2008-03-21_PERMIT FILE - C1980007A (4)

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West Elk Mine A more detailed discussion of the hydrogeologic characteristics of these units can be found later in this section. Baseline Monitoring Program This section discusses the program that MCC has implemented to monitor ground water quantity and quality resources in the pen-nit area. At least one year of baseline data will be collected prior to longwall mining under or within the angle-of-draw of a monitored water resource. Monitoring data are presented in the Annual Hydrology Reports. Groundwater Level and Quantity The currently monitored groundwater wells are described and listed in Exhibit 71. Exhibit 71 presents both the current hydrologic monitoring program as well as proposed additional monitoring sites for future mining plans including the South of Divide and Dry Fork permit revision area. Locations of the current and proposed monitoring wells are presented in Map 1 of Exhibit 71. A complete listing of all monitoring data are presented in the AHR's. SOM-23-1-1-1 (B Seam well), SOM-C-76 (F Seam well), and SOM-45-1-1-1, and SOM-45-H-2 (Barren Member wells) provide several years worth of baseline data for the South of Divide permit revision area. MCC re-introduced these monitoring wells into the monitoring program in 1995 prior to the permit revision application for the Apache Rocks and Box Canyon areas. SOM- 23-11-1 was removed from the monitoring program in June 1998 due to damage to the well from a landslide. Several new wells have been added to the monitoring program since the last permit revision relative to the planned mining in the South of Divide permit revision area. These include the Upper Dry Fork and Lower Dry Fork (alluvial/weathered bedrock wells), 03-11-1E and SOM-3E (E Seam wells) and SOM-3B (B Seam well). In addition, MCC re-introduced monitoring wells SOM-23-1-1-1, SOM-23-1-1-2, and SOM-23-11-3 into the monitoring network in 2005. A more detailed discussion and of the South of the Divide and Dry Fork permit revision areas hydrologic monitoring and monitoring well completion information is presented in Exhibit 71. Two hydrologic monitoring wells, SOM-127H and SOM-C-72H, were drilled into the B Seam in June 1988. Due to the construction of the maintenance shop, SOM-127-H had to be sealed and was replaced by SOM-129-H. Monitoring well JMB-12 is located on the Jumbo Mountain lease tract and was also completed to monitor the B Seam. JMB-12 was removed from the monitoring program in 1998, as the bottom of the well had been mined through with the B Seam. SOM C-72-H was removed from the monitoring program in 1999 for the same reason. Monitoring well LP-1 was constructed in 1994 to monitor the Rollins Sandstone. LP- 1 was removed from the monitoring program in 1998 because the well casing appeared to have sheared, likely due to local landslide activity, and was not providing reliable data. Three groundwater monitoring wells (So.W-1, So.W-3 and RAV-4b) were constructed in 1994 to gather additional baseline data in the permit area. Well So.W-3 was completed in the Rollins Sandstone, whereas So.W-1 and RAV-4b were completed in the B Sean. So.W-3 was removed 2.04-59 Revised June 2005 PRIG, March 2006; Rev. April 2006 PRIO, Sep. 2007PR12