Attorney General Bonta Submits Comment Letter Supporting First-Ever Proposed EPA Regulation of PFAS in Drinking Water

Wednesday, May 31, 2023
Contact: (916) 210-6000,

OAKLAND – California Attorney General Rob Bonta joined a multistate comment letter supporting the U.S. Environmental Protection Agency’s (EPA) historic effort to better protect Americans’ drinking water supply. Published on March 29, 2023, the EPA has proposed a new rule to set — for the first time ever — drinking water standards for certain per- and polyfluoroalkyl substances, commonly referred to as “PFAS” or toxic “forever chemicals.” These chemicals pose serious risks to public health and the environment. Nearly 100% of Californians tested have PFAS present in their blood and contaminated drinking water is a key route of this mass exposure. The EPA’s proposed rule would require drinking water that exceeds its PFAS limits to be treated. There is currently no federal regulation of PFAS chemicals in drinking water. 

“The EPA deserves to be commended for doing something that hasn’t been done before: aggressively tackling PFAS contamination in our drinking water,” said Attorney General Bonta. “Known to contribute to various types of cancers, liver diseases, diabetes, and other ailments, PFAS are a serious problem that require serious solutions. The EPA’s rule is backed by science, well within the agency’s legal authority, and would reduce risks to human health. I enthusiastically support it.”

The EPA’s proposed rule would apply to Public Water Systems (PWS). Under the federal Safe Drinking Water Act (SDWA), a PWS is defined as a system that has at least 15 service connections and/or that regularly serves at least 25 individuals on at least 60 days out of the year. Six PFAS chemicals, which are commonly found in drinking water in California and around the country, would be addressed by the EPA’s proposed rule: perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS), hexafluoropropylene oxide dimer acid (HFPO-DA) and its ammonium salt (known collectively as GenX), perfluorononanoic acid (PFNA), and perfluorobutane sulfonic acid (PFBS).

Specifically, the EPA’s proposed rule would:  

  • Set a contaminant limit of four parts per trillion for PFOA and PFOS;
  • Set a Hazard Index of 1.0 as the contaminant limit in drinking water for the four remaining PFAS chemicals — PFHxS, GenX, PFNA, and PFBS — and any mixture containing one or more of them. A Hazard Index greater than 1.0 indicates that the combined exposures may pose a potential risk to human health, while an index less than 1.0 suggests that the risks are likely to be low. A Hazard Index approach is widely accepted by regulators and the scientific community when exposure to a mixture of PFAS chemicals in drinking water occurs simultaneously. The EPA intends to provide water systems with a web-based form that will automatically calculate the Hazard Index for them; and
  • Require a PWS that exceeds the above limits to take action to treat and/or address the problematic water source.

PFAS are widely used in consumer products including food packaging, cookware, clothing, carpets, shoes, fabrics, polishes, waxes, paints, and cleaning products, as well as in firefighting foams designed to quickly smother liquid fuel fires. These so-called "forever chemicals" are stable in the environment, resistant to degradation, persistent in soil, and known to leach into groundwater.

The California Attorney General’s office is committed to addressing PFAS contamination. In November 2022, the office filed a lawsuit against PFAS manufacturers — including 3M and DuPont — for endangering public health, causing irreparable harm to the state's natural resources, and engaging in a widespread campaign to deceive the public; in November 2021, the office joined a multistate letter to the United States Senate supporting pending PFAS legislation; in June 2020, the office joined a multistate letter urging the EPA to regulate PFAS under the Safe Drinking Water Act; and in April 2020, the office joined a multistate letter to the EPA advocating rigorous PFAS standards for imported products under the Toxic Substances Control Act.

In filing the comment letter, Attorney General Bonta joins the attorneys general of Arizona, Colorado, Connecticut, Delaware, Illinois, Maine, Maryland, Massachusetts, Michigan, New Jersey, New York, North Carolina, Oregon, Pennsylvania, Wisconsin, and the District of Columbia. 

A copy of the comment letter can be found here.

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