Measures for Protecting Water Quality: Current Approaches and Future Developments

摘要

An important component in protecting the ecological quality of watercourses is the regulation of point source discharges. These are usually expressed in terms of "end of pipe" limits on certain physical parameters or on the concentrations of specific chemicals. Sometimes discharge licences take the form of Emis- sion Limit Values (ELVs) which are based on Best Available Technology with respect to emissions and apply to all discharges (usually for a specified industry sector) irrespective of the dilu- tion capacity of the receiving watercourse. Alternatively, they may be based on water quality standards (e.g., EQSs) for specific chemicals which describe thresholds below which no adverse impact on the receiving water is predicted and which take explicit account of available dilution at different discharge locations.