Case Explained: CENTER FOR BIOLOGICAL DIVERSITY v. U.S. ENVIRONMENTAL PROTECTION AGENCY ADMINISTRATOR, U.S. ENVIRONMENTAL PROTECTION AGENCY MOSAIC FERTILIZER, LLC

Court: United States Court of Appeals for the Eleventh Circuit Filed: 2026-08-12 The eleventh-circuit denied the Center for Biological Diversity’s petition for review of the Environmental Protection Agency’s approval of Mosaic Fertilizer, LLC’s application to use phosphogypsum in a road construction pilot project on private land. The court held that the EPA did not violate the Clean Air Act regulations found at 40 C.F.R. § 61.206 (Subpart R) and that its decision was not arbitrary or capricious under the Administrative Procedure Act. The court first established that it had jurisdiction, finding that the Center possessed associational standing because a member living near the facility demonstrated concrete and particularized injuries to his health and property use from radioactive emissions, which were traceable to the EPA’s approval and redressable by vacatur or remand. The court also rejected Mosaic Fertilizer’s argument that the case was moot due to the completion of construction, noting that a favorable decision could still alter the agency’s ongoing monitoring obligations or require reconsideration of the project’s conditions. On the merits, the court ruled that the regulatory text of Subpart R does not categorically prohibit road construction as an “other purpose” use of phosphogypsum; rather, the regulation permits such uses upon EPA approval if they are at least as protective of public health as disposal in a stack or mine. The court further determined that even if the EPA applied an incorrect risk threshold (3 in 10,000 instead of the Center’s preferred 9 in 100,000), any such error was harmless because the calculated risks for all exposure scenarios were orders of magnitude lower than either threshold. Finally, the court found the EPA’s risk assessment methodology well-supported and not arbitrary or capricious, as the Agency reasonably limited its analysis to the specific parameters of the pilot project, excluded the “reclaimer” scenario as implausible given the site’s existing industrial nature, and properly accepted older radium sampling data while conditioning approval on future sampling. Consequently, the petition was denied. Do It For The Case Law is a news reporting service. Nothing in this episode constitutes legal advice.