Assessing the Relationship Between Laboratory Whole Effluent Toxicity Test Data and In-Stream Biological Communities

The ability of whole effluent toxicity (WET) tests to predict in-stream effects to periphyton, benthic macroinvertebrates, and fish in a habitat-impaired stream was assessed. Habitat assessment data were useful in interpreting in-stream conditions for periphyton and benthic macroinvertebrates. Various periphyton and macroinvertebrate metrics identified siltation effects as opposed to water quality effects in-stream. Pathogen effects noted in fathead minnow WET tests were not reflected in the fish community. Overall, in-stream biological conditions confirmed the absence of water quality-related effects as predicted by WET tests.