Abstract
The deficiency of China's current pollution discharge permit system lies in the failure to improve the water quality effectively. This paper discusses the premise that the water quality of a water environmental functional zone (WEFZ) is mostly affected by industrial pollution sources. By reviewing the related policy, we noted the link between total emission control, effluent limitations and pollutant discharge permits to configure a practical framework for pollutant discharge permits based on water quality. China's pollutant discharge permit system provides an administrative foundation for reducing polluters' total emissions at the scale of the WEFZ, and it is best implemented through the imposition of limitations on polluters to identify the related treatment technology levels. Owing to the importance of limitations, the methodology of limitation classification and the related treatment technology classification are presented for the pesticide industry. Additionally, a comprehensive analysis of the pollutant reduction potential for the pesticide industry is conducted to determine the current level of sewage treatment. More importantly, this study offers an innovative way to investigate pollutant reduction potential and provides an example that may be useful to other key industries.