New federal guidelines about the amount of fluoride in drinking water supplies are not expected to change how much of the cavity-fighting agent is added to Lawrence’s drinking water.

A spokeswoman for the city’s utilities department said Lawrence’s drinking water already has less fluoride than the new guidelines announced by the Department of Health and Human Services on Monday.

“It looked like this was the direction it was heading for awhile, so we made the adjustment a few years ago,” said Jeanette Klamm, a management analyst with the utilities department.

The new guidelines announced by federal health officials recommend no more than 0.7 milligrams of fluoride be added per liter of drinking water. The previous guidelines recommended a range of 0.7 milligrams to 1.2 milligrams, with the higher amount being recommended particularly for colder weather regions of the United States.

Federal health officials made the new recommendation — the first change in federal fluoride standards in more than 50 years — in part because some kids are getting too much fluoride, which causes white splotches on their teeth.

Klamm said operators at the city’s two water treatment plants have directions to keep the amount of fluoride slightly below the 0.7-milligram guideline.

Lawrence has added fluoride to its drinking water for decades, as it became part of the public health trend that began in Grand Rapids, Mich., in 1945 when leaders there determined fluoride in the drinking water improved dental health.

The practice, though, has garnered opposition over the years. Opponents argue its health effects aren’t completely understood and that adding it amounts to an unwanted medication. Many public health officials, including the American Dental Association, continue to advocate for water fluoridation as an effective way to improve dental health.

A late Lawrence resident played a prominent role in the fight against water fluoridation. Albert Burgstahler, a Kansas University chemistry professor, served as the longtime editor of the scientific journal Fluoride, and he became one of the leading opponents of water fluoridation in the country prior to his death in 2013.

The idea of whether Lawrence should stop adding fluoride to its drinking water has come up at Lawrence City Hall sporadically over the years. It last was discussed in 2013 when then-City Commissioner Hugh Carter questioned whether the city was relying on adequate scientific research to support its use of fluoride. City commissioners directed the city auditor to prepare a report on the status of research on fluoridation. The report cited several studies by federally recognized organizations, and city commissioners never took any further action on the fluoride issue.

Klamm said the utilities department tries to stay out of the political debate that sometimes surrounds fluoridation.

“It was a decision that was made by the City Commission years ago,” Klamm said. “We take our direction from the commission on that.”

— The Associated Press contributed information to this report.