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I' <br />I' IV. GROUND WATER <br />GROUND WATER ELEVATIONS <br />Water levels in the alluvia] 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 the West Ridge spoils well are shown in <br />Figure 20. In reviewing the data, it 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 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 2003, preventing monitoring for the <br />remainder of 2003. 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 Wel] TR-1.5 intersects stratigraphy above [he Wadge coal seam while the alluvium in the vicinity of TR-3 <br />intersects stratigraphy below [he 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 lithologies 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. Prior to 2003, <br />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 2003 followed the expected trends 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 />27 <br />