2008-01-08_REPORT - C1980007 - Laserfiche WebLink

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West Elk Mine 2006 Annual Hydrology Report 43 • 5.3 Impacts to Stock Ponds and USFS Water Resources Numerous stock ponds and USFS water resources are located in the Project area. The USFS water resource sites are summarized in Table 8 and shown in Map 3. There has never been any known water loss or mining related water quality issues at any of these locations including WY2006 and none are expected in the future. 5.4 Ground Water MCC maintains a network of 28 ground water monitoring wells throughout the permit and lease areas. A summary of the ground water well monitoring schedule is presented in Table 5 and the well completion data is presented in Table 6. The locations of the ground water monitoring wells are shown on Map 2. The well water elevation and depth to water data are presented in Appendix F and the ground water quality data are presented in Appendix G. The casings in several monitoring wells have collapsed in the past several years and are likely the result of mining-induced subsidence. These wells include SOM-45-H-1 (Sept. 2002), SOM-2-H (Jul. 1999), SOM-16-H (Sep. 2000), 96-27-1 (Apr. 2002), SO.W-1 (Jun. 2002). Well 23-H-1 (Aug. 2006) has obstructed and damaged casing resulting from poor installation procedures, not related to mining activities. As a result, hydrologic data from these wells for WY 2006 are not available. 5.4.1 Impacts to Ground Water Quantity and Quality In general, there were no significant water quality changes in the ground water monitoring wells during WY 2006. However, there were several minor changes noted in the Upper Dry Fork Alluvial Well, Lower Dry Fork Alluvial Well, SOM 13, SOM 45-H-2, SOM 80, SOM C-76, 23-H- 3, 03-11-1, SOM 3E, 96-2-2, RAV 4B, 1-11-01, and SOM-3B. The Upper Dry Fork Alluvial well had a slightly elevated conductivity of 559 µmhos/cm compared to the maximum baseline value of 509 µmhos/cm. Lower Dry Fork Alluvial Well had slightly elevated conductivity of 513 µmhos/cm compared to the maximum baseline value of 497 µmhos/cm, elevated total iron of 5.66 mg/1 compared to the maximum baseline of 0.51 mg/1, elevated total manganese of 2.66 mg/1 compared to the maximum baseline of 2.48 mg/1, elevated ammonia of 0.16 mg/1 compared to the maximum baseline of 0.09 mg/1, elevated pH of 8.3 s.u. compared to the maximum baseline of 8.0 s.u., elevated sodium of 48.4 mg/1 compared to the maximum baseline of 45.8 mg/1, and phosphate of 0.18 mg/1 compared to the maximum baseline of 0.03 mg/1. Well SOM 80 had slightly elevated conductivity of 1,400 µmhos/cm compared to the maximum baseline value of 897 µmhos/cm and elevated pH of 8.3 s.u. compared to the maximum baseline of 8.1 s.u.. Well SOM 13 had slightly December 2007 HydrOGeo, Inc.