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For NPDESI4, the one excursion of the iron stream standard noted on <br />Table 14 was not a NPDES permit limit excursions. There is no permit <br />limit for iron at this outfall. <br />For NPDESI2, the one excursion of the selenium stream standard noted <br />above were not NPDES permit limit excursions. The permit limit for this <br />outfall for selenium is to "Report" only. This outfall has a NPDES <br />Compliance Schedule to meet the selenium limit by December 31, 2015. SCC <br />is currently investigating means of selenium control. SCC is also <br />performing an aquatic life survey in this drainage, and is also <br />investigating the possibility of a site- specific standard. <br />For NPDESI3, the two excursions of the selenium stream standard noted <br />above were not NPDES permit limit excursions. The permit limit for this <br />outfall for selenium is to "Report" only. This outfall will not have a <br />selenium limit until the CDPHE performs a `Reasonable Potential' <br />analysis during the next NPDES permit renewal. <br />Surface water Summar <br />The Yoast Mine PHC (PAP Tab 17, Attachment 17 -5) predicts TDS increases <br />to be observed at various stream sites during the irrigation season <br />(June - September) . The following table outlines those predictions along <br />with this year's observed averages. <br />Stream Site Predicted TDS values (mg /1) This years average TDS (mg /1) <br />YSGF5 1337 965 <br />NPDESIO 3938 2733 <br />NPDESI2 4291 2965 <br />WSSF3 (Seneca II -W site) 2118 dry in the summer and fall <br />No sites exceeded the PHC predictions. <br />TDS trends are increasing at NPDESIO, NPDESII, NPDESI3, NPDESI4, Stream <br />Site YSS2 and Spoil Springs 2 and 3. TDS values have decreased at Stream <br />Sites YSSF3, NPDESI2 and Spoil Springs 1 and 4. TDS values were stable <br />14 <br />