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Homestake Mining Company May 10,2019 <br /> Regular(112d)Operation Reclamation Permit Application Package <br /> This proposed amended reclamation plan seeks to update the current plan (HMC, 1984) and <br /> address the final earthwork and grading, geotechnical stability, outstanding water quality <br /> conditions (for both surface and groundwater), sediment controls, roads, and revegetation in <br /> areas not reclaimed. As appropriate, this amendment captures aspects of the currently-approved <br /> 1984 amendment and the subsequent series of technical revisions, plus any additional aspects <br /> of reclamation that have now come to be recognized as necessary. There are numerous areas of <br /> this amendment which HMC cannot yet fully define, though their subjects are identified herein; <br /> those areas will be fully defined and incorporated into an updated reclamation plan in the future <br /> through a series of technical revisions, as their details can be determined. For example, once the <br /> LPL is determined, HMC will be able to work with CDRMS to determine what additional measures <br /> will need to be implemented for final site closure and reclamation. <br /> At present, water quality is only a concern for surface water discharging from the Project at the <br /> surface water outfall (Outfall 001, monitoring point SW-33 as shown in Exhibit G, Map G-02), with <br /> dissolved uranium representing the primary concern from a water quality compliance perspective. <br /> At present, water quality at SW-33 on Indian Creek is regulated based on a Colorado Discharge <br /> Permit System (CDPS) permit (number C00022756) issued in 2010; this permit is expired but <br /> has been administratively extended. In addition, a Temporary Modification was issued for <br /> Marshall Creek in 2018 stipulating a "current condition" water quality standard for uranium; this <br /> Temporary Modification is set to expire on December 31, 2022. In cooperation with the Colorado <br /> Water Quality Control Division (CWQCD), HMC is currently working to define the "Lowest <br /> Practical Level' (LPL) for radionuclides in surface water; it is anticipated that this LPL will <br /> ultimately serve as the uranium compliance standard in the discharge permit, once defined. The <br /> Temporary Modification on Marshall Creek, as well as the delay in reissuance of the discharge <br /> permit, are currently providing time for HMC to establish the definition of the LPL, which will be <br /> based on implementable Best Management Practices (BMPs) for achieving uranium load <br /> reduction. <br /> Besides the objectives of reclaiming the site to meet the standards consistent with the desired <br /> post-mining land uses of wildlife and grazing, HMC adopted a general goal of minimizing <br /> maintenance to guide developing the amended reclamation plan. This will require that sufficient <br /> grading and revegetation be carried out to provide the long-term physical and erosional stability <br /> of the rock dumps and pit slopes, with drainage controls that can adequately convey the design <br /> storm events, and to confirm that water quality can meet the discharge water quality standards <br /> without employing year-round active treatments. <br /> EXHIBIT E-RULE 6.4.5(AMENDED RECLAMATION PLAN) Page 2 <br /> HOMESTAKE MINING COMPANY <br />