Laserfiche WebLink
provided in Appendix D1. NPDESI2 exhibits an increasing TDS trend, with <br />some recent stabilization (SF=0.5). <br />- NPDESI3. Construction of this pond was completed in December 2003. It <br />first began discharging on March 14, 2005. Average flow in 2005 was <br />0.017 cfs, 0.008 cfs in 2006 and 2007. The TDS trend is decreasing. <br />- NPDESI4. Construction of this pond was completed in September 2001. <br />It discharged for the first time on April 4, 2006. The average flow for <br />2006 was 0.020 cfs and was 0.004 cfs in 2007. TDS values are <br />increasing, but the peak is only 340 mg/1. <br />- Site YSS2. This site exists on Sage Creek below all potential Yoast <br />Mine discharges. Monitoring at this site was resumed in 1998 after the <br />monitoring requirement was discontinued in 1993 (although field <br />parameters were occasionally collected in 1994 to 1997). A statistical <br />summary of baseline chemistry data is provided in Appendix D1. Its TDS <br />plot indicates an increasing trend. <br />Grassy Creek / Annand Draw <br />- NPDESIO. This sediment pond on Annand Draw was completed in August <br />1996. Flow was observed at this site for the first time ever on February <br />24, 1997. Average flow this year was 0.065 cfs, which is 58a below its <br />historic (1997-2007) average, 0.157 cfs. This pond was dredged out in <br />2002. Baseline data for this site, both downstream (Site YSA4) and <br />upstream (Site YSAF4) of the pond, have been provided in Appendix D1. <br />NPDESIO recently exhibits a stable TDS trend (SF=0.5), peaking in 2002. <br />- NPDESII. This pond exists on a Grassy Creek tributary and was <br />completed in October 1997. Flow was first observed at this site in 1998. <br />No discharge occurred in 1999 or 2000. This year's average flow, 0.016 <br />cfs, is 16% below its historic (1998-2007) average, 0.019 cfs. This <br />year, this pond started flowing in March and stopped flowing in June. <br />Due to high sediment level, this pond was dredged out in the fall of <br />2003. TDS values recently exhibit an increasing trend. <br />10 <br />