Laserfiche WebLink
5.3.2.4 No.4 Dam (Eagle Park Reservoir Dam) Seepwater Pump System <br /> Description: Seepwater from the toe of No. 4 Dam is collected in a sump and pumped back to <br /> the No. 4 Dam Reservoir via a 4-inch pipeline, measuring 0.2 miles in length. There are also two <br /> small ponds located at the toe of the dam. One pond is a seepage collection sump and the other <br /> is for pumpback. <br /> Location: The collection system is located at the base of No. 4 Dam and the pipeline runs along <br /> the southwestern face of Sheep Mountain from the toe of the dam to the reservoir. <br /> Spill Potential: Failure of the lower 500 feet or so of pipeline could result in a discharge of <br /> seepwater to the Eagle River. A leak also has the potential to erode soil on the face of the dam <br /> and create a sediment load to the drainage. A rupture in the pipeline above the dam crest would <br /> be negligible as far as discharge to the Eagle River is concerned, because it would simply flow <br /> back into the reservoir. <br /> Potential Volume Spilled: The maximum estimated volume of seepwater potentially spilled is <br /> on the order of 1000 gallons. <br /> Prevention and Control: An earthen berm below the lower portion of the pipeline will divert <br /> any spillage to the collection pond. In the event of pump failure, the collection pond has a <br /> minimum surge capacity to hold over 24 hours worth of seepage. In addition, there is a stand-by <br /> pump installed, as well as a stand-by generator in the event of a prolonged electrical power <br /> outage. The water level of the collection pond is controlled to allow maximum surge capacity. <br /> Countermeasures: If the pipeline ruptures, the seepwater pump should be shut down until the <br /> line is repaired or replaced. If the main pump fails, the stand-by pump can be used until the main <br /> pump is replaced or repaired. In the event of any prolonged shutdown, portable engine-driven <br /> pumps could be used to prevent the overflow of the seepwater collection pond. Any now <br /> overtopping the collection pond should be controlled, at least temporarily, by building an earthen <br /> dike for containment. If practical under the conditions, a series of dikes can be built to. prevent <br /> flow from entering the Eagle River. Crushed limestone or slaked lime can be added to the <br /> escaping water to raise the pH. <br /> Nearest Clean-up Equipment: Portable engine-driven pumps are located onsite. Flexible <br /> plastic pipe and couplings are located in the Warehouse. Crushed limestone is available at the <br /> Tailing Delivery House and at the lime slaking facility. <br /> Monitoring: Visual checks of the pump system and pipeline are conducted daily. Failure alarm <br /> lights are visibly inspected from as far away as Robinson Lake Road. <br /> 51 <br />