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The water-level changes for the HI aquifer have generally been influenced less by slightly <br />less than average recharge during the previous seven years prior to the above average precipitation in <br />2005. The mining upgradient of HI well GF-4, which occurred several yeazs ago, has been long <br />enough in the past to allow water levels to fully recover. The water levels in this HI aquifer well <br />seem to be varying only slightly with changes in recharge rates. Water levels in this well were <br />slightly higher in 2005 with the above normal precipitation. The elevation of the backfill springs <br />likely limits the head buildup in the backfill aquifer, which, in tum, limits the maximum head in the <br />downgradient coal aquifer. Fairly steady water-level responses were observed in the two backfill <br />equivalent HI aquifer wells GF-5 and GF-7. Water levels seem to have reached recovered levels in <br />these two wells. The development of backfill springs may limit the maximum water level in some of <br />these azeas of the A pit. <br />The water levels in the three GE wells stabilized in approximately 1990. This is thought to • <br />be due to the length of time since dewatering stopped at the adjacent underground operation. <br />Gradually declining water levels were observed in these three wells with the above normal <br />precipitation. <br />Water levels in the backfill azeas are depressed and are not likely to ever recover to pre-mine <br />levels except near the northern end of the mine azea. Map 2-1 shows that the levels in the backfill <br />and downgradient aquifers are similar. Well pairs GD-3 & GD-2 and GF-11 & GF-6 present water <br />levels that aze very similaz in water-level elevation for the backfil] and downgradient QR aquifer <br />well. Mining is significantly increasing the permeability of the backfill aquifers which is a benefit <br />relative to potential yields from the aquifer. The increased permeability will likely not allow water <br />levels to recover to pre-mine levels in the reclaimed pits except near the northern (down-dip) end of <br />Trapper Mining Company 6-2 • <br />2005 Annual Report <br />