Poop in the Seine? Explaining Olympics swimming controversy, protests over Paris river pollution

There has been no hotter topic leading up to the start of the 2024 Paris Olympics than the Seine River.

The infamous waterway, which stretches 777 kilometers (483 miles), flows from northern France, down through Paris and into the English Channel at Le Havre. It's known as the perfect way for tourists to see the capital of France.

While it may be an appealing body of water to float on, no one has been allowed to dive into the Seine for a quick dip — until now. The Seine is scheduled to be part of the Olympic events, with some of the best swimmers in the world expected to tread through the river on their way to a potential gold medal.

Here is everything to know about the Seine River and whether it's safe to swim in.

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Why is the Seine so dirty?

The Seine River isn't exactly the top of the world when it comes to cleanliness.

Like most aging cities all around the world, Paris has a combined sewer system. That means both wastewater and storm water flow through the same pipes. When excess amounts of rain come to the area, those pipes reach full capacity.

Instead of the extra wastewater flowing into a treatment plant of some sort, the sewage flows into the Seine — creating the infamous smell and toxic waters.

Seine River poop protests

So, what's the deal with poop in the Seine River? It's all about protesting.

Despite the assurances by the government, those in the area did not feel as though the river was safe enough to swim in. When Paris mayor Anne Hidalgo promised to swim in the river to prove its upgraded conditions, protests began to use a hashtag online about defecating in the waters before Hidalgo's dip — # JeChieDansLaSeineLe23Juin, which means "I S— in the Seine on June 23."

A website was created that featured a calculator, which let users figure out at what time and which place they needed to defecate in the river for the sewage to reach the point of Hidalgo's attempt to swim in the Seine.

Hidalgo ended up not diving in on June 23, as snap elections caused a delay, but it left many people wondering if others would actually take the hashtag literally and use the river as their own personal toilet.

"At the beginning, the objective was to make a joke, by bouncing off this ironic hashtag," the website owner said to Indian Press . "In the end, are people really going to go s— in the Seine, or set up actions? Nothing is excluded."

Is it safe to swim in the Seine River?

The question as to whether the Seine River is safe to swim in is a controversial one. It's been a hot topic leading up to the Olympics, and likely will be until the events take place that require the Seine.

Swimming in the river has been banned since 1923. A few exceptions have been made here and there for different competitions, but for the most part, no one is allowed to use the Seine as a means for swimming.

The Paris Olympics is one of those exceptions. The government has been doing its due diligence to clean the waters — including pouring in $1.5 billion to make it safe to swim.

Most recently, Hidalgo kept her previous promise to swim in the Seine River , proving that it is safe for the upcoming Olympic Games. On July 17th, Hidalgo, Paris 2024 Olympic President Tony Estanguet, and Marc Guillaume, the top government official for the Paris region, all took a dive in the water.

"The water is wonderful," Hidalgo said to NBC News . "The water is very, very good. A little cool, but not so bad."

How deep is the Seine River?

The depth of the Seine River varies depending on where parts of the river are located.  In some places, the depths can reach 10 to 20 feet , while others can get as low as 25 to 30 feet.

Olympic swimming events in the Seine

There will be multiple Olympic swimming events that utilize the Seine River in the competition,

The men's and women's marathon swimming will take place in the historic waterway. The 10km race was first introduced at the Beijing Olympics in 2008.

In addition, the swimming portion of the triathlon will also take place in the Seine River. These athletes compete in three separate disciplines as a part of the entire race — swimming, running, and biking.

The Opening Ceremony parade also will take place in the Seine River.