A state board took a major step today in the long-running debate over how clean the Chicago River should be, proposing to make the river safe enough to swim in.

“I think this is a big turning point in the long, long battle to clean up the Chicago River,” said Jessica Dexter, staff attorney with the Environmental Law and Policy Center.

The Illinois Pollution Control Board has been mulling the issue for years. If the new standard is finalized, it would all but guarantee the Metropolitan Water Reclamation District would have to start disinfecting the treated sewage it pumps into the river system.

That agency delayed a much-anticipated vote Thursday over whether to adopt a pro-disinfection policy. It became obvious at the meeting that a clear majority of commissioners now support disinfection. But one commissioner blocked the vote, and District President Terry O’Brian reiterated his skepticism.

“President Obama when he took office said that for any public health and safety issues, environmental issues, energy issues, there should be science done,” said O’Brian. “And what are we doing? We’re throwing science out the window.”

Still, O’Brian said outright he would not veto a “yes” vote.

“It’s almost a race between the two agencies to see if the Water Reclamation District is going to step up and do this voluntarily or if they’re gonna wait until the USEPA and the Illinois Pollution Control Board forces their hand,” ELPC’s Dexter said.

Each agency is expected to reach a decision at its next meeting, both of which are scheduled for June 16th.