THE EFFECTS OF ARTIFICIAL CIRCULATION ON A SMALL NORTHEASTERN IMPOUNDMENT

Artificial circulation was applied at East Sidney Lake, a small, eutro phic impoundment in New York, to improve the water quality of the rese rvoir and tailwater. Treatment was successful at both reducing the sta bility of the reservoir and maintaining higher mean oxygen concentrati ons in the bottom waters. Discharge waters had lower metals and phosph orus concentrations during treatment years. However, vertical temperat ure differences, although minimal, were still sufficient to permit che mical stratification and some phosphorus release from the sediments. F requent mixing events during periods of low stability, and runoff from storm events, also appeared to increase transport of phosphorus into the epilimnion. Overall, treatment did not result in decreases in alga l populations or improvements in water clarity.