Federal Appeals Court Upholds EPA Approval for Florida Test of Fertilizer Byproduct in Road Base

Last updated: August 13, 2026

NewsWK — A federal appellate court has cleared the way for a controlled research project testing an industrial fertilizer byproduct in Florida road construction, rejecting an environmental group’s effort to block the trial. The ruling affirms federal regulatory authority to allow private scientific testing under strict environmental oversight.

A three-judge panel for the U.S. Court of Appeals for the 11th Circuit issued a decision supporting the Environmental Protection Agency‘s approval of a pilot project conducted by Mosaic Fertilizer. The project, undertaken in partnership with the University of Florida, examines the viability of using phosphogypsum—a byproduct generated during phosphate fertilizer manufacturing—as a road bed layer beneath traditional asphalt on private property in Polk County.

Why it matters here

For taxpayers and infrastructure managers across Florida, including local governments in Escambia and Santa Rosa counties, road construction costs and material durability are constant budget considerations. Finding safe, practical, and recycled alternatives for aggregate base materials could offer long-term economic and logistical benefits for state and municipal public works projects.

At the same time, public safety and groundwater protection remain top priorities for residents across Northwest Florida. The 11th Circuit’s ruling establishes that federal regulators may permit targeted, small-scale scientific research on private land without triggering immediate, statewide policy shifts. This decision balances the rights of private industry to conduct regulated research against the necessity of rigorous, evidence-based environmental oversight before any material is considered for broader public infrastructure.

The Road Project and Judicial Decision

Phosphogypsum naturally emits low levels of radon, leading federal regulations to historically require that the material be stored in regulated, open-air containment stacks. However, EPA regulations include provisions allowing individual, case-by-case exemptions for specific applications, provided the agency conducts a site-specific risk assessment.

The test project approved by the EPA consists of four 500-foot experimental road segments laid on Mosaic’s private property in late 2025. Researchers from the University of Florida are monitoring surrounding air, soil, and groundwater over an 18-month evaluation period to collect empirical data on potential environmental exposures and structural integrity.

The Center for Biological Diversity challenged the EPA’s approval in federal court, alleging that the research project created environmental hazards and would serve as an unexamined stepping stone toward sweeping regulatory changes across the state. The appellate court firmly rejected that argument.

Writing for the unanimous panel, Circuit Judge Stanley Marcus noted that the localized research project does not bind future regulatory decisions.

“Because the approval of Mosaic’s Road Project does not directly bear on potential future projects, which will be subject to separate Agency action and independent analysis, we can discern no basis to vacate or remand the Agency’s decision,” Marcus wrote.

Judge Marcus, appointed by President Bill Clinton, was joined in the decision by Circuit Judges Barbara Lagoa, appointed by President Donald Trump, and Robin Rosenbaum, appointed by President Barack Obama.

Regulatory History and Standards for Material Reuse

The regulatory framework governing phosphogypsum dates back several decades. In 1989, the EPA instituted a broad ban on off-stack uses of the material due to radiation concerns. A subsequent 1992 rule reaffirmed those restrictions for general public use, but formally established a path for applicants to seek individual, conditional approvals if thorough safety evaluations were completed.

In 2020, the EPA briefly approved conditional broader road use, but that approval was rescinded in 2021 after procedural requirements were not fully satisfied. Mosaic subsequently applied in 2022 for a narrowly focused research authorization, resulting in the EPA’s December 2024 approval for the current four-stretch test site.

Opponents of the project presented declarations from local property owners who expressed concerns regarding potential air and groundwater contamination, citing historical sinkhole activity in the broader region. However, the court concluded that speculative concerns regarding future off-site developments did not invalidate the EPA’s formal scientific approval for the specific, small-scale test track on private property.

Mosaic has maintained that scientific testing is necessary to determine whether phosphogypsum can safely transition from an industrial byproduct stored in stacks into a usable, recycled construction resource.

“At the end of the day, we welcome robust testing. We want people to know this is a safe and worthwhile resource, not byproduct discarded as waste,” the company stated regarding the project.

With the legal challenge resolved, the 18-month field test will continue as scheduled. Data collected by University of Florida researchers will be submitted for ongoing scientific and regulatory review to determine whether the material meets safety standards required for any future considerations.