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West Elk Mine <br />. Summarv of Surface Water Quality PHC's <br />Table 54 indicates that MCC's dischazges to the North Fork during 1996 from ponds MB-1 and <br />MB-2R resulted in increases in certain constituents. However, when the data are examined in <br />detail, the general conclusion is that these increases have resulted in no adverse impacts to any <br />existing beneficial uses. No stream standazds were exceeded as a consequence of MCC's <br />dischazges. No WET test failures occurred during 1996, relative to Daphnia magna and fathead <br />minnows. Despite the extraordinary circumstances that MCC had to deal with in 1996 (i.e., the <br />B East Mains fault inflow), there were only three NPDES permit exceedances, and these related <br />exclusively to total suspended solids and total iron, parameters which exhibit high "natural" <br />levels in the North Fork during spring runoff conditions. NPDES compliance for previous and <br />subsequent years is provided in the annual hydrology reports. <br />The increases in TDS would appear to pose concern upon initial inspection, for example, the <br />October TDS increase was from 90 mg/L upstream from the mine to 244 mg/L downstream from <br />the mine; however, WWE has thoroughly evaluated the implications of this and other TDS <br />increases, and the analysis demonstrates that the increases did not cause exceedances of relevant <br />criteria/standazds, nor did they result in any adverse impacts to downstream beneficial uses. In <br />addition, the CWQCD approved direct discharge of high TDS water from the BEM Fault inflow <br />to the North Fork via the emergency spillway of pond MB-1. Of potential concern is the high <br />sodium level in releases from the sedimentation ponds; yet conservative calculations show that <br />downstream irrigated agricultural lands would not have been adversely affected by the increased <br />sodiumlevels. <br /> <br />1.05-240 Revised Jwie 2005 PRIG; Rev. March 2006; Rev. May 2006 PRIG <br />