Laserfiche WebLink
value is due to retirement of the truck wash system. Review of the TDS <br />plot indicates a decreasing trend, with the peak value occurring in <br />September 2002. <br />Surface Water Site SW -S2-2 (SSG2). <br />This site exists on Grassy Creek downstream of discharges from PSCM <br />Ponds 002 and 003, but upstream of Site SSG3 and Scotchman's Gulch <br />(Yoast Mine NPDES Pond 010). Review of the TDS plot indicates an <br />increasing trend, with the peak TDS occurring in August 2013. <br />Surface Water Site YSG5. <br />This site is the furthest downstream surface water site in the Little <br />Grassy, Scotchmans Gulch and Grassy Creek drainages after exiting the <br />PSCM permit area. Therefore, it is the most significant monitoring site <br />with respect to showing the cumulative effects of mining in this area. <br />It displays a slightly increasing TDS trend, with the peak value <br />occurring in August 2013. <br />The PSCM PAP addresses potential impacts to surface water quality on <br />pages 2.05-84 to 91 (Vol. 1A). A summary of those impacts is presented <br />on Table 2.05.6(3), page 2.05.89. The Probable Hydrological Consequences <br />(PHC) focus on impacts caused by underground mine dewatering. As that <br />scenario has not occurred yet, the PHC predictions are not yet relevant. <br />However, on page 2.05.88, it is stated "...Pond 002 is heavily affected by <br />high-TDS water from the Seneca II spoils aquifer, and averages nearly <br />4000 mg/1". This year, the average TDS at Pond 002 (NPDES2) was 3925 <br />mg/1 (3888 in 2014), and its TDS trend is increasing (see above). At <br />Site YSG5 this year, the average TDS was 2670 mg/l (3183 in 2014). <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 />past two years, a hydrograph of historic flow measurements and a LOWESS <br />plot of TDS values. <br />17 <br />