Pierre’s water system could save a hefty chunk of change thanks to the state Department of Environment and Natural Resources’ new rule reducing the amount of fluoride required in the state’s drinking water.

The new rule comes after nearly a year of study and public comment at the state level. It will reduce the amount of fluoride the state’s 77 public drinking water systems need to a range of .5 parts per million to .9 parts per million from a range of .7 parts per million to 1.2 parts per million.

Pierre, like most of the communities along the Missouri River, should have enough naturally occurring fluoride in most of its wells to meet the new requirements. That means the city water department could save between $4,000 and $5,000 per month, said water Superintendent Dane Brewer. That means a savings of between $48,000 and $60,000 per year.

Those savings aren’t guaranteed. Mark Mayer of the DENR said about 25 water systems in the state may naturally meet the new lower fluoride requirements. But before they can stop having to add fluoride to their water, they’ll have to apply for an exemption and prove that they have enough naturally occurring fluoride in their respective systems.

Statewide the savings could be up to $400,000, Mayer said.

Preliminary testing of Pierre’s water supply found that water from 10 of its 12 wells has enough natural fluoride to meet the new recommendations, Brewer said. He did not know if any potential cost savings would impact customers’ bills.

The national discussion on reducing fluoride levels in drinking water actually began in 2011, Mayer said. The idea was lower the amount of fluoride recommended for drinking water and create a national minimum. research had shown that people needed less fluoride in their water because the chemical was found in more products today than when it was first required to be placed in water.

That decision was made in the 1960s as an effort to fight tooth decay and mouth diseases. The national recommendations for fluoride hadn’t been changed since 1962. The new national target for fluoride in drinking water was set at .7 parts per million on April 27, 2015, Mayer said.