Contribution of domestic water to urban pollutant flows: characterization and solutions for source control

International audienceEmerging contaminants are of increasing concern in megacities due to their wide utilization in all the field of anthropic activities (industries, building materials, household products, pharmaceuticals and personal care product), their ubiquity in air and urban waters, and their potential negative effect on health and aquatic ecosystems (as endocrine disruptors or induction of antibiotic resistance). The implementation of wastewater treatment plants with advanced treatments makes possible to limit discharges to the environment. But these expensive solutions do not allow to manage all the flows (stormwater, combined sewer overflows or persistent contaminants). The aim of our work was to promote reduction actions at source in order to limit the flows entering wastewater treatment plants and to reflect on the role of users and local authorities. A lever of action that seems natural to communities is the control of emissions from industries in the watersheds under consideration. In the Cosmet’eau project, a focus was made on another source of contribution to pollutant flows that is not necessarily taken into account: domestic wastewater. In the case of the Paris conurbation, heavily urbanized and scarcely industrialized, and for parabens, we (i) highlighted that the contamination of domestic wastewater is predominant compared to industrial wastewater, (ii) conducted a sociological study of alerts and consumer practices, and (iii) surveyed municipal departments to explore the potential for public policy at the local government level to reduce emerging domestic contaminants at the source