Significant public concern should attend the news that state regulators are allowing Mosaic Fertilizer in St. James Parish to expand its already-massive mound of slightly radioactive gypsum near marshes, neighborhoods and the Mississippi River.
The huge gypsum pile for now seems well designed and maintained. But this is Louisiana, where hurricanes rage, the water table is high and soils tend to be soft. The dangers of a leach or breach are obvious.
At some point, the dangers of processing the phosphate rock, from which phosphogypsum is a byproduct, will vastly outweigh the benefits. Better an industrial plant shutdown and the loss of hundreds of jobs than a colossal release of contaminated material -- radioactive and dangerously acidic -- that could harm the health of hundreds of thousands while killing plants and wildlife.
The point at which that stark choice presents itself hasn't been reached yet, but public vigilance and regulatory aggressiveness are essential.
Mosaic's plant crushes phosphate rock to make a fertilizer that substantially improves agricultural output nationwide. But for every pound of usable product, it leaves five pounds of waste.
The question of how to handle gypsum waste lends itself to no answers that are either easy or good.
After years of back-and-forth, the Environmental Protection Agency in 2020 approved gypsum's use in road-construction projects, deciding that it "will be at least as protective of human health, in the short-and long-term, as stacking."
The EPA under the Biden administration, however, quickly rescinded the approval, as environmentalists fear that roadway wear-and-tear or natural disasters could lead to radioactive materials escaping into groundwater.
Meanwhile, the pile in St. James Parish kept growing. Even though it had begun shifting in 2018 due to a weak zone in the underlying soils supporting it, the pile right now is about 200 feet high -- already 40 feet taller than Louisiana's Avery Island, the highest natural spot on the Gulf Coast -- and is projected to cover a whopping 1,300 acres with hundreds of millions of cubic yards of waste.
The latest approval would allow a new pile 160 feet high that also would serve as a buttress to stabilize the existing pile. Mosaic eventually wants that existing pile to reach as high as 310 feet.
The company, to its credit, continues to try to find other uses for the product. Although the EPA continues to ban gypsum's widespread use on public roads, it is allowing Mosaic to test it on a "small-scale road pilot project on private land in Florida." Still, that's a long way from an imminent solution.
State officials should not allow the pile to grow indefinitely. Frequent inspections should continue -- and unless redoubled efforts are successful in finding other safe uses, the state should give Mosaic some sort of "stop-piling" deadline, even if it means the facility eventually would need to shutter.