Micropollutant Removal from Wastewater: Facts and Decision-Making Despite Uncertainty

T he occurrence of a plethora of anthropogenic organic compounds in treated wastewater and hence in receiving water bodies is a well-established fact.It raises concerns about possible negative impacts on aquatic ecosystems and drinking water resources.In Switzerland, this has led to political decisions to mitigate the risk of adverse effects by upgrading the wastewater treatment plant (WWTP) infrastructure.These decisions have been recently criticized, first as being premature and second as being likely to drive receiving waters toward states that are not desired by society. 1 Given the current uncertainties and knowledge gaps, some aspects of this criticism warrant a broader discussion of the role of science in societal decision making.In this viewpoint, we would like to emphasize three aspects.