"A federal appeals court on Tuesday faulted EPA for failing to set drinking water limits for a chemical commonly used in explosives and rocket fuel.
Three judges of the U.S. Court of Appeals for the District of Columbia Circuit sided with environmental groups that had challenged EPA’s continuation of a Trump-era decision not to set Safe Drinking Water Act regulations for perchlorate — years after the agency had determined that rules were needed.
“Because the Safe Drinking Water Act requires that the agency ‘shall’ regulate after making a regulatory determination, EPA lacks authority to withdraw that determination and decide that it ‘shall not’ regulate,” wrote Senior Judge David Sentelle, a Reagan appointee, in the court’s majority opinion.
Perchlorate has been the subject of fraught back-and-forth for years. The compound has been a notorious contaminant near military sites and contractor facilities, entering groundwater and at times jeopardizing drinking water. It can interfere with the thyroid gland and hormone production, making it a notable public health risk, particularly for pregnant people and infants."