Arvada will stop adding fluoride to its water temporarily, due to a leaking tank at the Ralston Water Treatment plant.

“The city has notified dentists in Arvada and encourages residents to consult their dental health provider about ways to maintain dental health,” reads the city’s website.

Arvada used a liquid fluoride system, but the leaking tank is hazardous, and it is not feasible to simply replace it. The Colorado Department of Public Health and Environment (CDPHE) is working with the city to quickly convert to a power-feed system.

The Denver Post reports that fluoridation will resume in mid-2020.

The city’s voters approved the fluoridation program in 1967. Although some communities in Colorado have enough naturally-occurring fluoride in their water supplies to prevent tooth decay, adding small amounts of fluoride is a well-established method of reducing cavities by approximately 25%.

In a 2018 report that found that 15% of Colorado’s third graders had untreated tooth decay, CDPHE recommended community water fluoridation as one potential policy solution. Fewer Coloradans have access to fluoridated water than in the past. While 81.7% of the population lived in communities with fluoridation in 1992, that number dropped to 74% in 2014.

The Centers for Disease Control and Prevention named water fluoridation one of the 10 greatest public health achievements of the 20th century, alongside motor vehicle safety and the recognition of tobacco as a health hazard.