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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 had been mainly due to natural <br />increases in the recharge rate but declined some in 2012 and 2014 due to less or just normal recharge. <br />Water -level changes were observed in QR aquifer wells GD -2 and GF -6, along with associated <br />backfill wells GD -3 and GF -11. Water levels in wells GD -2 and GD -3 declined in 2006 and these <br />declines are thought to be due to some deep exploration drilling in this area. Water levels rose in <br />2008 and 2009, with overall steady water levels in 2011 through 2014 in well GD -2. A gradual <br />decline in water level in GD -3 was observed in 2012 through 2014. Additional monitoring with time <br />is needed to determine the significance of the decline in wells GD -2 and GD -3 but presently well <br />GD -2 has not completely recovered from the 2006 drop. Wells GD -2 and GF -6 are fairly close to <br />mined areas, steady water levels in 2013 and 2014 were observed in well GF -6. The 2012 <br />responses in well GF -11 indicated that water levels declined due to the decrease in precipitation in <br />2012 with smaller water level changes in 2013 and 2014 with normal and slightly above 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 mine quicker. The backfill aquifers are <br />generally more permeable than the native aquifer which also allows ground water to flow faster <br />through the backfill material resulting in more water in the aquifer at this location. The input of <br />additional water to the native aquifer at the north end (toe) of the mine has decreased the effects mine <br />dewatering has had on water levels in this portion of the aquifer. Water levels in wells GF -6 and GF- <br />Trapper Mining Company 6 -1 <br />2014 Annual Report <br />