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2.1 GROUND WATER-LEVEL CHANGES <br />2.1.1 SUMMARY <br />Significant mine activities during 2007 included the continued expansion of the A, F, G <br />and Z pits. Mining in the F pit, which started in 1997, continued in the M and Q seams with <br />additional mining in the I and L seams in 2004 through 2007. Mining was initiated in 2001 in the <br />G pit (H and K seams in 2007) and Z pit (I, K, L, M and Q seams in 2007). Dewatering occurred in <br />the A and F pits during 2007 at dewatering volumes of 27.53 and 7.00 ac-ft, respectively. Well <br />dewatering of 44.87 ac-ft was produced in 2007 near the G pit. <br />Annual precipitation for 2007 was greater than normal at 19.82 inches, compared to the <br />Trapper record and the long-term record (Figure 2-1). The 2005 and 2006 precipitation were also <br />above normal while the previous seven years of precipitation had been below normal, relative to the <br />Trapper average established since 1978 (see Figure 2-1). The 2007 average was 3.3 inches larger <br />than the Trapper average. The last three years were significantly above the long-term record <br />average. Recharge in this geographic setting is directly related to precipitation. <br />The effects of natural recharge variations on the respective aquifers can be observed in <br />wells located in undisturbed areas away from the influence of mining activities. Wells GC-2, GC-3 <br />and GP-9 are used to indicate natural response in the past but need to be used with caution starting <br />in 2000 due to mining moving into this area. Well GC-3 exhibited the alluvial water-level response <br />with a similar variation in water level in 2007 to those that have been observed historically. The <br />effects on the 3rd White Sandstone aquifer are observed in wells GC-2 and GP-9. Well GP-9 <br />shows awater-level rise in 2007 prior to a sharp decline in the fourth quarter, showing good <br />recharge with the above average precipitation over the last few years. The fourth quarter decline is <br />thought to be an error because an early 2008 measurement was similar to the third quarter value. <br />The water levels slightly rose in well GC-2 in 2007. The HI aquifer (GP-7) is characterized by a <br />water-level decline in this aquifer over the last few years. The KLM aquifer showed a larger water- <br />Trapper MiniQg Company 2-2 <br />2dQ~ Annual Report <br />