Laserfiche WebLink
<br />6.0 OBSERVED IMPACTS ON THE HYDROLOGIC SYSTEMS OF THE TRAPPER MINE <br />6.1 GRODND WATER <br />Water-quality changes in the Last few years for the 9R aquifer <br />are mainly due to natural variations in the recharge rate. Water- <br />level changes in 9R aquifer wells, GD2 and GF6, which are close to <br />active mining may have been slightly influenced by mining <br />activities, but are mainly due to natural changes. Water-level <br />changes in these two wells are similar to those from QR wells east <br />of the mining activities. Water-level changes in 9R well GA1 have <br />responded similarly to well GP1, but some of the GA1 change is <br />likely due to mining. <br />Upgradient mining can cause water-level rises in wells <br />• downgradient of the mining by allowing ground water to flow to the <br />downgradient end of mining quicker. Also. the backfill aouifers <br />are more permeable than the native aquifer which also allows ground <br />water to flow faster through the backfill material resulting in <br />more water in the aquifer at this location. The input of <br />additional water to the native aquifer at the north end (toe) of <br />the mining has decreased the effects mine dewatering has had on <br />water levels in this portion of the aquifer. <br />The water-level changes for the HI aquifer have also been <br />influenced by variations in recharge during the last few years. <br />The mining upgradient of HI wells GB5 and GF4, which occurred <br />several years ago. has been allowing the water levels in the HI <br />aquifer to rise. Some of this rise could be above pre-mine levels <br />• <br />6-1 <br />