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I ~ 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 2001. <br />2.2 GROUND WATER-LEVEL ELEVATION (PIEZOMETRIC MAP SUMMARI~ <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 2001 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-i, GP-5, and GP- <br />6 and backfill wells GD-3 and GF-il. The ground-water flow in the QR aquifer is mainly to <br />the north. Mining has only affected the QR aquifer close to the D, E, F and G pits by <br />causing drawdowns very near the pit edges: The installation of backfill wells GD-3 and GF- <br />ii has defined the depressed elevations in the backfill areas. The wells in this area <br />experienced fairly steady levels during 2001. The previous gradual declines and present <br />steady levels are likely due to less recharge in the last four years. The backfill water levels <br />will likely stabilize lower than the pre-mine levels due to the increased permeability of the <br />backfill aquifer, which allows the water in the aquifer to be transmitted at a lower gradient. <br />The gradient calculated for the backfill near D pit is 0.08 ft/ft, compared to the <br />undisturbed gradient of 0.14 ft/ft near well GP-6. The heads in the northern end of the <br />backfill aquifer will likey recover above the pre-mine level. Backfill springs are not <br />expected to develop near the northern end of the QR backfill because backfilt water levels <br />would have to recover greater than a few tens of feet. Table 2-1 of the 1990 Annual <br />Hydrologic Report (Hydro-Engineering, 1991) presents aquifer properties at Trapper Mine. <br /> <br />2-9 <br />