Where France’s €1.6bn plan to clean up the Seine for the Olympics went wrong

Good morning.

An ambitious project to clean up the River Seine has left French officials up to their eyes in it.

Almost 10 years, €1.6bn and a giant basin later, the lofty goals of transforming the river through Paris into a place where athletes could compete and a tranquil public swimming space seem to be draining away.

The Olympic opening ceremony, ordinarily held inside the host city’s stadium, took place on the river and the plan was to do a number of sporting events there too. But in an embarrassing turn of events, the men’s triathlon had to be postponed on Tuesday after water tests revealed that the river was too contaminated for safe swimming. The decision came despite the World Triathlon president, Marisol Casado, saying there was an 80% chance the event would happen on Tuesday. Concerns grew to the point that officials were suggesting the race might be turned into a duathlon if the situation does not get better.

After much suspense, both the men’s and the women’s triathlon are going ahead this morning. “We will swim,” World Triathlon said in a post on X. Though the news will be heartening to athletes, there are still questions about long-term solutions for keeping sewage out of the Seine.

For today’s newsletter, I spoke with Guardian environment reporter Helena Horton about why it has been so difficult to clean up the Seine. That’s right after the headlines.

Five big stories

In depth: Could France still someday make its ‘crazy idea’ work?

Officials have been discussing cleaning up the Seine since the late 1980s. The latest iteration of the plans began in earnest eight years ago and the government seemed optimistic that the notoriously murky river could be transformed in time for the Olympics. The hope was that the scheme would make it clean enough for Olympians to compete and, later, for citizens to take a dip during the increasingly hot Parisian summers. (Pictured above, athletes testing the waters in 2023.)

In the months running up to the Games, water quality testing results were persistently negative but officials blamed the findings on a particularly wet spring. The French president, Emmanuel Macron, promised to go for a swim himself, to show confidence in the scheme, but the fallout from the snap election seems to have kept him occupied.

Paris’s mayor, Anne Hidalgo, and the French sports minister, Amélie Oudéa-Castéra, have, in fact, taken the plunge – although it has since been revealed that pollution levels were too high on the day that Hidalgo got in the water.

The optimism from officials was not pure hubris – water quality in the Seine can change quickly because of rain, which can make pollution levels spike. Hot and dry summer weather was expected to keep these problems at bay, but heavy rainfall last weekend scuppered hopes.

“At the beginning, it seemed to be a crazy and not very serious idea,” Macron said. “But we decided it was the right moment to deliver this crazy idea and make it real.” Though they have managed to get athletes in the water, the unpredictability of contamination means that it is unlikely that residents will be hopping in the Seine to cool off any time soon.

The stinky Seine

It has been illegal to swim in the Seine for a century, but once Paris was chosen as a host for the Games, French officials became taken with the idea of showing off the capital as much as possible. The river became the centrepiece of the Paris Olympics’ PR machine.

Ultimately, though, there was not enough time or money put into the project to make it failsafe. While €1bn to clean it up seems big, the plan was executed “relatively cheaply” in the context of huge infrastructure projects, Helena says. The state-funded project has included investment in managing wastewater, filtering stations, treatment plants and storm basins to keep bacteria at bay.

The most important part of the clean water project is the cavernous runoff basin, which can hold 50,000 cubic metres of storm overflow water. That is about 20 Olympic swimming pools’ worth of water, according to Paris 2024.

The plan was never to purify the Seine, it was “to keep untreated water from being dumped” into the river, according to the lead engineer on the project. But even that goal was always going to be difficult to achieve, because older cities such as London and Paris have what is known as a combined sewage system. Countries with newer sewage systems tend to have two systems of pipes: one for all household wastewater, and one for stormwater from roofs, gutters, road runoff and the like.

But Paris’s historic system means there is only one system where all the water is mixed together. When it rains and the pipes are at risk of overflow, instead of backing up into people’s homes it flows into rivers and the sea. “This happens quite frequently,” Helena adds. This pollution makes it unsafe to swim in the river, and chokes out wildlife that might otherwise live there. Building the basin ensures that wastewater does not enter the river, so long as it’s not at capacity. The problem arises when it rains too much and the basin gets full. The overflows still happen, and there is no way of guaranteeing that the river is safe to swim in.

