Bioassays for water quality monitoring in the circular economy - WiCE

Freshwater from groundwater and surface water sources is becoming scarce in dry periods, which raises interest in the (re)use of alternative sources such as rainwater and treated domestic and industrial wastewater (effluent). This requires consideration of the potential risks resulting from circulating and potentially accumulating microbial and chemical contaminants in different water cycles, depending on the nature of water reuse. Therefore, it is important to gain insight into potential microbiological and chemical hazards. This knowledge is needed to safely and responsibly reuse water.
The current project focused on chemical hazards. Effect-based methods using in vitro cell models and bacteria (bioassays) offer a powerful approach to investigate relevant hazards of complex low-level mixtures in the water cycle without prior information on their chemical composition. Panels of bioassays covering endpoints relevant for ecosystem health and drinking water safety have been compiled and implemented in the water sector. In particular bioassays for investigating DNA damage or endocrine disruption are increasingly implemented within the water sector. These complement chemical analyses to assess the quality of (drinking) water sources and the effectiveness of treatment processes.
KWR has developed the Water Wise concept, an easy-to-use, transparent and consistent evaluation framework as a first step toward quantitative evaluation of microbiological and chemical risks inherent to new water cycles. Research and expert judgement on new water cycle-related hazards and risks are needed to further develop the framework (tool under development). Depending on the information fed into the tool and the Water Wise risk assessment outcome, the output may include a recommendation for the application of bioassays to assess the quality of alternative freshwater sources or to confirm the outcome of the tool.