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aquifer but could be defining the very small effects of the backfill aquifer upgradient. Sulfate <br />concentrations in backfill well GF -7 overall gradually declined in 2010 and 2013. The water levels <br />for the last few years have been fairly similar in well GF -7, indicating that these changes are not due <br />to new backfill being saturated but likely due to variations in recharge. Sulfate concentrations have <br />stayed low and steady in backfill well GF -5 except a slightly higher value in the first sample in 2013. <br />These small changes may be defining the very small effects of upgradient mining but the changes are <br />well within natural ranges. This monitoring indicates that if the HI aquifer has been affected in these <br />wells by upgradient mining, it has been very small. <br />Sulfate concentrations in well GNP -1, which are shown on Figure B -12, have been highly <br />variable indicating an increasing trend during 2006 and 2007 and an overall similar increasing trend <br />in 2008 through 2013. The water level in well GNP -1 had been steadily increasing for several years <br />prior to becoming fairly steady in 2002 and then gradually increasing the last seven years prior to a <br />small decline in 2012 and 2013. Sulfate concentrations may stay higher and variable while water <br />levels are gradually increasing. Sulfate concentrations in this well should be influenced by the sulfate <br />concentrations in the backfill aquifer upgradient of GNP -1. The sulfate concentrations in well GP -3 <br />had shown a gradual increasing trend but concentrations have been steady the last eleven years. <br />Overall steady sulfate concentrations have been observed in well GP -7. Sulfate concentrations in <br />eastern HI aquifer well GC -1 have been similar to the previous higher values in well GNP -1 and had <br />to be natural until the last few years. Therefore, a sulfate concentration of at least greater than 600 <br />mg/1 is needed to indicate that the increases may be due to the mining operation. The 2013 value <br />from well GC -1 was similar to past values. <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 the 2012 <br />Trapper Mining Company 3-6 <br />2013 Annual Report <br />