About 100 million people will be exposed to fewer cancer-causing “forever chemicals” under the country’s first-ever drinking water standards for PFAS finalized Wednesday by the EPA, White House officials said.

The Environmental Protection Agency finalized an enforceable 4 parts per trillion (ppt) limit on perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) in drinking water. The agency set a non-enforceable maximum contaminant level goal for PFOA and PFOS at zero, reflecting research showing that no level of exposure is risk-free from cancer and other diseases.

The rule also sets a limit of 10 ppt on three other categories of per- and polyfluoroalkyl substances (PFAS) in drinking water, including perfluorononanoic acid (PFNA), perfluorohexane sulfonate (PFHxS), and “GenX” chemicals. GenX chemicals are made by the Chemours Co., which owns the trade name, to produce fluoropolymers used in semiconductor chips.

The rule also set a limit on mixtures of each of those substances, in addition to perfluorobutanesulfonic acid (PFBS).

The substances, known as “forever chemicals” because they remain in the environment indefinitely, are considered carcinogenic and include coatings such as Teflon used in cookware.

Up to 6,700 water systems serving about 100 million people, or between 6 percent and 10 percent of all the drinking water systems in the U.S., will be affected by the new standards, senior White House officials said Tuesday in a call with reporters.

PFAS can be found in about 45 percent of U.S. drinking water sources, including public water systems and private water wells, U.S. Geological Survey scientists estimated in 2023. PFOA and PFOS pose the highest human exposure risk in drinking water, the study found.

Water systems nationwide will have to test for PFAS under the new standards, and then they’ll have five years to purchase, install, and operate PFAS-removal technology if contaminants are detected.

About $1 billion in infrastructure funding will be available to help water systems test for PFAS and remove it. An additional $12 billion is available for general drinking water system improvements, including addressing emerging contaminants such as PFAS, the officials said.

“The first national drinking water standards for PFAS marks a significant step towards delivering on the Biden-Harris Administration’s commitment to advancing environmental justice, protecting communities, and securing clean water for people across the country,” Brenda Mallory, chair of the White House Council on Environmental Quality, said in a statement.

The World Health Organization in 2022 issued less stringent guidelines for the substances. The WHO’s draft guidance recommends a limit of 100 parts per trillion (ppt) of either PFOA or PFOS in drinking water. It also recommends a total cap of 500 ppt for combinations of up to 30 PFAS.

Costly Compliance Expected

Water utilities will be required to monitor the PFAS, reduce levels exceeding the proposed limits, and notify their customers if the PFAS levels are above the EPA’s limits. The limits, the lowest level many laboratories can reliably detect, are tighter than any state has proposed.

Technologies such as granular activated carbon, reverse osmosis, and ion exchange systems can be used to remove PFAS from drinking water, according to the EPA.

The American Water Works Association said in 2023 that it would be costly for water systems to comply with the limits, citing research suggesting compliance would cost utilities $3.8 billion annually.

The EPA estimated that it could cost between $772 million to $1.2 billion for utilities to comply with the rule, with benefits ranging from $908 million to $1.2 billion.

“The vast majority of these treatment costs will be borne by communities and ratepayers, who are also facing increased costs to address other needs, such as replacing lead service lines, upgrading cybersecurity, replacing aging infrastructure and assuring sustainable water supplies,” AWWA said in a statement about the draft of the rule last year.