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Comparison of Surface Water Oualitv to Water Use Standards. The CDOH has established <br />eater quality standards for most stream segments in the state, including the Yampa River <br />and select tributaries (CD OH, 1991). Surface water in the Sage Creek and Dry Creek Basins <br />(Seneca 11-W) is categorized under Segment 12 of the Yampa River, and this segment has <br />only minimal standards established (dissolved oxygen, pH, end fecal coliforms only). <br />Since Segment 12 has no standards established for major ions or trace metals, standards <br />established by the Office of Surface Mining Reclamation and Enforcement (OSMRE) for <br />irrigation and livestock will be used to evaluate water quality at the Seneca II-W Mine. <br />The OSMRE's listing of the most stringent standards for irrigation eater recommended by <br />a variety of organizations (EPA, Wyoming DEO, etc.-OSMRE, 1989) has been compiled and <br />presented in Table 14 (Appendix A). Of all the surface water sites downstream of Seneca <br />II-W, only Sites SGS (Dry Creek) end FG4 (Sage Creek) have their waters used for <br />irrigation. Also, eater from Site FGt (lower Hubberson Gulch) has the potential of being <br />used for irrigation, although this has not been developed as such. Water quality from <br />these three sites were compared against these standards, and the comparison results are <br />presented in Table 15 (Appendix A). The comparison shoos high pH and sulfate values at <br />all three sites, high total manganese and total iron values at Sites FG1 and SGS and a <br />high dissolved manganese value at Site SGS. <br />Table 16 (Appendix A) presents the most stringent Livestock standards as compiled from <br />various organizations by the OSMRE (OSMRE, 1989). Surface water quality data measured at <br />all stream and NPDES sites during 1993 were compared with the standards list for <br />livestock drinking water, and the comparison results are presented in Table 17 (Appendix <br />A). Sites FG2, SG7, and FCS had no excursions. Some pH values at all other sites were <br />higher than the livestock standard. A total recoverable mercury value was in exceedence <br />of livestock standards at NPDES 006. <br />Tab 7 of the Seneca II-W PAP contains a section discussing the suitability of surface <br />water monitored at the Seneca II-W Mine for use as irrigation and livestock drinking <br />water. The section concludes that surface water is marginally suitable to unsuitable for <br />irrigation, and unsuitable for Livestock drinking water. The aforementioned comparisons <br />further substantiate these conclusions. <br />As a result of the de wa tart ng that occurred at the NPDES 005 pond (see preceeding NPDES <br />005 discussion), excursions of the NPDES total suspended solids (TSS) limit (30-day <br />13 <br />