Last week, residents of Birmingham, Alabama, were informed that their drinking water would no longer contain fluoride. Then came a twist: It turned out that their water utility had, without telling the public, actually stopped adding it years ago.

John Matson, a spokesperson for Central Alabama Water, which serves Birmingham and its surrounding suburbs, confirmed to NBC News that two of the utility’s four water filtration plants had temporarily stopped fluoridating in 2023, and a third had stopped in March 2024. The changes were made under prior leadership, he said, when the utility had a different name.

Matson said Central Alabama Water has found “no record” of the public being notified.

WBRC 6 News was first to report that fluoridation in Birmingham had been quietly halted as early as 2023.

The revelation came just days after the utility announced that as a new policy, it would not add fluoride to Birmingham’s drinking water moving forward. The decision was made based on “a comprehensive evaluation of safety, infrastructure and financial considerations,” Central Alabama Water said in a press release. It cited the high cost of maintaining and repairing its aging fluoridation systems, which it said would require more than $3.7 million.

Matson said the state’s departments of health and environmental management were immediately informed when fluoride first stopped being added to the water. The health department did not respond to a request for comment and the department of environmental management was not immediately available for comment.

The American Academy of Pediatrics and American Dental Association recommend adding fluoride to drinking water because it helps prevent cavities. Around 72% of people served by community water systems in the U.S. receive fluoridated water, according to the latest available data from the Centers for Disease Control and Prevention.

But a growing number of public water systems have begun to consider removing fluoride from drinking water.

Top health officials in the Trump administration have warned, without substantive evidence, that fluoride can have harmful effects. Robert F. Kennedy Jr. said in 2024, before becoming the country’s health secretary, that fluoridation was associated with bone cancer, thyroid disease, IQ loss and neurodevelopmental disorders. Scientists, however, say there’s not enough data to demonstrate a link. According to the CDC, which Kennedy now oversees, the only documented health risks of fluoridation are cosmetic issues such as discolored tooth enamel.

A year ago, Utah became the first U.S. state to ban fluoride in public water systems. Florida followed suit. At least 21 states introduced bills in last year’s legislative sessions to ban fluoride from being added to community water systems, according to the bipartisan National Conference of State Legislatures.

Central Alabama Water said last week that removing fluoride from drinking water “allows customers and their health care providers to make more individualized decisions about fluoride use.” The utility added that “many customers now receive significant fluoride from toothpaste and other topical products like mouthwash.”

Matson said the removal of fluoride in 2023 and 2024 occurred when the Birmingham Water Works Board was the area’s water utility. It became Central Alabama Water last year and is “committed to being transparent with its customers,” he said.

However, in a Wednesday court filing in Jefferson County, Alabama, a former attorney for the Birmingham Water Works Board alleged that “the individuals most responsible for allowing the fluoride systems to fall into disrepair are now running CAW.”

Birmingham Mayor Randall Woodfin wrote in a Facebook post on Tuesday that some of the top leaders at Central Alabama Water worked for the previous board.

“Y’all can get the same energy I gave the prior board when you are not transparent and honest with the customers,” Woodfin said. “You are not just a public entity. This is our water we are talking about. Stop playing with us.”

Many public health experts say there is no adequate replacement for fluoride in drinking water.

“It certainly is true that fluoride-containing toothpaste is effective at preventing decay, but it’s not true that that alone justifies removing fluoride from our drinking water,” said Dr. Scott Tomar, head of the department of population oral health at the University of Illinois Chicago.

Tomar said stripping fluoride from the water in Birmingham has unnecessarily put residents at greater risk for cavities.

“It has probably put youngest children at the greatest risk, because that’s usually where we see it show up first when fluoridation stops,” he said.