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• 1.5 times the pre-mine value. TDS for backfill well GF-7 has been much higher than the naturally observed concentrations but reduced in 1996. Additional monitoring will be :d to determine whether the TDS in backfill wed GF-7 is to the pre-mine level. It is likely that the TDS will probably be higher for several years before returning to pre-mine concentrations. Major constituent concentration in water in this well may be starting to decline. The water quality in QR wells GD-2 and GF-6 has been only slightly affected, if any, by the upgradient mining. The last few years TDS values for well GE-1 are higher than earlier values. These changes are within natural variations and probably not caused by mining. Continued monitoring will define whether a long term trend exists. The remainder of the QR wells are located east of present mining activities and could not have been affected. • The water quality in the four HI aquifer wells, GB-5, GE-2 and GP-3, which are _ close to active mining, have not been influenced by the mining. TDS has slightly increased during the last few years at well GF-4. This increase may be due to natural variations within the aquifer. Well GB-5 has experienced an overall decline in TDS for the last few years. The remainder of the HI wells east of the areas mined have not been affected. The TDS plot of the 3rd White Sandstone well GB-2 indicates it has probably not been affected by mining, and changes are within natural variations for this aquifer. Mining could have caused concentrations to vary in 3rd White Sandstone well GE-3 but the variations observed are also within natural variation. The 3rd White Sandstone wells GC-2 and GP-9 are east of the mining and, therefore, observed changes in water quality in these wells has to be natural. Increases in TDS in 3rd White Sandstonell P-8 were.~ar~e-in_ 1996 and could be due to. upgradient mining. Similar natural TDS concentrations have 6-3