2013-03-14_REPORT - C1981010 (7)

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Figure B -7 presents the TDS concentrations versus time for alluvial wells GC -3, P -1, J -1 and COY. TDS concentrations in Pyeatt alluvial well P -1 were variable in 2012 similar to historical level. The TDS concentrations in alluvial ground water in Johnson Gulch (J -1) have been fairly steady since 2000. The recent Johnson Gulch alluvial ground water is within the natural range for TDS in this aquifer. These TDS values and variations are very similar to the natural values and variations observed in Flume Gulch alluvial well, COY. Flume Gulch has two alluvial monitoring wells, GC -3 and COY. TDS concentrations overall have been steady in well GC -3 with variations observed the last three years similar to previous values. The 2012 TDS concentrations in the COY well were similar to higher values in well GC -3. The TDS concentrations in the COY well and historical variations in well P -1 show that the Johnson alluvial TDS concentrations are within natural alluvial concentrations in the alluvial aquifers in this area. 3.2 SULFATE Figure B -8 presents the sulfate concentrations for QR wells GD -2 and GD -3. Sulfate in backfill well GD -3 were steady between 2000 and 2009 and then increased during the last two years prior to a small decline in 2012. Sulfate concentrations in well GD -3 had been fairly steady at this peak concentration until the recent increase. This indicates that the sulfate fluctuations in the backfill aquifer may be larger than the native QR aquifer. Future monitoring of this well will define whether sulfate concentrations will increase in the backfill aquifer when water levels rise to a higher level in the backfill material. Concentrations in well GD -2 had overall gradually increased the last few years but declined in 2006 and 2007 prior to a larger increase in 2008 through 2012. The recent Trapper Mining Company 3 -4 2012 Annual Report