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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 <br />than average recharge in 2005 through 2011, the very low precipitation in 2012, and closer to normal <br />in 2013 through 2017. The mining upgradient of HI well GF -4, which occurred several years ago, <br />has 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 <br />well were overall slightly higher in 2007 through 2017 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 water -level responses were observed in the two backfill equivalent HI aquifer wells <br />GF -5 and GF -7. Water levels seem to have reached recovered levels in these two wells. The <br />development of backfill springs may limit the maximum water level in some of these areas of the A <br />pit but the backfill aquifer will maintain less fluctuation in water levels down gradient of the pit. <br />Water levels in most of the backfill areas are depressed and are not likely to ever recover to <br />pre -mine levels except near the northern end of the mine area. Map 2-1 shows that the levels in the <br />backfill and downgradient aquifers are similar. Well pairs GD -3 & GD -2 and GF -11 & GF -6 <br />present water levels that are very similar in water -level elevation for the backfill and downgradient <br />QR aquifer well. Mining is significantly increasing the permeability of the backfill aquifers which is <br />a benefit relative to potential yields from the aquifer. The increased permeability will likely not <br />allow water levels to recover to pre -mine levels in the reclaimed pits except near the northern <br />Trapper Mining Company 6-2 <br />2017 Annual Report <br />