Areal and temporal variability of selected water-quality characteristics in two hydrologic-benchmark basins in the northeastern United States

Two U.S. Geological Survey National Hydrologic Benchmark stations--Young Womans Creek near Renovo, Pennsylvania and Esopus Creek at Shandaken, New York--were studied to (1) define, both areally and temporally, variations of stream acidity and other water quality characteristics within the basins; (2) evaluate how well the data collected at the Benchmark station represent the water quality conditions upstream; (3) define relations between streamflow acidity or pH; and (4) provide a data base to detect trends in quality of headwater streams. Samples were collected at nine sites, including the Benchmark station, in each basin for three series of measurements over a range of streamflows. Along with streamflow, samples were analyzed for water temperature, specific conductance, pH, dissolved oxygen, acidity, alkalinity, dissolved sulfate, and dissolved nitrite plus nitrate. The results of the measurements indicated little water quality variation in the Young Womans Creek basin. Therefore, the data collected at the Benchmark station can be used to reflect upstream changes in water quality. The data collected at the Esopus Creek station did not reflect upstream conditions as well as the Young Womans Creek data because the water quality varied throughout the basin. Few strong relations were found between streamflow and the water quality characteristics examined in this study. The Esopus Creek data indicated the possibility of relationships between streamflow and alkalinity, dissolved nitrite plus nitrate, and specific conductance. No relations were found between streamflow and the Young Womans Creek water quality data. (USGS)