New EPA limits on 'forever chemicals' in drinking water could cost $1.5 billion to implement

• The EPA issued a new rule requiring water treatment facilities to remove some specific carcinogenic chemicals, commonly referred to as PFAS or "forever chemicals."
• Compliance with the rule will cost approximately $1.5 billion annually, according to the EPA, but other research suggests compliance could cost closer to $3.8 billion annually.

The Environmental Protection Agency, EPA, released long-awaited regulations Wednesday on some toxic "forever chemicals" found in drinking water.

Known as PFAS, the chemicals are per- and polyfluorinated alkyl substances. They are made by attaching two carbon molecules to fluorine, Tom Neltner explained to CNBC in 2023, when he was working as Environmental Defense Fund's Senior Director, Safer Chemicals. The bonds are incredibly strong and take a very long time to break down, earning them the nickname "forever chemicals."

The chemicals are helpful for many modern-day applications from weather-proofing clothing to creating non-stick pans. Over time, they can leach into the environment and end up in the water supply.

At least 45% of tap water in the US is known to have PFAS in it, according to the U.S. Geological Survey.

PFAS exposure over long periods may be carcinogenic and can result in serious illnesses that decrease a person's quality of life and even result in death, according to the EPA. Exposure during pregnancy and early childhood can also have adverse health impacts.

The EPA's new final rule sets limits on 5 individual PFAS: PFOA, PFOS, PFNA, PFHxS, and HFPO-DA (also known as GenX Chemicals.) The EPA also set a Hazard Index level for PFAS when two or more of four are mixed: PFNA, PFHxS, HFPO-DA, and PFBS.

The maximum contaminant level for PFOA and PFOS chemicals in drinking