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COLORADO LEGACY LAND <br /> 5. Please describe any changes in how water pumped from the mine pool will be conveyed to the Water <br /> Treatment Plant,which result from relocating the submersible pump.In addition,provide design details for <br /> any changes to the existing infrastructure.The Water Treatment Plant and associated infrastructure are <br /> designated as an Environmental Protection Facility,as such the Operator will be required to submit as-built <br /> drawings of the Water Treatment Plant and associated infrastructure as required by Rule 7.3.2.The Division <br /> will require as-built drawings and construction certification to be submitted within 30 days of approval of the <br /> Technical Revision. <br /> Response: <br /> Mine water will be pumped from the mine pool that is in the Jeffrey air shaft. This will be completed using a 60 HP <br /> submersible pump capable of providing 300 gallons per minute(gpm)at 550 feet of head.Mechanical and <br /> electrical adjustments will be made to optimize the pumping performance throughout the life of the dewatering <br /> system. The pump assembly will be supported using a head frame support structure located above the Jeffery-Shaft <br /> opening and constructed over the Ventilation shaft casing.A cable, Winch and sheave system will be installed to <br /> raise and lower the pump. All components are designed with the capability of lifting and lowering the worst-case <br /> scenario mass of 3 tons.All equipment will be supported using the head frame.Mine water will be pumped to the <br /> Water Treatment Plant through 4-inch High Density Polyethylene Pipe.Refer to the attached underground pump- <br /> ISO Al layout drawing. <br /> The installation of the 60 HP pump will require a new mine water discharge line that will be used to convey water <br /> from the Jeffrey Ventilation Shaft to the RO Water Treatment Plant. This is the most significant change to the <br /> overall treatment infrastructure.A 5-inch High Density Polyethylene Pipe will be routed from the shaft surface <br /> completion and down the hill side following the electrical pole path to the Water Treatment Plant. The difference <br /> in elevation is 150 feet with the plant being lower than the shaft.All other infrastructure is currently in place and <br /> can be easily adapted to accommodate the new influent stream.Refer to the included Site over view and Water <br /> Treatment Plant Area Layout for plumbing alignment. <br /> All water from the shaft will be collected in a temporary holding tank located on the east side of the Water <br /> Treatment Plant mesa. This tank is already in place and incorporated with in the current process.At this time the <br /> proposed tank is used as a redundant containment for the RO underflow or reject stream. The new piping will be <br /> installed to convey the water into the existing holding tank. The collected water will be processed through 2 RO <br /> units using automated booster pumps that are currently in place. The 2 RO discharge streams will follow the <br /> existing process flow.Refer to the attached Mine Pump 3.0 Piping and Instrument Diagram(P&ID). <br /> 6. Please provide a general discussion of how the mine pool will be managed as a result of lowering the <br /> submersible pump.The discussion should address the periods of time the Water Treatment Plant will be <br /> operational,the expected mine pool elevations during periods of water treatment,as well as during periods <br /> when the Water Treatment Plant is off-line. <br /> Response: <br /> The plant will be operated to maintain the mine pool elevation that is required by the permit which is 6452 FAMSL <br /> or 150 feet below the Steve Adit. The treatment strategy is to allow the operator the ability to lower the mine pool <br /> in elevation to 6202 FAMSL. Once the mine pool has been decreased to a significantly lower elevation,in-situ <br /> injection treatment can be conducted. To increase the effectiveness of the chemical injection the mine pool will be <br /> allowed to refill at the natural rate. The new 60 HP pump was selected to dewater the mine pool to a point low <br /> enough to maximize the chemical contact time of the injected media. The performance capabilities of the 60 HP <br /> pump will allow operator the ability to dewater to an elevation of 6202 FAMSL, <br /> The plant will be operated through the year on a part time basis and separated into two modes which are,a <br /> dewatering period and a natural attenuation period. Dewatering period will be conducted to keep the mine pool <br /> between the permit requirement of 6452 FAMSL and 6202 FAMSL.Performance data curves for the proposed <br /> pump indicate that the operator will even obtain an effective flow rate at an elevation of 6002 FAMSL. The <br /> PAGE 3 OF 16 <br />