Clean Seine: Paris races against time for Olympic waters

The Summer Olympics in Paris will begin on July 26th, 2024. Some swimming competitions will take place in the waters of the Seine, over which the capital of France is situated. Cleaning the murky river to enable athletes to swim was one of the longest-running, most expensive, and riskiest projects associated with this year's Olympics.

The state-supported plan, valued at 1.4 billion euros (about CAD 2 billion), included several years of work on sewage management, treatment plants, filtration stations, and stormwater tanks to reduce bacterial contamination of the river from fecal waste. The clean Seine is intended to benefit not only the athletes during the Olympics.

Summer temperatures in Paris are rising due to the climate crisis. After the Olympics, authorities plan to create local beaches and swimming areas along the Seine and the Marne. These are expected to open in 2025. Like Copenhagen, Munich, or Zurich, Paris and its surroundings want residents to enjoy open urban waters to cool off. At a press conference, Paris Mayor Anne Hidalgo stated: "When you're passing a river, you just want to get in and swim." She plans to do so as early as next month.

During the Olympics, open-water swimming and triathlon competitions will start at the Pont Alexandre III bridge, a marvel of 19th-century engineering on the edge of the Champs Élysées, with the Eiffel Tower in the background. The river water will be regularly tested before each event, and authorities are confident it will be clean. They promise that 75% of identified bacterial pollutants will be eliminated by the time of the games, exceeding the established goal.

Marc Guillaume, the prefect of the Paris region, announced at a press conference that there is no plan B for the Olympic events scheduled to take place in the Seine. The only exception might be moving the date by a few days in the case of prolonged, very heavy rains that could temporarily pour untreated water into the river.