This project falls within the field of environmental systems engineering. In recent years, there have been frequent incidents of water quality safety in China, which have attracted high attention from governments at all levels and the general public. With a dense urban population and numerous types of water quality risks, higher demands have been placed on the security of water supply. However, current technical research on water quality risk analysis and disposal is still insufficient, and the formulation of safety water supply plans for various types of water quality risks is mostly empirical, lacking in-depth research and promotion of supporting technologies for generating these plans. The situation regarding water supply safety assurance in Shanghai is not optimistic, and it also has the responsibility to lead domestically in this field. Tongji University has summarized years of research and application practice in this area, forming systematic research results from 'discovery' to 'resolution' of water quality risks. A complete safety water supply technology support system from 'source' to 'user' has been proposed, and the promotion and application of the technology have been realized. The project's innovation points include: (1) Risk Discovery - Comprehensive Analysis and Evaluation Technology for Water Quality Risks. Innovative research and development have been carried out in various water quality risk analysis and evaluation technologies such as rapid COD analysis technology based on pre-made reagents, toxicity detection technology for trace non-polar organic pollutants using Vero cells, pollutant toxicity assessment and prediction technology, toxicity detection of persistent pollutants using Caenorhabditis elegans, trace denaturation/renaturation recombinant DNA detection in water environment and gene diffusion risk assessment. A method library has been developed to overcome technical bottlenecks such as slow analysis and evaluation speed, low sensitivity, and reliability for conventional/non-conventional pollutants, enabling the analysis and evaluation of low-dose and complex pollution, and reducing costs. Risk mitigation - Water supply emergency treatment and disposal technology. For the first time, 11 representative pollutants from five major categories with high risk, great harm, and lasting impact were selected as research subjects for raw water delivery and water plant emergency treatment and disposal. A series of treatment and disposal technologies were developed for water quality risk events, mainly based on conventional water treatment processes, to ensure the supply of raw water and tap water, the quality assurance of networked water supply, and operational scheduling, forming a library of safe water supply emergency treatment and disposal technical methods. (3) Response to specific cases - Technology for generating water supply emergency plans. Based on the comprehensive analysis and evaluation of water quality risks and the research and development of water supply emergency treatment and disposal technologies, innovative approaches were developed to respond to the complex situations of different specific cases. These methods include case-based reasoning, genetic algorithms, Artificial intelligence methods such as artificial neural networks have been integrated into the generation of water quality risk case libraries and safety supply emergency plans, forming a technical system oriented towards resolving water quality risks in the generation of safety supply emergency plans. The technology developed in this project has been adopted and applied by the Shanghai Water and Environmental Protection Department, relevant raw water and water supply enterprises, successfully solving municipal water supply safety issues such as the raw water quality during the World Expo and the Huangpu River pig carcass incident. It has also been promoted for application in Jiangsu, Jiangxi, Guangdong, and other places, repeatedly resolving water quality risks and improving the management and technical level of local water and environmental protection departments, raw water and water supply enterprises, instrument and testing companies, design and research institutions. Relying on the achievements of this project, Zhenjiang City issued the 'Urban Water Supply Emergency Accident Response Plan', and Tongji University participated in compiling the Ministry of Science and Technology's 'Handbook of Practical Knowledge, Technology, and Products for Earthquake Relief No. 2'. "Safe Drinking Water and Water Supply" project has been granted 3 utility model patents, 1 invention patent application, 6 software copyright registrations; published 35 SCI papers, 8 EI papers with a total of 224 citations (including 172 secondary citations), 55 core journal papers, and one monograph; trained 2 postdoctoral fellows, 7 doctoral students, and 23 master's students. This project has promoted the development of water supply and water environmental protection industry in terms of water quality risk analysis and support for water supply contingency plans, and has facilitated the transformation of China's water quality safety assurance work from an experience-based approach to a scientific decision-making method supported by knowledge.