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fly ash pit (operated by the Hayden Station power plant) in October 1980 <br />and the diversion away from NPDES3 of runoff contained in the Northwest <br />Diversion Ditch (see the Seneca II Permit Application, Exhibit 7 -7, <br />Surface Water Hydrology Map and also the 1982 Seneca II AHR) in April <br />1982. Discharge volumes at the this site have also been affected by the <br />reduction in diameter of the discharge culvert (36 inches to 6 inches) <br />that occurred on July 19, 1988. A smaller volume pump and line from Pond <br />002 to the truck wash was installed in August 2001. The truck wash was <br />last used in 2007. These pump lines, which were siphoning water out of <br />Pond 002, were capped off on July 7, 2010. <br />This year's average flow value, 0.014 cfs, is 92% below the historic <br />(1980 -2012) average flow value, 0.167 cfs. This year's below average <br />value is due to retirement of the truck wash system and the below <br />average precipitation noted this year. Review of the TDS plot indicates <br />a decreasing trend, with the peak value occurring in September 2002. <br />- Surface Water Site SW -S2 -2 (SSG2) . This site exists on Grassy Creek <br />downstream of discharges from PSCM Ponds 002 and 003, but upstream of <br />Site SSG3 and Scotchmans Gulch (Yoast Mine NPDES Pond 010) . Review of <br />the TDS plot indicates an increasing trend (SF 0.2), with the peak TDS <br />occurring in August 2013. <br />- Surface Water Site YSG5. This site is the furthest downstream surface <br />water site in the Little Grassy, Scotchmans Gulch and Grassy Creek <br />drainages after exiting the PSCM permit area. Therefore, it is the most <br />significant monitoring site with respect to showing the cumulative <br />effects of mining in this area. It displays a slightly increasing TDS <br />trend, with the peak value 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) focuses 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 />14 <br />