DeSantis Signs Bill That Could See Radioactive Mining Byproduct Used in Roads

Republican presidential candidate Florida Gov. Ron DeSantis delivers remarks in Greensboro, North Carolina, on June 9, 2023. Win McNamee/Getty Images

Gov. Ron DeSantis on Thursday signed a bill that allows the Florida Department of Transportation to conduct a feasibility study to determine if the radioactive byproduct of phosphate mining can be used as a construction aggregate material for roads.

The new law adds phosphogypsum to the list of “recyclable materials” that can be used as road construction aggregate material. Critics say this poses a risk to public health.

Currently, the list includes ground rubber from automobile tires, ash residue from coal combustion and waste incineration facilities, oil combustion byproducts, recycled mixed-plastic material, construction steel made from scrap metals, glass, and glass aggregates.

The new measure allows phosphogypsum not to be classified as solid waste in Florida under specific circumstances or when it is used in accordance with regulations and approvals.

The Florida Department of Transportation has until April 2024 to conduct a study to assess the suitability and viability of incorporating phosphogypsum into road construction.

Phosphate rock mining is the fifth largest mineral extraction industry in the United States, with the majority of mining occurring in Florida, North Carolina, and Tennessee. Phosphate rock, used in fertilizers, contains small amounts of natural radioactivity like uranium and radium, according to the Environment Protection Agency (EPA).

When processed into fertilizer, the phosphorus is separated, leaving behind waste called phosphogypsum. Phosphogypsum is more radioactive than the original rock owing to the concentrated levels of uranium, thorium, and radium present in it.

If found to be suitable, the use of phosphogypsum as a construction aggregate material must comply with the specific regulations and guidelines set forth by the EPA. The bill states that the study “may consider any prior or ongoing studies of phosphogypsum’s road suitability in the fulfillment of this duty.”

Critics Highlight Risks

Critics frame the consideration of previous studies as fast-tracking the assessment process and argue that there is a lot of evidence that phosphogypsum is unsafe.

More broadly, the measure seeks to explore alternative uses for recyclable materials that currently contribute to landfill space issues. In order to assess the feasibility of using certain recyclable materials in road construction, the Department of Transportation is authorized to undertake “demonstration projects.”

Conservation organizations had called on DeSantis to reject the bill in February, expressing concerns that the use of phosphogypsum in road construction could negatively impact water quality and pose an increased risk of cancer for road construction workers.

“This would be an outrageous handout to the phosphate industry at the expense of the health and safety of Floridians and our environment,” Ragan Whitlock, an attorney at the Center for Biological Diversity (CBD), said in a statement in February. “If this bill becomes law, Florida roads would become ticking time bombs, waiting for the next storm event to expose our communities and waterways to this radioactive waste.”

The CBD cited an EPA report that found that the use of phosphogypsum in road construction may cause adverse effects to nearby surface and groundwater resources through the leaching of trace metals and radionuclides.

The EPA requires phosphogypsum to be stored in what is known as “gypstacks” because the radon it emits can cause serious harm to health, including cancer, genetic damage, and birth deformations. Phosphogypsum, including radium-226, has a long radioactive decay half-life of 1,600 years. In 1992, the agency determined that its use in road construction presents an unacceptable risk to public health.

In 2020, during the Trump administration, the EPA reversed its previous policy and granted approval for the use of phosphogypsum in road construction. However, owing to a lawsuit and petition filed by various environmental, public health, and union groups, including the CBD, the EPA rescinded its approval for the utilization of phosphogypsum in roads in 2021.

“Upon further review, EPA has determined that the approval was premature and should be withdrawn because the request did not contain all of the required information,” the EPA announced in 2021. “With this action, phosphogypsum remains prohibited from use in road construction projects.”

Storage of Phosphogypsum, Use in Farming

According to the EPA, for every ton of phosphorus produced, approximately five tons of phosphogypsum is generated.

Florida has the highest number of storage stacks in the United States, and they can be massive, ranging from 2 to 324 hectares (800 acres) in surface area and 3 to 60 meters in height.

These stacks are typically constructed on vacant or previously mined land without extensive preparation, and they are not covered with soil or any other material.

Given the significant amount of phosphogypsum waste produced, the industry is actively promoting research to explore potential uses and minimize the need for disposal, the EPA says. The primary and most common application of phosphogypsum is in agriculture.

Phosphogypsum is sometimes utilized in farming to provide calcium and sulfur to soils that are deficient in these nutrients. When used as a fertilizer, it is typically spread on the soil’s surface. In cases where it is required for pH adjustment or sediment control, it is mixed into the soil.

For agricultural use, phosphogypsum must have a radioactivity level below 0.37 Bq/g (10 pCi/g). Approximately 221,000 metric tons of phosphogypsum are taken from the stacks each year and used in agriculture.