The U.S. Air Force is contesting an Environmental Protection Agency (EPA) order to address PFAS contamination in Tucson's drinking water, arguing that the EPA lacks authority following the Supreme Court's recent ruling that overturned the Chevron doctrine. This legal challenge has raised concerns among experts, who assert that the ruling does not apply to the EPA’s enforcement orders and fear it may set a precedent for polluters to evade responsibility. The Air Force has been ordered to develop a $25-million filtration system for PFAS, which are linked to serious health issues, including cancer. The situation underscores the potential implications of the Supreme Court's decision, which limits regulatory power and could hinder environmental protections across the country. Critics note that the Air Force's refusal to comply with the EPA's directives could have dire consequences for public health in Tucson, where contaminated water sources pose an imminent risk. The dispute exemplifies the tensions between federal agencies and highlights the urgent need for effective regulation to safeguard drinking water.