Chicago River Swim Planned Despite Safety Concerns, EPA Data Shows
Once considered one of the dirtiest urban waterways, the Chicago River has seen significant improvements in water quality since the passage of the Clean Water Act in 1972. While organized swimming hasn’t been authorized in over a century due to ongoing concerns about combined sewer overflows, an upcoming event aims to showcase the river’s progress and highlight the importance of ongoing cleanup efforts.
The swim, planned for September, Chicago’s driest month, will invite 500 participants to swim 2.4 miles from the Clark Street Bridge through a loop course between State Street and Wolf Point. The event will support ALS research at Northwestern University and has long been a dream for organizer Doug McConnell, a Chicago-area native who lost his dad to ALS.
“We wanted it to be in Chicago, because we’re from here, Northwestern is here, and we’ve got this fabulous resource in the form of the Chicago River,” McConnell said. “It’s really the whole reason Chicago is here in the first place.”
However, some experts caution that heavy rains and a large urban population can still contribute to dangerous conditions, and swimming should be avoided following heavy rainfall or overflows.
“There’s been really, really major changes in how we manage our drinking water, and our wastewater and our environmental footprint as it relates to the river,” said Timothy Hoellein, an aquatic ecologist at Loyola University Chicago who studies urban ecosystems. “But when there’s been one of these combined sewer overflows, there’s more potential for disease-causing organisms and microbes in the water.”
The organizers of the swim emphasize strict safety measures and will monitor water quality data in the lead-up to the event. McConnell said the threat of a combined sewer overflow was front of mind in planning the event.
“We will monitor bacteria levels in the water, just like they do bacteria levels at Oak Street Beach, or, you know, at the indoor pools of health clubs,” McConnell said.
The Metropolitan Water Reclamation District (MWRD) records and regularly publishes the amount of fecal coliform in the river. Drinking or coming into contact with elevated levels of this type of bacteria may cause an upset stomach, vomiting, fever or diarrhea. It can also cause serious conditions or death in vulnerable populations such as children, older people and those with weak immune systems.
According to the Illinois Department of Public Health, the maximum safe level of fecal coliform in freshwater is 500 colony-forming units per 100 milliliters of water.
In 2023, MWRD reported an average of 1,536 cfu per 100 ml at Wells Street –– where swimmers will be –– down from a 2022 average of 5,290 cfu per 100 ml.
Despite the improvements, the Chicago Department of Cultural Affairs and Special Events (DCASE) has not yet permitted the event. Ald. Bill Conway, 34th, whose ward is where the swim would take place, said he was surprised to learn the event had been planned without collaboration with his office or DCASE.
McConnell said A Long Swim is working toward getting city approval and is hopeful the event will proceed as planned.
“We’re working with the Coast Guard, who is coordinating with the city,” he said. “We want to make sure we have the most successful and safe event possible.”
