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• 2005 Annual Hydrology Report for Trapper Mine 2.1 Climatological Data The 2005 National Weather Service Cooperative monthly summaries and the historical precipitation summary (1978-2005) are included in Section 2.5. 2005 precipitation totaling 18.79", provided 139 percent of the established historical pre-mining (44-YR) annual precipitation mean and 115 percent of the project-to-date annual precipitation mean (Figure 2-1 ). The highest monthly precipitation amount was recorded in June (3.63") with the second and third highest totals occurring in October and April (2.40" and 1.68" respectively). Precipitation amounts were below normal for the months of July and December. 2.2 Pit Dewatering and Consumptive Water Use for 2005 During 2005, Trapper dewatered approximately 24.90 acre-feet of water from three active pits and 45.67 acre-feet of water from G-Pit dewatering wells. (Table 1-1 of Section 2.5 shows the pumping volumes for each activity). An increase in pumping from dewatering wells is expected in 2005. All pit water was routed into the NPDES drainage system with resulting discharges monitored accordingly. Pit dewatering volumes were slightly lower in 2005 as compared to 2004. While the G-Pit dewatering wells showed an increase in volume over 2004 values. Approximately 69 acre-feet of water were used for dust suppression on haul roads and topsoil handling operations in 2005. This is similar to the 2004 total of 66 acre feet. Dust suppression water demands continue to be somewhat offset by the successful application of dust suppression chemical treatments on haulroads. Haul routes were similar in 2005 as 2004. Total water volume used by Trapper Mine in 2005 was approximately 140 acre-feet, almost equivalent to 2004 total of 144 acre feet. • 2.3 Mining Advancement and Ash Disposal Sites The 2005 Annual Reclamation maps (see Trapper's 2005 annual report), the Water-Level Elevation maps 2-1, 2-2 and 2-3 (included in this report) ,and permit Map M52 (see mine permit) depict the following mining activities through year-end: a) Project to date utility waste disposal sites. b) Project to date pit advancement (toe of pit). c) Project to date monitoring wells, and natural and spoil springs and seeps. In the 2005 report, all spring and seep sites within the permit area are depicted to provide location information for future reference. 2.4 Monitoring Points Refer to Map M52 in the mine permit for locations of all the operational hydrologic monitoring points. No new ground water monitoring wells were installed during 2005. Middle Flume #3, NPDES 020, was cleaned in 2005. As approved in TR-94, twenty-five sediment ponds will be retained as permanent structures on the site. This revision includes: No Name #2, #4 and #5; Johnson #6, #7R, #8R, #9R and #tOR; West Pyeatt #1 and #2; East Pyeatt #1, #2 and #3; Grouse #1 and #2; Oak #1 and #2; West Flume #1; Middle Flume #1 and #3; East Middle Flume #1; East Flume #1; Deer #1; Ute #1 and Horse Gulch #1. • Monitoring wells GB 1, 2, and 5 and GF land 2 were completely abandoned in 2005. GF-3 is sell experiencing surface flow from the top of the casing and will be abandoned in 2006.