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table does not include the units of concentration (mg /l or ug /1) for <br />each parameter. The units used for each parameter are the same as those <br />listed on the standards table (Table 11) and are also the same as those <br />used in the water quality reports. The frequency column on Table 12 <br />indicates, in this order: uncensored, that is, the number of exceedances <br />above the Method Detection Limit (MDL) / the number of exceedances <br />between the MDL and the Practical Quantitation Level (PQL) / censored, <br />that is, the number of .sample values below the MDL but the MDL was <br />higher than the standard / the total number of samples. Below is a <br />summary of standards that were exceeded. Given in parenthesis is the <br />source and use of each standard. Although the CDPHE does not indicate <br />between livestock and irrigation uses in their surface water <br />agricultural standards, they have done so in their similar ground water <br />agricultural standards (see Table 5). For the sake of discussion, SCC <br />chooses to use those ground water use standards classifications <br />(.livestock or irrigation) for surface water use evaluation. Following is <br />a list of standards exceeded this year. <br />Parameter <br />Manganese (CDPHE irrigation) <br /># of Sites / # of Excursions <br />3/10 <br />This summary indicates that only one CDPHE surface water agricultural <br />use standard were exceeded. The manganese standard was exceeded at six <br />sites. However, as indicated in the recently revised CDPHE Regulation <br />31, the standard of 0.2 mg /l, applies to plants grown in acidic ( <6.0 <br />pH) soils. In alkaline soils, as are found in the Seneca II region, a <br />more appropriate (EPA) standard would be 10 mg /l. The maximum manganese <br />value for any surface water site observed this year was 0.88 mg /l. <br />Premining manganese values often exceeded the 0.2 mg /l standard. <br />Table 13 shows the CDPHE receiving stream standards for Sage and Grassy <br />Creeks (Yampa Segment 13e, Reg. 33, January 2009). These aquatic life <br />standards were based on the presence of fish in the lower portions of <br />the creeks. However, the upper portions that the Yoast Mine discharges <br />into have no fish present. Table 14 provides a comparison of those <br />standards to water quality data collected this year from NPDES and <br />11 <br />