Municipal Affairs and Environment

Fluoride in Well Water

Fluorides are chemical compounds, which can be found in air, water, soil and almost all foods.The maximum acceptable concentration of fluoride in drinking water in Health Canada’s Guidelines for Canadian Drinking Water Quality opens new window is 1.5 mg/L (milligrams per litre).

What are the known sources of fluoride?

Fluorides are naturally released into the environment by weathering processes and by volcanic activity and may be produced in the manufacture of phosphate fertilizer, by aluminum smelting and by other chemical manufacturing.

Health benefits of fluorides

Many governments and health organizations, including Health Canada, the Canadian Public Health Association, the Canadian Dental Association, the Canadian Medical Association and the World Health Association endorse the fluoridation of drinking water to prevent tooth decay.A fluoride concentration of 0.8 to 1.0 mg/L has been recommended for those communities wishing to fluoridate their water supply.

Fluorides at optimum concentrations protect tooth enamel against the acids that cause tooth decay.

What are the environmental health concerns of fluoride?

In children, higher concentrations of fluoride in drinking water can cause dental fluorosis for children under the age of six during tooth formation. Dental fluorosis causes the staining and pitting of teeth.This is a cosmetic problem and not a health risk.

In adults, high levels of fluorides consumed for a very long time may lead to skeletal fluorosis.Skeletal fluorosis is a progressive but non life threatening disease in which the bones increase in density and become more brittle.In mild cases, the symptoms may include difficulty in moving, deformed bones and a greater risk of bone fractures.

Where have high fluoride levels been found in Newfoundland and Labrador water supplies?

The map shows where elevated fluoride concentrations and fluoride concentrations above drinking water guidelines have been found through water well testing of public and randomly selected private water supplies.Drilled wells in bedrock are more likely to have high natural fluoride concentration than dug wells. The green areas of the map are areas where because of the nature of the bedrock, there is a greater likelihood of elevated fluoride concentrations in well water.

Areas of Potential Fluoride Concentration in Well Water PDF (309 KB)

What can well owners do about high fluoride levels in well water?

It is recommended that private well owners test their wells for a standard list of chemical parameters, one of which is fluoride. If fluoride is found above drinking water guidelines, there are treatment systems such as reverse osmosis and distillation that can be installed to remove fluoride from drinking water.You will need to test your water after installing the treatment system to make sure it is working properly.


More information on fluoride in well water can be found from the following sources.


Health Canada, It’s Your Health (September 2005) opens new window

Province of Newfoundland and Labrador, Department of Natural Resources, Geological Survey. Geoscience Atlas of Newfoundland, open File NFLD/2687.

World Health Organization, Geneva, Switzerland, Water Sanitation and Health (WSH), Water Fluoridation (2001) opens new window

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