2011-03-14_REVISION - M1977493 (48)

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Permit Amendment (AM-06) - Climax Mine CM0000079 G-2.6.5 McNulty Well • The McNulty Well is a fresh water bedrock well located along the east side of the former Robinson TSF. Water pumped from the well is used as a backup source of fresh water at the Lime Station and SDP. G-3 Phase I Deposition Water Management The Phase I Deposition scenario is the initial period of mineral extraction and production when tailing is being deposited in Tenmile TSF. The most significant changes from the existing non-operating scenario to the Phase I Deposition scenario include the activation of a reclaim water system to supply water to the mill and a tailing delivery and deposition system. Both of these systems have an impact on water handling throughout the site. G-3.1 System Overview The current mine plan accounts for approximately 26 million tons of tailing being deposited in Tenmile TSF. A general arrangement of the Phase I Deposition system configuration is shown on Figure AM-06-G-02 and a schematic depiction of the Phase I Deposition facility configuration is shown on Figure AM-06-G-09. As highlighted on Figure AM-06-G-09, the most significant additional water handling facilities that will be required for Phase I Deposition include a new reclaim water pumping system to pump water from Robinson Lake to a new storage tank near the mill, and a new tailing delivery and distribution system to convey tailing from the mill to Tenmile TSF. These new facilities are generally replacements of existing facilities that have become outdated or deteriorated through the recent period of non-operation. Although mine operation will increase the consumption of water, there will still be excess process water that will require treatment and discharge from the site. Water treatment systems will continue to operate as required for compliance with regulatory requirements. Excess water will receive first-stage treatment in the SDP or the Tenmile TSF water pool, second-stage treatment in the Mayflower TSF water pool, and neutralization at the Mayflower pH Control Station prior to being discharged into Tenmile Creek. Reference Section G-8 for a description of the CIVIC water rights portfolio. For this scenario, changes will also be made to the water and wastewater distribution systems in the mill area, including new potable water and sanitary wastewater treatment facilities. G-3.2 TSF Development Climax intends to deposit tailing onto the TSFs using the upstream deposition method through a header and spigot tailing distribution system, similar to long-standing prior practices at the site. As the tailing slurry flows toward the water pool, the coarser tailing sands settle out first and become deposited on the beach between the dam crest and the water pool. The build-up of tailing sands on the beach effectively raises the height of the dam crest thereby creating additional water storage capacity. The finer tailing materials ("slimes' are transported to the water pool, where they settle to the bottom. During the summer months, tailing is deposited onto the beach through multiple spigots to promote dam crest raises. It has been assumed that annual spigot deposition will be completed for Tenmile TSF with two passes across the dam crest. The spigot deposition period typically lasts about five to six months, depending primarily on weather conditions. When the final set of spigots is used to complete a full pass, the entire dam crest will have been raised and the facility will gain water storage capacity. During the winter, however, shallow tailing slurry deposited from spigots would tend to freeze and could create ice lenses near the dam crest. Ice lenses could have stability implications on the TSF and the build-up of ice at the ends of the spigot pipes could restrict slurry flow toward the water pool. To mitigate these risks, tailing is deposited through larger-diameter and longer leadoffs during the winter months. These leadoffs produce a tailing stream that tends to flow directly into the water pool and little tailing is deposited on the beach. Tenmile TSF, which is formed by 3 Dam, is an existing facility that was first developed in the 1950's. The current Mine Plan calls for the deposition of approximately 26 million tons of additional tailing in the facility; primarily during the first few years of mineral extraction and production. The additional deposition is expected to raise the dam crest elevation by about 25 feet. As shown on Figure AM-06-G-02, tailing slurry will be Exhibit G G-6 May 2010