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surface water use evaluation. Of all the surface water sites downstream <br /> of Seneca II-W, only Sites WSDS (Dry Creek), WSSF3 (Sage Creek), WSH7 <br /> (mid-Hubberson Gulch) and WSHF1 (lower Hubberson Gulch) have their <br /> waters used for irrigation. Following is a list of standards exceeded <br /> this year. <br />Parameter # of Sites / # of Excursions <br />Manganese (CDPHE irrigation) 10/13 <br />Selenium (CDPHE irrigation) 1/1 <br />This summary indicates that only two CDPHE surface water agricultural <br />use standards were exceeded. The manganese standard was exceeded at ten <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-W region, a <br />more appropriate (EPA) standard would be 10 mg/1. The maximum manganese <br />value for any surface water site observed this year was 1.49 mg/1 at <br />Spoil Spring 1. Premining manganese values often exceeded the 0.2 mg/1 <br />standard. <br />The irrigation selenium standard was exceeded once. Spring 5-50 had a <br />value barely above the standard, 20 ug/1, with a value in May of 20.2 <br />ug/1. <br />Table 11 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. These standards were based on the presence of fish in <br />the lower portions of the creeks. However, the upper portions that <br />Seneca II-W discharges into have no fish present. All standards for 13d <br />and 13e are the same except for selenium (see Table 11) Table 12 <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 />~_ <br />Parameter # of Sites / # of Excursions <br />~~ <br />