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the last few years. The sulfate concentration in well GLEV-3 are similar to those in well GMP -1 but <br />have to be natural due to the ground -water flow direction at this well. Therefore, a sulfate <br />concentration greater than 600 mg/1 is needed to indicate that the increases may be due to the mining <br />operation. The 2015 value from well GC -1 was similar to past values but significantly less than the <br />value to the east from well GLEV-3. <br />Figure B-13 presents the sulfate concentrations for three 3rd White Sandstone wells. The <br />previous eleven years of sulfate values from well P-8 had overall gradually decreased while overall <br />the last six years values have slightly increased. The magnitude and timing of the prior increase in <br />sulfate concentrations in well P-8 indicate that this is due to mining. The sulfate changes in wells <br />GC -2 and GP -9 are within the natural range of concentrations for this aquifer. Figure B-13 presents <br />the sulfate concentrations for well P-5. Well P-5 contained only a small amount of water for a <br />sample in 2014. The prior sulfate concentrations in well P-5 were natural and show that the 2014 <br />relatively high value could be natural for this sandstone. <br />Figure B-14 presents the sulfate concentrations for alluvial wells GC -3, P-1, P-3, J-1 and <br />COY. The sulfate concentrations in alluvial well P-1 have been variable but within historical natural <br />values for this well. The 2015 sulfate concentration for Johnson Gulch well J-1 was similar to recent <br />higher values and similar to the natural levels in the Flume Gulch alluvium at well COY. Sulfate <br />concentrations in the Flume Gulch wells (GC -3 and COY) have fluctuated from approximately 300 <br />to 1200 mg/1. <br />Trapper Mining Company 3-7 <br />2015 Annual Report <br />