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July 30, 2010 3 of 24 <br />BEDROCK MONITORING WELLS <br />When asked by the Board whether it would be possible to install sentinel wells to detect any <br />migration of water from the mine pool along the Schwartz Trend, Mr. David Bird stated that it <br />would be difficult to find the Schwartz Trend and install downgradient monitoring wells. Mr. Bird <br />stated, "the problem is, the Schwartz Trend as shown on geologic maps changes... Hitting it might <br />be difficult." <br />In reality, the surface expression of the Schwartz Trend is several hundred feet wide and easily <br />identified on the ground. The outcrop and dip of the Schwartz Trend rocks are shown on <br />numerous geologic maps. One can stand at the geologic contact and clearly see the difference <br />between quartzite rocks of the Schwartz Trend and the mica schist (to the south) or gneiss (to the <br />north). <br />At the same time, DRMS insists that Cotter has the ability to drill a hole several hundred feet from <br />the surface, hit an 8-ft by 8-ft target, and install a pump in the shaft. This is a "double standard" of <br />insisting that Cotter can easily drill and hit an 8-ft wide target below ground, yet DRMS would <br />find it difficult to intersect the 280-hundred foot wide Schwartz Trend with a monitoring well. <br />URANIUM TREND IN THE MINE POOL <br />DRMS and Cotter agree that the trend of dissolved uranium concentrations in the mine pool is <br />decreasing with time. We have no reason to believe that this consistent 8-year trend will cease <br />(unless, of course, the mine pool is disturbed and oxidants reintroduced by pumping or other <br />activities). If the trend continues undisturbed, uranium concentrations will eventually reach <br />background. Cotter does not expect that background uranium concentrations in the water present <br />in the ore deposit ever were, or ever will be, 0.03 mg/L. <br />DRMS stated in the hearing, as reflected in the draft Order, that it would take 17 years for <br />groundwater in the mine pool to reach 0.03 mg/L uranium, based on a linear trendline calculated <br />by Excel for data from 2002 to April 2009. When the trendline presented by DRMS in the hearing <br />is extended out (whether in Excel or on paper), it shows that the water in the mine pool would <br />reach 0.03 mg/L uranium in July 2024, which is 14 tears from now (Figure 2). However, a linear <br />regression analysis of DRMS's trendline gives an R value of 0.80. (The R2 value, or "coefficient <br />of determination", is a number from 0 to 1 that indicates how closely a trendline corresponds to <br />the actual data. The higher the R2 value, the better the "goodness of fit" of a trendline and the <br />more reliable the prediction.) <br />The linear regression for the trendline presented by Whetstone has an R2 value of 0.91, which <br />gives a more robust and reliable prediction than does an R2 value of 0.80. We believe that the <br />most representative dataset for predicting future trends is represented by the most recent three <br />years of data shown in Figure 3. This figure omits the data from 2002-2003 (while mine water <br />levels were still rising rapidly) and the substantial data gap prior to 2007. Based on all samples <br />collected from June 2007 to June 2009, uranium concentrations are dropping at a consistent rate of <br />3.83 mg/L per year. At this rate, uranium concentrations in the mine pool would reach <br />background concentrations in nine years (Figure 4). For the period from October 2002 to June <br />2009, the average rate of decline in uranium concentrations was 3.51 mg/L per year.