What is effluent (wastewater) toxicity testing?
Whole effluent toxicity (WET) tests were developed as a tool for evaluating the potential harmful effects of effluents discharged into surface waters. Although quantities of pollutants can be analytically determined in samples, these measurements may fall short of actually identifying toxic discharges. Aquatic toxicity tests offer a more direct measure. They measure an observable toxic response to the interaction of toxicants and other constituents within the sample. Biological availability and interactions are inherently included. In these tests, carefully chosen indicator organisms are exposed to whole effluent and/or effluent dilutions for a pre-determined time period in order to observe the effluent’s effect on the organisms, and thereby, approximate it’s potential to effect organisms within the receiving water. Thousands of NPDES permittees around the country are required to run these “bioassays” to ensure compliance with environmental regulations. [ Back to top.
