Paris 2024 & World Triathlon statement on Swimmability of the Seine

 

With the Paris region having recently experienced the heaviest summer rainfall on record over the last 20 years, the quality of the water in the river Seine has dropped below the levels established by public health authorities and World Aquatics in order to protect the health of swimmers. As a result, the Open Water Swimming World Cup 2023 planned for this weekend on the Seine was cancelled.

Prior to and even during the recent rainy period in Paris, water quality in the Seine has regularly achieved the levels required for healthy public swimming, demonstrating the progress that continues to be made. In early July, swimmers took to the Seine at the Bras Marie, one of the three Paris city-centre sites earmarked for public swimming facilities from 2025.

For Paris 2024 and World Triathlon, the health and safety of athletes is our top priority. We will therefore, together with the relevant authorities, continue to carefully monitor water quality over the coming days, in the confident expectation - based on the current weather forecast - that elite athletes will compete in the Seine later this month, at the World Triathlon and Para Triathlon Test Event Paris scheduled for 17-20 August.

In the unlikely event that water quality does not meet the requirement of World Triathlon and public health authorities, a contingency plan is in place which would see the race(s) shifted to a duathlon format.

With a year to go before the Games, the efforts to make the Seine swimmable, led by the State and the City of Paris, continue to significantly improve the quality of the water in the Seine.

Existing and additional measures implemented from now through to 2024

As a reminder, major measures have already been taken over several years to improve the quality of the water in the Seine, thanks to the commitment of a number of stakeholders (the State, the City of Paris, SIAAP and the 93 and 94 departmental councils in particular). Work has already been carried out and is having an impact in dry weather: the disinfection of discharges from the two wastewater treatment plants upstream of Paris on the Seine and Marne rivers was brought into service in early summer 2023 and work is under way to gradually bring buildings and boat connections up to standard.

The clean-up drive is also continuing with the most significant water quality improvement projects due to be completed in the coming months, particularly to cope with exceptional weather events in the order of those which have regrettably necessitated this weekend’s cancellation.

Between now and 2024, new infrastructure will be delivered to further improve the treatment of water during heavy precipitation and thus improve water quality. The Austerlitz storage basin, a cylinder 50m in diameter and more than 30m deep, will store more than 50,000 m3 of water, the equivalent of twenty Olympic swimming pools. This reservoir will allow event organisers to be better prepared for exceptional weather events by preventing wastewater from being discharged into the Seine in the event of heavy rain. Thanks to this basin, the excess water will flow into the sewer system for treatment.

Other facilities are currently under construction and will be operational in 2024: the structures planned for the Ru Saint-Baudile catchment area (Seine-Saint-Denis), the VL 8 (a 10-kilometre long high-capacity collector between Essonne and Val-de-Marne) and the Val-de-Marne rainwater treatment plant, which, like the Austerlitz basin, is designed to receive rainwater and treat it before it is discharged into the natural environment. All boats and floating establishments located upstream of the site will be connected to the sewers.