How Paris cleaned up the Seine for the Olympics

Public swimming is planned for 2025.
By Teodosia Dobriyanova  on 
Atheletes jump in the river Seine, with Pont Neuf and the Eiffel Tower in the background. Caption reads "Olympic effort"
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Now that's an Olympic effort. The Seine river is swimmable again after a century-long ban. On July 17, Paris’ mayor Anne Hidalgo took a swim in the Seine after a race to clean up the river in time for the 2024 Olympics.

The enormous cleaning effort took several years and cost around $1.5 billion. One of the most monumental changes is a new underground system which is designed to hold rainwater and stop the river from overflowing during storms, preventing the city’s sanitation network from spilling into the Seine. Paris and LA-based tech monitoring company Fluidion is tasked with taking daily readings of the Seine’s pollution levels. If pollution levels remain low during the Olympics, athletes competing in swimming races like the triathlon are set to swim in the Seine, while public access is planned for 2025.


This isn’t the first attempt to clean up the river. In 1990, Paris’ mayor at the time and president Jacques Chirac vowed to clean the Seine within three years but their promise wasn’t fulfilled.

Picture of Teodosia
Teodosia Dobriyanova
Video Producer

Teodosia is a video producer at Mashable UK, focussing on stories about climate resilience, urban development, and social good.


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