2010-04-16_REPORT - C1982056 (3)

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40 3.8 2009 Inflow Survey During the fall of 2009, an inflow study was conducted underground. Flow rates and field parameters were recorded for measurable inflows from the accessible areas of the underground mine. Results of the 2009 survey are presented on Figure 117, 2009 Inflow Study Mined Area (in map pouch at back of report). Note that this map also includes some historic data for former sites, most of which have dried up. The WMD was closed in 1996. At that time inflows were 52 gpm. Note that water elevations for the WMD were monitored periodically at the Fish Creek Borehole. Our best estimate is that inflows for the WMD are still on the order of 50 to 60 gpm. Longwall mining was completed in the EMD by early-January 2001. Production from the NMD, 12 Rt Longwall Panel, was underway by late January 2001. The EMD was permanently sealed in October 2001 removing all access to the 6 Rt and 7 Rt gate roads. Thus, no measurements are available in this area for 2006. Historical data is available in previous AHRs. The last flows measured for 2000 showed seasonal variations, with an average annual flow of approximately 65 gpm. The EMD was monitored periodically at the TORT well shaft during 2009. Northern Mining District (NMD): At the time of the 2009 inflow study, the mine operation had completed the 23 Rt panel. During 2009, the main sources of water came from the two most recent shafts in the 6MN area, and two fault crossings. Total inflow is estimated to be on the order of 80 gpm. Inflows continued in the Northeast Submains, although there appears to be a continued decrease in ceiling dripping. The highest inflows were about 20 gpm for the new 6MN shaft, and about 15 gpm from a floor sump at inflow site 8 (IF8) with a conductivity of 2270 (Trout Creek Water). This may have been impacted by the addition of roof drip collection to the sump system. The next highest inflow was at raise bore area (IF 38 and IF 37), which was on the order of 10-gpm (down from an estimated 20 gpm in 2005), Field conductivity measurements were about 1500 umhos/cm. This site is a blend of Wadge and Twentymile Sandstone water. Inflow at the remaining sites (primarily roof drippers) were either dry or significantly lower, often less than a gallon per minute. New Western Mining District (WMD): The 2009 inspection along the newly completed 17LT and 18LT gate roads indicated estimated inflows of 15 to 20 gpm. The majority of sites were modest roof drippers, with sites 55 and 57 exhibiting the highest flows, both on the order of 5 to 6 gpm. 3.9 Water Balance In early 2009, TCC conducted a water balance study to better access water use and allocations for mine operations, as well as mine dewatering. Attached is a flow chart (see tab at back of this AHR) illustrating water movement for the mine in early 2009. Note that there have been some changes in flow patterns since this study, which will be reflected in the 2010 AHR. • 16