QUANTIFYING LAND USE AND WATER QUALITY CHANGES WITHIN A SMALL RURAL WATERSHED IN SOUTHEASTERN OHIO (1961-2004)
Specific conductance and pH values were measured in tributaries just north and south of North Crooked Creek. Initial comparison of pH values collected in November 2007 to those last collected by the USGS in 1979-1980 show pH values in the range of 6.45 to 7.66 compared to the USGS values of 7.1 to 8.5. Specific conductance values are highest (1632 microsiemens) closest to the spots of acid-mine drainage/exposed mine spoils in the eastern portion and decrease downstream. In the southwestern portion of the subwatershed, two tributaries in an identified agricultural zone initially tested with pH values of 6.89 and 6.90 and the two lowest specific conductance values (465 and 391) so far. High pH, specific conductance, and sulfate concentration values (or conversely, low bicarbonate values) are often associated with surface mining and acid-mine drainage within a subwatershed. Acid-mine drainage is often the cause of poor water quality within the Wills Creek watershed, and within the North Crooked Creek subwatershed extremely localized spots of acid-mine drainage/exposed mine spoils are found in the northern and eastern portions.