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. the mined area, where levels may be limited by the elevation of backfill springs from the northern <br />pits in this area. <br />Significant drawdown has developed adjacent to the pits but the extent of these drawdowns <br />is very limited due to the small transmissivity in these aquifers. Recovery of the water levels has <br />occurred over a few years as the pits have moved away from an area. Some water levels will likely <br />not recover to their pre-mine levels due to the different flow characteristics developed with the <br />backfill aquifer and the controlling of the maximum head by backfill springs. <br />Variations in natural recharge to the 2nd White Sandstone affect this aquifer greatly. Mining <br />effects on the system have not been detected. <br />The TDS of water in backlill wells GD-3 and GF-5 are somewhat higher but similar to <br />those of the native aquifers in these areas. TDS for GF-5 is approximately 1.5 times the pre-mine <br />value but is within natural variability of this aquifer. TDS values for backfill wells GF-7 and GF-11 <br />aze much higher than the naturally observed concentrations. TDS in well GF-7 has shown some <br />decline from the peak values in the early 1990's and has been fairly steady for the last eight years at a <br />slightly lower level. The TDS in well GF-11 is lower and may have reached its peak in 2001. It is <br />likely that the TDS will remain higher for many years before returning to pre-mine concentrations in <br />these two wells. The change in major constituent concentration in water in these two wells will <br />likely decrease during wet cycles and gradually decline as readily soluble constituents are removed. <br />The water quality in QR wells GD-2 and GF-6 has been only slightly affected, if at all, by the <br />upgradient mining. The 2005 TDS values for well GE-1 were variable in 2005. These changes aze <br />within natural variations and may or may not be caused by mining. The remainder of the QR wells <br />are located away from present mining activities and could not have been affected, with the excepfion <br />Trapper Mining Company 6-3 <br />2005 Annual Report <br />