Chlorine & Fluoride

Information on chlorine and fluoride added to drinking water

Each water supply plant has varying types of treatment systems in place based on the source water quality. You can see each water supply plant, along with the individual types of treatment systems in place based on the source water quality, all contained in the Where Does My Water Come From mapping application.

Chlorine

Halifax Water is required by Nova Scotia Environment to maintain a chlorine residual of at least 0.2 mg/L (milligrams per litre or parts per million) in all parts of the distribution system to protect against microbial contamination.

Halifax Water plant operators add enough chlorine to meet the minimum at the most remote areas of the distribution system. This ranges from 0.5 mg/L in winter to 1.5 mg/L in summer. Therefore, the amount of chlorine in your water is between 0.2 and 1.5 mg/L.

Putting a pitcher of water in the refrigerator for a few hours will help any chlorine taste disappear.

Fluoride

Halifax Water fluoridates water in the Pockwock and Lake Major water supply plants. Health Canada’s recommended minimum concentration of fluoride in drinking water to provide optimal dental health benefits is 0.7 mg/L, which is the dose targeted by Halifax Water during treatment. Plant operators monitor concentrations in the treated water on a daily basis to ensure that the target fluoride levels are being achieved at all times.

Due to system maintenance requirements, fluoride is currently not being added to the treatment process at either supply plants. Any changes to the status of fluoride levels will be noted on the Halifax Water website.

Fluoridation practice is regulated by Nova Scotia Environment through operating approvals and the Guidelines for Canadian Drinking Water Quality published by Health Canada. Health Canada has reaffirmed its position that there is no significant risk of adverse health effects of a fluoride level of up to 1.5mg/L.

The fluoride Halifax Water uses in the drinking water system must meet the American Water Works Association standards, and more importantly National Sanitation Foundation (NSF)/American National Standards Institute (ANSI) Standard 60, which is a standard for additives to drinking water.

Water fluoridation is one of a number of public health measures where additives are used to achieve health benefits in a population. Find more information on those health benefits from Health Canada.

Fluoride FAQ

Why did Halifax Water decide to stop fluoridating?

Halifax Water has not decided to stop fluoridating; mechanical/equipment issues at the Pockwock Lake and Lake Major Water Supply Plants have caused interruptions to the process.

  • The Pockwock water supply plant was experiencing intermittent leaks, and repairs were required. This system is expected to be back online by the end of the year. 
  • The fluoride storage tank at Lake Major was at end of life and became a safety risk.  As a result, it was taken offline, and a plan was put in place to replace it. However, external environmental factors mandated additional changes in the treatment process to maintain compliance. This has delayed the replacement of the fluoride tank as the facility has limited chemical storage space.

Who did Halifax Water report the treatment change to?

All drinking water treatment changes, including changes to fluoridation, are reported to Nova Scotia Environment and Climate Change (NSECC) as part of Halifax Water’s Approval to Operate permit.

Is it a requirement to add fluoride to drinking water?

While adding fluoride to drinking water is not a regulatory requirement or mandatory in Nova Scotia, it has traditionally been decided by communities and public health officials. Halifax Water is currently reviewing these issues with the current HW Board and the Minister of Health and seeking guidance on the next steps.

  • In 2014, the HW Board of Commissioners endorsed the addition of Fluoride for Lake Major and Pockwock. 
  • This decision included support from the IWK, the Nova Scotia Dental Association and the Dalhousie University Faculty of Dentistry.