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defining the very small effects of upgradient mining but the changes are well within natural ranges. • <br />This monitoring indicates that if the HI aquifer has been affected in these wells by upgradient <br />mining, it has been very small. <br />Sulfate concentrations in well GMP-1 have been highly variable indicating an increasing <br />trend during the last two years. The water level in well GMP-1 had been steadily increasing for <br />several years prior to becoming fairly steady in 2002 and then gradually increasing the last three <br />years. Sulfate concentrations may stay variable even with fairly steady water levels. Sulfate <br />concentrations in this well should be influenced by the sulfate concentrations in the backfill aquifer <br />upgradient of GMP-1. The sulfate concentrations in well GP-3 had shown a gradual increasing <br />trend but concentrations have been steady the last five years. 4vera1l steady sulfate concentrations <br />have been observed in well GP-7. Sulfate concentrations in eastern HI aquifer well GC-1 have <br />been similar to the previous higher values in well GMP-1 and had to be natural until the last few <br />years. Therefore, a sulfate concentration of at least greater than 600 mg/1 is needed to indicate that <br />the increases may be due to the mining operation. The 2006 and 2007 values from well GMP-1 <br />increased to above this level. <br />Figure B-13 presents the sulfate concentrations for three 3rd White Sandstone wells. T`he <br />last six years of sulfate values from well P-S had gradually decreased after a large increase over five <br />years but the 2007 values show a small increase. The magnitude and timing of the sulfate <br />concentrations in well P-8 indicate that this increase 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 was dry the last six years. The sulfate <br />concentrations in well P-~ are natural and show that relatively high values naturally exist in this <br />sandstone. <br />Trapper Mining Company 3-6 <br />2007 Annual Report <br />