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. exceedence out of two samples). Below is a summary of standards that <br />were exceeded. Given in parenthesis is the source and use of each <br />standard. Although the CDOH does not indicate between livestock and <br />irrigation uses in their surface water agricultural standards, they have <br />done so in their similar ground water agricultural standards (see Table <br />5) For the sake of discussion, SCC chooses to use those ground water <br />use standards classifications (livestock or irrigation) for surface <br />water use evaluation. Following is a list of standards exceeded this <br />year. <br /> <br />J <br />Parameter <br />Manganese (CDOH irrigation) <br /># of Sites / # of Excursions <br />6/11 <br />This summary indicates that only one CDOH surface water agricultural use <br />standard was exceeded. The manganese standard was exceeded at six <br />sites. However, as indicated in the recently revised CDOH Regulation 31, <br />the standard of 0.2 mg/1, applies to plants grown in acidic (<6.0 pH) <br />soils. In alkaline soils, as are found in the Seneca II region, a more <br />appropriate (EPA) standard would be 10 mg/1. The maximum manganese value <br />for any surface water site observed this year was 0.886 mg/1. Premining <br />manganese values often exceeded the 0.2 mg/1 standard. <br />Table 11 shows the CDOH receiving stream standards for Sage and Grassy <br />Creeks (Yampa Segment 13e, Reg. 33, December 2005). These standards were <br />based on the presence of fish in the lower portions of the creeks. <br />However, the upper portions that the Yoast Mine discharges into have no <br />fish present. Table 12 provides a comparison of those standards to water <br />quality data collected this year from NPDES and stream sites in the Sage <br />and Grassy Creek basins. Standards that were exceeded are: <br />Parameter <br />Iron, Total Rec. <br />Nitrite <br />Selenium <br />Sulfide <br /># of Sites / # of Excursions <br />6/9 <br />2/3 <br />2/4 <br />5/6 <br />13 <br />