The city of Calgary is shutting off the equipment that pumps fluoride into the supply of drinking water for Calgarians.

The move was made on a direction from council and the official receipt of Alberta Environment's authorization.

Water Services say that it will take approximately one week for fluoride concentrations to return to natural levels.

Fluoride occurs naturally in the drinking water supplies from the Bow and Elbow Rivers, in concentrations that vary throughout the year.

Fluoridation of water is known to prevent tooth decay but opponents claim that it can cause greater health problems, is not effective enough based on costs, and has a dosage that cannot be precisely controlled.

Water Services constantly monitors the condition of the water and you can see a water quality report on the city's website at