Methodology for Derivation of Water Quality Criteria for Protecting Aquatic Environment and Future Development

Water quality criteria for aquatic environments are numerical concentrations or narrative statements to support and protect designated water uses, based on data quantifying the response of aquatic organisms to toxic pollutants in laboratory tests. In general, the main process being used around the world for establishing criteria for the protection of freshwater aquatic environment can be summarized as the following: (a) selecting the most sensitive species and testing toxicity to them and (b) application of evaluation methods to obtain the water quality criteria. The data requirement, tested organisms and three calculation methodologies were discussed in detail. In China, establishing appropriate and effective water quality criteria for protecting aquatic environment is an urgent task and national strategy. The systematic and feasible experience from other countries and international organizations can be a valuable guide for the Chinese Environmental Protection Departments. This review put forward research direction and developing trends involved in this research field in China. Future research on water quality criteria is prospected. Criteria development for protecting the aquatic environment needs to focus efforts on macrophytes toxicity, potential and mixture toxicity, emerging contaminants, and method improvement and update in order to protect the aquatic environment most comprehensively and effectively.