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2.1 GROUND WATER-LEVEL CHANGES <br />2.1.1 SUMMARY • <br />Significant mine activities during 2004 included the continued expaz>.sion of the F, G and Z <br />pits. Mining, which started in 1997, continued in the M and Q warns with additional mining in the I and <br />L seams in 2004. Mining was initiated in 2001 in the G pit (H, K, L, M and Q seams in 2004) and Z <br />pit (I, L, M and Q seams in 2004). Dewaterirtg occurred in the A, F and G pits during 2004 at <br />dewatering volumes of 16.16, 10.91 and 10.13 ao-ft, respectively. Well dewatering of 40.68 ac-ft was <br />produced it 2004 near the G pit. <br />Annual precipitation for 2004 was slightly less than normal at 13.56 inches, compared to the <br />Trapper record and equal to the long-term record (Figure 2-1). The last seven years of precipitation <br />have been below normal, relative to the Trapper average established since 1978 (see Figure 2-1). The <br />three years previous to the last seven years were above the Trapper average. Recharge in this <br />geographic setting is directly related to precipitation . <br />The effects of natural recharge variations on the respective aquifers can be observed in wells <br />located in undisturbed areas away from the inthxertce of inining activities. Wells GC-2, GC-3 and GP-9 <br />are used to indicate natural response in the past but treed to be used with caution starting in 2000 due <br />to miring moving into this area. Well GC-3 exhibited the alluvial water-level response with a simt7ar <br />variation in water level in 2004 to those that have been observed historically. The effects on the 3rd <br />White aquifer are observed in wells GC-2 and GP-9. Well GP-9 shows awater-level rise in 2004, <br />showing good recharge with the slighly below average precipitation while water levels gradually <br />declined in well GC-2. The HI aquifer (GP-7) is characterized by fairly gradualwater-level decline in <br />this aquifer in 2004. Tbe KLM aquifer showed a larger water-level decline in 2001 in well GP-8 abe <br />contimred on a smaller decline rate in 2002 through 2004. Some pit dewatering occurred from the G <br />pit in 2004 along with significant well dewatering in this area <br />Trapper Mining Company 2-2 • <br />2004 Annual Report <br />