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• Water-level elevations for the Johnson Gulch alluvial well J-1 are also presented <br />in Figure A-15. The J-1 water levels remained steady in 2000. <br />2.2 GROUND WATER-LEVEL ELEVATION (PIEZOMETRIC MAP SUMMARY) <br />Hydro-Engineering developed three piezometric maps to show the water level <br />flow patterns for the QR, HI and 3rd White Sandstone aquifers at Trapper Mine. Water <br />levels from the Fall of 2000 were used to develop these maps. <br />Map No. 2-1 presents the water-level elevations for the QR aquifer. The <br />water-level elevation is presented for the QR wells: GD-2, GE-1, GF-6, GP-1, GP-5, and GP- <br />6 and backfill wells GD-3 and GF-11. The ground-water flow in the QR aquifer is mainy to <br />the north. Mining has only affected the QR aquifer close to the D, E and F pits by causing <br />drawdowns very near the pit edges. The installation of backfiB wells GD-3 and GF-li has <br />defined the depressed elevations in the backfill areas. The wells in this area experienced a <br />gradual decline in levels during 2000. These gradual declines are likely due to less <br />recharge in the last three years. The backfill water levels will likely stabilize lower than the <br />pre-mine levels due to the increased permeability of the backfill aquifer, which allows the <br />water in the aquifer to be transmitted at a lower gradient. The gradient calculated for the <br />backfill near D pit is 0.08 ft/ft, compared to the undisturbed gradient of 0.14 ft/ft near weft <br />GP-b. The heads in the northern end of the backfill aquifer will likely recover above the <br />pre-mine level. Backfill springs are not expected to develop near the northem end of the <br />QR backfill because backfill water levels would have to recover greater than 100 feet. <br />Table 2-1 of the 1990 Annual Hydrologic Report (Hydro-Engineering, 1991) presents <br /> <br />2-9 <br />