SIOUX FALLS, S.D. (KELO) – The Paris Olympics are approaching and the French government is working hard to clean the long-polluted Seine River and make it safe for swimming events.
With Paris’ ramped up efforts to improve the water quality of the Seine and the recent 32 million gallons of wastewater discharged into the Big Sioux River after the floods, does that make the Big Sioux dirtier than the Seine?
Travis Entenman, the managing director for Friends of the Big Sioux River, said the organization tests the waters for E. coli, Total Suspended Solids (TSS) and nitrates. As of 2024, 75% of the Big Sioux River is impaired for both TSS, which includes top soil or river bank erosion and E. coli.
“We have a really big issue with the E. coli, that is a bacteria that primarily comes from livestock manure, either on farm fields or livestock in the water, but also pet waste or kind of the primary drivers depending on where you are within the watershed,” Entenman said.
He added that, unfortunately, the quality of the water worsens when water levels are high, like after a flood, because the water runoff is picking up pollutants and adding them to the river.
Combined with the 32 million gallons of partially treated sewage that was purposefully discharged into the river to keep it away from homes, the water quality of the Big Sioux isn’t at its best.
“The majority of the river does not meet the designated use standards,” Entenman said. “So quite honestly, swimming is probably not advised in most of the river, outside of just like when it’s flooding. There is a lot of debris in the river that’s dangerous and in and of itself, but when it comes to pollutants and E. coli levels, you should be cautious about recreating in the river.”
France on the other hand, has been a lot more strict about people entering the Seine River. Swimming has been banned in the river since 1923, with a few exceptions. According to the CBC, the city has tried many times to clean up the river, but the water has always tested unsafe.
However, when Paris was announced as the home for the 2024 Olympics, serious efforts began to clean the river in order to host swimming events. The city has spent $1.5 billion, AP News said, to clean up the long-polluted river.
Data provided by the Fluidion Open Data Initiative on E. coli bacteria levels in the Seine showed 852 colony-forming units per 100 milliliters as of July 16, down from 1,459 on July 15, the CBC reported.
The World Triathlon Federation determined that 900 cfu/100 ml is considered safe for competitions. For comparison, the Big Sioux River only meets 25% of the beneficial use standard of limited contact recreation, which is 1,178 cfu/100 ml.
Entenman said it can be hard to compare the water quality of the Big Sioux River and the Seine because the environments and landscape of the two rivers are very different from each other– the Big Sioux runs through mostly rural, farm lands and the Seine runs through an urban city– which both present their own nasty, unique challenges.
Paris has a combined sewer system, which means wastewater and storm water flow through the same pipes into the Seine. That, mixed with the pollutants from tour boats and vehicle pollution, left the water near hazardous for decades.
Although the Big Sioux and Seine aren’t necessarily apples to compare, Entenman did say one thing the rivers have in common is they’re both in need of a good clean and they both have people dedicated to improving the water quality.
“I’m not familiar with all the nuances of Paris and the water quality out there, but I do know that they’re spending millions upon millions of dollars to help clean up the river to make it usable for the Olympics,” he said. “And it just shows that you actually have to put a lot of resources into water quality to actually help improve it.”
Friends of the Big Sioux River’s mission is to build awareness and understanding within the community about water safety, what’s in the water and how people can help.
“We’re getting people more intimately connected with the river and kinda get over the general apathy of like ‘Yuck, it’s a dirty river and there’s nothing we can do about it,’” Entenman said. “Well, that’s not quite true. We need to get over that and try to start making positive changes.”
