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.. Dan T. Mathews - 2 - April 18, 1990 1t is unfortunate that the bedrock well M6 was eliminated from the monitoring plan so early in the mine's history. This greatly limits the ability to determine nature and timing of imoacts on bedrock aquifers from the infilled, updip Easi Pit. We11s W9 and W10, however, are also completed in the Fruitland Fm. and are in a position to record hydrologic effects of updip mining and infillino of the Barren Ridge area. While the water from these wells appears to show evidence of increased mineralisation with time, suggesting some effects of recharge from the updip pit and spoil, the water character has fluctuated over the past two years and may indicate the general increase in TDS has stopped and that impacts of mining no longer predominate. As expected, water in the backfilled East Pit from W16 has increased in dissolved content since the spoil aquifer began to develop. It is interesting to note that the possible spoil spring sampled for the first time in 1969 below the Barren Ridge area appears more to resemble water from the Fruitland Fm or from the alluvium, excluding water from well A-1, than from the spoil aquifer in the East Pit. If this water is representative of what will eventually reach Stollsteimer Creek and its alluvium from the spoils aquifers developed at the mine, it is considerably less mineralized than the worst case projection employed in the CHIS to calculate the post-minino imoacts of the operation. Asa result of the above evaluation, I recommend that the elimination of surface and around water monitoring proposed by the operator to take place after completion of reclamation of the mine be approved. Impacts of the minino_ to date on surface and around water in the area have not been observed to be in excess of those anticipated. Those following reclamation may even be less than the negligible impacts projected during the permitting process. JCS/eas 6214F