Water quality monitoring programs often include toxicity testing of ambient waters with the assumption that observed toxicity is due to existing anthropogenic discharges. These assessments rarely consider the potential that water column toxicity may originate from contaminated sediments. The objectives of the study were to (1) demonstrate that contaminated sediments can cause measurable water column toxicity and (2) illustrate the utility of short-term marine toxicity tests in these assessments. The approach used in the study demonstrates that contaminated sediments do have the potential to cause water column toxicity and that marine water column toxicity tests are sufficiently sensitive to detect this toxicity. In order to determine the contribution of the various sources of contamination to total water column toxicity, the data generated using the approach and other pertinent site information (hydrodynamic models, effluent and receiving water toxicity) can be integrated into a water column toxicity model. (Copyright (c) 1993 American Society for Testing and Materials.)