Stream Water Quality of Two Small Watersheds as Affected by Surface Coal Mining
1983
Dick, W. A. | Bonta, J. V. | Haghiri, F. | Page, Ricky
Two small watersheds in eastcentral Ohio were selected for investigation of stream water quality prior to, during, and after surface coal mining and reclamation. Watershed C06 contained sandstone and shale overburden, and Watershed M09 contained limestone, sandstone, and shale. Water quality was monitored by measuring 39 parameters in the stream-water samples collected. Duration curves for the four parameters regulated by the Office of Surface Mining (OSM) showed that most samples collected from the two study watersheds exceeded the 70 mg L⁻¹ regulation level for suspended solids concentration. Approximately 50 and 30% of the water samples collected at Watershed C06 during the mining and reclamation period and the post-reclamation period, respectively, exceeded the regulation level (4000 µg L⁻¹) for manganese (Mn). Twenty percent of the pH values at Watershed C06 during the mining and reclamation period were also below the lower regulation level (pH 6). Concentrations of the major cations and anions, suspended solids, and dissolved solids were correlated with flow rate (log values) during the premine and post-reclamation periods. Samples collected at similar flow rates at Watershed M09 showed concentrations of parameters were either not significantly affected or decreased in the post-reclamation samples, compared with the premine samples. A similar comparison for samples collected at the C06 watershed showed parameter concentrations were generally higher during the post-reclamation period. Parameters which were not detected in any samples collected from the two watersheds were arsenic (As), chromium (Cr) VI, mercury (Hg), and sulfide (S²⁻), while cyanide (CN⁻) was not detected at M09. Parameters that were only rarely detected were antimony (Sb), cadmium (Cd), lead (Pb), zinc (Zn), silver (Ag), copper (Cu), phenols, and phosphorus (P).
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