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(Updated June 2020)

Valley Water began fluoridation in 2016, but many areas of the county remain unfluoridated.

NOTE: The information provided is based on approximate water service areas; please check with your water retailer for the most accurate fluoride concentration in your drinking water.

Numerous research studies and more than 70 years of experience have demonstrated that fluoridating public drinking water is not only safe and effective, it is the best method of improving oral health in a community.

The U.S. Centers for Disease Control and Prevention (CDC), the American Dental Association (ADA), the American Medical Association, the American Cancer Society, the American Academy of Pediatrics, the National Institutes of Health, the National Parents-Teachers Association, and the World Health Organization support drinking water fluoridation.

November 2011, Valley Water’s Board of Directors took actions that led to Valley Water   providing optimal levels of fluoride at its three water treatment plants. Implementation of fluoridation was completed in December 2016 for eastern Santa Clara County, and is planned to be completed in the future for western Santa Clara County.

Many consumers may not be familiar with its benefits or may be concerned about its addition to the drinking water.

  • The answers to some of the more frequently asked questions about fluoride are provided below

To express fluoride related comments or concern, please call the Valley Water fluoride information line at 1 (408) 630-2020. For questions on drinking water safety, members of the public are encouraged to contact Dr. Howard Pollick, Professor at the UCSF School of Dentistry, at 415-476-9872 or [email protected].

Comments or questions directed to Valley Water can be submitted through our Access Valley Water system.

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Frequently asked questions 

Q1. What is fluoride?  
Fluoride is an abundant naturally-occurring element found in rocks, soil, and fresh and ocean water. When fluoride is present in drinking water at optimal levels, it has been shown to promote oral health by preventing tooth decay. Fluoride is a mineral that is commonly found in the environment. Fluoride reaches water sources by leaching from soil and rocks.

Q2. Why is Valley Water fluoridating its water supplies?  
Valley Water, as a wholesale water supplier, relies on the health recommendations provided by medical professionals and relevant government agencies.

Community water fluoridation is supported by most major national and international health organizations. Supporters include: the ADA, American Medical Association, American Academy of Pediatric Dentistry, CDC, and the World Health Organization.    

Valley Water is exempt from the state law which mandates fluoridation because as a water wholesaler we have fewer than 10,000 service connections; however, local health officials have advocated for large-scale fluoridation in order to maximize the public health benefits and minimize the cost of treating drinking water. Fluoridation at our three drinking water treatment plants is the most cost-effective means of providing this proven health benefit to Santa Clara Valley.

Q3. How much fluoride is in my drinking water?  

Since beginning fluoridation of northeast Santa Clara County in 2016, Valley Water has supplemented the naturally-occurring fluoride in your drinking water to a target of 0.7 ppm. This is the optimal level recommended by the California State Water Resources Control Board’s Division of Drinking Water (DDW) [1], with a control range of 0.6 ppm to 1.2 ppm. [2].

Valley Water continuously monitors fluoride levels in the drinking water produced at its treatment plants using real-time analyzers as well as daily analytical measurements performed by certified operators.

When added to drinking water at the optimal level, the effectiveness of fluoride in reducing tooth decay has been documented in scientific literature for more than 70 years [3] [4] [5].

Any water system relying on Valley Water for 100 percent of its treated drinking water will benefit from fully-optimized fluoride concentrations. If a water system blends Valley Water supplies with other non-fluoridated supplies, additional fluoride treatment would be necessary within the system to maintain optimal fluoride levels. If no additional fluoride is added in the blended system, fewer overall health benefits would be provided. Interested consumers should contact their water provider to find out how much fluoride, if any, is in their tap water.

Q4. If I use a fluoridated toothpaste, am I already getting enough fluoride to protect against decay?  
According to the ADA,  “even in an era with widespread availability of fluoride from other sources, studies show that community water fluoridation prevents at least 25% of tooth decay in children and adults throughout the life span.” [6] [7].

Q5. What chemical is Valley Water using to fluoridate its supplies?  
Valley Water selected fluorosilicic acid as the most cost-effective bulk chemical to be used in the district's treatment processes. This is the most commonly used fluoride additive by large water systems and is approved for use by DDW, who regulates the drinking water that we serve. The selected fluorosilicic acid is certified for compliance with the American National Standards Institute (ANSI) and National Sanitation Foundation (NSF) Standard 60. ANSI/NSF Standard 60 ensures that chemicals used to treat drinking water do not contribute contaminants to the water.

Q6. Should I mix infant formula with fluoridated water?  
The ADA states that “it is safe to use fluoridated water to mix infant formula. If your baby is primarily fed infant formula, using fluoridated water might increase the chance for mild enamel fluorosis, but enamel fluorosis does not affect the health of your child or the health of your child’s teeth.” [8] However, if you prefer not to use fluoridated water for infant formula, you may choose to breastfeed, use ready-to-feed formula, and/or use low-fluoride bottled water to mix your formula. [9][10] Parents and caregivers are encouraged to talk to their dentists and pediatricians about what’s best for their child.

Q7. I would rather not drink water that has fluoride added to it, what choices do I have?  
You have several choices. Many brands of bottled water contain some levels of fluoride. You can call the consumer information number on the bottle's label and ask about the level of fluoride and whether this level is naturally low. Other brands of bottled water take tap water and then further treat it. The additional treatment, if by reverse osmosis or distillation may remove a significant amount of both naturally occurring fluoride and any fluoride added through fluoridation.  

You can also use home treatment devices that utilize reverse osmosis systems or distillation. For a list of state-certified devices, check the State Water Board website: Residential Water Treatment Devices.

NSF International, a not-for-profit testing organization, also certifies certain reverse osmosis home treatment devices and distillation units for the reduction of fluoride. You can search on-line for NSF-certified products at: Home treatment devices must be maintained according to the manufacturer's instructions to ensure their effectiveness.

Q8. Will fluoridated water harm my pets?  
No. “Fluoride in levels administered for drinking water is safe for humans and all animals. Over 50 years of research and experience have shown fluoridation at optimal levels does not harm people or the environment.” [11] 

Q9. Where can I get more information about fluoride? 
The ADA and CDC both have websites that provide extensive information about fluoride and fluoridation. Go to or


  1. U.S. Department of Health and Human Services Federal Panel on Community Water Fluoridation. U.S. Public Health Service Recommendation for Fluoride Concentration in Drinking Water for the Prevention of Dental Caries. Public Health Rep. 2015;130(4):318-331.
  2. California State Water Resources Control Board. Fluoridation by Public Water Systems. Available at Dental Association. Oral Health Topics. Fluoride: Topical and Systemic Supplements. Key Points.  
  3. American Dental Association. Fluoridation Facts. 2018:5
  4. ADA 2005:13. Brunelle JA, Carlos JP. Recent trends in dental caries in U.S. children and the effect of water fluoridation. J Dent Res 1990;69(Spec Iss):723-7. Available at  
  5. Ripa LW. A half-century of community water fluoridation in the United States: review and commentary. J Public Health Dent 1993;53(1):17-44. Available at  
  6. Campaign for Dental Health. Is Using Fluoride Toothpaste Enough?
  7. American Dental Association. Fluoridation Facts. 2018:20.  
  8. American Dental Association. Fluoridation FAQs. Available at (accessed on August 23, 2019)
  9. Centers for Disease Control and Prevention. Community Water Fluoridation—Overview: Infant Formula and Fluorosis. Available at (accessed August 23, 2019).
  10. American Academy of Pediatrics. Healthy Children. FAQ: Fluoride and Children. Available at
  11. San Francisco Public Utilities Commission: Fluoridation. Available at