2013-03-14_REPORT - C1982056 (3)

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NMD: At the time of the 2010 inflow study, the mine operation had completed the 23 Rt panel. The primary sources of water came from the two most recent shafts in the 6MN area, and two fault crossings. Total inflow was 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 (1F8) 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 (new WMD): The 2012 inspection along the 17LT and 18LT gate roads indicated estimated inflows of less than 10 gpm. The majority of sites were modest roof drippers, with sites 67 and 68 exhibiting the highest flows, both on the order of 0.25 to 1 gpm, respectively. The majority of the drippers seen in 2011, had dried up by 2012. 3.9 Water Balance In early 2009, TC conducted a water balance study to better access water use and allocations for mine operations, as well as mine dewatering. A flow chart was provided in the 2009 AHR, illustrating water movement for the mine in early 2009. Note that there have been some changes in flow patterns since this study. Another mine water balance is may be performed in 2014, which would require expenditures for flow meters at key locations. 4.0 SUBSIDENCE IMPACTS Fish Creek: Historically, hydrologic monitoring of potential subsidence impacts from the earlier 17 and 18 - Right Panels utilizes four alluvial wells and four nearby surface sites. These sites are shown on the attached First Half 2008 Subsidence Map. These include alluvial well AVF -14 and associated surface site SW -14 (upstream of 17 -Right subsidence zone). Also utilized are alluvial well 008 -AU3 and associated surface Site 305 (downstream of 17 -Right subsidence zone). Note that sites 305 and 008 -AU3, were designated under TR03 -42 as downstream subsidence monitoring sites. Alluvial well AVF -15 and associated surface site SW -15 are located between the two sets of upstream and downstream sites, presently within a ponded subsidence zone. Localized ponding occurred in this area in September /early- October of 2004. The creek bed flow path subsequently reestablished itself. A portion of Fish Creek was last subsided in 2006. In that year, a short segment of Fish Creek crossed approximately 160 feet into the zone of anticipated subsidence (based on the subsidence limit line) along the extreme eastern edge of the 19 -Right Longwall Panel. Minimal subsidence impacts were noted along roughly 500 linear feet of Fish Creek, in this area. Note that during 2007, no significant ponding effects were observed in this area, with the exception of site AVF -15, which appears to be in a permanently ponded area. Hydrologic monitoring in 2012 did not indicate significant water quality impacts to Fish Creek. Note that seasonal 16