On a rainy, cold day like today open water swimming is probably the furthest thing from your mind, and the suggestion of jumping into the Chicago River, of all places, even further away. But on Sept. 22, the city will, for the first time in nearly 100 years, play host to those willing to get wet for a mile or two swim along the Riverwalk.

“The starting line will be between Clark and Dearborn streets. Swimmers will go east to Wabash and then circle back to Wolf Point,” said Doug McConnell, founder of A Long Swim.

While Chicago is no stranger to hosting large-scale open water swim events including Big Shoulder and the Chicago Triathlon, organizers admit overcoming people’s perceptions about the cleanliness of the Chicago River is their biggest challenge.

Friends of the Chicago River is supporting the event for exactly that reason: to help get the word out that the river as actually approved for swimming 13 years ago.

“Many people are aware of the tunnel and reservoir plan, which is colloquially called deep tunnel. And that has reduced the chance of having any sewage in the river, which is people’s main concern by 85%, from what is the historic river that people used to worry about. And so today, on an average day it really is cleaner than it used to be and it is clean enough for swimming in most places,” said Margaret Frisbie, Friends of the Chicago River.

They hope the swim will not only be a celebration of the riverfront’s renaissance, but also serve as a fundraiser for ALS research, a cause near and dear to McConnell’s heart and at the heart of all the events he organizes.

“It was actually after my sister was diagnosed that she had the idea of open water swimming because it was such a perfect contrast to the challenges that ALS patients go through,” he said.

The inaugural Chicago River Swim will take place on September 22. Registration is already open and it will be capped at 500 qualified swimmers who must show documented proof of previous open water swims in order to be approved.