Laserfiche WebLink
1 <br />within the unconsolidated spoils aquifer as flow passes through. It is <br />believed the lower values recorded during mid-summer to early fall represent a <br />' flushing of the dissolved constituents with an increase being experienced as <br />the flow through the spoils lessens and the in place water stagnates. This <br />seasonal trend is general to all of the major cations and anions. The spring <br />(NPDES discharge point No. 006) associated with the spoils aquifer would be <br />' expected to have similar values as evidenced by comparable TDS concentrations. <br />TDS values (Figure 11) closely follow the specific conductivity for all the <br />wells, as expected. <br />Calcium (Figure 11) is the major cation found in all the wells with <br />concentrations of magnesium (Figure 12) and sodium (Figure 13) occurring in <br />lesser quantities. TR-1.5 generally contains the lowest concentrations of <br />cations with a slight increase occurring downstream at TA-3 and TR-4. It is <br />expected that the cyclic nature of these parameters beginning to develop in <br />1989 will continue in the future with a buildup in concentrations occurring <br />during the fall and winter months with a flushing action occurring during the <br />' spring and summer. The sodium level for WR-1 of 459 mg/1 obtained during <br />October, 1991, is believed to be an analytical error as earlier sample points <br />' in 1991 followed expected trends <br />Bicarbonate (Figure 12) and sulfate (Figure 13) are beginning to show a <br />' trend of topological change similar to that observed in the surface waters. <br />Upstream (TR-1.5) of the spoils spring, bicarbonate is the major anion with <br />' sulfate concentrations increasing rapidly along the mine area. This increase <br />may be caused by the spoils spring discharge where leaching of pyritic and <br />organic sulfur occurs as the flow passes through the spoils. The bicarbonate <br />' value for TR-4 of 895 mg/1 obtained during May 1990, is believed to be an <br />analytical error as the sample points before and after the sample date are <br />consistent with earlier trends. The bicarbonate duplicate sample value of 106 <br />mg/1 also suggests that this value is erroneous. <br />' Dissolved iron and manganese remained at low levels during 1991 as in <br />previous years. A decreasing trend may be occurring for both iron and <br />manganese at all locations but WR-1. It is interesting that WR-1 often <br />contains the lowest values for these two parameters for the majority of the <br />1989, 1990 and 1991 monitoring periods (Figure 14). Since 1988, a sharp <br />' increase in manganese concentrations has been noticed for the first portion of <br />the annual monitoring period, at WR-1, with a significant decrease occurring <br />LJ <br />