Technical Guidance Manual for Performing Waste Load Allocations. Book 2. Streams and Rivers. Chapter 3. Toxic Substances

摘要

The document addresses methods for predicting concentrations of individual constituents resulting from pollutant loads to the aquatic environment. Within the context of the waste load allocation (WLA) process, the methods predict the ambient concentrations expected to result from existing or projected pollutant loadings. By relating the predicted concentrations to ecosystem or human health effects levels, an appropriate level of pollution abatement can be specified, tailored to protection of the environment of a specific site. As the focus of the material is the prediction of ambient concentrations, it will not address all facets of the allowable load determination. In order to use predictions effectively, it is also necessary to establish (a) a target for allowable concentrations, and (b) a target frequency for not exceeding the allowable concentrations.