State regulators have removed the recreation advisory that’s been in effect for the Ohio River near Louisville for the past month, after harmful algal blooms caused hazardous conditions.

Regulators made the call today after a week’s worth of water sampling indicated that the levels of microcystin toxins — produced by the algae — in the water near Louisville had dropped below the advisory threshold. This is the area where athletes participating in the Ironman triathlon are scheduled to hold a 2.4 mile swim on Sunday; race organizers confirmed late Friday the event would go on as planned.

ohior_hab_1009wholeErica Peterson | wfpl.org

The advisory remains in effect for a large portion of the Ohio River in Kentucky; it reaches from the West Virginia border to the Cannelton Locks and Dam near Hancock County. In that stretch, only the area from Cardinal Harbor in Oldham County to the McAlpine Locks and Dam in Louisville is exempted.

Lanny Brannock, a spokesman for the state Department for Environmental Protection, said Kentucky has been focused on testing the river near Louisville over the past week because of the Ironman race, but testing has occurred in other places. The Ohio River Sanitation Commission has been spearheading a lot of the testing on the river, and that data shows the microcystin levels are dropping in many places.

Erica Peterson is WFPL's Director of News and Programming.