Risk assessment methods of water supply system in terms of reliability and operation cost

Abstract

Following the end of the Second World War, domestic consumers in the countries of Central and Eastern Europe region, including Poland, normally paid a small percentage of the cost of drinking water while the rest was paid by the state in the form of subsidies. After 1990 water charges suddenly increased and reached a significant proportion of the household s average income. This led to a considerable decrease of water consumption and not fully utilised capacity of existing plants. One of the decisive factors of the decrease of water consumption was installation of meters. Whether the observed falling trend of water consumption can be stopped and when it might happen has been unknown until now. In fact, knowledge on the impact of price changes on water demand is insufficient. Moreover, there is no satisfactory model to explain the existing phenomenon. After joining European Union significant outlays on water supply systems were taken to improve water quality. European Water Framework Directive claims that Member States shall take account of the principle of recovery of the costs of water services, including environmental and resource costs, having regard to the economic analysis ( ) and in accordance in particular with the polluter pays principle (Water Framework Directive, European Union).