Why Can You Swim in the Seine but Not the Potomac River?

['Lindsey Byman', '.Wp-Block-Co-Authors-Plus-Coauthors.Is-Layout-Flow', 'Class', 'Wp-Block-Co-Authors-Plus', 'Display Inline', '.Wp-Block-Co-Authors-Plus-Avatar', 'Where Img', 'Height Auto Max-Width', 'Vertical-Align Bottom .Wp-Block-Co-Authors-Plus-Coauthors.Is-Layout-Flow .Wp-Block-Co-Authors-Plus-Avatar', 'Vertical-Align Middle .Wp-Block-Co-Authors-Plus-Avatar Is .Alignleft .Alignright'] Washingtonian 2025-09-23 00:00:00

By the late 1960s, about 60 percent of the city’s sewage went into the river. Year Swimming Was Banned: 1923The Cleanup Plan: In 1990, Paris’s mayor set a goal to open the Seine to swimmers. Efforts picked up in 2015, when the city announced that the river would be swimmable for the 2024 Olympics. The city incentivized houses and houseboats to connect to the city’s sewage plant instead of dumping into the water. : The Seine was used for events in the 2024 Olympics, though there were some lingering issues from elevated bacteria levels.