Water at 102 sites in 59 coal-mine ponds in eastern Oklahoma was sampled at lease twice during June to November 1977-81 to determine temperature, specific conductance, dissolved oxygen, pH, and dissolved sulfate, chloride, iron, and manganese--as part of a study of the hydrology of the Oklahoma coalfield. These determinations show that during June to October water in ponds deeper than ~10 ft was stratified; ponds which had little or not change of temperature with depth generally were shallow or were sampled in early November. Temperature, dissolved oxygen, and pH usually decreased with depth, whereas specific conductance usually increased with depth. Concentrations of dissolved sulfate, chloride, iron, and manganese varied from site to site. Specific conductance, which is a measure of dissolved solids in the water, ranged from 93 to 4,800 mmho/cm at 25oC. Some physical and chemical characteristics of the mine-pond water are related to the coal bed adjacent to the pond. Mean specific-conductance values and dissolved-sulfate concentrations were greatest in ponds associated with mining of Dawson, Weir-Pittsburg, and Secor coals. Mean dissolved-iron concentrations were greatest in ponds associated with mining of the Dawson, Secor, and Hartshorne coals. Mean dissolved-manganese concentrations were greatest in ponds associated with mining of the Dawson, Weir-Pittsburg, and Secor coals, but greatly exceeded secondary drinking-water limits regardless of coal bed mined.
