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L.J <br />• <br />I~ <br />SECTION 2.Q 2QQ3 Annual Hydrology Report for Trapper Mine <br />2.1 Climatological Data <br />The 2003 National Weather Service Cooperative monthly summaries and the historical precipitation <br />summary (1978-2003) are included in Section 2.5. 2003 precipitation totaling 14.14°, provided 104 <br />percent of the established historical pre-mining (44-YR) annual precipitation mean and 86 percent of the <br />project-to-date annual precipitation mean (Figure 2-1 ). The highest monthly precipitation amount was <br />recorded in November (2.52") with the second and third highest totals occurring in February and March <br />(2.00" and 1.57" respectively). Precipitation amounts were well below normal for the months of January, <br />May, July and October. For the fourth year in a row, the temporal distribution of precipitation resulted in a <br />much drier than usual growing season. <br />2.2 Pit Dewatering and Consumptive Water Use for 2003 <br />During 2003, Trapper dewatered approximately 22.7 acre-feet of water from four active pits and 31.5 acre- <br />feet of water from G-Pit dewatering wells. (Table 1-1 of Section 2.5 shows the pumping volumes for each <br />activity). An increase in pumping from dewatering wells is expected in 2004. All pit water was routed into <br />the NPDES drainage system with resulting discharges monitored accordingly. Pit dewatering volumes <br />were slightly higher in 2003 as compared to 2002. <br />Approximately 86 acre-feet of water were used for dust suppression on haul roads and topsoil handling <br />operations in 2003. This is slightly higher than the 2002 total of 80 acre feet. A relatively dry summer and <br />fall season contributed to the increase in dust suppression water application. Dust suppression water <br />demands continue to be somewhat offset by the successful application of dust suppression chemical <br />treatments on haulroads. Haul routes were similar in 2003 as 2002. Total water volume used by Trapper <br />Mine in 2003 was approximately 140 acre-feet, much higher than the 2002 total of 100 acre feet due to the <br />increase in pit and well dewatering. <br />2.3 Mining Advancement and Ash Disposal Sites <br />The 2003 Annual Reclamation maps, the Water-Level Elevation maps (2-1, 2-2 and 2-3), and permit Map <br />M52 depict the following mining activities through year-end: <br />a) Project to date utility waste disposal sites. <br />b) Project to date pit advancement (toe of pit). <br />c) Project to date monitoring wells, and natural and spoil springs and seeps. In the 2003 report, all <br />spring and seep sites within the permit area are depicted to provide location information for future <br />reference. <br />2.4 Monitoring Points <br />Refer to Map M52 for locations of all the operational hydrologic monitoring points. No new ground water <br />monitoring wells were installed during 2003. <br />No additional NPDES discharge points were constructed during 2003. Outfall 006 was reclaimed and <br />Outfalls 003 and 010 were permitted to remain as permanent structures in accordance with TR-92. <br />No new pit dewatering wells were installed during 2003. Monitoring ceased in wells GB 1, 2, and 5 and <br />GF 1, 2, and 3, along with West Buzzard, Etk, Cottonwood, Cottonwood East, Wapiti, No Name and <br />Johnson Springs as a result of SL-4 Phase III Bond Release. The six wells will be abandoned in 2004. <br />Monitoring well GP-1 was mined through in 2003 <br />