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IV. GROUND WATER <br />GROUND WATER ELEVATIONS <br />Water levels in the alluvial wells at the Edna Mine have remained constant over the <br />period of record with minor fluctuations occurring seasonally. Elevations of the water in the <br />alluvial wells and the West Ridge spoils well are shown in Figure 20. In reviewing the data, it <br />is apparent that the spoils well (WR-1) has reached steady state and exhibits consistent <br />seasonal fluctuations. The seasonal fluctuations result from spring snowmelt causing a <br />mounding of water in the perched aquifer which drains over the summer via discharge from a <br />spring on the lower portion of West Ridge near the elevation of Trout Creek. Monitoring <br />Well TR-4 was broken off and plugged by livestock in July 2002, preventing monitoring for <br />the remainder of 2002. The well was repaired in the spring of 2003. <br />Ground water wells TR-1.5, TR-3, TR-4 and WR-1 all maintained levels and trends, a <br />slight decrease of water level during the annual sampling season, similar to historical data <br />during 2006. Ground water well elevations are provided in tabular format in Appendix B. <br />GROUND WATER QUALITY <br />Comparisons of water quality data gathered from the alluvial wells at the Edna Mine <br />must be exercised with caution due to the differing stratigraphic units intersected along Trout <br />Creek adjacent to the various wells. The alluvium in the vicinity of Well TR-1.5 intersects <br />stratigraphy above the Wadge coal seam while the alluvium in the vicinity of TR-3 intersects <br />stratigraphy below the Wadge seam. Alluvium in the vicinity of TR-4 intersects even lower <br />stratigraphic units than those at TR-3. The influence from contact with the differing lithology <br />can not be quantified; therefore, differences between the wells may not be responses to mining <br />related activities. Groundwater samples from TR-4 show an increase in several parameters <br />over the cowse of 2003-2004. Prior to 2003, parameters at the well had stabilized. Therefore, <br />it is assumed that this increase is due to the well repairs. <br />As previously mentioned, the ground water quality at the Edna Mine is monitored via <br />30 <br />