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• 3. Seal Decline and Other Areas of Ground Water Inflow <br />The Whirlwind Mine will require the installation of a bulkhead seal in the lower portion of the decline <br />to ensure that the water seeping into the decline from the lower Brushy Basin aquifer is not allowed to <br />enter the mine workings. The lower bulkhead will be constructed near the base of the decline within a <br />zone of competent sandstone of high compressive strength. The hydraulic loading on this seal is <br />expected to be relatively low i.e., about 38 feet of hydraulic head based on a maximum of 630 feet of <br />Brushy Basin intercept on a 6 % grade. However, the seal design is based on the assumption that the <br />water will back to the surface. Design details and the estimated costs of the seal are presented in <br />Appendix K <br />Energy Fuels will also attempt to seal off other ground water inflows into the mine that may still exist <br />at the time of closure. This will likely consist of grouting and/or sealing of areas where water may be <br />seeping into the mine through natural fractures or more permeable zones. The cost of a contingency <br />seal in the Packrat workings has been included in the reclamation bond as described in Appendix L. <br />• Energy Fuels and the Division of Reclamation, Mining and Safety believe that the likelihood of a seal <br />in the Packrat workings is low, however, the Division requested the additional bond so that its potential <br />cost is covered for a worst case scenario. <br />The ground water-bearing zone above the Whirlwind seal is perched and present only at the base of the <br />channel sandstone unit; therefore, the water level behind the seal is expected to stabilize at or near the <br />ground water inflow point within the decline. Energy Fuels will monitor the water elevation above the <br />lower seal until it reaches equilibrium plus an additional 5 quarters (i.e., 1.25 years). Once the <br />monitoring period is completed, the remainder of the mine site can be reclaimed. <br />4. Place Ore Pad Liner, Pad Cover Material, and Treatment Sludge in Mine <br />Over the life of the mine, percolation of rain water through the ore stockpile may result in <br />radionuclides leaching into the compacted pad immediately below it; therefore, the 3.5 feet of cover <br />material and the ore pad liner will be excavated over the 0.5-acre stockpile area shown on Map C-2. <br />This material will be disposed of inside the mine above the seal and water pool. This area of the <br />Whirlwind Mine 07 (rev. April OS) E-4 <br />