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.
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.
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.
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.