NRDC v. U.S. EPA (Perchlorate)

Perchlorate is a highly toxic component of rocket fuel, munitions, and fireworks that threatens the drinking water of millions of people across the United States. Perchlorate contamination, which has already been found in drinking water and other media that could lead to tap water contamination in at least 45 states, often flows from U.S. Department of Defense (DOD) or DOD contractor facilities and activities. The chemical compound is especially dangerous to the developing brains and thyroids of fetuses, infants, and young children—and it’s often communities of color and low-income communities that are hardest hit.

The American Academy of Pediatrics, multiple independent scientists, and many states have been urging the U.S. Environmental Protection Agency (EPA) to take action. Although the EPA’s own scientists formally determined the need to regulate perchlorate in tap water in 2011, the agency has continued to resist issuing a standard. 

So in 2016, after the EPA blew past the statutory deadline for action, NRDC sued the EPA in the Southern District of New York (SDNY), kicking off a legal back-and-forth that has spanned a decade. Under the Obama administration, the EPA signed a consent decree and agreed to issue the standard by 2019 (which NRDC later agreed to extend into 2020). But under the first Trump administration, the EPA took public health protections two steps back, purportedly reversing the agency’s earlier finding that a perchlorate standard is necessary. 

NRDC immediately went to court, challenging the EPA’s action in the U.S. Court of Appeals for the D.C. Circuit. After hearing strong arguments against the EPA’s decision, in June 2023, the three-judge panel overturned the Trump EPA’s reversal. Two judges held that the EPA lacked the authority to reverse itself once it had decided that the perchlorate standard was needed, while the third judge said that the agency’s rationale for the reversal didn’t hold water scientifically or legally. (In September 2023, the full D.C. Circuit also rejected the request of water industry intervenors, the American Water Works Association, to rehear the case before a full panel of 11 judges.) 

NRDC promptly restarted the SDNY case that was put on ice during the challenge in the D.C. Circuit. And in January 2024, EPA signed a revised consent decree, agreeing to finalize these limits by August 2027. In January 2026, the EPA proposed to set the new federal standard at 20 parts per billion, even though several states have set far more protective standards for perchlorate in drinking water. Our lawyers and experts are advocating for stronger standards to be included in the final rule, and will continue to monitor the deadlines in this case until the job is done. The protection of our children from toxic perchlorate depends on it.