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Untreated Water (control sample) - DO levels decreased slightly during the first 24 <br />hours that the sample was open to the atmosphere from 6.30 mg/L to 5.93 mg/L, then <br />increased slightly over the following 48 hours from 5.93 mg/L to 6.15 mg/L at 72 <br />hours into the test. <br />T-Floc B-21L (polymer flocculent) - Tested at 30 mg/L, DO levels consistently <br />increased from 5.79 mg/L (before addition) to 6.77 mg/L. <br />Magnafloc 110-L (polymer flocculent) - Tested at 0.63 mg/L, DO levels initially <br />increased from 6.04 mg/L (before addition) to 6.55 mg/L within 5 minutes, but <br />decreased slightly over the next 24 hours to 6.33 mg/L. <br />Sodium Metabisulfite - Tested at 13 mg/L, DO levels initially increased from <br />6.24 mg/L (before addition) to 6.37 mg/L within 5 minutes, but decreased slightly <br />over the next 60 hours to 5.82 mg/L, followed by an increase to 5.99 mg/L at 84 <br />hours. <br />The above results indicate that the Magnafloc 110-L and sodium metabisulfite create a <br />slight decrease in DO levels until the oxygen demand of the solution is met. However, at <br />the concentrations that these chemicals were added during the June 24-26, 2008 WET test <br />(the same concentrations they were tested at), the decrease is not sufficient to explain the <br />large drop observed during the initial stages of the WET test. <br />Initial DO levels observed prior to conducting the failed WET test were at a low during <br />the first day (4.58 mg/L) but increased the following 5 days (6.68 to 7.50 mg/L). <br />Similarly, a sample collected on June 24 indicated that chemical oxygen demand (COD) <br />was at 56 mg/L (the highest recorded during discharge sampling), but was at 14 mg/L in <br />a sample of discharge collected two days later on June 26. <br />A batch run of mine water was treated on July 28-31, 2008. DO levels were monitored <br />and COD samples were collected on a daily basis. The results of the field tests indicated <br />DO levels dropped slightly (decrease of 0.27 to 1.45 mg/L) over the initial 24 to 48 <br />hours, before beginning to rebound. The DO field test data indicates that the treatment <br />process decreases oxygen levels slightly, but not to the level where it would impact <br />aquatic species. The analytical results indicate that COD ranged from <1 to 3 mg/L. <br />These levels are far below the COD of 56 mg/L observed during the June discharge event <br />in which the WET test failed. The DO field tests and COD analytical results are attached <br />to this report. <br />Conclusion <br />Based on the bench scale and full-scale testing, Energy Fuels believes that the low DO <br />and high COD levels observed levels were an isolated event. Prior to the June discharge, <br />water was pumped from the treated water tanks to the untreated water tank for cleaning <br />purposes and installation of bird ladders (required by the BLM). Some precipitant from <br />these tanks was pumped over along with the water. It is possible that the treated water <br />Fne rgy Fuels,, Inc. 44 Union Blvd, Suile 600 <br />wtanv.er?ar > 1i.iels.ct>nx 1 atewood, Colorado 80229 <br />1111one:303-074-21, 1,10 <br />Fax : 303-974-2141