For the 2024 Paris Olympics, organizers aim to utilize the Seine River for multiple swimming events, including the triathlon and mixed relay, as part of a broader initiative to open up the waterway. Over the past century, however, the Seine has grown increasingly polluted, which has inhibited swimming in the iconic waterway. Due to this extreme pollution, the mission to make the Seine accessible for both Olympic and pedestrian use, known as the Swimming Plan, has required tremendous effort. The ambitious 1.5 billion dollar plan to alleviate contamination in the Seine has involved both impressive feats of engineering and substantial support from the Parisian community.
The Seine has not always been dangerously polluted. In the 1900s, Parisian residents regularly swam in the waterway through the hot summer months. However, the antiquated Parisian sewer system, increasingly overwhelmed by the city’s growing population, began leaking sewage into the Seine. So, in 1923, the mayor declared the river unfit for swimming. Despite a brief attempt at cleaning the Seine in the 1990s, the river remained largely neglected by the Parisian government. It was not until Paris’s 2016 Olympic bid that a concentrated effort to bring back swimming was announced. With a deadline of 2024, the river cleanup effort was expedited, inspiring engineers and city officials to tackle the Seine’s pollution with haste.
One of the most daunting tasks associated with decontaminating the Seine is revamping the Parisian sewer system. Developed in the mid nineteenth-century by French engineer Eugene Belgrand, this sewer system uses gravitational tunnels to transport stormwater and sewage to water treatment facilities. But when faced with excessive rainstorms, the system begins spilling wastewater into the river. Lead engineers in charge of the Swimming Plan combatted this issue by constructing a massive basin capable of holding surplus rainwater. Located under the Austerlitz train station, this monumental structure, over one hundred feet in length, can carry the volume of twenty Olympic swimming pools. Upon a heavy storm, the basin will collect rainwater before slowly feeding it into a nearby treatment plant. Additionally, two major wastewater treatment plants, located in Marne Aval and Seine Valenton, have been overhauled for the cleanup effort. Now equipped with ultraviolet lamps, these plants will greatly reduce levels of dangerous fecal bacteria in the river. By improving Paris’s outdated sewer system, a major source of the Seine’s pollution has been lessened.
Much of the river’s pollution stems from homes and boats directly dumping sewage into the waterway. In the suburban outskirts of Paris, teams have painstakingly gone door to door asking homeowners to reconfigure their pipes. Although homes are awarded a six thousand euro grant to cover the cost of construction, only a quarter of those asked agreed to the proposition. But many of those that did comply cited their support of the Swimming Plan’s mission as the primary motivator. In conjunction with this effort, a 2018 law forced all boats on the Seine to connect to the main sewer system. Many boat owners have objected, claiming that the government has treated them unfairly. But more and more boat owners have begun installing new sewage connections, a promising sign for the Swimming Plan. Though not completely successful, these efforts have nonetheless contributed to the overall goal of cleaning the Seine River.
The Parisian government is under immense pressure for the Swimming Plan to succeed. Along with various swimming competitions, organizers plan to hold the Olympic ceremony on the Seine with a flotilla of boats representing each country, making Paris the first to host this iconic ritual outside of a stadium’s walls. The Seine River cleanup may also have implications beyond the City of Lights. Smaller cities, including Zurich, Munich, and Copenhagen, have opened urban swimming, but the massive scale of the Swimming Plan may inspire other major European cities to follow suit and contribute to the defense against environmental degradation. However, this plan is not guaranteed to succeed. This summer, multiple test events were set to take place on the Seine. They were met with varying degrees of success as multiple events were canceled due to dangerous concentrations of E. coli bacteria. As Olympic organizers have stated, there is no Plan B for swimming competitions on the Seine: unsafe conditions will merely mean an event is postponed. But if this project can turn out successful, it will mark a significant turning point in both the city’s history and the ongoing fight for environmental preservation.