2014-11-19_INSPECTION - M1977493

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PERMIT #: M- 1977 -493 INSPECTOR'S INITIALS: ECS INSPECTION DATE: November 18, 2014 OBSERVATIONS This was a routine monitoring inspection for the Climax molybdenum mine, a 112d -3 hard rock mine operated by the Climax Molybdenum Company — a division of Freeport McMoRan. This site is located at the summit of Freemont Pass on Highway 91. DRMS representatives for this inspection, Eric Scott, and Elliott Russell, arrived on -site at approximately 0900. DRMS was guided/accompanied on the inspection by Climax representatives Brian McGill and Aaron Hilshorst. The DRMS inspection started with a site safety briefing; followed by a general discussion of the site overall, and the results of a recent groundwater study conducted by TetraTech for Climax to attempt to further characterize groundwater between Robinson Dam and the Eagle Park reservoir. Climax has been proactive in gathering additional data to help characterize the groundwater hydrology in this area to determine if additional groundwater protection measures are necessary in this drainage. To date, it appears that the concentrations of several constituents of possible concern in the shallow aquifer monitoring wells have leveled off or even begun to decrease. DRMS then toured the mill, observed the active open pit and the McNulty Gulch OSF area. DRMS noted that the "North 40" low -grade ore storage area has again significantly expanded since the previous inspection, and that the Ceresco Ridge haul road was now well under construction and will likely be completed in early 2015. Waste rock from active mining continues to be deposited on the previously existing footprint of the McNulty Gulch OSF. DRMS recently approved a revision to the McNulty OSF that will allow Climax to increase the height of the OSF while awaiting approval to expand from the current OSF footprint. Activity related to the expansion of the McNulty Gulch OSF as approved has not yet commenced. Mill tailings deposition moved from the Tenmile TSF to the Mayflower TSF during August of 2014 after the successful startup of the new water treatment plant. Because there is remaining tailings capacity in the Tenmile TSF, it will remain available online as a "backup" for tailings deposition for the next several years in the event that there is an upset or some other temporary issue preventing the Mayflower TSF from being utilized. The addition to the avalanche diversion berm located on the west side of the new water treatment plant has been completed and was prepared to be seeded. The topsoil stockpiles created from the stripping of the first 50 foot high perimeter of the Mayflower TSF and parts of Searle Gulch near the south end of the Tenmile TSF dam have also been sloped, seeded and stabilized with BMP's to prevent erosion. While on site DRMS also observed many other features associated with the current operation of the site, such as the Robinson Dam cutoff wall, the bio- solids generation area, Storke Yard pump station, and other water capture, routing, diversion and treatment for the site. All were observed to be operating as designed. Climax also continues to gather data for the characterization of recently identified, likely impacted, groundwater to surface water seep(s) near the base of the reclaimed Stork Yard area. Although some of the seeps show indications that the water is impacted, data collected to date show no observable effects on the surface water of the Arkansas drainage. Mr. Lazuk stated that additional information continues to be gathered by Climax to this end so that an appropriate remediation can be implemented, if needed. Because CDPHE is the primary regulatory entity for surface water quality, Climax has also contacted CDPHE regarding the seeps, and is currently awaiting guidance /direction from CDPHE with regard to these seeps. DRMS will evaluate the data and any potential remedial plans as provided by Climax. No other issues of concern were noted during this inspection. Page 2 of 2