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IV. GROUND WATER <br />GROUNDWATER ELEV ATION5 <br />Water levels in the alluvial wells at the Edna Mine have remained constant over the period of record with minor <br />fluctuations occurring seasonally. Elevations of the water in the alluvial wells and [he West Ridge spoils well are shown in <br />Figure 20. In reviewing the data, it is apparent that [he spoils well (WR-1) has reached steady state and exhibits consistent <br />seasonal flucmations. The seasonal fluctuations result from spring snowmelt causing a mounding of water in the perched <br />aquifer which drains over the summer via discharge from a spring on the lower portion of West Ridge near the elevation of <br />Trout Creek. <br />Monitoring Well TR-4 was broken off and plugged by livestock in July 2002, preventing monitoring for the <br />remainder of 2002. The well was repaired in the spring of 2003. <br />GROUND WATER QUALITY <br />Comparisons of water quality data gathered from the alluvial wells at the Edna Mine must be exercised with caution <br />due to [he differing stratigraphic units intersected along Trout Creek adjacent to the various wells. The alluvium in the <br />vicinity of Well TR-1.5 intersects stratigraphy above the Wadge coal seam while the alluvium in the vicinity of TR-3 <br />intersects stratigraphy below the Wadge seam. Alluvium in the vicinity of TR-4 intersects even lower stratigraphic units than <br />those at TR-3. The influence from contact with the differing lithology can not be quantified; therefore, differences between <br />the wells may not be responses to mining related activities. <br />Groundwater samples from TR-4 show an increase in several parameters over the course of 2003-2004. Prior to <br />2003, parameters at the well had stabilized. Therefore, it is assumed that this increase is due to the well repairs. <br />Temperature/pH <br />Temperature (Figure 21) and pH (Figure 22) in 2004 followed the expected [rends with temperature exhibiting <br />typical seasonal fluctuations and pH remaining relatively constant over the monitoring period. The amount of temperature <br />fluctuation in Well TR-4 is somewhat greater than expected suggesting the flow to the perched aquifer, although subsurface, <br />is very shallow. <br />26 <br />