Technical Bulletin No. 0486: Initial Review of Some Outfall Dispersion Models and an Asymptotic Jet Dispersion Model for Use in River Systems

EPA and some states are considering new approaches for defining the mixing zone for effluents in receiving waters. One approach is described in EPA's Technical Support Document for Water Quality Based Toxics Control. The objective of this approach encompasses protection of the aquatic habitat during acute short term exposure as might occur during drift through the mixing zone. It also calls for the absence of any chronic toxicity at the edge of the mixing zone, the latter being defined as some function of time after effluent release.