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displays an increasing TDS trend. Baseline data for this site has been <br />provided in Appendix E1. <br /> <br /> <br />The Seneca II-W PHC, Table 17-42b, predicts an irrigation season (June- <br />September) average TDS value of 676 mg/1 on Sage Creek, while a value of <br />755 mg/1 was observed this year. The value observed this year was only <br />79 mg/1 greater than the predicted value. However, the maximum TDS value <br />observed during the same time frame at NPDES 015 and NPDES 009 was only <br />460 mg/1. It should be noted that the PHC predictions were based data <br />from 1982 to 1989, when Site WSSF3 had an average flow of 1.18 cfs in <br />June thru September. However, this year, Site WSSF3 had an average flow <br />of only 0.62 cfs in June thru September. Since there was less dilution <br />water, TDS values were higher than predicted this year. <br />Springs. Spring data may be found after surface water data in Appendix <br />E. Data provided are a water quality report for the past two years, <br />historic flow measurements and remarks, a LOWESS plot of TDS or <br />electrical conductivities (EC, corrected to 25° C, since 10/1/89), and a <br />historic listing of percent milliequivalents of major ions and TDS. <br />Baseline water quality statistics for springs downstream of mining (when <br />available) has been provided in Appendix E1. Springs with a flow less <br />than 5 gpm (0.011 cfs) are analyzed for field parameters only. In <br />Appendix E, all native springs have a WSPG prefix (e.g., Spring 5-45 = <br />wSPG45) while all spoil springs have a WSSPG prefix. <br />Spring 5-23 is located at the headwaters of the 006 Gulch, in an <br />ephemeral stream channel. This spring is upstream of mining and should <br />not be affected by mining. The EC plot indicated a stable trend since <br />1997. <br />Spring 5-46 is a developed spring first monitoring during the 1979 <br />spring survey. This spring became part of the required monitoring <br />program in 2000. It is located immediately below the 005 Pond. The EC <br />plot indicates an increasing trend (SF=0.5) since 1996. <br />19 <br />