E.P.A. Decides Against Limiting Perchlorate in Drinking Water

The Biden administration said on Thursday that it would not impose limits on the amount of perchlorate in the water.

The Environmental Protection Agency's announcement shocked public health advocates who had denounced the Trump administration for opting not to regulate perchlorate. The chemical is used in rocket fuel. Exposure can cause a decrease in I.Q. in newborns.

The Trump administration found that perchlorate did not meet the criteria for regulation because it did not appear in drinking water at levels of public health concern.

After President Biden took office, the agency launched a review of the decision and endorsed it, saying it was supported by the best available peer-reviewed science.

Setting up new monitoring tools and doing more to clean up contaminated sites are some of the actions the E.P.A. will take.

In a statement, the agency said it will continue to consider new information on the health effects and occurrence of perchlorate. California and Massachusetts have set their own limits for perchlorate.

The measures aren't enough according to the senior strategic director for health at the Natural Resources Defense Council.

He said that it was unscientific to not regulate the contaminant that was in millions of people's drinking water.

High concentrations of perchlorate have been found in at least 26 states and are often found near military installations where it has been used as an add-on to rocket fuel. Perchlorate can stunt the production of hormones essential to the development of fetus, infants and children, if it is interfered with by the thyroid gland.

Bill Romanelli is a spokesman for the Perchlorate Information Bureau, a coalition funded by Aerojet Rocketdyne and American Pacific Corporation.

The decision by E.P.A. that perchlorate does not merit additional federal regulation is based on the best available scientific information and assures access to clean water.

He said that perchlorate is one of the most studied environmental chemicals.

The fight over perchlorate began in the early 2000s when the administration of President George W. Bush decided not to regulate it.

The decision was reversed by the Obama administration, who found that perchlorate in drinking water posed a serious health risk for as many as 16 million people. The highest concentration of perchlorate in water that the most sensitive populations, like pregnant women, should ingest is 15 micrograms per liter.

The fight dragged on because the Defense Department and military contractors tried to block the controls.

The health finding was overturned by the Trump administration in 2020 because it was not in the public interest.

Environmental groups suspended their lawsuit after President Biden took office.

The American Academy of Pediatrics told the agency that perchlorate can cause a significant drop in the IQ of newborns.

The litigation against the E.P.A. will resume with the goal of forcing the agency to impose standards for perchlorate.