Water quality issues in pollutant trading

As part of implementing the watershed approach for water pollution control, interest is being focused on pollutant trading. The pollutant trading programs that have been developed thus far are based on total chemical constituent concentrations and fail to properly consider that for many chemical constituent sources and types of chemical constituents the total chemical constituent concentration in a source or within the waterbody is a poor measure of potential water quality impacts. Pollutant trading should be based on trading chemical constituents that are adversely impacting the designated beneficial uses of a waterbody, i.e. cause pollution, rather than the total chemical constituent concentrations within the various sources for which trades are being considered. (KEY TERMS: pollutant trading; point/nonpoint source; water quality criteria/standards; water quality.