2008-01-08_REPORT - C1980007 - Laserfiche WebLink

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West Elk Mine 2006 Annual Hydrology Report 45 • feet thick. The well casing in SOM-45-H-1 collapsed between June and September 2002 and the well is no longer functional. The dropping water level in SOM-45-H-2 stabilized in WY 2005 and has recovered slightly in WY 2006. Ground water levels appear to have stabilized and are recovering since mining operations ceased in this area in 2000-2001. Water levels are expected to continue to rise in WY 2007, due to natural recharge. The casing in Well 96-27-1 collapsed between September 2001 and April 2002 and the casing in Well SO.W.-1 collapsed between April and June 2002. The casing in well 23-H-1 was obstructed in August 2006. As a result, these wells are no longer functional. The water level in monitoring Well SOM-76, installed in the F-Seam, has dropped over 50 feet since WY 2003, including a 5 foot drop observed in WY 2006. This is most likely the result of seasonal variation or possibly mining operations in the Northeast Panel area. Water levels will likely rise in Well SOM-76 after mining operations cease in this area. The water level in monitoring well SOM-3-E has shown a continuing decline in water level since installation in 2003, with the exception of a suspect measurement in 2005. The steady decline in water level may be a function of drought conditions in recent years and is not believed to be the • result of mining activities. Monitoring Well SOM 129-H showed a rise of about 50 feet in water levels early in WY 2002, remained high in WY 2005 and WY 2006 with the exception of a suspect sharp rise in October 2005. Monitoring Well RAV-4b, completed in the B-Seam, had a sharp drop in water level of about 36 feet in WY 2003, remained steady in WY 2004, and dropped again in WY 2005 (20 feet). The lowering of the ground water level in this well is likely due to mining of the Northeast Panel area and dewatering of the B-Seam. Water level rose slightly in WY2006. This is likely due to mining and dewatering and subsequent recharge of the B-Seam. The water level in this well may continue to rise in WY 2007. Monitoring Well 01-11-1, completed in the B-Seam, showed a rise in water level from November 2001 to April 2002, but has steadily dropped about 120 feet over the ensuing period through September 2006. This is likely due to mining and dewatering of the B-Seam. The water level in this well may continue to fall in WY 2007. Monitoring Well SOM-3B, installed in the B-Seam, is located up-gradient of current mining • operations. The water level in this well has steadily dropped about 15 feet in 3 years. However, during the WY2006 the water level increased several feet. This change may be the result of natural December 2007 HydroGeo, Inc.