REP32708 - Laserfiche WebLink

Home Browse Search

Draft West Elk Mine 2005 Annual Hydrology Report 40 The water level in monitoring Well SOM-76, installed in the F-Seam, has dropped over 30 feet since WY 2003, including a 15 foot drop observed in WY 2005. This is most likely the result of seasonal variation or possibly mining operations in the Northeast Panel area. Water levels will likely rise in Wel] SOM-76 afrer mining operations cease in this area. The water level rose by 7 feet in monitoring well SOM-3-E in WY 2005. However, this observation is suspect because two of the three data points for WY 2005 showed the continuing and consistent declining water level trend observed in previous years Monitoring Well SOM 129-H showed a rise of about 50 feet in water levels early in WY 2002, remained high in WY 2004 and rose sharply (44 feet) in WY 2005. The source of the most recent sharp water level increase in not believed to be due to mining activities and may be the result of measurement error. 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 azea and dewatering of the B-Seam. The water level in this well will likely continue to fall in WY 2006. 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 80 feet over the ensuing period through September 2005. This is likely due to mining and dewatering of the B-Seam. The static water level in this well may continue to fall in WY 2006 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 2 years. This change may be the result of natural seasonal variation or possibly the result of down gradient dewatering of the B-Seam during mining operations. Monitoring Well 23-H-1 completed in the B-Seam, showed water level fluctuations of 40 feet during the baseline data collection period in WY 2005. The casing of this well is believed to be compromised or broken and water levels may be influenced by shallow ground water inflows and not representative of impacts related to the B-Seam ground water zone. No other monitoring wells showed significant water level changes during WY 2005 6.0 ADEQUACY OF THE MONITORING PROGRAM Since 7999 the West.:Elk 'Midehydro[ogic'iinonitoring programihas ;operated m accordance, wath Techitical_;Revisro`~7~ov__88 (appoved r?>Altgust 199J).and Minor~~viston-x~o_;2:08 (approped September 2006 HydroGeo, Inc.