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iii iiiiiiiiniiiiii <br />999 <br />Doc Date:12/11/2001 <br />• 3.0 GROUND-WATER QUALITY <br />~~o AN(5 <br />Appendix B presents the ground-water quality data for the Trapper Mine. This <br />appendix tabulates all of the historical data in Table B-1 and presents TDS and sulfate plots <br />versus time to convey changes in the major constituent water quality. <br />Appendix B also presents the spring and seep water-quality data. Water quality <br />for the springs and seeps are included in this section because their source is ground water. <br />Section 3.7 presents a discussion of the spring and seep water-quality data. <br />3.1 TOTAL DISSOLVED SOLIDS (TDS) <br />Figures B-1 through B-9 present plots of the TDS concentrations for the Trapper <br />' Mine wells. The wells have been grouped together based on aquifers. Figure B-1 presents <br />• the TDS concentrations for wells GF-1 and GF-2. Well GF-1 is completed in the 20 Mile <br />Sandstone, while GF-2 is completed in the U aquifer. The TDS in 20 Mile well GF-1 does <br />not show a consistent trend with time with typical TDS values being around 500 mg/I. TDS <br />concentrations in U aquifer well GF-2 gradually increased from 1992 through 1995 then <br />gradualy decreased followed by fairly steady concentrations in 1999 and 2000. <br />Figure B-2 presents the TDS concentrations versus time for three QR aquifer wells <br />GD-2, GD-3 and GE-1. Well GD-3 is a backfill well in the QR aquifer. TDS concentrations <br />were fairly steady in 2000 in well GD-3, while an overall gradual increase has been <br />observed in this backflll well for the last ten years. The fluctuation in this backfill aquifer is <br />well within natural ranges and may be very similar to variations that would have occurred <br />in the QR aquifer at this location. Some of the TDS in the backflll aquifer may be due to <br />• leaching from the backfill material. The TDS in this backfill aquifer is greater than it is <br />3-1 <br />