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differentiate between livestock and irrigation uses in their surface <br />water agricultural standards, they have done so in their similar ground <br />water agricultural standards (see Table 5). For the sake of discussion, <br />SCC chooses to use those ground water use standards classifications <br />(livestock or irrigation) for surface water use evaluation. Of all the <br />surface water sites downstream of Seneca II -W, only Sites WSD5 (Dry <br />Creek), WSSF3 (Sage Creek), WSH7 (mid - Hubberson Gulch) and WSHF1 (lower <br />Hubberson Gulch) have their waters used for irrigation. Following is a <br />list of standards exceeded this year. <br />Parameter # of Sites / # of Excursions <br />Manganese ( CDPHE irrigation) 10 /11 <br />This summary indicates that only one of the CDPHE surface water <br />agricultural use standards was exceeded. The manganese standard was <br />exceeded at nine sites. However, as indicated in the recently revised <br />CDPHE Regulation 31, the standard of 0.2 mg /1, applies to plants grown <br />in acidic ( <6.0 pH) soils. In alkaline soils, as are found in the Seneca <br />II -W region, a more appropriate (EPA) standard would be 10 mg /1. The <br />maximum manganese value for any surface water site observed this year <br />was 1.28 mg /l at Spoil Spring 3. Pre - mining manganese values often <br />exceeded the 0.2 mg /l 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 />20 <br />