In thousands of communities across the United States, drinking water is contaminated with chemicals known as perfluoroalkyl and polyfluoroalkyl substances (PFAS). PFAS are used in a wide range of products, such as non-stick cookware, water and stain repellent fabrics, and fire-fighting foam, because they have properties that repel oil and water, reduce friction, and resist temperature changes. PFAS can leak into the environment where they are made,...