2011-08-08_REVISION - M1977493 (33)

Home Browse Search

• • • Technical Revision (TR -18) Environmental Protection Plan Climax Molybdenum Company Permit No. M- 1977 -493 Dam are monitored visually by Climax personnel. allow for extensive observations. Tenmile TSF and 3 Dam: The Tenmile TSF, 3 Dam, and ancillary facilities such as Tenmile Decant and Tenmile Tunnel are monitored visually by Climax personnel. Piezometers are utilized to monitor water levels in the dam. Periodic inspections also include monitoring seepage to detect unusual flow quantity or clarity changes. Mayflower TSF and 5 Dam: The Mayflower TSF, 5 Dam, and ancillary facilities such as the riser /decant system are monitored visually by Climax personnel. Piezometers are utilized to monitor water levels in the dam. Periodic inspections also include monitoring seepage to detect unusual flow quantity or clarity changes. 5 Dam Seepwater Collection and Return System (Mayflower Pump Station): The 5 Dam seepwater collection and return system at the Mayflower pump station is monitored visually. The pump station contains both stand -by pumps and a stand -by generator set should mechanical or power failures occur. Telemetry to the mill is used to monitor the Mayflower Pump Station remotely. As with all the TSFs, its location, size, and function T -6 Groundwater Groundwater at hardrock mine sites in Colorado is regulated through the DRMS under authority of Senate Bill 89 -181. The groundwater program at the Climax Mine entailed drilling four monitoring wells and conducting sampling and analysis of those wells. The first two wells (GWM -1 and GWM -2) were completed in 1984 in the Tenmile Creek valley below the Mayflower TSF. The third well, located in the Eagle River watershed (Eagle Valley MW, or EVMW) between the Robinson Dam and Eagle Park Reservoir, was installed in late 1993. Likewise, the fourth well was drilled and completed in late 1993 in the Arkansas River watershed (ARwell) at the southwest corner of the reclaimed Arkansas gravel pit. Groundwater has been monitored in the Eagle River and Arkansas River watersheds since late 1993. These monitoring wells have generally been sampled quarterly, weather and site conditions permitting, in general accordance with the 1995 Groundwater Monitoring Plan submitted as TR -08. Revisions to the monitoring program and the schedule for ongoing groundwater monitoring, as well as information on groundwater quality data, are presented in the Water Quality Monitoring Plan included as Appendix T -C. Per Rule 3.1.7(2)(a), the Water Quality Monitoring Plan (Appendix T -C) presents a discussion of the hydrogeologic conditions and practice -based controls which are specific to the three drainages at the Climax mine site. T -7 Surface Water In addition to the water information provided in Exhibit G, information relative to surface water containment and control facilities, surface water quality, the Climax treatment and discharge permit, and surface water monitoring and sampling programs have been discussed thoroughly in Section T -5.0 and in the appendices referenced in that section. The CDPS Permit also contains a discussion of the surface water program at Climax. Maps showing water related features are found in the Figures AM- 06 -T -01 and AM- 06 -T -02. As discussed previously, the Climax Mine site lies within the headwater areas of three watersheds — the East Fork of the Arkansas River, the East Fork of the Eagle River, and Tenmile Creek, with most of the mine's water treatment/management activity occurring within the Tenmile Creek drainage area. Discharge to Tenmile Creek occurs in accordance with CDPS Permit No. CO- 0000248. Before Climax implemented its current water treatment/management system, there was a near complete absence of stream life in Tenmile Creek upstream of its confluence with West Fork Tenmile Creek near Copper Mountain. These conditions were attributable primarily to acid mine drainage from historic mining activity within the headwaters area of Tenmile Creek. Over the past 40 years, Climax has implemented a water treatment/management system in the Tenmile headwaters area, which has included reclamation of many historic mining sites, and capture and treatment of impacted waters from many inactive mines in the drainage area. Since Climax has implemented its water treatment/management scheme, Tenmile Creek has recovered to support a viable and reproducing fishery downstream from the point of the Climax EPP: Revision R1 T -31 July 2011