Per- and polyfluoroalkyl substances (PFAS) are a large class of approximately 4,700 synthetic chemicals widely used for their oil and water repellency, temperature resistance, and friction reduction—and have been linked to a variety of serious health effects including kidney and testicular cancer, thyroid disease, decreased fertility, and decreased response to vaccines. These toxins are found virtually everywhere: air, soil, water, food, plants, wildlife, and in the bodies of people. Every day, people can be exposed to mixtures of PFAS chemicals from eating food, breathing air, or coming into contact with dust, carpets, paints, waxes, clothing, upholstery, and personal care products like dental floss. For millions of people, their primary exposure to PFAS is through their drinking water. Despite the known health risks of PFAS, no enforceable national drinking water standards have been set. We cannot wait for the federal government to respond. To address the extraordinary health threat posed to people across the country from widespread PFAS-contaminated drinking water, states must act now.