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

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West Elk Mi77e from the monitoring program, because of a problematic completion that caused a blockage, preventing the well from providing any data. Monitoring wells 96-2-2 and 96-27-1 were completed above and in the E Seam, respectively, during the 1996 exploration project. Baseline data collection began in the fan of 1996. Sufficient baseline data were collected and the wells are now part of the regular monitoring program. Unfortunately, monitoring well 96-27-1 was rendered useless as a result of B Seam mining passed underneath and the well is not longer providing any data. Drill hole 96-15-1 was drilled during the 1996 exploration program and was completed as a water monitoring well in the B Seam. Because the well was venting a significant amount of gas, water measurement and sampling was precluded. The well has been fitted with a vent to allow de- gassing. In the event that the well discontinues producing gas, the well could be incorporated into the monitoring program. In 2001 and 2003, MCC drilled and constructed monitoring wells 01-11-1B in the B Seam and 03-11-1E in the E Seam, down-dip of the Box Canyon longwall panels. These wells were drilled prior to longwall mining of panel 18 (the northernmost Box Canyon panel) to assess potential down-gradient impacts and are currently being monitored. Five additional wells were constructed in 2003 to supplement the monitoring program of West Elk Mine. These included two alluvial/weathered bedrock wells in the Dry Fork of Minnesota • Creek (Upper Dry Fork and Lower Dry Fork), two E Seam wells (one in the South of Divide pen-nit revision area (SOM-3E) and one down-dip of the Box Canyon Panels (03-11-1E)) and one B Seam well (SOM-313), also in the South of Divide permit revision area. These wells are currently being monitored as part of the ongoing hydrologic monitoring program and are addressed in Exhibit 71 for the South of Divide Area. Additional information about each of these monitoring wells (i.e., location, ground surface elevation, screened interval, and total depth) can be found in Table 2 in Exhibit 71. Groundwater Quality MCC has selected the water quality parameters listed in Table 6 for baseline laboratory analysis to characterize baseline and ongoing groundwater quality. These include iron and manganese, because the detection of these elements (or changes in their observed concentrations) may represent conditions in which metals are mobilized. Additionally, changes in conductivity and TDS can indicate changes in water quality that need to be further investigated. As a result, monitoring of these selected parameters provides a detection system for mining-induced changes in water quality. Therefore, once full-suite analyses have been collected at a site for at least five years, these indicator parameters (pH, conductivity, TDS, and iron) will be collected on an annual basis. Analyses are completed as outlined in the Guidelines for Collection of Baseline Water Quality and Overburden Geochemistry Data (CDMG, 1982). Results are reported in the Annual Hydrology Reports (AHR). If not already provided in AHR's, baseline data will be provided to CDMG prior to longwall mining under or within the angle-of-draw of a monitored water resource. 2.04-60 Revised June 2005 PRIG, A7arch 2006; Rev. April 2006 PRIG, Sep. 2007PR12