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• longer a flowing well. Figure A-14 shows the water-level <br />elevations in the Twentymile Sandstone at GF1. Water levels have <br />shown little change since August 1987. Water levels were <br />gradually increasing in well GF2 (see Figure A-15) until mid-1987 <br />when the levels declined. Levels in 1988 compare well with <br />values seen in late 1986 and early 1987. These values are <br />approximately two feet higher than late 1987 values. The water <br />levels had risen at a fast rate in the KLM aquifer in this area <br />through 1987 (see Figure A-16, well GF3>. Water levels appear to <br />have stabilized during 1988. Water levels in well GF4 continued <br />to rise until June, 1987 and remained steady until December 1987 <br />when levels rose for the first three quarters of 1988. Levels <br />remained steady for the remainder of the year (see Figure A-17). <br />Most of the recent water-level rise in the KLM and HI aquifers at <br />the GF wells is thought to be caused by the upgradient mining <br />releasing ground water and recovery from mine dewatering. <br />Present levels may be close to pre-mine levels. <br />Figure A-18 shows that water level in backfill well GFS has <br />steadily risen since its installation. Water levels since the <br />latter part of 1987 may indicate that levels may have peaked and <br />are beginning to stabilize in the backfill aquifer near well GFS. <br />Pre-mine water levels may have been greater in the HI aquifer at <br />site GFS. The average water levels in well GF6 for 1988 have <br />declined steadily from levels for 1986 and 1987 (see Figure A- <br />19). Water levels in the OR aquifer are thought to be reflecting <br />historical precipitation influences. Upgradient mining in 1983 <br />• could have caused some water-level fluctuations. Overall trends <br />are thought to have been caused by natural influences. <br />2-8 <br />