Some environmental groups argue that the EPA can’t legally weaken the regulations. The Safe Water Drinking Act gives the EPA authority to limit water contaminants, and it includes a provision meant to prevent new rules from being looser than previous ones.

The EPA will rescind much of the Biden administration's first nationwide drinking water standard aimed at protecting people from toxic "forever chemicals" known as PFAS found in many household items,

The administration said it wants to rescind and reconsider whether limits are needed for four PFAS that chemical companies are still producing and using in the U.S. — despite known health risks.