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Abstract The work detailed here has sought to analyse the effects of emergency states on water-supply pipelines. For this purpose, a model hydraulic pipe network was created in Epanet 2, on the basis of actual operational data. Using the model, pipeline failures were simulated, and their effects described. The research methodology entails the simulated closure (i.e. failure) of individual pipes in the supply network, as followed by comparative analysis of the distribution of pressure across that network, in failure-free conditions and during a failure. The effects of failure in individual sections could thus be determined, in relation to the area with pressure lowered below the required value, the duration of that pressure reduction, and the potential number of recipients affected by limitation of water supply. The areas most exposed to pressure fluctuations in the water supply as a consequence of pipe-failure are thus pinpointed, with simulation results also serving in in the calculation of indicators for the risk of failure. Highlights • Operating data of the water network functioning in the city are used. • The areas most exposed to pressure fluctuations in the water supply as a consequence of pipe-failure are thus pinpointed. • The method presented, and the results it has generated, provide a basis for quantitative risk testing. [ABSTRACT FROM AUTHOR]

The aim of the study is to analyse and assess the water supply network failure frequency in last ten years, with particular emphasis on the last year of the analysis. The analysis is based on actual data obtained from the water company. The study contains the analysis of the network failure with division into used material, the type of network and place of failure occurrence. Also the failure rate was calculated. Continuous changes in the age and material structure of the water network cause the need for conducting failure frequency research because data on failure rate are the key indicators for operational policy of water supply systems. [ABSTRACT FROM AUTHOR]

The paper presents issues related to risks associated with the operation of small water supply systems on the background of water consumer safety assessment made on the basis of risk analysis. Definition of water consumer safety loss as a risk associated with the water consumption of poor quality or water lack was proposed. For this purpose, a three-parameter matrix is implemented with the parameters of the probability of a representative accident scenario, the losses of the water consumers and their protection. Risk management, together with the implementation of protective barriers of small water supply system against threats is a fundamental condition for the continued operation of the system. [ABSTRACT FROM AUTHOR]

This paper first presents the results of polling on the subject of potable water in crisis situations, with respondents from south-eastern Poland's Subcarpathian region asked for their opinions on the level of nuisance associated with water supply interruptions and water quality, levels of consumption and water companies' quality of service. Among the respondents 53% regard the quality of the water they receive as satisfactory, while a quarter see it as only average. However, respondents are relatively satisfied with the corporate response when supplies are interrupted, as methods and means of notification are judged effective by 60%. Continuing with work to assess possibilities for water companies to improve their performance in crisis situations, the present study generates an Analytical Hierarchy Process allowing recipients to determine importance criteria where quality of service is concerned. This could facilitate management by water companies, providing for centralised control and comparison that help secure services of appropriate quality. The process can also help protect different groups of recipients, as safety is evaluated through analysis of functioning, and of failures and losses. [ABSTRACT FROM AUTHOR]

The water-supply system is one of the basic and most important critical infrastructures. Water supply service disruption (water quality or quantity) may have serious consequences in modern societies. Water supply service is subject to various failure modes. Failure modes are specified by their degradation mechanisms, criticality, occurrence frequency and intensity. These failure modes have a random nature that impacts on the network disruption indicators, such as disruption frequency, network downtime, network repair time and network back-to-service time, i.e., the network resilience. This paper focuses on the water leakage failure mode. The water leakage failure mode assessment considers the unavoidable annual real water losses and the infrastructure leakage index recommended by the International Water Association's Water Loss Task Force specialist group. Probabilistic statistical modelling was implemented to assess the seasonal index, the failure rates and the expectation value of the "mean time between failures." The assessment is based on real operational data of the network. Specific attention is paid to the sensitivity of failures to seasonal variations. The presented methodology of the analysis of the water leakage failure mode is extendable to other failure modes and can help in developing new strategies in the management of the water-supply system in normal operation and crisis situations. [ABSTRACT FROM AUTHOR]