2007-03-16_REPORT - C1981010 ‎(8)‎

• Permit No: C1981010
• IBM Index Class Name: REPORT
• Doc Date: 3/16/2007
• Doc Name: 2006 AHR Section 2.0 Ground Water Levels
• Annual Report Year: 2006
• Permit Index Doc Type: Hydrology Report
• Media Type: D
• Archive: No

well GP -8 and continued on a smaller decline rate in 2002 through 2005 with a water level rise in
2006. A significant amount of well dewatering occurred from the G pit area in 2006.
Steady water levels had been observed in the previous four years in well GMP -1 while a
small increase was observed in 2005 and 2006. The previous ten years show a water level rise due
to the movement of Pit A to the east of this area. No dewatering was produced from the Z pit in
2006 while some dewatering occurred from the A, F and G pits. The decrease in water levels in
wells GD -2 and GD -3 in 2006 were caused by deep exploration drilling in this area. The water
levels in KLM well GP -2 overall gradually increased in 2006. The previous decline could have
been caused by the decrease in recharge and mining in this area.
Water -level changes are discussed in more detail in the following section.
2.1.2 WATER - LEVEL CHANGES
Water -level changes for 2006 are presented in Figures A -1 through A -14 in Appendix A.
The table in Appendix A list all historical data for the Trapper Mine. The wells are grouped on the
water -level plots according to aquifer where possible but, in most cases, are grouped by similar
water -level elevations. Table A -1 in Appendix A presents a tabulation of the water -level elevations
for each of the monitoring wells. Figure 2 -1 presents the total annual precipitation at the Trapper
Mine from 1978 through 2006. Precipitation declined from a high in 1983 to a low in 1988 and had
increased again to a peak in 1993 with a below average value in 1994. The years 1995 through
1997 had above average precipitation relative to the Trapper Mine record, while 1998 through 2004
were below. The precipitation in 2005 and 2006 was above normal. Water levels in many of the
wells reflect the natural variations in recharge. These changes may lag the actual precipitation
events due to the time it takes the head change to move through the aquifer to the monitoring well.
Trapper Mining Company 2-3
2006 Annual Report