2019-06-28_REVISION - M1977004 (9)

Home Browse Search

Homestake Mining Company May 10,2019 Regular(112d)Operation Reclamation Permit Application Package The following reclamation activities are proposed within the Landslide Crest Mitigation area: • The upper east slope will be logged and clear-cut to allow for grading and revegetation. • Tension cracks above the eastern crest of the South Pit will be graded to mitigate concentrated infiltration. Sloping toward or around the pit will be performed to facilitate overland flow and minimize channelization. • Extraction and injection wells, water conveyance piping, and reagent dosing systems located in the South Pit area will be maintained as needed to support insitu uranium load reduction in the underground mine working. Additional injection/extraction wells may be installed or replaced as necessary, with approval obtained through Technical Revision requests. Upon completion of the Water Management OU, water recirculation and reagent dosing systems will be removed and disposed of in accordance with regulatory requirements. Injection and extraction wells will be plugged and abandoned using standard procedures or retained for future operating use as necessary for water quality management. Surface disturbances associated with injection system will be regraded and reseeded as necessary. • Monitoring wells/piezometers will be maintained for water level measurement and water quality sampling as long as the Water Management OU is in operation. Additional piezometers may be installed or replaced as necessary as the groundwater monitoring program evolves. Following reclamation of the Water Management OU, piezometers will be plugged and abandoned using standard procedures or retained for future operating use as determined by HMC. All materials removed during wellhead abandonment will be properly disposed of. After surface features of the abandoned wells have been removed, the site will be graded to prepare it for seeding. Existing roads and drainage features within this operable unit are located on private property and will remain open to accommodate general site access and surface water management. The South Pit will be regraded to the final topography shown on Exhibit F Map F-0213, with sections presented on Exhibit F Map F-02C. 5.3. Operable Unit 3: Indian Rock Dump The current topography for the IRD is shown on Exhibit F Map F-03A. 5.3.1. Previous Reclamation The majority of the IRD, including existing roads, drainage features, and the low-grade ore stockpile, has been regraded to its final slopes, terraced, and reseeded. A 36" Corrugated Metal Pipe (CMP) has been installed to convey collected stormwater from the 10300 bench of the IRD to the bottom to mitigate excessive erosion on the face of the lower dump slopes. Per the CDRMS Minerals Program Inspection Report performed on July 25, 2018 (CDRMS, 2018b), the slopes appear stable and vegetation is becoming well established on the reclaimed slopes. 5.3.2. Proposed Reclamation The following reclamation activities are proposed within the IRD area: EXHIBIT E-RULE 6.4.5(AMENDED RECLAMATION PLAN) Page 69 HOMESTAKE MINING COMPANY