Downtown Chicago is poised to make a historic splash with the announcement of the Chicago River Swim, an unprecedented open-water event slated for September 22. In an aquatic homage to the city's environmental strides, 500 swimmers will plunge into the once-polluted waters, navigating a course flanked by Chicago's architectural spectacles.

A Long Swim, the nonprofit at the helm of this initiative, aims to celebrate the river's transformation while backing ALS research. It's a call to arms – or rather, legs – for swimmers who meet the qualifying standards. World-renowned swimmer and nonprofit co-founder Doug McConnell conveyed to PR Newswire, "What was once unimaginable is now possible. We are committed to conducting a safe event, backed by the latest in water quality technology and a thorough safety plan."

To ensure the safety of the participants and the river's readiness for the historic swim, organizers are banking on real-time water quality monitoring data from organizations like H2NOW. The swim will take athletes on a transformational journey, sandwiched between the Clark and Dearborn Street bridges, and finish with a family-friendly bash near the Clark Street Bridge.

From a conduit for cholera to a champion of urban renewal, the Chicago River's clean bill of health is met with a dash of controversy, reminiscent of its tumultuous past detailed on RunSignup. As the site of former open-water spectacles in the early 1900s and swimming triumphs by the likes of Johnny Weissmuller, the river is en route to reclaiming its storied aquatic legacy, albeit with the advanced oversight of several environmental protections and infrastructural marvels like the Deep Tunnel project.

The enthusiasm for the river's revival isn't just treading water. As noted on ChicagoRiverSwim.org, this event not only underscores the environmental turnabout but also resonates with civic pride and the city's readiness to reconnect with its flowing artery. The anticipated September event is already stirring waves of interest amongst the local community, swim enthusiasts, and city-dwellers eager to witness history in the making once again along the banks of the Chicago River.