Was this inevitable?

Forecasting is notoriously difficult, but the impact of the climate crisis on weather patterns is well known. “Because of the climate breakdown, we are getting heavier rain in northern Europe than we are used to at strange times of the year,” Helena says. “We’ve had that in the UK this year, and it was part of the reason we have had record sewage overflows. So, in some ways, the problem holding the triathlon [in the river] should have been predicted.”

After months of boasting about the scheme, “the way things have panned out is not going to really raise confidence in the Parisians who might want to go swimming in the river in the next few years”, Helena says.

But it is not all doom and gloom. Even gradual improvements in the river have brought wildlife slowly back to the Seine – French authorities have counted more than 30 species of fish, compared with three in 1970.

Is there a long-term solution?

Realistically, a long-term strategy to transform the Seine would need far more intervention, investment and, crucially, foresight. It is a major undertaking: the sewage systems are so vast and so old that fixing the problem will require building new sewers.

“They really should have been replaced incrementally over time,” Helena says. “To build the super-sewers that you would need under cities like Paris and London to completely reduce sewage pollution, the French government would need to dig up the city and probably spend tens of billions over decades – but they are not incentivised to do that.”

What else we’ve been reading

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The appearance of a convicted rapist at the Olympics has shocked many, but the reaction has been muted in his home country of the Netherlands – so it’s fascinating to read Renate van der Zee on why Steven van de Velde’s selection hasn’t caused uproar. Toby

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Sausage trifle, drag queens and Jane’s sad little life. For daytime TV, Come Dine With Me has produced an inordinate amount of unforgettable moments. Now 20 and replicated all over the world, Dylan B Jones celebrates the top 100 tropes of the daily culinary extravaganza. Toby

Sport

Paris 2024 | Team GB have bagged two more gold medals with a win in the 4x200m freestyle race ahead of the US and Australia, and a Games record in the men’s trap shooting final from Nathan Hales, together doubling Great Britain’s gold medal haul.

Football | Former footballer Joey Barton has pleaded not guilty to an offence of malicious communications in relation to posts directed at the pundit Eni Aluko. Barton appeared at Warrington magistrates court accused of conveying an indecent or offensive messagein connection with posts on X that he made about the former England international.

Cricket | Matthew Mott has been sacked as coach of the England men’s white-ball team with immediate effect, following crisis talks with Rob Key over the weekend. The team’s assistant coach, Marcus Trescothick, has taken over on an interim basis.

The front pages

“‘You can’t help but cry’: hundreds pay tribute to stabbing victims” says our Guardian lead headline this morning, while the Daily Express asks “Why were they taken from us?”. “Stabbing horror families reveal their devastation” reports the Times and the Daily Telegraph says “Violence erupts over child killings”. The Daily Mail has “Faces of the innocent little Taylor Swift fans killed in cold blood by ‘despicable human being’”. The Metro calls the victims “Our little innocents”. “No words can describe our devastation” – that’s the i while the Daily Mirror says “Keep smiling and dancing … heartbreaking tributes to 3 young victims of kids’ club knife attack”. Top story in the Financial Times is “Reeves warns budget will raise taxes as row over £22bn fiscal hole deepens” – the front-page picture slot is reserved for Keir Starmer bearing flowers in Southport.

Today in Focus

Cartoon of the day | Martin Rowson

The Upside

A bit of good news to remind you that the world’s not all bad

A British-Ghanaian businesswoman is on a quest to woo Africa’s delivery drivers away from polluting petrol motorcycles, and towards ebikes. Valerie Labi is the founder of Wahu, producers of Ghana’s first electric bicycle, founded to combat unsustainable, unreliable and expensive transport in the country. During the Covid pandemic, Labi began buying secondhand pushbikes to convert into ebikes. Four years on, the company has launched a platform for delivery riders, opened an assembly plant in the country’s capital, Accra, and is about to close on an $8m investment round. Wahu plans to eventually produce 50,000 ebikes a year across Africa, making huge cuts to carbon emissions. It’s good for drivers’ pockets, too: each bike costs just $13.60 a month to power, compared with $250 for a petrol vehicle. “If I see a problem and I think it can be solved, I follow that thread,” says Labi.

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