The incorporation of toxicity testing into the assessment and management of effluents and contaminated sediments
Citation:
Mount, Dave, G. Ankley, D. Mount, AND T. Norberg-King. The incorporation of toxicity testing into the assessment and management of effluents and contaminated sediments. SETAC North America, Minneapolis, MN, November 12 - 16, 2017.
Impact/Purpose:
This presentation will be part of a historical retrospective session on the research history of the NHEERL/MED laboratory which was founded 50 years ago. This particular presentation provides an overview of the effluent toxicity and sediment toxicity research efforts of the 1980’s and 1990’s, recounting the major research objectives and accomplishments. No new data or conclusions are presented.
Description:
Following the initial push during the 1970’s to develop numerical water quality criteria for many environmental contaminants, it became clear that the protection of surface waters from chemicals in municipal and industrial effluents would require more than just criteria for specific pollutants. To supplement chemical-specific limits, whole effluent toxicity (WET) monitoring and control was conceived, which offered three important advantages over chemical-specific limits alone: 1) toxicity testing can detect effects from unknown or unmeasured chemicals; 2) testing the toxicity of intact effluent automatically considers the aggregate effects (whether antagonistic, additive, or synergistic) of all chemicals present; and 3) effects of effluent or receiving water chemistry on chemical bioavailability was intrinsically considered. During the 1980’s the Duluth laboratory invested heavily in a research program to support implementation of WET-based permitting, with the goals of 1) developing toxicity test methods that could meet the practical demands of effluent testing; 2) demonstrating the connection between effluent/ambient water toxicity and effects on instream communities; and 3) developing methods to identify the causes of effluent toxicity so that the sources of WET could be effectively controlled. Through the 1990’s, a conceptually similar research program was undertaken to provide tools for contaminated sediment assessment, offering some of the same advantages as were offered by WET for toxicants in effluents detection of unknown or unmeasured chemicals, and implicit consideration of mixtures and bioavailability. The sediment research program contained many similar elements, including the development of methods for measuring sediment toxicity, and methods to identify the causes of toxicity in toxic sediments. Additional research was focused on methods to develop numerical criteria for specific sediment toxicants that could address the considerable challenge of addressing factors affecting the bioavailability of sediment contaminants. This presentation provides an overview of the practical needs, technical challenges, and scientific accomplishments addressed by the effluent and sediment research programs. This abstract does not necessarily reflect U.S. EPA policy.