The Paris Sewer Renaissance: Data, Health and Participatory Science

Aging urban wastewater infrastructure, often overlooked, can become a powerful lever for environmental and public health policy. Through the lens of the Parisian sewer system, this article highlights the growing pressures on sanitation networks – from combined sewer overflows to emerging chemical contaminants – and the limits of current treatment technologies. Yet, it also illustrates how wastewater can serve as a valuable resource. Initiatives like OBÉPINE have demonstrated the feasibility of wastewater-based epidemiology at scale, while participatory initiatives such as those performed in EGOUT show that citizen engagement and scientific monitoring can go hand in hand. Together, these efforts redefine wastewater as more than waste: It is a mirror of collective behavior, a platform for community science and a tool for decision-making. As cities face urgent climate and health challenges, this work calls for policies that reconnect people with infrastructure and invest in data-driven, inclusive approaches to urban sustainability.