2008-01-08_REPORT - C1980007 - Laserfiche WebLink

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West Elk Mine 2006 Annual Hydrology Report 47 • flume. Pressure transducers and data loggers were installed in the open stream channels at the Deep Creek stations. Control channel sections were established at each site in 1996; however flumes were not installed at these locations in order to limit impacts based on U.S. Forest Service concerns. The Deep Creek stream channel is very dynamic and has changed considerably since the sites were established. As a result of erosion and sediment deposition, the control channels used to calibrate the pressure transducers and gauge the stream flows are constantly changing and the flow data collected for Deep Creek in WY 2002 (HydroGeo, 2003), WY 2003 (HydroGeo, 2004), WY 2004 (HydroGeo, 2005), WY 2005 (HydroGeo, 2006), and WY 2006 (this report) are not considered reliable. The data and graphs presented in this report were developed using a rating curve developed from recent channel geometries but the raw data for these stations remains suspect. The well casings have collapsed in six monitoring wells SOM-45-H1 (Sept. 2002), SOM-2-H (Jul. 1999), SOM-16-H (Sep. 2000), 96-27-1 (Apr. 2002), SO.W-1 (Jun. 2002), and SOM-23-H-1 (Aug. 2006). Water quality and water level data were not collected from these wells in WY 2006. 7.0 SUMMARY • During WY 2006, all aspects of hydrologic related mining operations at the Project were conducted in accordance with all permit and regulatory compliance stipulations. Based on the surface water, ground water, spring and seep, underdrain, and mine inflow monitoring data collected to date, Project mining operations did not cause any significant impacts to local surface or ground water resources in WY 2006. As MCC's mining operations shift from the west side of the Project area to the south and east side, the Project's hydrologic monitoring program will need to be revised accordingly. Anew comprehensive hydrologic monitoring plan was proposed as part of the South of the Divide Permit Revision Application (MCC, 2006). This plan was approved by the CDRMS in June 2006 (CDRMS, 2006) and will be implemented in WY 2007. A multi-year drought was abated with below but near normal precipitation in WY 2003 and WY 2004. Continued improvements in climatic conditions in WY 2005 and WY 2006 resulted in slightly below to average precipitation which gave rise to slightly below to near average flows in area streams. Spring flows in the Project area were higher than in the previous five years, but still remain generally below the historic norm. The static water levels in most of the ground water monitoring wells have remained relatively . constant over time, in some cases showing only seasonal variations. However, monitoring wells located above-or down-gradient of active longwall mining operations often show lowered water December 2007 HydroGeo, InC.