Laserfiche WebLink
I 5.3.2 Tailing and Industrial Water System in the Eagle River Drainage <br />• 5.3.2.1 No. l Dam Seepage Collection Facility (SCF) <br />Description: The SCF consists of several components designed and constructed to deliver <br />seepage water from No. 1 Dam to a pump station where the seepage is pumped back to the Ten <br />Mile Drainage Basin. The SCF components are as follows: <br />• a series of drop inlet structures around the perimeter of a small basin at the base of No. 1 <br />Dam that captures subdrain inflow; <br />• a 1500 foot long pipe that delivers seepage water to the pump station; <br />• a clay-lined dike downgradient from the drop inlets to encourage ponding of seepage water <br />and collection within the system; <br />• a small holding pond at the pump station created by another earthen dike to encourage <br />ponding at the pump station; <br />• an electrical substation for power; <br />• the pump station itself which is a 24 ft x 36 ft building enclosure, housing two 300 <br />horsepower pumps and sump (capability exists to expand to three pumps); and <br />• a 5100 foot long, 20 inch diameter HDPE pipeline to deliver the pumped seepage water to the <br />Ten Mile Tailing Pond. <br />Location: The SCF is located within the boundaries of the existing Robinson Lake, except for <br />the pipeline that connects the SCF and the tailing pond. Generally, the pump station's location <br />can be described as 2000 feet west of base of No. 1 Dam. <br />Spill Potential: Under normal operating conditions, the water level of Robinson Lake is <br />controlled by transferring water into the Industrial Water System via pumps and a distribution <br />network. Should the No. 1 Dam Seepage Collection Facility fail, for whatever reason, the <br />seepage water would flow into Robinson Lake. In the event of an emergency overflow condition, <br />the reservoir's spillway would dischazge duectIy into the Upper North Interceptor Canal which, <br />in turn, dischazges into the Eagle River. This is not likely to occur, and sand-bagging the <br />reservoir spillway to retazd flow is a control option. Several hundred gallons could be spilled <br />into the Eagle drainage, but the Upper North Interceptor Canal "cut-out" would have to be <br />sabotaged by plugging for this to occur. <br />If the overland pipeline from the pump station to the tailing ponds should rupture, spillage would <br />report to the SCF system or Robinson Lake. <br />Prevention and Control: Because the system is monitored frequently as described below, the <br />likelihood of unnoticed failure of system components is greatly reduced. <br />Countermeasures: High water levels in Robinson Lake can be mitigated using portable diesel <br />pumps to deliver water back to the No. 1 Dam Seepage Control Facility, thereby increasing surge <br />capacity. Also, by conducting a lazge drawdown of Robinson Lake in the fail of the yeaz, <br />. Robinson Lake's capacity to withstand a high precipitation event is greatly increased. This is a <br />normal operating procedure employed annually at Climax. <br />55 <br />