Laserfiche WebLink
Technical Revision (TR -18) Climax Molybdenum Company <br />Environmental Protection Plan Permit No. M- 1977 -493 <br />visually by designated employees. <br />T - 5.5.2 Eagle River Watershed <br />Robinson TSF and 1 Dam: As discussed previously, 1 Dam has been reconfigured, stabilized, and <br />reseeded. Monitoring of this EPF is conducted visually by various mine personnel. Piezometers are <br />utilized to monitor water levels in the dam. <br />Robinson Lake and Dam: Visual monitoring of Robinson Lake is performed routinely by Climax <br />personnel. When the construction of the Robinson Lake Pump Station is completed and the facility <br />brought online, it will operate as the main level control for Robinson Lake. A water level indicator will be <br />installed to continuously monitor the water level within Robinson Lake. The water level indicator will be <br />connected telemetrically to the mill control room to provide immediate notification should water levels <br />exceed set points for high water action levels. <br />Robinson Dam is considered to be a jurisdictional dam by the Dam Safety Branch of the Colorado State <br />Engineer's Office (SEO) and must therefore meet the dam safety and inspection requirements of the <br />SEO's "Rules and Regulations for Dam Safety and Dam Construction." The Dam is inspected regularly <br />by Climax personnel and generally once per year by SEO personnel. <br />A total of nine piezometers are located in the Robinson Dam embankment. Climax personnel routinely <br />monitor the piezometers and maintain a database of phreatic water levels. <br />A foundation drain system is located on the right downstream abutment of the dam. The flow rate from <br />the drain is monitored regularly by Climax personnel and recorded during the SEO's Dam Safety <br />Engineer's inspections. A small collection pond near the toe of the dam also collects dam seepage. This <br />system is monitored regularly by Climax personnel; however, this system also collects some surface <br />runoff and shallow subsurface flows from the area to the left of the dam embankment. <br />Six structural monuments are located along the crest of the dam for monitoring for ground movement. <br />These monuments are surveyed once per year, or more frequently if requested by the SEO, to monitor for <br />indications of settlement, sliding, or dam instability. <br />Warren's Pump System: Warren's Pump Station is checked regularly by mine personnel and contains <br />appropriate alarms to provide immediate notification should pump failure occur. <br />Robinson Lake Seepage Pump Station: Water level readings from a level probe in the wet well control <br />the on /off operation of the pumps. A backup generator, which is located in the Robinson Lake Pump <br />Station, provides backup power to the seepwater system in the event of a power failure. This system is <br />monitored regularly by Climax personnel. <br />4 Dam Seepage Collection and Pump Station: This seepage return station is checked regularly by mine <br />personnel. Water level readings from a level probe control the on/off operation of the pumps. In addition, <br />a beacon alarm is situated atop the dam to alert personnel in the case of pump failure. A back -up pump <br />is situated at the station as well as a back -up generator set to run the seep pump in case of power failure. <br />The channel immediately below the 4 Dam seepage collection system primarily conveys only water <br />released from the Eagle Park Reservoir (EPR) and localized run -off from precipitation or snowmelt <br />events. As part of its EPF monitoring program, Climax will visually inspect the stream channel below the <br />seepage collection system and EPR outlet works during periods of no natural flow or discharge from the <br />reservoir. <br />Robinson Lake Pump System: The pump station is designed for normal operation with two pumps <br />running. A third pump is installed as a backup during normal operating conditions and could be used to <br />evacuate additional water from Robinson Lake if needed. Pressure indicators on the intake and <br />discharge sides of the pumps will control operation of the pumps and will also be tied to automated <br />alarms to warn of upset conditions. As with the other pump stations at Climax, the pump station pressure <br />EPP: Version R2 <br />T -32 December 2011 <br />