
CHICAGO (WLS) -- Hundreds of people are jumping into the Chicago River willingly this weekend.
The competitive open water race has been a long time coming downtown.
This weekend's Chicago River Swim marks the return of competitive open-water swimming right on the river.
This will be the first time that there will be coordinated competitive swimming on the river in nearly a century.
More than 300 qualified athletes will compete in one and two mile courses along the main stem of the river in an effort to raise funds for ALS research and youth swimming lessons and promoting water safety.
The team has been conducting safety rehearsals, testing lifeguard support on kayaks, paddle boards and motorboats, setting up large, yellow buoys and unveiling the inflatable finish line.
One man who will be swimming the two-mile course this weekend has a deeply personal connection to the cause.
"I lost my mother brother and aunt to ALS and now I have another brother who is fighting ALS and I've had friends and other people that I've known, neighbors who have contracted it," swimmer Tim Rooney said. "People that are fighting and living with it now and it's just a chance to work towards the cure and highlight the city of Chicago by swimming in the river."

More than just an open-water swim, this event celebrates environmental progress, community impact and a renewed connection to the river.
This of course is backed by extensive safety measures.
The UIC School of Public Health has been testing the water for the past three weeks and says the water quality has been looking good, well below the EPA guidelines, and all things are a go.
"We've been testing it for the last three weeks so the first sample was taken the day after Labor Day on September 2," UIC School of Public Health Professor Abhilasha Shrestha said. "The week after that we did three days Monday, Wednesday Friday. And this week we have tested Monday Wednesday Thursday and we're going to the lab right now to test the Friday samples and will also be testing tomorrow leading up to the event on Sunday."
The event was supposed to happen last year, but organizers were denied a permit and relocated the swim to Lake Michigan.
The city has now already given the green light for this year's event.
Visit www.chicagoriverswim.org for more information.