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represents a composite of Foidel Creek and Middle Creek similar to <br />• the surface water quality in Middle Creek below the confluence. <br />Concentrations of TDS and major ions in the alluvium appear to have <br />stabilized since 1990. The data does not indicate any significant <br />change in the trace metals concentrations although iron and <br />manganese concentrations are extremely variable. <br />8poila <br />Two wells in the Mine 3 spoils were installed in 1985 to monitor <br />water levels and water quality in mine spoils. The location of <br />these spoil wells is provided in Figure 2. One spoil well, <br />008-SP-4A has remained dry since it was installed. During 1992, <br />this was determined to be the result of a separated casing. As a <br />result of this finding, CYCC installed a replacement spoil <br />monitoring well (008-SP-4B) near the northern embankment of Pond <br />M35 (Site 76). Due to the timing of this installation, CYCC will <br />not provide monitoring information for the replacement well until <br />the 1993 AHR submittal. <br />Water Levels - The plot of the historic water levels in spoil well <br />008-SP-5A is presented on Figure 10. The water level has a similar <br />pattern to that of the alluvial wells, it rises during spring <br />runoff and then declines during the summer and fall. The general <br />trend in water levels in spoil well 008-SP-5A exhibits a relatively <br />slight decline similar to that of overburden well 008-70658. This <br />• trend appears to represent a climatic influence, suggesting that <br />water levels in the spoil have equilibrated and are not fluctuating <br />due to past mine disturbance. <br />Water Quality - The water quality data is summarized in Tables 12 <br />and 13 for the spoil well. The historic dissolved solids <br />concentrations for the well is plotted on Figure 11. While highly <br />variable, the dissolved solids concentration does not appear to be <br />increasing but in fact, shows a slight decrease since 1989. The <br />water is a calcium-sulfate type with high bicarbonate and <br />relatively low SAR. The water is higher in dissolved solids than <br />the background bedrock levels and the spoil spring discharges. The <br />data does not indicate any significantly high trace metals <br />concentrations except for relatively high dissolved manganese which <br />appears to have declined dramatically in 1991. Monitoring in <br />subsequent years will reveal whether this decline is persistent and <br />represents a geochemical change or flushing effect. At this point <br />in time, whether the decline in manganese is persistent is not <br />known. <br />. Page 4 <br />