In a decision that appeared to underscore the federal Environmental Protection Agency’s persistent difficulties with meeting regulatory deadlines, a U.S. District Court Judge found last week that the agency failed to place required restrictions on a pervasive chemical found in drinking water — and one that may have worrying health implications, particularly in young children.

Bretz did admit during court proceedings that the EPA had dropped the ball on perchlorate. The agency, she was quoted as saying, “blew it.”

Judge Edgardo Ramos ruled on a lawsuit filed earlier this year by the Natural Resources Defense Council, the New York-based environmental advocacy group, which was seeking to force the federal agency to set limits on the use of perchlorate. The substance, which can be naturally occurring or manmade, is a common ingredient in explosives and rocket fuel, and the EPA has estimated that it may contaminate the drinking water of up to 16.6 million Americans. The precise impacts of varying exposure levels are still being studied, but the evidence was enough to prompt the agency to designate it a “contaminant of concern,” and to begin developing regulations to address it.

In May, the EPA admitted that it is at least three years behind a legal deadline to produce those regulations.

In an email message, a spokeswoman for the agency, Enesta Jones, said the EPA could not comment on ongoing litigation, and Elizabeth Bretz, a federal attorney representing the agency in the case, said that she was unable to discuss the matter without the permission of the Department of Justice, which did not respond to multiple queries.

But according to the legal news service Law 360, Bretz did admit during court proceedings late last month that the EPA had dropped the ball on perchlorate.

The agency, she was quoted as saying, “blew it.”

This is not the first time that the EPA has missed regulatory deadlines, even within the last year. In December 2015, the Center for Biological Diversity accused the agency of missing deadlines for risk assessment of three common chemicals used in pesticides. According to St. Louis Public Radio, in March of 2016 a Missouri attorney sued the agency over missing several deadlines to manage radioactive contamination at a Missouri landfill. A report released in August by the Competitive Enterprise Institute, a conservative think tank, found that 84 percent of the EPAs Clean Air Act deadlines are overdue, by an average of 4.3 years.

In February 2011, the EPA determined that perchlorate poses a threat to human health and should be regulated in drinking water.

Perchlorate is highly soluble in water, and once in the body the chemical clogs up proteins that normally transport iodide into the thyroid gland to form thyroid hormones, said Angela Leung, an assistant professor of medicine at UCLA. In adults, failure to form these hormones can affect things like weight and cholesterol, but in children and pre-natal babies it can affect brain development — though the extent of the risk is still not fully understood.

“One can argue that [in adults] even mildly decreased thyroid hormone levels may not manifest itself, because one can potentially overcome problems with a little bit of a slower metabolism, or a little high cholesterol,” said Leung. She added that “even slight thyroid hormones that are lower in pregnant women and children, those can have devastating clinical effects.” 

A 2014 study also looked at perchlorate in the urine of 487 mothers in the UK and Italy. It concluded that mothers with the highest concentration of perchlorate in their urine were three times as likely to have children that, by the age of three, had IQ levels in the bottom 10 percent of those studied.

“Perchlorate is a chemical that’s often used by the Department of Defense and NASA, so they have different views about how it should be regulated and that’s holding things up.”

Still, Leung said that there is still a great deal of uncertainty as to how perchlorate affects individuals, and how it might be treated.

Meanwhile, the EPA’s delay in regulating the chemical may be due in part to disagreements both inside and outside the agency. According to a transcript of a pre-trial conference, when asked whether the blame for the delay should rest on an in-house disagreement among EPA scientists, Bretz replied: “Correct and there’s also various other agencies that have weighed in on the issue. Perchlorate is a chemical that’s often used by the Department of Defense and NASA, so they have different views about how it should be regulated and that’s holding things up.”

Erik Olson, the director of the health program at the NRDC and a former EPA lawyer, said that when it comes to perchlorate the EPA had “a lot of pressure from the defense contractors and the defense department, and the White House – under the Bush Administration in particular – to stop the EPA from moving forward.”

Olson said that the NRDC witnessed that pressure after it filed Freedom of Information requests. For example, after the Department of Defense (DOD) was reportedly unhappy with an EPA review of perchlorate’s health risks, both the DOD and the EPA commissioned a National Academy of Sciences (NAS) panel to review the report. Letters indicate that the NAS panel included people with ties to the defense industry and the Department of Defense, including Richard Bull, a former perchlorate researcher and paid expert witness for Lockheed-Martin.

And while Olson said that he thinks the science on the health risks of perchlorate is “solid,” Leung, at UCLA, isn’t so sure. She wants to see more rigorous research done on the effects of perchlorate.

“Without a little bit more causal data, in specifically the vulnerable populations, I am not sure that we can jump to conclusions of being particularly worried [about perchlorate] and alter our lifestyle,” said Leung. “But I think it is an opportunity for us to pursue research in this field, to exactly figure that out.”

Debate remains over exactly how many deadlines the EPA missed. While the agency says that it only failed to meet one deadline, the NRDC maintains the agency dropped the ball twice. But both sides have agreed on the need to finally regulate perchlorate. According to a recent court order, The EPA will submit a regulation timeline by October 21st, and the NRDC will decide whether to accept or challenge it.

In a pretrial conference, Judge Ramos said that EPA officials need to have “somewhat of a fire lit under them.”

But that fire might not be enough. As long as there is pressure inside and outside the EPA to oppose perchlorate regulation, said Olson, there will be opportunities to slow the process down.

“The politics,” he said, “don’t disappear just because there’s a proposed rule on the streets, or just because the agency has agreed that they are going to try to get a proposed rule out.”