Analysis of risk and failure scenarios in water supply system

Water supply system is complicated technical system which belongs to underground urban infrastructure. Its accurate functioning determines everyday live stability of citizens. Risk analysis is a key phase of the process of water supply safety management. The aim of this paper is to present new propose of methods for risk of the first type (associated with quantity of supplied water) and the risk of the second type (associated with quality of supplied water) analyses in water supply system. The paper contains the description of matrix methods for risk analyses and methods describing cause-and-effect relationship of failure events (fault tree analysis).