Paris 2024 Olympic Games: the water of the Seine will be “clean”, Macron promises again

Emmanuel Macron, who promised to swim in the Seine for the Olympics, assured Tuesday that the water in the river would be “clean”, on the occasion of the inauguration of a rainwater treatment station in Champigny -sur-Marne, a crucial link for the holding of certain events. Being able to swim in the Marne and the Seine is “one of the events of the century”, declared Sports Minister Amélie Oudéa-Castéra during this inauguration in Val-de-Marne. “We are ready, on time, on D-94” of this summer’s Olympic Games in Paris, and “we will also be there for our heritage,” she added.

Saturday evening, on the show The Studio of Legends on Europe 1, the Minister of Sports explained that “the connection of barges and boats to the sewer system, plus all the mechanics of disinfecting the water leaving the treatment plants” were in the process of being implemented. finishing. Enthusiastic, she assured that the promise would be kept: “There will be several measuring points for the water quality of the Seine, eight today and 35 from June. So it’s a huge industrial project and we will do everything to be ready for an extraordinary show.”

Macron promised to swim in the Seine

The Head of State also welcomed this “key step in making the Seine swimmable” on his X account. “Mobilized all together, State and elected officials, we are getting there. The water from the Seine will be fresh… but clean,” he wrote on the social network. Before launching, frozen emoticon in support: “I can confirm it for you!”

A key step in making the Seine swimmable, the rainwater depollution station in Champigny-sur-Marne is ready! Mobilized all together, State and elected officials, we are getting there.

The water of the Seine will be fresh… but clean.

I can confirm it for you!

— Emmanuel Macron (@EmmanuelMacron) April 23, 2024

Emmanuel Macron has in fact committed on several occasions to swimming in the Seine during the Games, without however setting the date of the meeting or specifying whether he will do so in public. Downstream of the rainwater treatment plant (SDEP) inaugurated in Champigny, the Marne flows into the Seine, where open water swimming events and the swimming part of the triathlon are to take place this summer.

Return 700 liters per second of water to the main tributary of the Seine

The latter give a cold sweat to the organizers of Paris 2024, the cleanliness of the river depends heavily on the weather: in the event of a major stormy episode in the preceding days, which would result in the mixture of rain and wastewater being evacuated into the Seine, they could be postponed or even canceled, as was the case during test events last August. The measures taken to clean the Marne and the Seine should also make it possible to swim there, which has no longer been possible since 1970 in the first case and since 1923 in the capital’s river.

The objective of the SDEP is to return 700 liters per second of water into the main tributary of the Seine, or “the equivalent of an Olympic swimming pool per hour”, specified Olivier Capitanio, president of the Val-departmental council. de-Marne, present at the inauguration ceremony. With the Austerlitz basin, built in Paris and inaugurated at the beginning of May, the Champigny station, construction of which began in the fall of 2020 at a cost of more than 53 million euros, is a major project.

Fed by two water intakes, it is smaller than Austerlitz (8,000 m3 compared to 50,000 m3), but has a dual functionality: underground, two lobes with a depth of up to 20 m and a diameter of 35 m receive rainwater, one to store it, the other to clean it in three stages.

First, screens to separate the waste. Then, settling blades to separate the water from the sand and mud. Finally, the main technological innovation lies in the presence of around a hundred ultraviolet lamps to obtain, assure its operators, 99.9% healthy water, free of bacteria.