An estimated 173 million gallons of wastewater from the old Piney Point phosphate plant property have been discharged to Tampa Bay as of Wednesday afternoon, according to the Florida Department of Environmental Protection.
The releases through Port Manatee have continued for more than a week after the site’s owner, HRK Holdings, reported a leak in a reservoir holding about 480 million gallons of polluted water. That total was down to 258 million gallons Wednesday, the state said.
Workers are holding some water in other storage on site, which keeps it out of Tampa Bay, Manatee County officials have said. Some of it is also being trucked to other locations.
The state is working with two companies to try to strip or reduce nutrients from the discharges before the water reaches the bay, according to the Department of Environmental Protection. More than 38 million gallons are being drained from the pond each day, regulators said.
The leak set off a crisis in Manatee as authorities worried it would cause berms around the pond to burst under pressure, triggering a catastrophic flood. Officials ended evacuation orders late Tuesday for more than 300 homes around Piney Point, explaining that engineers said the risk had dropped for an immediate disaster. State troopers reopened nearby U.S. 41.
As the polluted releases continue, there remain serious environmental concerns for Tampa Bay. The wastewater, officials have said, is high in nutrients, including nitrogen that scientists say could fuel algal blooms that trigger fish kills.
State and local specialists are monitoring water quality around Port Manatee. The Department of Environmental Protection reported Wednesday that samples around the discharge point in the port have shown elevated levels of phosphorus, another nutrient found in the wastewater.
Phosphogypsum stacks, consisting of a radioactive leftover from producing fertilizer, surround the reservoir, but state officials have said the water itself is not radioactive. It is slightly acidic, environmental regulators say, and is made up of seawater from an old dredging project, rainwater and a polluted byproduct of the fertilizer industry.
Scientists from the University of South Florida set off on a research boat Wednesday to begin studying how the wastewater will affect the bay.