Are ‘forever chemicals’ present in all U.S. water sources? | Fact brief

Per- and polyfluoroalkyl substances, or PFAS, are not present in all U.S. water sources at detectable levels under current testing. But PFAS, also known as “forever chemicals,” are widespread.

PFAS, a group of manufactured chemicals used in products since the 1940s, have been linked to decreased fertility, developmental delays, increased risk of cancer and more.

A U.S. Geological Survey study in 2023 found at least one PFAS compound in roughly 45% of U.S. drinking water samples tested, with urban water sources three times as likely as rural ones to be contaminated. Researchers only tested for 32 of the 12,000-plus known types of PFAS, not all of which can be detected with current tests.

Maine requires public water systems to test for PFAS and follow an interim safety standard covering six compounds. The state has been doing more testing, responding to contaminated sites and updating its rules to match new federal drinking water standards.