Depletion of epilimnetic oxygen and accumulation of hydrogen sulfide in the hypolimnion of Onondaga Lake, NY, U.S.A.

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Department of Civil, Environmental, and Geospatial Engineering


The depletion of epilimnetic DO during fall, and the accumulation of H2S in the hypolimnion during summer, are documented for polluted hypereutrophic Onondaga Lake, NY, U.S.A. The fall epilimnetic DO depletion is so severe that in many, if not all years, the New York State standard for minimum DO of 4 mg- L-1 is violated for periods as long as 1 mo. The depletion is caused by the transport of O2 demanding species, particularly H2S, from the hypolimnion into the epilimnion. Hydrogen sulfide accumulates progressively through the summer, mostly via SOinf4sup2-reduction, to unusually high concentrations; a maximum of 1.65 mM has been observed. These conditions are apparently manifestations of hypereutrophy, and thus may be subject to remediation through P management efforts.

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Water, Air, and Soil Pollution