The Centers for Disease Control operates a website called “My Water’s Fluoride.”  On the home page it states:  “It is important to know the level of fluoride in your drinking water.  My Water’s Fluoride (MWF) allows consumers to learn about the fluoride level in their drinking water.”  However, the fluoride levels seen on the website are often false.  If a water system is adding fluoride to the tap water, a practice known as fluoridation, this website automatically assigns it a “default” fluoride level of 0.70mg/L regardless of what actual testing shows or what fluoride level the water system is trying to achieve. 

Nowhere on the MWF website are visitors told that they are viewing “default” values for systems with fluoridation instead of actual test results.  The website is also deceptive about missing data.  For some water systems the CDC has stated it did not get fluoride test data from the states.   Instead of admitting they have no data the CDC simply omits any mention of the fluoride level for these systems.  Website visitors are left in the dark when they look up their water system and find no fluoride level.   

When a water system is not adding fluoride then what is seen on the website is supposed to be based on actual testing.  But even for these water systems the MWF is unreliable because it sometimes has test values that are very old and outdated.   An example is Radiance Water Supply Corporation in Texas.  The CDC’s MWF site says it has 1.3 mg/L but that test was from 1998.  There have been 4 fluoride tests done in the years since 1998 and 1.3 mg/L is not the current fluoride level according to the state of Texas.

When asked about this the CDC came up with this curious explanation: 

 “…Where fluoride is naturally occurring in water systems, the fluoride levels are typically consistent over time and that value is displayed in MWF. In water systems that adjust fluoride levels, a variety of factors affect small, natural variations in measuring fluoride levels. Because MWF is not designed to provide real-time data, adjusted systems use a default value of what they adjust toward. The default value, agreed upon by participating states, is 0.7 mg/L, the level recommended by the Public Health Service in 2015.”

But this response is also untrue.  Not every water system in the country is trying to adjust towards 0.7 mg/L and some have higher levels based on the older recommendations about fluoridation.  In Minnesota the state legislature never changed the mandatory fluoridation law that required all water systems to add 1.2 mg/L fluoride to the water.  So many Minnesota water systems are still are adding 1.2 mg/L to the water and are required to do that unless they ask the state for permission to lower the amount.  One system, North St. Paul, intends to stay at 1.2 mg/L until the state orders them to lower the level.  But on the CDC’s MWF site the fluoride level for North St. Paul has been wrongly reported as 0.7 mg/L since 2015.

The CDC says it uses default values because it’s website is not designed for real-time data.  But there is no such thing as real-time data when it comes to fluoride testing or anything else in found in public water systems.   And who ever said we want or need real-time data for fluoride?

The CDC response is ironic in that large water systems that add fluoride do daily testing for fluoride and generally report these numbers each month to state agencies, which then pass the reports on to the CDC.  These monthly reports are the closest thing there is to real time data, but the CDC is not willing to use this monthly test data when it comes to the MWF website.  The CDC keeps this data hidden from public view in what’s called the Water Fluoridation Reporting System, which can only be accessed by CDC officials.  

The reason the CDC hides the fluoridation data is revealed in their response to questions about this.   To maintain confidence in fluoridation they want to avoid questions from the public about the slight variations seen in the actual fluoride testing done in fluoridated areas.  Those slight variations make fluoridation look less than perfect.  So the CDC thinking is to let the public believe they are getting water with a perfectly maintained fluoride concentration, even if it’s not true.    

Doug Cragoe is a fluoride activist and researcher.  As a result of his work, false information promoting fluoride has been removed from the the websites of government agencies including the EPA, the CDC, and the NIDCR.