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The Yoast Mine lies within the headwaters of Grassy Creek and Sage Creek watershed. The <br /> southwest portion of the permit drains to the west towards Sage Creek,which ultimately flows to <br /> the north-northeast towards the Yampa River. A small area on the southeastern end of the permit <br /> drains southeast towards Grassy Creek,which flows to the northeast near the southern end of the <br /> permit area before bending to the north towards the Yampa River. The remainder of the permit <br /> area drains to the north-northeast towards Armand Draw. Armand Draw reports north to <br /> Scotchmans Gulch, which flows to the east-northeast to Grassy Creek. Runoff from the <br /> reclaimed mine discharges from five NPDES Outfalls: Outfalls 010 located near the northern <br /> end of the mine discharges to Armand Draw, Outfall 011 discharges to the southeast to an <br /> unnamed tributary of Grassy Creek, and Outfalls 012, 013, and 014 located along southwest <br /> permit boundary all discharge to unnamed tributaries to Sage Creek(Map IA and 1B). <br /> Ongoing stream monitoring points include YSGF5 and YSG5 within the Grassy Creek watershed <br /> and YSSF3 and YSS2 within the Sage Creek watershed. YSGF5 is located downstream of <br /> Outfall 011 but upstream of Scotchmans Gulch. Monitoring point YSG5 is located downstream <br /> of Scotchmans Gulch and receives drainage from both Outfall 010 and 011. Monitoring at YSG5 <br /> did not begin until after mining began in the watershed and therefore no background data is <br /> available for this location. This portion of Grassy Creek also receives drainage from the adjacent <br /> Sage Creek Mine. Sage Creek monitoring point YSSF3 is located upstream of Outfalls 012, 013, <br /> and 014 and YSS2 is located downstream of Outfalls 012, 013, and 014. <br /> Analytical results for the Grassy Creek (YSGF5, YSG5) and Sage Creek(YSSF3,YSS2) stream <br /> points between 2014—2018 are included in Tables 1 —4. Table 5 provides a comparison of the <br /> pre-mine and post-mine total suspended solids (TSS) for these locations. The range of TSS <br /> concentrations observed between 2014—2018 are lower than the ranges observed prior to mining <br /> at Sage Creek YSSF3 and YSS2. Although Grassy Creek stream point YSG5 does not have <br /> location specific baseline data the post mining TSS range does fall within the pre-mine range <br /> observed upstream at Grassy Creek YSGF5. The post mining TSS range at YSGF5 exceeds the <br /> pre-mine range. The post mine TSS range at YSGF5 is skewed by the sample collected <br /> September 11, 2018. The 495 mg/L TSS in this sample was more than four times greater than the <br /> TSS in any of other samples collected from 2014—2018 (n:18; range: 10 -118 mg/L). The TSS <br /> measured at downstream point YSG5 during the same event was 36 mg/L. Minimal flow was <br /> SL-7 - 32 <br />