Enlarge (credit: Layland Masuda) Today, the Environmental Protection Agency announced that it has finalized rules for handling water supplies that are contaminated by a large family of chemicals collectively termed PFAS (perfluoroalkyl and polyfluoroalkyl substances). Commonly called "forever chemicals," these contaminants have been linked to a huge range of health issues, including cancers, heart disease, immune dysfunction, and developmental disorders. The final rules keep one striking aspect of the initial proposal intact: a goal of completely eliminating exposure to two members of the PFAS family.