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Topsoils in this area are described in the Natural Resource Conservation Service soil survey of <br /> the area as sandy, cobbly loam and sandy clay loam. This is typical of the topsoils in this area <br /> that have readily visible alluvium mixed in with soil. Aggregate in the area consists of significant <br /> portions of river rock ranging in size along with sand. No clay lenses or zones have been <br /> identified in the materials onsite. <br /> 3_1 GALENA Results <br /> Table 1 shows the lowest factor of safety for each station. <br /> Table 1 —Lowest Factor of Safety at Each Station <br /> Station Lowest Factor of Safety Notes <br /> 8+80 _ 1.14 Failure circle is within topsoil berm only. <br /> 31 8+20 _ 1.62 Toe of topsoil berm is close to ditch <br /> 61+50 1.31 ; Failure circle is entirely within pit <br /> Station 38+20 is inherently stable, above and beyond the DRMS requirement of a factor of safety <br /> of 1.5. Station 61+50 is below 1.5 but is above the standard engineering minimum of 1.3. It is <br /> also an active mining slope, and thus is a temporary slope. Final backfilling and grading will <br /> eventually bring it to a final permanently stable slope. The FOS circles can be seen on Map C-4 <br /> under each station. <br /> Station 8+80 shows that the topsoil berm's south facing slope is not stable enough for either <br /> DRMS standards or standard engineering minimums. The lowest factor of safety (1.14) shows a <br /> failure circle that would see a fairly thin circle of material on the face of the berm slide off down <br /> towards the toe of the berm. It should be noted that no failure circle extends beyond the toe of the <br /> berm. The GALENA data shows that a failure circle with a factor of safety of 1.5 would extend <br /> from the toe of the berm toward roughly the midpoint of the berm top. This FOS circle is shown <br /> on the attached Map C-4 under Station 8+80. <br /> 4. Conclusion <br /> The slope stability analysis of stations 38+20 and 61+50 show that there is no risk to the ditch or <br /> power poles south of the operation. The slopes are either stable or the failures that could take <br /> place would not come within 100 feet of the nearest structure. <br /> Station 8+80 shows that the south side of the topsoil berm is not stable. The failure circle for a <br /> FOS of 1.5 (DRMS minimum in this case) would not lead to a slope failure outside of the berm, <br /> but would see a significant portion of the berm slide down onto the flat portion of the property to <br /> the immediate south. The entirety of the failure slide would be topsoil which is to be removed <br /> and used in reclamation. Additionally, the berm has been in place for over 15 years with no signs <br /> of slope failures. This is expected since it has a factor of safety greater than 1.0 and is made of <br /> consistent material top to bottom. <br /> Since the DRMS minimum standard for FOS in this situation is 1.5,the berm that passes through <br /> Station 8+80 needs to be regraded to a shallower slope on the south side. United Companies, the <br />