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Alluvial Groundwater <br />Fluctuations in depth to alluvial water do not appear to indicate a significant impact from mining, per the <br />historical data in the 2014 AHR. <br />Water quality data for the downgradient alluvial well (PAW -9 in Table B-6 in the 2014 AHR) was <br />compared to groundwater regulations, Regulation No. 41, The Basic Standards for Ground Water (Reg. <br />41). The comparison was made for parameters in the current monitoring plan (Table 28 in the PAP). The <br />relevant parameters and the Reg. 41 standards are as follows: <br />• pH-6.5to 8.5 <br />• Chloride (dissolved) — 250 mg/1 <br />• Sulfate (dissolved) — 250 mg/1 <br />• Iron (dissolved) — 0.3 mg/1 <br />• Manganese (dissolved) — 0.05 mg/l. <br />Exceedances of these standards include dissolved iron in 2013 and dissolved manganese in 2009, 2011, <br />and 2013. For most of these year/parameter combinations, the concentrations in these downgradient wells <br />are larger than in an upgradient alluvial well (PAW -1), and the upgradient concentrations do not exceed <br />the applicable standard. The exceedances are not well over standards, and they do not appear to be a <br />general pattern; for example the 2014 concentrations for dissolved iron and dissolved manganese are both <br />an order of magnitude below the standard. However, this is cause for some concern. Has the Water <br />Quality Control Division (within the Colorado Department of Public Health and Environment) been <br />notified by NECC regarding these exceedances of standards? During future AHR reviews, NECC and <br />DRMS should continue to monitor these parameters closely. <br />Groundwater in the Allen Seam <br />For this review, Well NEW4 was selected by the Division as representative of a down gradient well. It is <br />down dip of a majority of the workings at the New Elk Mine, and it is in the Allen Seam. Table B-9 <br />shows a dramatic change in the elevation of this well from 2008 to 2010. Please explain the likely <br />reason for this change <br />No water quality data has been collected for Well NEW4 since 2008, despite the fact that the current <br />PAP does not discuss inactivation of this well. Please explain the recent lack of water quality data for <br />this well. <br />Review of New Elk Mine AHRs <br />Page 2 <br />