2019-06-28_REVISION - M1977004 (11)

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Homestake Mining Company May 10,2019 Regular(112d)Operation Reclamation Permit Application Package through 1962). The Pinnacle Mine was shut down in 1962, and solution mining from the underground mine workings was started in 1968 through 1972. In 1970, an open pit was developed for the heap leaching of low-grade ore. HMC acquired the Pinnacle Mine property from Pinnacle in 1972. Under HMC, the Mine was developed using open pit mining methods from 1979 to 1984 from two pits(North and South Pits). Open pit mining operations ceased in 1984, due to suppressed uranium prices and a major pit wall failure on the north east wall of the North Pit. Safety concerns for operating in the pit bottom, combined with dropping uranium prices in 1983, led to the curtailing and eventual cessation of mining operations. Approximately 275,000 dry tons of ore were produced yielding 2.0 million pounds of uranium ore) from the open pit mine operations. No milling or processing was performed onsite, as run of mine ore was shipped to Grants uranium mill in New Mexico for processing. The initial open pit mine plan was based on development of the North Pit, followed by development of the South Pit, with waste rock from the South Pit being used to backfill the North Pit and a pit lake being formed in the South Pit. As a consequence of the cessation of mining operations, the North Pit was not completely excavated and waste rock backfilling from the South Pit was not undertaken. This resulted in the partial backfilling the South Pit and a pit lake being formed in the North Pit. 2.3. Reclamation Plan and Technical Revision History The reclamation plans and associated technical revisions submitted for the Mine are summarized as follows: • Mine Permit M-1977-004 (April 19, 1978). The Mined Land Reclamation Board (MLRB), Department of Natural Resources, State of Colorado issued a Development and Extraction Mining Permit in which an application, reclamation plan and related permit fees were submitted for an open pit and underground mining operation. A summary of the reclamation activities presented in Appendix B of the permit application are as follows: o Monitor and minimize infiltration of water through the waste and overburden dumps. o Prepare a geotechnical program for evaluating stability problems in the mine rock dump, in addition to conducting a regular annual geotechnical inspection program of the dumps until all dumps have been completed. o Construct waste or overburden dumps such that "pockets" of radioactive ore or waste material are buried such that radioactive or toxic material will not enter the drainage of finished dumps. o Should water discharge exceed applicable standards, the discharge will be treated to achieve compliance with standards. o Locate ore stockpiles where runoff can be diverted, or contaminated water collected. o Regardless of whether a pit lake does or does not form in the mined pit, water will be treated to assure compliance with applicable standards before such waters are EXHIBIT E-RULE 6.4.5(AMENDED RECLAMATION PLAN) Page 4 HOMESTAKE MINING COMPANY