Nearly 100 days before the Paris 2024 Olympic Games, the NGO Surfrider Foudation warned on Monday of the “alarming” state of the waters of the Seine, where several Olympic events are to be held, after carrying out a sampling campaign on six months. Out of 14 measurements that the association carried out between the end of September 2023 and the end of March 2024 under the Alexandre-III and Alma bridges, seat of future triathlon and open water swimming events, thirteen were found to be “above or even very well above the thresholds recommended for swimming.
Contamination with E.coli bacteria
With regard to the 2006 European “swimming” directive and the scales of the swimming and triathlon federations, the concentrations of two bacteria indicative of fecal contamination, Escherichia coli and enterococci, must not exceed 1,000 colony forming units (cfu)/ 100 ml in E. coli and 400 cfu/100 ml in enterococci. Beyond that, the water is considered unsuitable for swimming.
The analyzes carried out by Surfrider, in partnership with the Eau de Paris laboratory (the same as the Paris town hall) and Analy-Co, “carried out randomly and with a predefined schedule in order to overcome weather conditions (rain, sun , flooding…)”, show concentrations of E.coli regularly higher than 2,000 cfu/100 ml (maximum of 7,250 under the Alma bridge on February 7, 2024) and 500 cfu/100 ml for enterococci ( maximum of 1,190 on February 7).
The period analyzed is not part of that envisaged for swimming in the Seine, which will be reserved for the summer months. However, other analyzes sent to AFP at the beginning of 2024 by the Paris town hall had already shown that between June and September 2023, none of the 14 Parisian water sampling points had reached a sufficient level of quality at with regard to European directives.
“Growing concerns”
Faced with these “alarming” results, Surfrider expresses its “growing concerns about the quality of the water of the Seine” and points out the “risks” for athletes, and beyond for Ile-de-France residents, “of evolving in contaminated water” . Faced with the “lack of visibility” and communication from the authorities, the association calls in an open letter for accessibility to the event locations “before and during” the entire duration of the Games in order to be able to continue to take its own samples there.
The triathlon events (July 30 and 31, August 5) and open water swimming, now called marathon swimming (August 8 and 9) remain particularly threatened by heavy precipitation which would degrade the water of the Seine, via discharge into its bed of wastewater mixed with rainwater. At the beginning of August 2023, the dress rehearsal for the open water swimming event had to be canceled due to water quality thresholds being significantly exceeded.