SIPIBEL: a pilot site for studying hospital and urban sewage. Key lessons from five years of monitoring and research

SIPIBEL is a pilot site located on the Arve River in the French-Swiss catchment. SIPIBEL studies hospital and urban effluents, especially the micropollutants in care and hygiene products (residues of drugs, detergents, and biocides) and resistant bacteria. A monitoring system and research programs were developed to address this subject and answer three questions: (1) Does the separation of hospital effluent in the wastewater treatment plant optimize the treatment of hospital and urban effluents? (2) Do these effluents pose an environmental and/or health risk ? (3) What can be done to reduce the discharge of pharmaceuticals into the environment? Stakeholders in this region worked with scientists on this pilot site to find answers to these questions. Over five years, SIPIBEL characterized 22 sampling points (raw and treated wastewater, Arve River, and Geneva aquifer), monitoring 130 parameters (physicochemical parameters including 15 pharmaceuticals, microbiological parameters, and bioassays) and compiling and qualifying more than 40,000 data items by January 2016. The monitoring revealed specific characteristics of hospital compared to urban effluent and made it possible to determine their treatability as well as the impact of the treated effluents on the aquatic environment. It also enabled us to answer the initial question, by showing that it is not useful to treat the hospital effluent separately here. These results allowed restoration of the "normal" situation in April 2016: hospital and urban effluents are now treated in a single treatment line. The studies and the research programs developed at SIPIBEL produced significant progress in knowledge and modeling of pharmaceutical residue flows in the sewage system, the effectiveness of the additional treatments by ozonation, greater understanding of what becomes of the micropollutants in the sewage sludge and in the aquatic environment and their impact on aquatic micro-organisms, the development of analytical tools, and the identification of ways to reduce the discharge of pharmaceuticals in the environment.