Drinking water risk assessment in practice: the case of Swedish drinking water producers at risk from floods

To achieve a safe and reliable drinking water supply, water producers need to manage a large range of risks regarding both water quality and quantity. A risk management approach where risks are systematically identified and handled in a preventive manner is promoted by the World Health Organization and supported by researchers and drinking water experts worldwide. Risk assessment is an important part of such a management approach, and a variety of tools for risk assessment are described in the literature. There is, however, little knowledge of how drinking water risk assessment is performed in practice, including which tools that are actually used. This study investigates the use of risk assessment tools, and the approach to risk management, on a local level in the Swedish water sector. It is based on interviews with key persons from a targeted selection of water producers. We find that the application of tools as well as the approach to risk assessment and management differs considerably between the water producers. The tools most frequently used are mainly the ones promoted or required by Swedish national organizations. Although many of the water producers have done some kind of risk assessment, most have not implemented a risk management approach. Furthermore, their knowledge of the concepts of risk and risk management is often limited. The largest challenge identified is to prioritize risk assessment, so that it is actually performed and then used as a basis for managing risk in a systematic way.