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fall of 2014 were used to develop these maps. The structure maps for the coal seams were used to <br />extend the piezometric contours in the proposed permit extension area on the east side of Trapper <br />Mine. The dip of the beds change from mainly to the north to the northwest in the extension area. <br />This will cause the gradient in the ground water to gradually change from the north to the northwest. <br />Map No. 2 -1 presents the water -level elevations for the QR aquifer. The water -level <br />elevation is presented for the QR wells: GD -2, GF -6 and GP -5 and backfill wells GD -3 and GF -11. <br />The ground -water flow in the QR aquifer is mainly to the north. Mining has only affected the QR <br />aquifer close to the D, E, F, G, K, L and Z pits by causing drawdowns very near the pit edges. The <br />installation of backfill wells GD -3 and GF -11 has defined the depressed elevations in the backfill <br />areas. The wells in this area experienced some fluctuating water levels during 2014. The water level <br />changes in 2014 are likely due to seasonal recharge in recent years. The backfill water levels will <br />likely stabilize lower than the pre-mine levels due to the increased permeability of the backfill <br />aquifer, which allows the water in the aquifer to be transmitted at a lower gradient. The gradient <br />calculated for the backfill near D pit is less than 0.05 fl/ff, compared to the undisturbed gradient of <br />0.12 ft/ft. The heads in the northern end of the backfill aquifer will likely recover above the pre -mine <br />level. Backfill springs are not expected to develop near the northern end of the QR backfill because <br />backfill water levels would have to recover greater than a few tens of feet to reach the lower land <br />surface elevations. Table 2 -1 of the 1990 Annual Hydrologic Report (Hydro- Engineering, 1991) <br />presents aquifer properties at Trapper Mine. The permeabilities from the backfill aquifers are <br />significantly greater than the coal aquifers that they replace. <br />The water -level contours extend through the pit areas for the F, G and Z pits because the R <br />seam was not mined in these pits and therefore the QR aquifer still exist under these pit floors. Some <br />drawdown would be expected in these areas of the QR aquifer and are indicated by the contours. <br />Trapper Mining Company 2 -9 <br />2014 Annual Report <br />