Laserfiche WebLink
Specific Conductivity/Total Dissolved Solids <br />Specific conductivity (Figure 23) and total dissolved solids (Figure 24) values for the three alluvial wells have <br />remained fairly constant over the majority of [he period of record. While Conductivity and TDS values at sites TR-3 and <br />TR-4 are consistent with values obtained during the baseline studies, these parameters and several others have elevated <br />rapidly and remained elevated at TR-1.5 since 1995. The source of the elevated values is not readily identifiable. A few <br />factors which may have contributed to the elevated values were mentioned in the 1996 Report (i.e., inundation of the area in <br />late spring of 1995 and the laying of telephone cable immediately upstream of the area during the summer of 1995). If the <br />elevated values resulted from those activities, the values should have returned to more historic levels during the 1996-2003 <br />monitoring periods. However, the values have remained elevated. It appears that the alluvium in this area is reflecting <br />upstream alluvial water containing high levels of TDS, possibly from an old abandoned underground mine up the Little <br />' Trout Creek drainage (Exhibit 3.1-1). This conclusion is based partially on the similarity of the water quality between TR- <br />1.5 and WR-1. <br />Conductivity and TDS in Well WR-1 have progressed from an elevated state each spring to a lower state in the fill <br />for the past several years. This phenomenon was caused by infiltration of snowmel[ water leaching various minerals within <br />the unsaturated zone of reclaimed spoil. As the enriched flow was released over the course of the summer, the conductivity <br />' values lessened to that of the stagnant saturated zone. The mounded aquifer exhibits a more diluted state each spring with a <br />return to steady-state as the summer progresses. <br />Calcium/Magnesium/Sodium <br />Calcium (Figure 25) is the major cation found in all of [he wells with concentrations of sodium (Figure 26) and <br />magnesium (Figure 27) occurring in lesser quantities. The sodium concentration ai TR-1.5 in May 2001 was 179 ppm. This <br />value is inconsistent with the historical sodium concentrations and the levels after May 2001. Therefore, either sample <br />contamination or laboratory error is suspected. TR-1.5 generally contained the lowest concentrations of cations with a slight <br />increase occurring downstream at TR-3 and TR-4 for the majority of the record. However, elevated levels of these <br />parameters at TR-1.5 began to occur in 1995 consistent with [he elevated Conductivity and TDS levels previously <br />mentioned. Elevated levels of sodium concentration occurred at TR-4 during the 2004 and 2005 sampling period compared <br />with those of the last decade. However, the sodium concentration levels remain within historical levels found in Trout <br />Creek. <br />30 <br />