Laserfiche WebLink
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 steady or gradually <br />declining mainly due to near normal precipitation, except for a small rise in well GD -3 in 2016. <br />Water -level changes were observed in QR aquifer wells GD -2, GF -6 and GLEV-1, along with <br />associated backfill wells GD -3 and GF -11. Water levels in wells GD -2 and GD -3 declined in 2006 <br />and theca APA;"; c ori. +hnn�r}++ +n ha Tina +n onma Al r% sw lnr +inn drill;"" in *hie ovna �x7o+ar lavnlo <br />VJV �.tV V....V. —V LLiV L4b11L LV VV � -- LV JV111V 11VVr/ VAp1V1{.LL1W.. NA. -1116 111 L111J LLlVK. •1 LLLVl V V1J <br />rose in 2008 and 2009, with overall steady water levels in 2011 through 2016 in well GD -2. A <br />gradual decline in water level in GD -3 was observed in 2012 through 2015 with a small rise in 2016. <br />Additional monitoring with time is needed to determine the significance of the decline in wells GD - <br />2 and GD -3 but presently well GD -2 has not completely recovered from the 2006 drop. Wells GD -2 <br />and GF -6 are fairly close to mined areas, overall steady water levels in 2013 through 2016 were <br />observed in wells GD -2 and GF -6. The 2012 responses in well GF -11 indicated that water levels <br />declined due to the decrease in precipitation in 2012 with smaller water level changes in 2013 <br />through 2016 with near normal precipitation. These wells are located near the downgradient toe of <br />D and E pits and/or at the interface of upgradient backfill and the downgradient native QR aquifer. <br />These well locations seem 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 />2016 Annual Report <br />