Laserfiche WebLink
limit are compared to table standards found on this website, page 87: <br />http://www.epa.gov/waterscience/criteria/ammonia/99update.pdf <br />No ammonia excursions occurred this year. <br />SCC runs two different mercury tests, a high level test with a MDL of <br />0.2 ug /1 (for streams and NPDES sites) and a low level test with a MDL <br />of O.0002 ug /l (for certain NPDES sites only). All high level test <br />values this year were less than the detection limit., which is normally <br />0.2 ug /l. All low level tests were below the 0.01 ug /1 stream standards. <br />NPDES Effluent Criteria (Permit No. CO- 0000221). No excursions of NPDES <br />effluent criteria occurred this year. For NPDESI2, the three excursions <br />of the selenium stream standard noted above were not NPDES permit limit <br />excursions. The permit limit for this outfall for selenium is to <br />"Report" only. This outfall has a NPDES Compliance Schedule to meet the <br />selenium limit by December 31, 2015. SCC is .currently investigating <br />means of selenium control. SCC is also performing an aquatic life survey <br />in this drainage, and is also investigating the possibility of a site - <br />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 Summa <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/l) This years average TDS (mg /1) <br />YSGF5 1337 820 <br />NPDES10 3938 2408 <br />14 <br />