Paris 2024: Cleaning the Seine for Olympic Swimming

In a historic move for the 2024 Summer Olympics, the Seine River in Paris is set to host Open Water Swimming events despite a century-long ban due to contamination concerns. This initiative, led by Paris Mayor Anne Hidalgo, emphasizes the river’s cultural significance, flowing past iconic landmarks like the Eiffel Tower. However, the road to clean water hasn’t been easy. The river suffers from sewage overflow during heavy rains, leading to high levels of E. coli, a pathogen indicating fecal contamination. Despite promises from both Hidalgo and French President Emmanuel Macron to swim in the Seine themselves, poor water quality remains a genuine concern. Preliminary events, including a swimming test in August 2023, were canceled over unacceptable E. coli levels, with water samples exceeding the permissible limit of 1,000 colony-forming units per 100 mL. To address these problems, Paris has invested in a $1.5 billion infrastructure project, building the Alwood Basin—an underground reservoir designed to manage excess water and prevent contamination. This project hopes to reduce the frequency of sewage discharges into the Seine, enabling safe swimming conditions for Olympic events. As the games approach, ongoing monitoring will be essential to ensure the safety of athletes and spectators alike. Looking beyond the games, plans are underway to open swimming sites along the Seine in 2025, highlighting a long-term commitment to revitalizing this historic waterway for public use.