Liner tear possible at Mosaic’s New Wales ‘gypstack,’ fertilizer company says

There’s another possible tear in the liner beneath a pile of Mosaic’s mildly radioactive phosphate waste at its plant in Mulberry, according to a pollution notice the Tampa-based Fortune 500 company filed to Florida environment regulators.

If confirmed, it would mark at least the third problem since 2016 at the company’s phosphate fertilizer manufacturing facility in Polk County.

Data from Mosaic’s New Wales facility showed a change in water pressure at its active south gypsum stack, a sign there may be a tear in the lining, “which could result in an indeterminate volume of process water released to the environment,” the company alerted the Florida Department of Environmental Protection on Saturday.

When a liner tears, water can mix with the phosphate waste, called phosphogypsum, and seep into groundwater underneath the gypstack. That can cause caverns or sinkholes to open beneath the tear.

Rainfall and “process water” is usually stored in ponds on top of active gypsum stacks. State environment regulators told the Tampa Bay Times there’s no process water above the area of this possible tear.

If a tear is confirmed, it’s located in an area where a recovery well could capture and contain any releases and prevent it from polluting water underground. Even with no process water above the phosphogypsum, pollutants could still be released from below, environmental advocates fear.

Still, an inspection report from Saturday shows the possible tear was deemed by the company as a “critical condition” event, which means a written report of the problem — and the company’s plan to fix it — needs to be submitted to the state within one week.

Mosaic intended to begin drilling to investigate this week, according to the inspection report.

This development could be the latest environmental issue for the company’s gypstack — located at the same facility Mosaic and Gov. Ron DeSantis’ state transportation agency want to use for a controversial test to study roadway construction with phosphogypsum.

In 2016, a sinkhole stretching 152 feet opened beneath the New Wales gypstack and resulted in 215 million gallons of contaminated water draining into the aquifer below.

It also wouldn’t be the first time the protective liner has torn: Mosaic acknowledged a liner tear and a resulting 300-foot “cavity” at the gypstack as recently as March of last year, according to a letter from the Florida Department of Environmental Protection. That confirmation wasn’t made public by the state or the company until months after the initial incident report.

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That liner tear last year was in the eastern section of the gypstack. This potential tear is in the northwestern part, according to state environment regulators.

For concerned environmental advocates, this incident is the latest example of gypstack troubles, stemming from the phosphate industry, that threaten human and environmental health.

“There’s been a history of failure of liners that Mosaic has had management with,” said Glenn Compton, chairperson of the local environmental advocacy group ManaSota-88. “This is just another example of one of the legacies that the phosphate industry is leaving behind, one of pollution that we have to be concerned with every time there’s a stack that has a failure.”

It’s always a concern whenever a protective liner tears in a gypstack, Compton said.

In February, the Florida Department of Environmental Protection told the Times there were no indications of structural integrity issues at the gypstack. When asked if the agency still believes the same this week, a spokesperson responded that conditions at the site “are currently stable.”

A Mosaic spokesperson said the company can’t yet confirm a liner tear and they “continue to investigate” the incident. Though the south gypstack is still active, the possible tear is in a part of the stack that is not taking in any more waste byproduct, spokesperson Jackie Barron wrote in an email to the Times.

After the 2016 sinkhole, Mosaic “committed to heightened transparency for notable events.” But a number of subsequent requests from the Times this week for more details about the potential liner tear — including via phone calls, texts and emails — have gone unanswered by the company.

Mosaic is required to investigate, a process that includes confirming company data, to determine whether a liner tear is the cause of a change in gypstack water pressure. State environmental regulators are at the facility overseeing that investigation, according to Florida Department of Environmental Protection spokesperson Alexandra Kuchta.

State environment regulators are also investigating whether there are any violations, a need for penalties or other enforcement, Kuchta told the Times.

Environmental advocates point to this possible liner tear as a signal that Mosaic’s gypstack has structural issues, and they fear it could lead to more frequent and devastating environmental issues. They say it’s reminiscent of the Piney Point disaster in 2021, when millions of gallons of tainted water were sent into Tampa Bay. That crisis was triggered when a leak in that stack’s liner caused a partial breach.

“This latest liner tear is emblematic of the significant operational and regulatory failures that have threatened our aquifer and water quality for decades,” said Ragan Whitlock, a staff attorney at the Center for Biological Diversity, a nonprofit that has litigated against the phosphate industry in recent years.

“It is incumbent upon Mosaic and the Florida Department of Environmental Protection to provide the public with a full, timely understanding of what is happening at this stack system,” Whitlock said. “We should not accept being kept in the dark any longer.”