Laserfiche WebLink
Janet Binns <br />Page 5 <br />April I5, 1999 <br />Sodium (mg/l) 175 71 <br />Magnesium (mg/I) 211 254 <br />Potassium (mg/l) N/A N/A <br />Sulfate (mg/I) 1790 1860 <br />Bicarbonate (mg/l) 613 636 <br />Total Dissolved Solids (mg/1) 3060 3210 <br />Comparison of water sampling results from we11008-77-58 to spoil water quality data indicate a <br />distinct and recognizable movement of spoil water 500 feet downgradient to well 008-77-58. <br />Increased concentrations in the spoil water of calcium, magnesium, sulfate, and bicazbonate <br />cause slightly elevated levels of the same constituents in 008-77-58 over the baseline conditions. <br />A decreased spoil water concentration of sodium, likely due to cation exchange, appears to cause <br />a decrease in sodium concentration in the well water when compared to the baseline condition. <br />Although changes in the quality of the water in the monitoring well aze evident, due to dilution <br />and dispersion, it is apparent that water quality downgradient is not impacted to the degree that <br />any current of future uses will be impaired. Given the large degree of change of water quality <br />over 500 feet, it can be assumed that insignificant changes will occur at any appreciable distance <br />down gradient from the pit. <br />Bedrock Water Quantity <br />Figure 4 of the 1998 Annual Hydrology Report for Mine No. 3 indicates the water level in well <br />008-79-58 has recovered to levels neaz the early 1979 elevation of 6716 feet M.S.L. and shows a <br />seasonal variation of 5 feet. Figure 5 indicates [he water level in well 008-79-6, 2500 feet <br />northwest of 008-77-58, has been nearly static at approximately 6660 feet M.S.L. with a <br />variation of about 5 - 8 feet seasonally. Water level at the time of installation of this well <br />indicates the formation was likely already dewatered to some degree by mining activities, so <br />direct correlation to true baseline conditions is not possible. Water levels in both wells are <br />between 4-16 feet from the surface on average, which indicates nearly complete recovery for this <br />portion of the Twentymile Park ground water basin. <br />