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6.0 OBSERVED IMPACTS ON THE HYDROLOGIC SYSTEMS <br />OF THE TRAPPER MINE <br />6.1 GROUND WATER <br />Water -level changes in the last few years for the QR aquifer have been fairly steady mainly <br />due to near normal precipitation. Water -level changes were observed in QR aquifer wells GD -2, <br />GF -6 and GLEV-1, along with associated backfill wells GD -3 and GF -11. Water levels in wells <br />GD -2 and GD -3 declined in 2006 and these declines are thought to be due to some deep exploration <br />drilling in this area. Water levels rose in 2008 and 2009, with overall steady water levels in 2011 <br />through 2017 in well GD -2. A gradual decline in water level in GD -3 was observed in 2012 through <br />2015 with overall steady levels since the decline. Additional monitoring with time is needed to <br />determine the significance of the decline in wells GD -2 and GD -3 but presently well GD -2 has not <br />completely recovered from the 2006 drop. Wells GD -2 and GF -6 are fairly close to mined areas, <br />overall steady water levels in 2013 through 2017 were observed in wells GD -2 and GF -6. The <br />2012 responses in well GF -11 indicated that water levels declined due to the decrease in <br />precipitation in 2012 with smaller water level changes in 2013 through 2017 with near normal <br />precipitation. These wells are located near the downgradient toe of D and E pits and/or at the <br />interface of upgradient backfill and the downgradient native QR aquifer. These well locations seem <br />to be relating to changes in precipitation with very little lag in time. <br />Upgradient mining can cause water -level rises in wells downgradient of the mining by <br />allowing ground water to flow to the downgradient end of the backfilled area quicker. The backfill <br />aquifers are generally more permeable than the native aquifer which also allows ground water to <br />flow faster through the backfill material resulting in more water in the aquifer at this location. The <br />input of additional water to the native aquifer at the north end (toe) of the mine has decreased the <br />effects mine dewatering has had on water levels in this portion of the aquifer. Water levels in wells <br />Trapper Mining Company 6-1 <br />2017 Annual Report <br />