In modern conditions, ensuring the reliability and safety of water supply systems is a primary task for the industrial economy and the safety of life of the population of Ukraine. Constant bombing and damage to critical infrastructure facilities, including water management facilities, endangers the stability and quality of the country's water resources. In this context, conducting research on the identification of man-made risks in water treatment systems using various technologies, as well as developing strategies to increase the reliability and safety of operation of water supply systems are becoming relevant for the industrial sector of Ukraine. In order to increase the reliability of water treatment units and their operational safety, man-made risks were investigated when using ion exchange, electrodialysis, and water distillation technologies at thermal power plants. It is shown that during normal operation of the ion-exchange water purification system with an average productivity of 400 m3/h, in the case of frequent changes in the concentration of salts at the inlet, the risk of receiving underpurified water is 0.0783. This value must be taken into account for the assessment of economic and social-ecological risks, since it exceeds the generally accepted value of 0.01. When using electrodialysis water purification and frequent changes in the concentration of salts at the inlet, the risk of receiving underpurified water is 0.0271. This value is also greater than 0.01 risk accepted as acceptable. The water distillation technology has enough margin to compensate for any deviations in the purification process and gives a very low risk. However, the distillation process is more effective in removing only soluble impurities, while in the case of suspended substances, in particular of organic origin, there is a risk of exceeding the limit of 0.01.