Laserfiche WebLink
• is available in previous AHRs. The last flows measured for 2000 showed seasonal variations, with an average <br />annual flow of approximately 65 gpm. <br />At the time of the 2005 inflow study, the mine operation was at 127+50 of the 18 Rt panel. During 2005, inflows <br />continued in the Northeast Submains, although there appears to be a continued decrease in ceiling dripping. The <br />highest inflows were on the order of 18-10 gpm from a floor sump at IF8 with a conductivity of 2268 (Trout <br />Creek Water). This conductivity was somewhat higher than last year (2205 umhos/cm), and may have been <br />impacted by the addition of roof drip collection to the sump system. The next highest inflow was at raise bore <br />area (see IF 38 and IF 37 on Figure 117, which was on the order of 2i gpm (down from an estimated 30 gpm in <br />2002), which is on same order as 2004. Field conductivity measurements were 1519 umhos/cm. This site is a <br />blend of Wadge and Twentymile Sandstone water. Inflow at the remaining sites were significanfly lower, often <br />less than a gallon per minute (see specific volumes on Figure 117). <br />4.0 SUBSIDENCE IMPACTS _ <br />During the second-half of 2005, water quality data was collected from established sites along Fish Creek in areas <br />underlain by gate-roads or longwall panels, as well as from representative downstream sites located away from <br />the subsidence area. (See Second Half 2005 Subsidence Survey Report). <br />Fish Creek: Hydrologic monitoring of potential subsidence impacts from the 17-Right Panel utilizes three <br />• alluvial wells and three nearby surface sites. These sites are shown on the attached Second Half 2005 Subsidence <br />Map. These include alluvial well AVF-14 and associated surface site SW-14 (upstream of 17-Right subsidence <br />zone). Also utilized are alluvial well 008-AU3 and associated surface Si[e 305 (downstream of 17-Right <br />subsidence zone). Note that sites 305 and 008-AU3, were designated under TR03-42 as subsidence monitoring <br />sites. <br />Alluvial well AVF-15 and associated surface site SW-15 are located between the two sets of upstream and <br />downstream sites, presently within a ponded subsidence zone. Localized ponding occurred in this area in <br />September/early-October of 2004, and has persisted through the second half of 2005. <br />Hydrologic monitoring did not indicate significant water quality impacts to Fish Creek. In August 2005, iron <br />concentrations for surface sites SW-14, SW-15, and 305 ranged from 820 ug/1 to 1670 ug/I. Seasonal fluctuations <br />of iron concentration occurs at the surface sites. Increases in iron concentration are often related to accumulation <br />and leaching of iron-bearing strata/sediments during spring runoff erosion. Some elevated iron concentrations <br />may also be related to ponding effects (e.g. increased solids in ponded samples). <br />Structures remained essentially unaffected during the period with the exception of the predicted impacts to [he <br />Union Pacific Railroad and Fish Creek as reflected in the data and on the associated subsidence map. No adverse <br />impacts, i.e. imminent failure of structure, were evident . <br /> <br />13 <br />