The U.S. Geological Survey collected water-quality and other hydrologic data for surface water in the coal-mining region of southwestern Indiana. These data were collected at 85 sites in 19 counties during October 1979 and at 21 of the 85 sites in 12 of the 19 counties monthly from January through September 1980. The samples were collected during steady flow. Samples were also collected at 8 of the 21 monthly sites during unsteady flow caused by storms. Samples were collected prestorm; on the rising, peak, and falling stream stages; and poststorm, after flow had stabilized.
Water samples were collected at each site for determining concentrations of major ions, selected metals, nutrients, and suspended sediment. Specific conductance, pH, water temperature, dissolved oxygen, and instantaneous discharge were also determined at each site. During October 1979, streambed-material samples were collected at 74 sites for determining concentrations of acid-soluble constituents on sediment smaller than 63-micron diameter. During March 1980, streambed-material samples were collected at 14 sites for determining the quantity of coal in streambed sediments.
