Perfluoroalkyls (PFAS) are a group of chemical agents that do not degrade and can accumulate over time, with detrimental effects on human health. The EPA says the rule will reduce PFAS exposure for approximately 100 million people, prevent thousands of deaths, and reduce tens of thousands of serious illnesses.
Two types of those substances, PFOA and PFOS, will be limited to 4 parts per billion, the lowest level that tests can reliably detect. All public water supply systems have three years to complete their initial monitoring of these chemicals, and must inform the public of the level of perfluoroalksyls measured in their drinking water. Utilities say the EPA underestimates the cost of the rule and overestimates its benefits. They argue that water rates will rise and struggling utilities will have a harder time. It will cost about $1.5 billion a year, but doing so will prevent nearly 10,000 deaths for decades and significantly reduce serious illnesses, the EPA says.