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Figure 2-1 presents total annual precipitation at Trapper Mine • <br />from 1978 to 1993. Precipitation declined from a high in 1983 to <br />a low in 1988 and has increased from 1991 to 1993. Water levels in <br />many wells reflect the natural variation in recharge. These <br />changes may lag the actual events due to the time it takes the <br />water to flow through the respective aquifers to the monitoring <br />wells. Shallow aquifers may even reflect monthly variations in <br />precipitation and recharge. <br />Well GA1 (QR aquifer) water levels (Figure A-1) were fairly <br />steady in late 1991 and early 1992, probably reflecting a balance <br />in natural recharge and dewatering in the adjacent D pit. A slight <br />rise in water level was noted in December, 1992, followed by a <br />large increase of 19.9 ft. between March, 1993 and June, 1993, <br />remaining at that level for the rest of the year. This increase • <br />reflects an increase in natural recharge and the shut-down of <br />dewatering wells in D pit. The shut-down period was mid-June <br />through October, 1993, for the west well. There was also very <br />little well pumpage from October through December, 1992. The <br />middle well was only pumped in January, 1993, and the east well was <br />not pumped at all. During this time, dewatering was limited to pit <br />pumpage in August, September, November, and December, 1993 (Table <br />1-1). The RLM and QR wells used as a baseline for precipitation/ <br />recharge impacts on undisturbed aquifers (GP2, GP1, and GP6) show <br />very little change, +1 ft., and +1.5 ft., respectively, far less <br />than the observed changes in GA1. <br /> <br />2-4 <br />