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2.0 Water Treatment Chemistry <br />MW The water treatment plant was designed to treat mine water over a range of reported <br />values for Radium, Uranium, Arsenic, and Selenium. Historical mine drainage data for <br />the Packrat Mine was obtained from draft Permit No CO-0043575 (Umetco Minerals <br />Corporation) that was prepared in the mid 1990s. Water quality data for the Urantah <br />Decline (i.e., Whirlwind Tunnel) was obtained from recent water sampling of the mine <br />sump by Energy Fuels. The water in the Whirlwind Tunnel will be the first water <br />removed from the mine and treated for discharge. This water is of better quality than the <br />water historically sampled in the Packrat Mine and is generally represented by the lower <br />range of activity levels and concentrations presented below for each constituent of <br />concern. The discharge standards presented below are from Colorado Discharge Permit <br />System (CDPS) Permit No. CO-0047562 issued for the facility. <br />Removal of most metals is commonly accomplished by raising the pH of the feed water <br />to a pH of 10.00 or higher, with the addition of lime or caustic. This treatment will <br />produce metal hydroxides, which are insoluble in water. The drawback to this method of <br />treatment is that it produces large volumes of sludge that can require high doses of <br />flocculent to produce a dense enough solid for settling or filtration. If the water treatment <br />system selected for this facility were to require lime addition to raise the pH above 9.0, <br />the final step of the treatment process would consist of adding acid prior to release to <br />lower the pH below 9.0 to stay within the discharge limits. Because of the practical <br />difficulties associated with lime treatment, other traditional water treatment methods <br />9 were selected as described below. <br />Radium <br />Expected range of activity levels: 5 to 15 pCi/L <br />Discharge standard: Maximum discharge limits of 5 pCi/L. <br />Radium is traditionally removed from waters by the addition of barium chloride (BaCI). <br />Test work by Hazen on water with a similar chemical profile found that the addition of 30 <br />mg/L of BaCI is sufficient to reduce the Radium levels to 1.2 pCi/L, which is less than <br />the target discharge level. <br />Recent bench scale testing by Lyntek at another Energy Fuels mine in the same formation <br />(near La Sal, Utah) with similar water showed a 69% reduction in the Radium level when <br />treated with barium chloride and ferric sulfate, at the design dosage. The untreated water <br />had a Radium-226 level of 13 (+/-1) pci/L, which was reduced to 4.0 (+/- 0.9) pci/L. <br />Test work by Hazen Research and others has identified the optimum pH for radium <br />removal at 8.0 to 9.0, which is the reported naturally occurring pH of the mine discharge <br />(8.4 to 9.0). Therefore, no pH adjustment is anticipated at this time. <br />C. <br />5