A SURVEY OF MAJOR ION CONCENTRATIONS IN SURFACE WATER ACROSS A SEQUENTIALLY RECLAIMED SURFACE MINE, THE WILDS, SOUTHEASTERN OHIO

Reclamation of surface mining at The Wilds proceeded from north to south and encompassed several changes in reclamation laws. Today surface water, exclusive of springs, can be divided into three geographic regions based on characteristic levels of total dissolved solids (TDS). The northern region typically has TDS values between 1200 to 1400 mg/L. TDS values in the middle region range between 800 to 1100 mg/L and in the southern region range between 100 to 500 mg/L. The pH values of surface water at The Wilds vary between 6.5 and 9.0 and appear to be primarily controlled by the limestone-rich spoil. Northern region lakes are fed by surface runoff/groundwater or a combination of surface runoff/groundwater and springs, have very small drainage basins and are flow-through lakes. Lakes in the middle region are fed by a combination of surface runoff/groundwater and springs, have large drainage basins and are flow-through lakes. Most of the southern region lakes are fed by surface runoff only, have small drainage basins and are not flow-through lakes. Southern region lakes based on TDS values appear to be above the groundwater table.

Major ion concentrations (exclusive of Na) of selected surface waters from the three regions were determined by a combination of field titration and colorimetric techniques. Ca, Mg, sulfate, bicarbonate, and Cl concentrations were determined for two lakes from the northern region, two lakes and a stream from the middle region, and a spring and a lake from the southern region. The spring in the southern region typically has TDS values between 1500 to 1800 mg/L. In general, the concentration of the major ions roughly correlates with the TDS value of the surface water. The major ion concentrations of the lakes in the northern and middle regions; however, do not appear to represent a simple mixing of surface runoff and groundwater. The northern and middle region lakes have higher Ca, Mg, and sulfate concentrations and lower bicarbonate concentrations than would be expected for a simple mixing of groundwater and surface runoff.