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This year's average flow value, 0.053 cfs, is 34~ of the historic (1980- <br />2004} average flow value, 0.154 cfs. However, the operation of the <br />truck wash system, and the timing of flow measurements, tends to greatly <br />influence the flow values reported. Review of the TDS plot indicates an <br />increasing trend. <br />- Surface Water Site SW-S2-3 (SSG3). This site monitors discharges from <br />pre-SMCRA mining areas before they enter Grassy Creek at a point just <br />below Site SW-S2-2. This site was re-established in June 1997. Not <br />enough data has been collected yet to detect any trends. It was dry in <br />June through September the past four years. <br />- Surface Water Site SW-S2-2 (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 th e 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 2840 mg/1 was observed. A value of 2341 mg/1 was predicted in <br />September, while a value of 3780 mg/1 was observed. It should be noted <br />that the PHC predictions were based on long-term average values. <br />Individual monthly TDS measurements may be affected by annual changes in <br />climate (such as the lower than average precipitation noted the past <br />several years), and by the relative contribution of flow values from <br />Ponds 002 and 003 (as affected by the truck wash system). <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 EC (electrical <br />conductivity, corrected to 25° C, since 10/1/89) values, and finally a <br />18 <br />