Water fluoridation can be a controversial topic, and it continues to spark discussion in 2025. Utah is set to become the first state to ban fluoridation as the State’s legislature recently approved the statewide prohibition of fluoridation in drinking water. Governor Spencer Cox says he plans to sign the legislation that will go into effect May 7, 2025. South Dakota’s Legislature recently considered removing the statewide requirement for community water systems serving more than 500 people to add fluoride to drinking water, but the bill failed in the Senate. The Montana Legislature also heard testimony on legislation to prevent fluoridation.
Given the ongoing nature of this debate, arguments for and against fluoridation are likely to resurface in the headlines, with strong talking points on both sides. As water experts, we are often asked by clients, family, and friends: What is the right answer? The reality is that fluoridation is not a one-size-fits-all solution. The decision depends on multiple factors, including local water chemistry, regulatory requirements, and community needs.
Fluoridation Standards and Regulations
Fluoride naturally occurs in water sources due to the erosion of natural deposits, and industrial discharges can also contribute to the presence of fluoride in water. However, many public water systems add fluoride to help prevent tooth decay. Today, over three-quarters of the U.S. population receives fluoridated drinking water.
The U.S. Environmental Protection Agency (USEPA) has set the maximum contaminant level (MCL) for fluoride at 4.0 mg/L. Additionally, a secondary standard of 2.0 mg/L was established to address potential cosmetic concerns, such as dental fluorosis. Meanwhile, the U.S. Department of Health and Human Services (HHS) recommends a fluoride concentration of 0.7 mg/L to maximize dental health benefits while minimizing risks.
The Case for Fluoridation
The Centers for Disease Control and Prevention (CDC) has ranked water fluoridation among the top ten public health achievements of the 20th century. Decades of research show that fluoride strengthens tooth enamel, reducing the risk of cavities and decay.
Beyond oral health, some health professionals suggest that the benefits of fluoride extend to overall well-being, whereas poor dental health can lead to eating difficulties, malnutrition, and even an increased risk of systemic diseases. Fluoridated water also plays a role in reducing healthcare costs, particularly for low-income communities that may lack access to regular dental care.
Many leading health organizations—including the World Health Organization (WHO), the Centers for Disease Control and Prevention (CDC), the American Dental Association (ADA), and the National Academies of Sciences, Engineering, and Medicine (NASEM)—continue to support water fluoridation as a safe and effective public health measure.
Concerns About Fluoridation
Despite the potential for dental benefits, fluoridation can be controversial. Too much fluoride can cause dental fluorosis, which creates white spots or streaks on teeth. Rarely, people who are exposed to high amounts of fluoride for an extended period of time can develop skeletal fluorosis, which causes joint pain and stiffness.
One of the most common objections to fluoridation is the issue of personal choice. Unlike fluoride toothpaste, which individuals can choose to use or avoid, water fluoridation affects entire communities. Critics argue that public water systems should focus solely on providing safe drinking water—not delivering medical treatments.
As one commentator put it:
“A water provider’s job is to deliver the safest water possible. Does adding fluoride make the water safer? No. It does not. We don’t add Vitamin C to drinking water, even though it has health benefits. So why add anything that doesn’t directly improve water safety?”
In a groundbreaking decision in the fall of 2024, a Federal district court ordered the USEPA to regulate the “unreasonable risk” posed by fluoridated water. While the court did not mandate specific actions, this ruling could have significant implications for municipal water systems and public health policies moving forward. More information on that decision is provided here.
What Does This Mean for Water Systems?
For AE2S, it means taking a nuanced approach to fluoridation. Every client, water system, and community is unique. Regulations also vary from state to state. South Dakota requires fluoridation for systems serving more than 500 people while Utah will soon ban it. North Dakota and Wisconsin leave it up to local discretion.
Ultimately, fluoridation is not a universal solution. Rather, the decision to fluoridate reflects a policy choice that has to be made with careful consideration of both benefits and drawbacks. What works for one community may not be the right fit for another.
That is why, as water professionals, we focus on understanding local water chemistry, community needs, and evolving regulations to help our clients make informed decisions.
If you have questions about fluoridation, reach out to Nate Weisenburger, AE2S Drinking Water Practice Leader.