State of the Tap: Policy Actions on Fluoride in Drinking Water

Fluoride is a naturally occurring mineral found in air, soil and water at varying levels, depending on location. Studies in the 20th century showed that water with higher levels of naturally occurring fluoride was linked to lower rates of dental decay. These findings led to the widespread adoption of community water fluoridation to improve oral health in America.

In recent years, states have introduced and enacted legislation to mandate water fluoridation or to repeal existing mandates, permitting local municipalities to decide. Initiatives repealing mandated water fluoridation cite experts suggesting potential health concerns from water with fluoride levels twice as high as the recommended levels set by the U.S. Public Health Services. Efforts to mandate community water fluoridation reference studies linking fluoridated water to a reduction in dental decay.

5 Things to Know about Fluoride in Drinking Water

Most Americans drink fluoridated water. As of 2022, about 72% of municipal water systems in the U.S. provide fluoridated water, reaching more than half the population.
Fluoride can help prevent cavities. When added at the recommended level of 0.7 milligrams per liter, fluoride strengthens tooth enamel and can reduce the number of cavities by about 25%.
Too much fluoride during development can affect tooth appearance. During childhood, while teeth are still forming, consuming water that exceeds recommended levels of fluoridation along with exposure to other fluoridated products like toothpaste, can lead to mild dental fluorosis and affect the appearance of teeth. This may result in white flecks, spots or lines on the enamel.
States and local governments determine community water fluoridation. States and local governments make policy decisions about whether to fluoridate public water supplies. In areas with naturally high fluoride levels, states may remove excess fluoride, while others may increase it to reach the recommended levels for dental health.
Alternative fluoridation methods include fluoridated milk and table salt. In rural areas that rely heavily on private wells, water fluoridation might not be practical. Some governments have adopted alternative strategies, such as fluoridating milk and table salt, to help prevent dental decay.

5 State Actions on Fluoride in Drinking Water

Specifying the Concentration of Fluoride in Water. The U.S. Virgin Islands enacted legislation (Bill 51) in 2021 updating statutory language by replacing “fluoride content of” with a specific concentration—0.7 milligrams per liter. The bill also mandates that beginning in 2025, and every three years thereafter, fluoride levels shall be adjusted in accordance with any updated guidelines promulgated by the U.S. Department of Health and Human Services.
Requiring Notifications for Customers. In 2021, Iowa enacted HB 390 requiring public water supply operators or owners to notify the state’s oral and health delivery system bureau and all customers at least 90 days prior to taking any action to permanently discontinue fluoridation in its water supply. Washington enacted legislation (HB 1251) in 2023 mandating that any public water system considering the start or discontinuation of fluoridation on a continuing basis shall notify its customers and the Department of Health at least 90 days prior to a vote or decision on the matter.
Requiring Fluoride in Public Water Systems of Certain Sizes. At least 12 states have laws?mandating communities of a certain size fluoridate the public water system, including California, Delaware, Georgia, Illinois, Kentucky, Louisiana, Minnesota, Mississippi, Nebraska, Nevada, Ohio and South Dakota.
Prohibiting Addition of Fluoride in a Public Water System. Throughout the 2025 legislative sessions, at least 12 states have introduced bills prohibiting or repealing provisions related to the addition of fluoride in public water systems. Utah is the first state to enact this type of bill. The state enacted HB 81, prohibiting the addition of fluoride to water that is part of, or will be introduced into, a public water system. The law also outlines that a political subdivision may not enact or enforce an ordinance that requires or permits water fluoridation. Previously, in 2023, Utah enacted HB 77, which required that no fluoride may be added to or removed from public water supplies—whether state, county, municipal or district—without the approval of a majority of voters in an election in the area affected.
Grants for Screenings. In 2024, the Colorado Legislature amended its’ Oral Health Community Grants Program through SB 142, establishing the oral health screening pilot program. The pilot program provides screenings to kindergarten and third grade students to assist communities in attaining optimal levels of fluoride in drinking water to prevent dental decay. The bill includes provisions for: parental notification and opt-out rights; reporting screening outcomes to parents and guardians; providing referrals if dental concerns are identified; and, ensuring protection of confidential health data.

Original article online at: https://www.ncsl.org/health/state-of-the-tap-policy-actions-on-fluoride-in-drinking-water