PHOENIX — Fluoride in water supplies helps prevent tooth decay in adults and children, according to the Centers for Disease Control. It is naturally found in water and soil but some cities and states add fluoride to the water supply to increase levels to 0.7 ppm, the optimal level for preventing cavities.
However, adding fluoride to water still doesn't sit well with some. Critics have argued that the health effects of fluoride aren't completely known and say adding it to the water system could be considered an unwanted medication. In 2015, the government lowered the recommended amount of fluoride in water after kids were getting "splotchy" teeth.
However, experts say adding fluoride to water is one of the 10 greatest public health achievements of the 20th century.
Today, about 75% of Americans are drinking fluorinated water, according to the CDC.
What cities in the Valley add fluoride to their water supply?
12News contacted water departments across the Valley today to learn which ones add fluoride to their water supply. Five Valley cities add fluoride:
Phoenix
The Phoenix Water Service Department said the addition of fluoride to the water supply "aligns with recommendations from public health agencies, including the U.S. Centers for Disease Control and Prevention (CDC), which endorse fluoridation as a safe and effective method to prevent tooth decay.
"Phoenix maintains the fluoride concentration at the optimal level recommended by the CDC to ensure safety and efficacy for all residents."
For more detailed information about Phoenix Water's fluoridation practices, click here.
Mesa
The City of Mesa sent this response to 12News:
Fluoride occurs naturally in our drinking water at an average rate of 0.4 parts per million. Equipment installed by the City increases the rate to 0.7 parts per million, in accordance with the American Dental Association's recommended level for dental health in warm climates.
Tempe
Officials with the City of Tempe said the addition of fluoride to the water "complies with Federal drinking water standards in order to maintain adequate fluoride levels in drinking water for dental health. This is done by adding additional fluoride to a concentration of 0.7 ppm. At this level, fluoride strengthens the enamel of teeth and helps to prevent tooth decay, erosion and cavities."
For more information on Tempe's fluoridation practices, click here.
Glendale
Glendale also adds fluoride to its water.
"Glendale has naturally occurring fluoride in our drinking water and we supplement per City Council direction. The current target concentration of fluoride in Glendale’s drinking water is well below the regulatory standards of the Environmental Protection Agency (EPA). The City of Glendale is in full compliance with the drinking water standards outlined in the federal Safe Drinking Water Act (SDWA), administered by the EPA and the Arizona Department of Environmental Quality."
Goodyear
Officials with the City of Goodyear said it does not add fluoride to its water. The city provides drinking water with safe levels of fluoride that occur naturally and sent this additional information:
- The city tests its water supply throughout the year and publishes an annual water quality report.
- The last report (published in 2023/data from 2022), showed fluoride in the drinking water provided by the city of Goodyear averages 0.46 mg/l.
- Drinking water containing more than 4 mg/l of fluoride (the US Environmental Protection Agency’s drinking water standard) can increase your risk of developing bone disease. At low levels, fluoride can help prevent cavities.
- Tap water delivered to residents served by Goodyear’s Utilities Department continues to surpass all federal and state drinking water standards.
The other Valley cities say only naturally occurring fluoride is present.
For more information on fluoride in drinking water, click here.
Watch 12News+ for free
You can now watch 12News content anytime, anywhere thanks to the 12News+ app!
The free 12News+ app from 12News lets users stream live events — including daily newscasts like "Today in AZ" and "12 News" and our daily lifestyle program, "Arizona Midday"—on Roku and Amazon Fire TV.
12News+ showcases live video throughout the day for breaking news, local news, weather and even an occasional moment of Zen showcasing breathtaking sights from across Arizona.
Users can also watch on-demand videos of top stories, local politics, I-Team investigations, Arizona-specific features and vintage videos from the 12News archives.
Roku: Add the channel from the Roku store or by searching for "12 News KPNX."
Amazon Fire TV: Search for "12 News KPNX" to find the free 12News+ app to add to your account, or have the 12News+ app delivered directly to your Amazon Fire TV through Amazon.com or the Amazon app.
Up to Speed
Catch up on the latest news and stories on the 12News YouTube channel. Subscribe today.