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Since monitoring was resumed in 2006 to July of 2013, the water level has <br />remained relatively stable. As indicated above, the No. 5 Mine pump was turned <br />off in July of 2013; no further pumping at this site is anticipated in the near future. <br />Historical field conductivity data for the Trout Creek Sandstone wells indicate no <br />adverse water quality impacts related to mining. The conductivity levels appear <br />elevated to the levels observed in the 80's. This may be related to consistent <br />pumping at the site. MCM must continue to monitor this trend at the No. 5 mine <br />well. <br />Middle Sandstone - Outlying Wells <br />The most significant hydrologic impact caused by Mines 5 and 6 may be an <br />approximate 60 -foot drawdown of ground water in the Middle Sandstone as <br />observed in wells TR -4, TR -7a, 8 1 -01 and 83 -03. Water elevation in wells 83 -01 <br />and 83 -02 are above baseline water levels. This drawdown persisted as recently as <br />2013, which is the most recent reporting year, although the water levels have <br />stabilized. This drawdown is comparable to the worst -case drawdown projected for <br />the overlying Twentymile Sandstone at a one -mile radius. The water level in the <br />Middle Sandstone well farthest from the mine workings, 83 -03, dropped 50 ft. from <br />1985 to 1997 and then began a gradual recovery until 2001 when the mine went into <br />temporary cessation. Since 2006, the water level at this well dropped by about 25 <br />feet and began to recover in 2011 and has since been rising. <br />Section 2.04.7 of the permit describes the pre -mine characteristics of the bedrock <br />aquifers and indicated that the Middle Sandstone aquifer often exceeds the primary <br />and secondary EPA drinking water standards for boron, chromium, dissolved solids, <br />fluoride, iron lead, manganese, sulfate and selenium. The 2013 water quality data <br />indicated elevated conductivity levels of this aquifer and will continue to be <br />monitored by MCM. Overall, the trends in water levels and the water quality <br />indicate mining has not adversely impacted the Middle Sandstone aquifer outside <br />the permit boundary. <br />Twentymile Sandstone <br />Water level monitoring data reported through the 2013 annual hydrology report had <br />shown no substantial change in the piezometric levels in the Twentymile Sandstone <br />that could be attributable to mining activities. The water quality data for the two <br />Twentymile Sandstone wells, No. 9 Mine Well and Well 259, showed no adverse <br />impact has likely occurred. <br />Williams Fork Alluvium <br />Ground water levels in the alluvium have remained fairly regular, with normal <br />seasonal fluctuations apparently related to changes in river levels. Ground water <br />levels in the alluvium are plotted in Figure 22 in Section 2.04.7 of the permit <br />application package. Annual hydrology reports through 2013 indicate no depletion <br />has occurred and suggest that mining appears to not have affected Williams Fork <br />River alluvial water quality. <br />Williams Fork Mines 26 Permit Renewal 06 <br />C- 1981 -044 December 8, 2014 <br />