Acting Manatee County Administrator Scott Hopes said the situation at the former Piney Point phosphate plant is “very much under control now.”
Water from the breach has been routed to an unused retention pond on site that has a liner in it, according to Hopes.
And around 34 million gallons a day are being moved as part of the controlled release through pumps, vacuum trucks and other methods, officials said.
Hopes said they have successfully released approximately 180 million gallons of water.
A leak in a containment wall was discovered about a week ago, and residents in the area were evacuated Thursday, officials said.
At least 137 people and 36 pets were impacted by the evacuation orders, but as of Tuesday afternoon they could return safely, Manatee County Public Safety Director Jacob Saur said at a news conference.
There is “diminished risk” to outlying areas, which is allowing the evacuation orders to be lifted, he said.
There are still some road closures in place in the area, Saur said, but US Highway 41 was opened Tuesday.
Officials have said they are sending wastewater into Port Manatee and Tampa Bay, where it will ultimately flow into the Gulf of Mexico and be pushed southward by the Gulf Stream.
Florida Agriculture Commissioner Nikki Fried said Tuesday the state had “averted a huge, catastrophic event.”
Had workers not slowed down the leak, the water would have devastated homes and taken a natural gas plant offline.
The Florida Department of Environmental Protection and the US Environmental Protection Agency are testing the water in the pond and the release, she said. The water quality is still safe, she said, but they will continue to monitor it until the breach is fixed.
State Sen. Janet Cruz also pointed out that if contaminated water were to reach the water table, the implications could be dramatic.
“We’re going to monitor the land that’s right next to (Piney Point) to make sure that … the water that’s going into the fruits and vegetables are safe for human consumption,” Cruz said.
Officials said controlling the release of water from the pond allows it to mix safely with the water in the bay.
Water in the storage ponds at the Piney Point reservoir site is acidic but not radioactive, according to Noah Valenstein, secretary of the state’s Department of Environmental Protection.
A remotely operated underwater vehicle is expected to be at the wastewater reservoir breach Wednesday to patch the underwater leak and try to control the flow of water.
The Piney Point facility is about 40 miles south of Tampa’s city center, but the population density area is “extremely low,” Hopes said.
The Piney Point site started as a phosphate rock processing business run by a few companies since the 1960s before eventually being owned by the Mulberry Corporation under the name Piney Point Phosphates, according to 2004 congressional testimony.
Since Mulberry abandoned the site after declaring bankruptcy in 2001, the Piney Point site has been maintained by the state of Florida, Manatee County and the Environmental Protection Agency, according to a 2003 EPA news release.
The leak is not the first time Piney Point has been in danger of collapse. Record rainfall in late 2002 created 280 million gallons of acidic wastewater at the site, which, according to the 2003 EPA news release, “triggered an extreme emergency situation by weakening the dikes and threatening to exceed the capacity on site.”
CNN’s Nick Valencia reported from Bradenton, and Kay Jones and Konstantin Torpin reported from Atlanta. CNN’s Devon Sayers, Paul Murphy, Steve Almasy, Hollie Silverman and Alta Spells contributed to this report.