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Modifications to the Approved Reclamation Plan <br /> CC&V proposes replacing the language contained in Section 12.4.3 of the current Reclamation Plan <br /> (Amendment 11, February 2017)with the following language that is more specific to the AGVLF. <br /> Reclamation Plan for the AGVLF <br /> Reclamation of the AGVLF will include rinsing, regrading, revegetating, decommissioning of pipes and <br /> pumping features, and monitoring. Each of these steps is discussed below. <br /> Rinsing: Active leaching for gold recovery is expected to be completed at the AGVLF by approximately <br /> 2025. After completion of active leaching,the VLF will be rinsed using two rinsing cycles of recirculated <br /> solution and fresh water and will require approximately six years to complete. It is anticipated the initial <br /> rinse cycles will be followed by a rinsing cycle using dilute hydrogen peroxide (H2O2) to complete <br /> removal of cyanide (the need for this H2O2 rinse will be evaluated during the initial VLF rinsing). The <br /> financial warranty is based on two standard water rinsing cycles and one H2O2 rinsing cycle over an <br /> approximate six-year period. The rinsing procedure will employ a rinse-rest strategy as approved in prior <br /> submittals. The VLF will be rinsed in segments with portions being actively rinsed while other areas are <br /> allowed to "rest". Rinse water and H2O2 will be circulated using the VLF pumping systems at a pumping <br /> rate of approximately 28,000 gpm. <br /> Rinsing criteria previously approved for the AGVLF is an average concentration of 0.2 mg/L CNWAD in <br /> the rinseate from meteoric water mobility testing on representative sampling of the spent ore, or in return <br /> flows derived from the neutralized ore, or both. A four-year monitoring period will follow the rinsing to <br /> demonstrate compliance with the standard. Physical reclamation of the AGVLF will be completed in <br /> approximately two years and will start concurrent with the monitoring period. <br /> Upon achieving the CNWAD removal criteria, the AGVLF liner system will be perforated to prevent <br /> excessive accumulation of stormwater infiltration in the neutralized ore behind the toe berms and to <br /> move meteoric drain down stormwater into the underlying diatreme rock. A drill rig will be used to drill <br /> from the surface of the ore on the VLF through the synthetic and clay liners into the closure drains and <br /> underdrains, where appropriate. Holes will be drilled to puncture the liner above these features installed <br /> at several locations beneath the Pregnant Solution Storage Areas (PSSAs). This will allow conveyance of <br /> post-reclamation precipitation through the material on the AGVLF and into the underlying diatreme. <br /> Down Gradient Reclamation: Following the achievement of the CNWAD removal criteria for the <br /> AGVLF and following the breaching of the liner systems, down-gradient appurtenances will be <br /> decommissioned and reclaimed as follows. <br /> Pipes, pumps and other structures will be removed from the underdrain collection system, <br /> decontaminated and disposed of as scrap metal or disposed of in a licensed landfill in accordance with <br /> state and federal regulations. The concrete pump-back vault side walls and bottom will be broken up <br /> using a hammer attachment to a backhoe, followed by burial onsite with surrounding fill material. Ponds <br /> will be backfilled with berm materials and re-contoured. The entire area will then be graded to blend with <br /> the surrounding topography, followed by reclamation. <br /> Regrading: The slopes of the AGVLF will be re-contoured to an overall slope of approximately <br /> 2.5H:1 V. Benches created during ore stacking will be retained on the south and west slopes, as <br /> appropriate, for geotechnical and erosional stability. Minimum one-foot high rock berms will be placed <br /> at the edge of the minimum twenty feet wide benches to retain water on the benched areas to minimize <br /> erosion on the side slopes. The berms were sized to retain a five-year storm event. Benches will be <br /> roughened using tracked equipment. The topography shown on Drawing F-1 (site-wide) and F-7 <br /> (AGVLF Detail) and the associated cross sections provided in Attachment 1 show the final design <br /> configuration for the AGVLF. These slopes have been developed based on an overall slope criterion of <br /> 2.5H:1 V. <br />