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levels within historical natural values for this well The Lewis Shale well P-3 was dry during 2005. • <br />The 2005 sulfate concentration for Johnson Gulch well J-1 was similar to recent higher values and <br />slightly higher than the natural level in the Flume Gulch alluvium at well COY but could be due to <br />the dry cycle. Sulfate concentrations in the Flume Gulch wells (GC-3 and COY) have fluctuated <br />from approximately 400 to 1100 mg/I. <br />3.3 pH <br />Field pH is an important parameter to monitor because some coal spoils have the potential to <br />increase acidity of the ground water, which increases the mobility of most heavy metals. A pH of <br />less than 5 would generally be needed to greatly increase the mobility of most heavy metals. <br />Available pH data is tabulated in Table B-1 of Appendix B. The field pH of water from the <br />GC wells has generally been slightly above 7.0 and has been at similar values since the initiation of • <br />disturbance in this area. <br />Field pH from well GD-2 slightly decreased in 2005 but is still neaz neutral. The upgradient <br />mining in the QR seams has not significantly affected the pH in this azea of the aquifer. The pH <br />values from bac)~11 well GD-3 are 7.0 and 6.4 for 2005, which is neaz the values in the native <br />aquifer at well GD-2. The QR aquifer at GE-1 has values above neutral for 2005. The pH of water <br />from well GE-2 in 2005 was similar to values observed during previous yeazs for this well. The pH <br />values for well GE-3 were near 9 in 2005. <br />Similaz pH values were observed for the HI aquifer at well GF-4 in 2005 to those observed in <br />previous yeazs. Backfill well GF-5 had field pH values above 7.0 in 2005, while the field pH for <br />backtill well GF-7 was near neutral. The field pH values in bacl~"ill well GF-11 for 2005 were <br />Trapper Mining Company 3-8 <br />2005 Annual Report <br />• <br />