In excess of 300 homes in the zone have been requested to be cleared, and a motorway close to the Piney Point supply has been shut off.
Inhabitants were sent a text-based notification advising them to venture out from home right away.
Authorities said the 77-section of land (31-hectare) supply holds a huge number of gallons of water containing phosphorous and nitrogen from an old phosphate plant.
The lake where the break was found is in a pile of phosphogypsum, a radioactive byproduct from the assembling of compost.
The water contains limited quantities of normally happening radium and uranium, and the stacks can likewise deliver radon gas.
Endeavors to fix the release late on Friday, by stopping the opening with rocks and different materials, were ineffective.
Florida Governor Ron DeSantis announced the highly sensitive situation on Saturday.
Manatee County Administrator Scott Hopes told a question and answer session that there were concerns the water could flood the zone, which is generally agrarian.