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GF -6 and GF -11 are thought to be at or above the baseline levels for this reason. The slightly higher <br />water levels in well GD -2 in 1998 than those observed in 1986 after six wet years indicates the post - <br />mine levels under the same conditions may be higher. Springs are not expected to develop at the <br />north end of the D, F and K pits. <br />The water -level changes for the HI aquifer have generally been influenced less by higher than <br />average recharge in 2005 through 2011, the very low precipitation in 2012, and closer to normal in <br />2013 through 2016. The mining upgradient of HI well GF4, which occurred several years ago, has <br />been long enough in the past to allow water levels to fully recover. The water levels in this HI <br />aquifer well seem to be varying only slightly with changes in recharge rates. Water levels in this well <br />were overall slightly higher in 2007 through 2016 with the near and above normal precipitation <br />except for the low 2012 value. The elevation of the backfill springs likely limits the head buildup in <br />the backfill aquifer, which, in turn, limits the maximum head in the downgradient coal aquifer. <br />Fairly steady to slightly lower water -level responses were observed in the two backfill equivalent HI <br />aquifer wells GF -5 and GF -7. Water levels seem to have reached recovered levels in these two wells. <br />The development of backfill springs may limit the maximum water level in some of these areas of <br />the A pit but the backfill aquifer will maintain less fluctuation in water levels down gradient of the <br />pit. <br />Water levels in the backfill areas are depressed and are not likely to ever recover to pre -mine <br />levels except near the northern end of the mine area. 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 are very similar in water -level elevation for the backfill 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 />Trapper Mining Company 6-2 <br />2016 Annual Report <br />