Time added that in 2022, "1.9 million cubic meters of untreated wastewater" poured into the Seine, so it is unfortunately still polluted. In 1923, Paris officials banned swimmers from the Seine due to the high levels of metal and fecal bacteria in the water, per Forbes.

Fortunately, the city says that as a result of recent infrastructure upgrades, the amount of untreated wastewater that ended up in the Seine in 2022 was 90% lower than 20 years ago. Despite this progress, pollution is still a problem; last year, 1.9 million cubic meters of untreated wastewater was spewed into the Seine.

The Seine's water is polluted with high levels of heavy metals, nutrients, sediment, and bacteria. This is mainly caused by the waste water and the surface runoffs from Paris. Heavy Metals include copper, cadmium, lead, and zinc.

On such occasions, the mixed water and waste discharges into the Seine through 44 storm drains. Over 2 million cubic meters (528 million U.S. gallons) of sewage-contaminated water finds its way into the river this way, leaving the river infested with a host of harmful bacteria.