The state's Department of Environmental Protection is monitoring what it calls "seepage" at the former Piney Point phosphate plant.
According to a press release Thursday, three small leaks were found along the south wall of the reservoir late Wednesday night, producing about three gallons a minute.
They say the leaks are contained.
"Currently, there is no indication of any concern with the integrity or stability of the stack system, and there will be no offsite discharges at this time," according to the release.
Contractors are working to determine where the leaks are originating. If they worsen, the water could be pumped back into the reservoir, the release said.
In April, about 215 million gallons of wastewater were discharged from the site into Tampa Bay.
Last month, regulators issued a permit to allow hundreds of millions of gallons of the polluted water to be pumped 3,000 feet below the surface.
