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Homestake Mining Company May 10,2019 <br /> Regular(112d)Operation Reclamation Permit Application Package <br /> In contrast, the sericite clay-lined low-grade ore stockpile also located within the IRD likely <br /> contributes less uranium load given its placement above the saturated zone in the IRD. <br /> 3.3.4.5. Tie Camp Rock Dump <br /> Similar to Indian drainage, flow gains along Tie Camp drainage downstream of the TRD are <br /> indicative of groundwater discharge of flow and uranium load likely ultimately sourced from the <br /> dump, despite decreasing flows from the TCRD toe drain. As with the IRD, uranium load may be <br /> coming from a combination of dispersed sources (low-grade ore distributed through the dump) <br /> and/or localized hot-spots, including the sericite-lined low-grade ore stockpile and/or the disposal <br /> cell. However, the latter possibility is not likely to be significant given the placement of material <br /> above the water table. A third possibility is that some of this uranium load enters the TCRD from <br /> outside, including water flow from the Chester Fault/underground mine workings disturbed zone <br /> to the northeast (based on tracer results described above). <br /> 3.4. Slope Movement <br /> The following discussion in this section is provided to comply with the requirements of Hard Rock <br /> and Metals Rule 6.5— Geotechnical Stability Exhibit. <br /> 3.4.1. History of Slope Movement <br /> HMC began excavating the North Pit in 1979, and indications of slope movement became <br /> apparent shortly thereafter. Since then, slope movement has occurred at multiple locations, <br /> including other locations in the North Pit, the South Pit, IRD and the TRD (Figure 3-15). These <br /> events range from small rotational failures in overburden to large complex landslides in bedrock. <br /> The significant slope failure events documented at the site include: <br /> 1. The East Wall of the North Pit (since 1979). <br /> 2. The East Wall 10,500 ft slope failure (1980). <br /> 3. The Northwest Corner slope failure (March 1983). <br /> 4. The South Wall Slope failure (April 1983). <br /> 5. The Northeast Corner slope failure (March 1983). <br /> 6. The Northeast Corner slope failure October 1983). <br /> 7. The South Wall slope failure (since 1996). <br /> 8. The East Wall of the South Pit (since at least 2005). <br /> EXHIBIT E-RULE 6.4.5(AMENDED RECLAMATION PLAN) Page 38 <br /> HOMESTAKE MINING COMPANY <br />