WASHINGTON — The Trump administration will soon propose softening limits on toxic “forever chemicals” in drinking water, beginning the formal process of rolling back portions of the first-ever federal PFAS regulation that was finalized under former President Joe Biden.

Jessica Kramer, head of the Environmental Protection Agency’s Office of Water, told a conference focused on safe drinking water access that the agency planned to rescind and revisit certain PFAS limits she said the Biden administration had issued improperly. The proposal has not yet been released, but officials have previously indicated they will rescind limits on three types of PFAS — including GenX substances detected in North Carolina — as well as a restriction on a mixture of several PFAS varieties, then reconsider them.

“We need drinking water rules that are legally defensible,” Kramer said at the conference. “We need drinking water regulations that are not susceptible to legal challenge because the explicit process in the Safe Drinking Water Act wasn’t followed.”

The Biden administration had faced allegations that it moved too quickly on the less-common PFAS types the agency now wants to revisit. The original limits were part of a sweeping rule that for the first time set enforceable federal standards for PFAS in tap water, finding that exposure increased the risk of cardiovascular disease, certain cancers, and low infant birth weight.

Under the planned changes, the agency would keep the tight 4-parts-per-trillion limits on the two most common and studied PFAS compounds, known as PFOA and PFOS, but would give water utilities two additional years — until 2031 — to meet those standards. EPA Administrator Lee Zeldin described the delay as “common-sense flexibility” when the agency first signaled the move last year. “This will support water systems across the country, including small systems in rural communities, as they work to address these contaminants,” Zeldin said at the time.

The agency said it remains committed to helping utilities reduce PFAS in drinking water and noted that billions of dollars in additional funding have been made available to assist with the expensive treatment processes required to remove the chemicals.

The proposal arrives amid scrutiny from the Make America Healthy Again movement, championed by Health Secretary Robert F. Kennedy Jr., which has urged action on PFAS contamination and other corporate environmental harms. On drinking water more broadly, the Trump administration has said it will defend tough standards to reduce lead in tap water — a stance that contrasts with its efforts to roll back health protections for coal and other polluting energy sources.

Melanie Benesh, vice president of government affairs with the nonprofit Environmental Working Group, said the EPA’s approach on PFAS was “more surgical and measured” than its handling of other environmental rules, “in part because of the resonance of these issues among voters.” But Benesh also argued the move is likely illegal, pointing to a provision in the Safe Drinking Water Act that prevents the agency from issuing regulations weaker than those already in place.

The public will have a chance to comment on the proposal before any change is finalized.