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more appropriate (EPA) standard would be 10 mg /l. The maximum manganese <br />value for any surface water site observed this year was 2.08 mg /l at <br />Spoil Spring 1. Premining manganese values often exceeded the 0.2 mg /l <br />standard. <br />Table 12 shows the CDPHE receiving stream standards for Dry Creek (Yampa <br />Segment 13d) and Sage Creek (Yampa Segment 13e). Sage Creek was <br />resegmented by the CDPHE in 2003. Regulation 33 was further revised in <br />December 2005 and August 2008. These standards were based on the <br />presence of fish in the lower portions of the creeks. However, the upper <br />portions that Seneca II -W discharges into have no fish present. All <br />chemical standards for 13d and 13e are currently the same. Table 13 <br />provides a comparison of those standards to water quality data collected <br />this year from NPDES and stream sites in those basins. Standards that <br />were exceeded are: <br />Parameter # of Sites / # of Excursions <br />Iron, Total Recoverable (TR) 6/7 <br />Mercury 1/1 <br />Selenium 2/5 <br />Four of the seven iron exceedances were from NPDES sites. All but one of <br />the exceedances occurred during snowmelt runoff. They were likely due to <br />high suspended solids values, normally observed during snowmelt runoff. <br />This strict aquatic life standard (1.0 mg /1) was exceeded in over half <br />of the premining stream samples. <br />There was a Temporary Modification for the TR iron standard on Grassy, <br />Sage and Dry Creeks based on "existing quality ". SCC participated in the <br />Colorado Water Quality Control Commission's December 13, 2010 Temporary <br />Modification Rulemaking Hearing. The Commission approved SCC's proposals <br />for ambient -based TR iron standards to Dry Creek (Segment 13d) and Sage <br />Creek (Segment 13e). These standards will become effective on June 30, <br />2011. Those standards are: <br />20 <br />