PARIS — After months of anticipation, Paris Mayor Anne Hidalgo took a dip in the long-polluted Seine River on Wednesday, fulfilling a promise to show the river was clean enough to host open swimming competitions during the 2024 Olympics—and the opening ceremony on the river nine days away. [time-brightcove not-tgx=”true”] Clad in a wetsuit and goggles, Hidalgo plunged into the river near the imposing-looking City Hall, her office, and the Notre Dame Cathedral.