2024-05-17_REVISION - M1977493 (4)

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Interceptor canals may also be constructed within the pit to reduce the volume of water requiring pumping. A system is currently under construction that is located downstream of the primary collection and containment system. This new system will provide a means of collecting additional impacted water below 5 Dam. This system will collect and convey the impacted water into the existing Mayflower Pump System for eventual delivery into the Mayflower TSF water pool. G-2.10 Water Treatment Systems The current water treatment process at the site generally consists of two-stage pH adjustment using slaked lime. First-stage treatment consists of raising the pH of the water to circumneutral,followed by precipitation of solids in a clarifier or water pool. Second-stage treatment consists of raising the pH to about 9.5, again followed by precipitation of solids in a clarifier or water pool. After second-stage treatment, the effluent is neutralized using sulfuric acid priorto discharge into Tenmile Creek. The primary facilities currently used for water treatment are the Lime Station, SDP, Tenmile TSF, Mayflower TSF, and the PDWTP. The Sludge Densification Plant (SDP) was commissioned in 2007 to improve first-stage water treatment capabilities at the site. The primary purpose of the SDP is to generate dense sludge from the highest solid generating waters at the site, as well as to improve the removal of aluminum and molybdenum. The maximum capacity of the SDP is approximately 6,900 gpm. Flows above this capacity are routed directly to first-stage treatment in the Tenmile TSF as described below. The impacted waters from the underground mine workings (5-Shaft),the Storke area, Camp area, North 40 OSF, and McNulty OSF are collected and delivered to the SDP through the former ETDL. Impacted waters from 1 Dam, 4 Dam, and the Robinson Lake area are collected and conveyed to the SDP through the Warren's Pump System and 2 Dam Pipeline. Lastly, impacted water from 3 Dam is collected and conveyed to the SDP through the 3 Dam Seepwater Pump System. Less impacted waters tributary to Tenmile TSF bypass the SDP and flow directly into Tenmile TSF water pool.All of these water sources receive first-stage treatment in either the SDP or the Tenmile TSF water pool, or both. Impacted seepage from 5 Dam is pumped to the water pool on Mayflower TSF using the Mayflower Seepwater Pump System. The first-stage effluent from the Tenmile TSF water pool is decanted into the Tenmile Tunnel through the Tenmile Decant and delivered to Mayflower TSF. The bulkhead inside the Tenmile Tunnel can also be configured to direct watertoward Robinson Lake. These valves, however,are normally closed during periods when water is not needed for mine production. The high density sludge generated at the SDP is delivered to the Sludge Disposal Cell located on Tenmile TSF. In the current configuration,the SDP continues to be used to provide first-stage treatment of impacted waters, with the sludge pumped into the disposal cell located on the east side of the Tenmile TSF. First-stage treatment of other impacted water takes place in the Mayflower TSF water pool. The pH of the tailing slurry is expected to be consistent with first-stage treatment. Excess water in Mayflower TSF is delivered to the PDWTP using the Mayflower Plant Barge. The PDWTP is required to provide second-stage treatment of the impacted waters prior to discharge to Tenmile Creek. The flow capacity of the PDWTP is a nominal 14,000 gpm, which limits the total discharge capacity of the process water system. This makes it necessary to utilize detention storage during the spring snowmelt season to manage impacted water at the site. Sludge that is generated at the treatment plant is hauled by truck to a disposal cell located along the east side of Mayflower TSF. The main detention storage capacity during spring runoff will continue to be the water pools on the Mayflower and Tenmile TSFs,with some additional storage provided by Robinson Lake. The water management plan for the site is used to determine the appropriate drawdown in these storage facilities prior to the snowmelt season to maintain water levels within defined limits.The operational storage capacity of the Mayflower TSF water pool increases somewhat as tailing is deposited in this facility. The annual volume of water that is treated and released from the Climax Mine site at the PDWTP over the last 9 years has been about 9,340 acre-feet (approximately 5,800 gpm average annual rate). Peak flows through the system vary significantly depending upon climatic conditions, with a maximum release rate of 14,000 gpm. Exhibit G G-8 May 2024