Swimming is a recreational activity that takes place in natural surface waters. These waters are therefore susceptible to be contaminated by short-term pollution and so become dangerous for bathers. The current bathing water directive (2006/7/EC) demands, for such bathing sites, an efficient surveillance with monitoring and an early warning system. The aim is to prevent bathers from being exposed to pollution. The first water directives in France set out the legal thresholds that must not be surpassed, using faecal bacteria as an indicator of water pollution. E. coli are chosen as indicators of recent faecal pollution and intestinal enterococci are used to highlight older pollution. The present study proposes the future development of an Early Warning System in Paris for bathing and for the aquatic activities of the Olympic Games in 2024.

This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 820954.