The Charles River was once considered among the most polluted waterways in the country, but a nonprofit says it's now clean enough for a permanent swimming area.
The Charles River Conservancy on Tuesday released a feasibility study in conjunction with Stantec Engineering for an enclosed floating dock on the river near the Boston-Cambridge line.
Jennifer Gilbert, chairwoman of the conservancy's Swimmable Charles committee, tells The Boston Globe the location near the Museum of Science was chosen because of its accessibility.
The conservancy says the Charles is now one of the cleanest urban waterways in the U.S. and is considered safe for swimming, although sediment may still contain hazards.
In addition to releasing the study, the conservancy launched an Indiegogo.com campaign to raise $25,000 to fund the project's first stage.