Florida eyes plan to use radioactive mining waste in roads

Mosaic Inc. is backing legislation that would allow the use of phosphogypsum in road construction.
A Mosaic phosphogypsum stack stands behind a fence in Bartow on Friday, Feb. 24, 2023.
A Mosaic phosphogypsum stack stands behind a fence in Bartow on Friday, Feb. 24, 2023. [ LAUREN WHIDDON | Fresh Take Florida ]
Published April 17|Updated April 17

MULBERRY — With much less notice than the Florida abortion, guns and education culture wars, a battle between environmentalists and a Fortune 500 mining giant is playing out in Tallahassee that critics fear could have devastating long-term health consequences.

On one side is Mosaic Inc., a Tampa-based mining and fertilizer company that has pumped hundreds of thousands of dollars into the campaign coffers of Republicans across the state, including Gov. Ron DeSantis. Mosaic also spent $20,000 to entertain lawmakers at a gathering last year spearheaded by one of its key allies in the Legislature, Rep. Lawrence McClure, R-Plant City, who reported last year that he owned $6,000 of company stock.

Trying to stop them is a slew of environmental groups, warning of a triple threat — the contamination of Florida’s air, water and soil that could increase the risk of cancer if a measure gaining steam in the Legislature wins approval.

What’s the fight all about? Phosphogypsum.

Mosaic is backing bills that would allow the use of the mildly radioactive fertilizer waste, which emits radon gas, in road construction. While it’s used for that purpose in Canada and across Europe, it has been banned in the U.S. for such uses by the Environmental Protection Agency.

Environmentalists who are trying to put the brakes on the legislation say it would contaminate aquifers, pollute the soil and emit radon gas into the air, harming not only road construction crews but also drivers and others.

For now, about 1 billion tons of phosphogypsum is stored in 24 “gyp stacks” — some 50 stories tall — that dot skylines across the state, according to the Florida Industrial and Phosphate Research Institute. Thirty million tons of the waste are produced each year.

The largest is the New Wales gyp stack in Mulberry, which stretches across about 704 acres. It’s owned by Mosaic.

The state continues to stack gypsum unnecessarily because it’s not operating with the most current information, said a spokesperson for Mosaic, Jackie Barron.

In 2016, a massive sinkhole opened up at the New Wales stack, and more than 200 million gallons of contaminated water leached into the aquifer. In 2021, 215 million gallons of wastewater were released into Tampa Bay to stop a leak at the Piney Point phosphogypsum stack.

Incidents like these have sparked concerns among environmental groups and residents who live near these water reservoirs.

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Meanwhile, Florida’s Legislature is moving to approve measures exploring the reuse of the byproduct.

Bills in the House and Senate that would authorize the Florida Department of Transportation to undertake demonstration projects and studies evaluating the use of phosphogypsum in road construction are headed for floor votes, facing virtually no opposition among lawmakers.

The House Infrastructure Strategies Committee approved the bill Monday afternoon with an amendment extending the deadline for the suitability studies from January to April 1, 2024. Reps. Anna Eskamani, D-Orlando; Michael Gottlieb, D-Davie; Johanna Lopez, D-Orlando; Christine Hunschofsky, D-Parkland; and Hillary Cassel, D-Dania Beach, voted against the bill.

The transportation department said it is in the process of reviewing the legislation to determine potential impacts it may have.

McClure, the House bill’s sponsor, told his colleagues the measure would unlock the potential of beneficially reusing phosphogypsum.

“The U.S., including Florida, is behind the rest of the world,” he said at a House Transportation and Modals Subcommittee hearing. His district encompasses part of Hillsborough County, where part of Mosaic’s Four Corners Mine is located.

Around the world, McClure said, phosphogypsum is safely used in roads and concrete.

Countries throughout South America, Asia, Europe and Africa permit the reuse of phosphogypsum, according to The Fertilizer Institute, an industry advocacy group whose members include Mosaic.

In October 2020, under the Trump administration, the EPA gave the green light to using the waste in road construction. But the agency withdrew its approval in 2021 following a lawsuit from environmental groups, including the Center for Biological Diversity.

McClure and Sen. Jay Trumbull, R-Panama City, the sponsor of a companion bill in the Senate, did not return multiple phone calls and emails to discuss their bills.

Mosaic spent about $20,000 last year on food, drinks, lodging and entertainment for Conservative Florida, a political committee where McClure is the chairperson, according to state campaign finance figures. The $6,000 in Mosaic stock that McClure reported owning in June is a small portion of the $211,000 in his securities portfolio.

Mosaic and its subsidiaries donated about $742,000 in the last election cycle mostly to Republican groups, including $100,000 to help elect Republicans in the state House and Senate, $75,000 to the state Republican Party and $75,000 to DeSantis’ reelection campaign.

Jane Blais, an environmental advocate and representative from Right to Clean Water, pleaded with lawmakers to request more information on the potential impact of the legislation, noting that phosphogypsum is high in radium 226, a natural radioactive substance with a half-life of 1,600 years.

“That means 1,600 years from now, there’s still going to be radium in everything you put down on the ground,” she said.

The radium decays slowly and forms radon, a gas, which is the leading cause of lung cancer among nonsmokers and is responsible for about 21,000 deaths a year in the U.S., according to the U.S. Centers for Disease Control and Prevention.

Ragan Whitlock, a staff attorney for the Center for Biological Diversity, pointed to the EPA’s prohibition of using phosphogypsum as a construction material and studies on the safety of road workers and members of the public who would come in contact with the roadways.

In 2021, the EPA said The Fertilizer Institute had not provided enough information on the safety of the material and that the agency would approve a request for phosphogypsum use only if “the proposed use is at least as protective of human health as placement in a stack.”

Whitlock expressed concern about degradation of roadways and the possible contamination of groundwater resources.

A group at the University of Florida, working under Tim Townsend, an environmental engineering professor, is currently conducting Mosaic-funded studies on the potential beneficial reuses of phosphogypsum.

The studies explore the idea of a circular economy — or taking materials regarded as waste products and developing them into something beneficial like road-building.

This legislation would take these studies to the next step, said Barron, the Mosaic spokesperson. If the bill passes, Florida would have the material ready for road construction quickly if approved by the EPA.

“This is not a new area of research,” Barron said. “It’s just another material under consideration.”

This story was produced by Fresh Take Florida, a news service of the University of Florida College of Journalism and Communications. The reporter can be reached at

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