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• Now - - <br /> 3.0 GROUND-WATER QUALITY <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/l. TDS <br /> concentrations in U aquifer well GF-2 gradually increased from 1992 through 1995 then <br /> gradually decreased prior to a small increase in 1999. <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. A decline in <br /> concentrations in well GD-3 occurred in 1999 after increasing over the previous two years. <br /> The fluctuation in this backfill aquifer is well within natural ranges and may be very similar <br /> to variations that would have occurred in the QR aquifer at this location. Some of the TDS <br /> in the backfill aquifer may be due to leaching from the backfill material. The TDS in this <br /> • backfill aquifer is greater than it is downgradient in the R Coal at GD-2. The large decrease <br /> 3-1 <br />