Add To Favorites

A 200-foot-tall toxic waste pile caused an emergency in 2019. Should Louisiana let it grow?

The Advocate - 2/27/2024

Feb. 26—More than five years after its massive mound of radioactive mining waste began inexplicably shifting in St. James Parish, Mosaic Fertilizer is asking state regulators to declare complete its emergency efforts to halt the pile and to allow it to build a new wing that would cover more than 330 acres of farm land.

Barred from reusing the waste or dumping it in the Mississippi River, as companies once did, Mosaic has piled up the material for decades on hundreds of acres behind its Uncle Sam plant. The mound grew so high that a few years ago aviation warning lights were required near its roughly 200-foot peak.

Known as phosphogypsum, the chalky, whitish material laced with slightly radioactive elements and heavy metals is inextricably linked to Mosaic's production of phosphate fertilizer through the Uncle Sam plant and its sister Faustina facility along the river.

Mosaic officials have told regulators the planned expansion would actually improve the pile's safety after the 2019 stability scare.

Eventually rising 150 feet high over several years, the new wing would allow production at the long-standing operation to continue while Mosaic reevaluates how much it can continue to stack waste gypsum on the older part of the pile.

"We've had operations in St. James Parish for 55 years. Today, on both sides of the river, we employ a total of 300 people plus another 200 contractors," said Jackie Barron, Mosaic spokeswoman. "Many of those family members have called the parish home for generations. The extension allows us to continue to do the important work we started five decades ago, producing a critical source of domestic fertilizer relied on by farmers across the country."

Under state and federal regulators' oversight, Mosaic performed a battery of geologic and other tests after the shifting began to determine the cause, but also the safety of the proposed site of the new wing.

Critics say the new request for expanded dumping, despite the recent stability scare, is emblematic of a flawed practice that has seen catastrophic failures and environmental contamination in other states and it should be halted.

The expansion would also further industrialize the majority Black northern half of St. James that opponents say already struggles with pollution, these critics say.

"Mosaic has long struggled with managing its existing gypsum pile, exacerbating our environmental concerns," said Sharon Lavigne, who leads the Rise St. James environmental group. "Increased fertilizer production can only lead to the creation of more gypsum stacks, further threatening our public health."

Plenty of gypsum

Gypsum is left over from turning mined phosphate rock into phosphoric acid, which is used in the process to make Mosaic's fertilizer across the river at the Faustina plant, company officials say.

But, for every ton of phosphoric acid made at Uncle Sam, 5.5 tons of waste gypsum are left over, Mosaic says in regulatory papers.

Visible from the Sunshine Bridge, the waste gypsum is pumped as a slurry from the Uncle Sam plant up into large lakes atop various levels of the huge mound near Convent, gradually raising the height of the pile.

Probably in late 2018, the waste pile began shifting, coming to regulators' attention in January 2019 and prompting emergency measures to slow the mound's northward movement toward La. 3214.

Mosaic experts determined that an underlying, natural geological weakness in clay 75 to 100 feet deep was the cause of the shifting, perhaps aided by a small earthquake in May 2018, according to a company conclusion supported by regulators.

The company decided it needed to remove weight and pressure off the deep weak spot, according to a subsequent company analysis.

The company gradually dewatered a 140-acre lake of toxic and highly acidic process water that had been a primary dumping site for the gypsum slurry. Regulators worried it could leak if the shifting wall broke open.

Officials also shifted gypsum slurry deposition to lakes on the south side of the pile, reshaped the northern slope and took other measures to cut weight and pressure on the weak spot underground.

Parts of the shifting northern wall of the pile have bulged out more than nine feet since those early days in 2019 but have not broken open, Mosaic monitoring shows.

The response efforts have cut the daily movement markedly, stopping it completely in many spots and slowing it significantly in others, one-third to 1 1/2 inches per year, according to the latest company reports.

Is 300-feet high still safe?

Mosaic has been in discussions with DEQ and EPA for several years, first to figure out what happened and then under what conditions it could be allowed to begin dumping more gypsum on the section of the pile that was moving.

Before 2019, the company had plans to stack waste another 100 feet high to 300 feet total in the area, regulatory papers say.

Though Mosaic has asked DEQ to end the emergency status and also asked the agency to lift an early agency order over the incident, the company is still telling DEQ it is revaluating how and under what conditions it would reuse the part of the pile that was moving.

The accelerating construction of the new wing represents an interim fallback position in lieu of a full resumption of dumping in those older areas, known as "Stack 4," according to regulatory papers.

The new wing would start in a cane field in front of the current waste pile and along La. 3214 and eventually be stacked against the northern slope of the pile that was moving, according to schematics in regulatory filings.

Mosaic officials say the weight and pressure of the new wing should help halt any more movement in the north slope, while giving the weak spot underground time to squeeze down and stiffen further under the pressure of the existing pile.

The new wing would also buy the company years more capacity to dump phosphogypsum in the interim, Mosaic officials say.

Mosaic has proposed using seismic and other enhanced monitoring efforts to determine how and where to dump gypsum and whether to go back to Stack 4.

In regulatory papers, however, the EPA faulted Mosaic's past monitoring and testing efforts for missing a few early warning signs of the underground weak spot that led to the waste pile's movement.

The company had simultaneously pushed successfully in the 1990s and 2000s for state regulators to allow the height of the pile to be far higher and steeper, EPA noted, than early designs from the 1980s that were cautious of the region's weak clays.

Mosaic says it now has an expanded monitoring network. In negotiations since 2019, EPA and DEQ officials have also added a series of operational safety steps in the company's pending solid waste permit that were borrowed from a 2015 EPA consent decree.

EPA and Louisiana Department of Environmental Quality officials weren't able to immediately respond to requests for comment Friday.

Deemed hazardous?

DEQ is planning a public hearing on Mosaic's expansion request and other permit changes at 6 p.m.March 7 at the St. James Parish Courthouse in Convent.

Meanwhile, a national environmental group has informed the EPA that it plans to sue and force the agency to consider ending the use of the waste piles altogether within the next two months.

In 2021, the Center for Biological Diversity petitioned the EPA to reconsider an exemption known as the Bevill Amendment, citing stability concerns, sinkhole formation and massive toxic process water discharges from phosphogypsum piles in Convent and Florida, but the EPA hasn't acted despite past promises to do so.

The exemption allows phosphogypsum and the acidic process water associated with it to be treated not as hazardous waste and stored in open waste piles.

The group pointed out that the EPA itself predicted before it allowed the exemption in 1991 that the fertilizer industry would expand, "increasing its hazard and contaminant release potential."

Citing a failed 2020 industry petition to EPA seeking to repurpose gypsum for road construction, the environmental group noted the fertilizer industry itself was concerned about the public perception of the stacks that, at the time, held more 1 billion tons of gypsum in Florida alone.

At the time, the industry was generating 46 million tons of phosphogypsum per year, which was "significantly more than the combined total of all regulated hazardous waste produced by all generators in the nation," according to the industry petition.

"The U.S. phosphate industry is becoming increasingly monopolized by serial polluters like Mosaic, which makes billions every year but avoids having to safely dispose of its radioactive waste by insisting it would be too costly," said Ragan Whitlock, a Florida-based attorney with the center. "We'll never stop the phosphate industry's damage until state and federal regulators stop rubber-stamping expansion permits."


(c)2024 The Advocate, Baton Rouge, La.

Visit The Advocate, Baton Rouge, La. at

Distributed by Tribune Content Agency, LLC.