2019-06-28_REVISION - M1977004 (9)

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Homestake Mining Company May 10,2019 Regular(112d)Operation Reclamation Permit Application Package approach being pursued in the underground mine workings. However, as more information is gained on the locations of discrete sources within the IRD, more localized/targeted approaches (including but not limited to phosphate injection) may be employed for those zones. Pilot testing of the phosphate injection strategy was conducted in 2015 and 2016. In 2017, two field-scale water recirculation and phosphate dosing/injection systems were constructed and operated; one installed on the IRD for dosing phosphate into saturated waste rock, and one on the South Pit for dosing phosphate into the former underground mine workings. These systems were also operated during the 2018 field season. To date, phosphate injections have resulted in noticeable decreases in uranium concentrations in groundwater downgradient of target injection zones and in seepage water emanating from the Chester Fault springs. Additional details are included in the most recent LPL Update Memorandum submitted to the WQCD and WQCC in July 2018 (Arcadis, 2018). 4.4. Post Mining Land Uses—Wildlife and Grazing Rule 3 of the Hard Rock and Metals Rules and Regulations sets forth the reclamation performance standards applicable to these post-mining land uses. As required under Rule 3.1 the reclamation plan proposed in this amendment will include all necessary features to support these intended and desired post-mining land uses. Within the framework of all future investigations and reclamation tasks to be performed, the Mine is divided into ten OUs. Each OU possesses its unique set of necessary reclamation tasks, with varying timeframes and prioritization; the reclamation needs and timeframes of the individual OUs are discussed in Section 5, below. This amendment, which addresses the updated reclamation plans for the predominantly privately (HMC) owned and more mining-affected areas of the site, focuses only on wildlife and grazing for the remainder of the reclamation. The reasons for this are(1)the mining-affected areas are almost exclusively privately-owned by HMC who does not wish for its private lands to be used for recreation, (2) most of the areas not affected by mining activities lie on USFS-managed lands and already possess recreation-compatible attributes, and require no further reclamation, and (3) reclaiming to post-mining land uses of wildlife and grazing is largely compatible with recreation. The existing reclamation plan was approved as a permit amendment in 1984 for wildlife, grazing, and recreation. HMC has been seeding disturbed areas to grass and forbs for over thirty years, on a variety of disturbed areas and with various additional inputs such as fertilizer, mulch, and different seed mixes. The results, as reported in the annual reports to CDRMS, document the success of the diverse reclamation treatments carried out. The major features of the areas reclaimed to-date include slopes, benches, and drainageways, covered by open grasslands and forest vegetation. Past revegetation efforts included the planting of thousands of seedling trees and shrubs. This resulted in a poor outcome due not only to the short growing season and harsh site conditions, but to the severe impacts of browsing elk and deer. A similar range of slope gradients, topsoil and growth medium replacement, and seed mixes will be used. The planting of seedling trees and shrubs will not be continued under the amended plan. These topics are discussed in detail below. EXHIBIT E-RULE 6.4.5(AMENDED RECLAMATION PLAN) Page 61 HOMESTAKE MINING COMPANY