MOUNT VERNON — The fluoridation of drinking water in the United States began in the late 1940s in an attempt to reduce cavities in both children and adults. In 1969, Ohio passed legislation requiring any community of more than 5,000 residents, and its own water treatment system, to fluoridate its drinking water.
Depending on the population of the community, fluoridation was required to start either Jan. 1, 1971 or 1972. Additionally, Ohio provided communities the option of holding a referendum to opt out of fluoridation of its water supply.
Mount Vernon was one of 30 cities that voted for exemption from the fluoridation requirements. Seven of those cities have since voted to reverse their original decision, leaving 23 cities exempt.
“Mount Vernon does not fluoridate its water,” said Judy Scott, administrator of treatment and distribution for the Mount Vernon Water and Wastewater Department. “Back when it became a law for communities with a population of 5,000 or more, they had an opportunity to vote against it. And Mount Vernon did vote against it. But for communities that do (fluoridate) they must add fluoride if the naturally occurring amount is less than 0.8 parts per million and bring it up to between 0.8 and 1.3 ppm of water.”
Scott said the Mount Vernon water supply, which largely comes from wells located in the Mount Vernon well field, part of which is located in Riverside Park, does have some naturally occurring fluoride in the water. According to Scott it is below the detection limit which is 0.5 ppm.
Other communities in Knox County with their own water supply do not fluoridate either because they are too small to be required to do it, the natural level of fluoridation falls within Ohio EPA requirements or both.

