Laserfiche WebLink
stream sites in the Sage and Grassy Creek basins. Standards that were <br />exceeded are: <br />Parameter <br />Iron, Total Rec. <br />pH <br />Nitrites <br />Selenium, Pot. Diss. <br /># of Sites / # of Excursions <br />4/5 <br />1/1 <br />1/1 <br />2/3 <br />The total recoverable iron standard (1.0 mg /1) was exceeded five times <br />this year. Excursions were normally related to high suspended solids. No <br />NPDES excursions for this iron standard occurred this year (see the <br />following `NPDES Effluent Criteria' section for a further discussion) . <br />This strict aquatic life standard was exceeded in 38% of the premining <br />stream samples. <br />The pH standard (6.5 -9.0) was exceeded on July 17 at NPDESI3 with a <br />value of 9.07. The cause was most likely algae growth. See the following <br />`NPDES Effluent Criteria' section for a further discussion. <br />The nitrite standard (0.05 mg /1) was exceeded on July 7 at Site YSS2 <br />with a value of 0.06. Nitrites are unstable in aerated water (Hem, <br />1989), and will oxidize to nitrates. <br />Three samples from two sites exceeded the chronic selenium standard, 4.6 <br />ug /1 (potentially dissolved). No samples exceeded the acute standard, <br />18.4 ug /l. One of these excursions were at NPDESI2, with a value of 5.2 <br />ug /1. Two of these excursions were at NPDESI3, with values of 5.4 and <br />8.4 ug /l. See the following `NPDES Effluent Criteria' section for a <br />further discussion. <br />Table 13 also shows selenium excursions in the dissolved and total <br />recoverable forms. SCC is performing these analyses voluntarily in order <br />to determine differences in the methods. They should not be considered <br />violations, as the required form for NPDES compliance is potentially <br />dissolved. <br />12 <br />