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last several years in well GF-6, downgradient of well GF-11. Sulfate concentrations for the <br />last several years have also been relatively steady in QR wells GP-5 and GP-6. As <br />expected, the sulfate concentrations are greater in downgradient well GP-5. The 1997 <br />value shows that the significant increase in sulfate concentration that occurred in eastern <br />QR well GP-1 in 1996 was an outlier. <br />Figure B-13 presents the sulfate concentrations for KLM aquifer wells GA-2, GF- <br />3, GP-2, GP-4 and GP-ti. A gradual declining trend in sulfate concentrations for the last <br />few years have been shown in well GF-3. Sulfate concentrations in eastem wells GP-2 and <br />GP-8 vary significantly but should be natural due to their location in the eastem portion of <br />the Trapper permit area. A significant decline in sulfate concentration has occurred over <br />the last few years in well GP-4. Some decline in TDS has been observed in this well during <br />this period of time but at a much smaller amount than sulfate. <br />Sulfate concentrations for the HI aquifer wells are presented in Figures B-14 and <br />B-15. The sulfate concentration in wells in the HI aquifer wells in Figure B-14 are fairly <br />similar except for the values in backfill well GF-7, which are substantially greater than those <br />in downgradient well GF-4. Avery gradual increase in sulfate concentration in <br />downgradient well GF-4 had been observed over the last few years but the values were <br />steady in 1997. This increase is well within the natural variation of sulfate concentrations <br />in the HI aquifer but could be due to the effects of the backfill aquifer upgradient. Sulfate <br />concentrations in backfill well GF-7 significantly decreased in the last portion of 1995 and <br />1996 and 1997. The 1997 values were slightly greater than the 1996 concentrations <br />indicating that the overall declining trend since 1993 may have ceased. Sulfate <br /> <br />concentrations in well GMP-1 have been gradually increasing with time, with the exception <br />3-6 <br />