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through September the previous five years, but was flowing during those • <br />months this year. <br />- Surface water Site SW-S1.-2 (SSG2) This site is the furthest <br />downstream surface water site in the Little Grassy and Grassy Creek <br />drainages prior to exiting the permit area. Therefore, it is the most <br />significant monitoring site with respect to showing the cumulative <br />effects of mining in this area. Review of the TDS plot indicates an <br />increasing trend. <br />On page 7-242 of the Seneca iI PHC, predictions of TDS values at this <br />site were made. A value of 1233 mg/1 was predicted in June, while a <br />value of 2700 mg/1 was observed. A value of 2341 mg/1 was predicted in <br />September, while a value of 4020 mg/1 was observed. It should be noted <br />that the PHC predictions were based data from 1981 to 1986, when Site <br />SSG1 (Grassy Creek upstream of Seneca II discharges) had an average flow <br />of 2.60 cfs in June and 0.16 cfs in September. However, this year, Site <br />SSG1 had a flow of only 0.54 cfs in June, and was dry in September. • <br />Since there was less dilution water from SSGl, TDS values at SSG2 were <br />higher than predicted this year. <br />Springs. <br />Spoil spring data may be found after the surface water data presented in <br />Appendix D. Spoil spring data provided are water quality data for the <br />year, historic flow measurements, and a LOWESS plot of TDS or EC <br />(electrical conductivity, corrected to 26° C, since 10/1/89) values, and <br />finally a listing of historic percent milliequivalent values for major <br />ions and TDS values. In addition, a flow hydrograph is provided for <br />Spoil Spring 1. <br />- Spoil Springs 1 and 2. Both these spoil springs are located above the <br />NPDES 004 pond. Spoil Spring 1 is a large spring that was further <br />developed and fitted with a V-notch weir by the USGS on September 8, <br />1987. Its EC plot indicates a decreasing trend. Spoil Spring 2 is a <br />18 <br />