Fluoride in Calgary's water

Fluorides are chemical compounds naturally found in air, water, soil and almost all foods. Fluorides are commonly released into the environment by erosion resulting in natural concentrations in surface and ground waters.

Fluoride naturally occurs in the Bow and Elbow Rivers, in concentrations varying throughout the year, between 0.1 and 0.4 mg/L.

Health Canada’s Guidelines for Canadian Drinking Water Quality continue to recommend optimal fluoride dosing to be 0.7 mg/L and has set a maximum allowable concentration of 1.5 mg/L. 

For answers to common drinking water questions like water hardness, water taste, odour or appearance, or water pressure, visit Drinking Water in Calgary.

1957-1971

• Calgarians vote against adding fluoride to its drinking water four times in 1957, 1961, 1966 and 1971.

1989-1991

• In a 1989 plebiscite, Calgarians voted in favour of adding fluoride to the city's drinking water. By 1991, fluoride was being added to Calgary's drinking water at a target of 1.0 mg/L.

1998-1999

• In 1998, The City and Alberta Health Services reviewed water fluoridation as a public policy, and a panel of five experts recommended a reduction in the level of fluoride to 0.7 mg/L. This change was adopted in 1999 following a second plebiscite where Calgarians again voted in favour of fluoridation by 55 per cent.

2011

• The City of Calgary discontinued the addition of fluoride to Calgary's drinking water as directed by Council on May 19, 2011.

2021

• As part of the 2021 General Election, 62 per cent of electors voted in favour of reintroducing fluoridation of the municipal water supply.
• On November 15, 2021, Council directed Administration to implement water fluoridation of the drinking water system.

The estimated costs to reintroduce fluoridation (updated July 2023):

• Capital costs for infrastructure at the two water treatment plants - $28.1 million
• Annual operating costs - $864,000 per year
• Annual maintenance costs - $100,000 to $200,000 per year

In 2020, a $10.1M project estimate was shared in Council but was considered a high-level conceptual estimate. This cost estimate did not account for inflation, nor the additional project scope later identified in the detailed project design phase.

Current operating and capital budgets do not include the costs associated with reintroducing fluoridation, although reintroduction of fluoridation is not expected to increase water rates. Final costs will be provided in The City’s annual water rates.

Existing infrastructure, which had reached the end of its life cycle in 2011, was decommissioned and removed following the Council decision to stop fluoridation.

Construction activities are well underway and are nearing completion. Building the essential equipment at both the Bearspaw and Glenmore water treatment facilities is expected to be complete by the end of October 2024. Commissioning activities commence in November with fluoridation expected to be in place by Q1 2025.

The compound which will be used to fluoridate Calgary’s water will be hydrofluosilicic acid, the same compound used prior to 2011. This compound is currently used by approximately 75 per cent of the utilities in North America that fluoridate their water.

Fluoride will likely be added to drinking water during the disinfection process, (Step 3 below). More information on The City’s water treatment process is available at /content/www/en/home/water/drinking-water/online-tour.html.