The Trump administration is preparing to propose changes to federal PFAS (“forever chemicals”) drinking-water limits first set under President Joe Biden, an EPA official said, signaling a rollback that would keep some of the tightest protections while loosening others.

EPA Office of Water head Jessica Kramer said the agency intends to rescind and revisit certain limits she described as improperly issued by the Biden administration, starting what she said will be a new process that follows the requirements of the Safe Drinking Water Act. She spoke Thursday at a conference in Washington, D.C., focused on ensuring access to safe drinking water and wastewater.

Kramer said the proposal would move the agency toward a more legally defensible rules framework. She described a concern that the earlier process was not susceptible to challenge because the explicit statutory process under the Safe Drinking Water Act was not followed, according to her remarks.

The plan would begin the formal process of rolling back parts of what AP described as the first-ever PFAS limits in drinking water finalized during the Biden administration. Those earlier EPA officials said the rule increased risks tied to cardiovascular disease, certain cancers, and low birth weight, AP reported in the agency summary accompanying the conference remarks.

While details of the proposal were not yet released, officials previously said the EPA would propose rescinding limits on three PFAS types, including “GenX” substances found in North Carolina, and then reconsider them. The EPA would also “do the same” with a limit on a mixture of several PFAS, according to AP’s description of prior official statements.

Kramer said EPA’s intent includes rescinding and revisiting those Biden-era limits, which she said were improperly issued, and restarting the process so the agency can “follow the law.” The move also responds to allegations that the Biden administration moved too quickly on limits for some of the less common PFAS forms that the Trump administration is now targeting for rescission.

In contrast to the proposed rescissions for some PFAS types, the Biden administration’s rule set tight standards for two widely present PFAS chemicals—PFOA and PFOS—at 4 parts per trillion. AP reported that EPA said it plans to keep those standards but give utilities two additional years, until 2031, to comply, with Administrator Lee Zeldin previously describing the extended deadline as “common-sense flexibility.”

At the same time, EPA said it remains committed to helping utilities reduce PFAS in drinking water. AP reported the agency provides technical assistance and that billions of dollars in additional funding have been available to help utilities install and navigate the treatment systems often needed to remove the chemicals.

Outside the agency, critics questioned both the policy direction and the legal footing. Melanie Benesh of the nonprofit Environmental Working Group said the EPA action is likely illegal, arguing that under the Safe Drinking Water Act, EPA cannot issue regulations weaker than those already in place. Benesh also said the rollback reflects how regulatory decisions can be influenced by voter resonance, contrasting it with other moves the Trump administration has made that she said cut health protections for coal and other polluting energy sources.

The EPA said the public would have a chance to comment before the change is finalized, according to AP.