The Chicago River is cleaner than you think

Through concentrated efforts, the Chicago River is at its cleanest levels on record and the river is primed for swimming. 

For 50 years, advocacy groups like Friends of the Chicago River, Current, and Urban Rivers have worked to clean up and celebrate this unique natural resource. The turnaround has been remarkable and the river is constantly moving toward greater biodiversity. It is now home to countless wildlife including more than 80 species of fish.

The Chicago River is a self-sustaining ecosystem whose health is directly impacted by weather patterns and environmental activity. Water quality readings are typically positive, however there are occasions where conditions are less than ideal. Like any organized open water swim or sanctioned triathlon, the Chicago River Swim will only operate in waters that are deemed safe for human exposure.

Additionally, the river's main channel is fed directly from Lake Michigan. Every time the Chicago Harbor Lock opens, hundreds of thousands of gallons of lake water flow into the Chicago River and head downstream. The event's swim course will be set entirely in the main channel.

Water Testing Process

Analysis for the suitability of Chicago River water for swimmers will come from the advanced qPCR testing protocol through the Department of Environmental and Occupational Health Sciences at the University of Illinois Chicago School of Public Health. This is the same testing system utilized by the Chicago Park District to analyze water quality at their beaches.

The testing measures for the DNA of fecal indicator bacteria, enterococci, which can signal fecal contamination and, by extension, the possible presence of harmful fecal pathogens for anyone who come into direct contact with the water, such as swimmers.

Private testing will began 19 days prior to the event. Water samples will be collected along the course over nine days leading up to the event. The last test will be the day prior to the swim, which will support the final Go/No-Go decision for the swim.

Water quality testing thresholds for the Chicago River Swim are noted in the table below (which mirrors Chicago Park District beach standards)..

Latest Water Testing Results

Included below are periodic qPCR water quality results by location within the Swim Course (at each bridge). The chart on the left includes the full scale of possible readings within the results chart above. The chart on the right offers an isolated look into the "Green" (<1,000 CCE per 100mL) readings above. As of September 20, all readings have been within the "Green" range meaning "No swim restrictions."

The Chicago River Swim will continue to monitor conditions and ultimately make decisions while using this data, as well as publicly accessible data and input from MWRD, the Chicago Department of Public Health and other public safety officials.