From Source To Tap - The Multi-Barrier Approach To Safe Drinking Water

Drinking Water Treatment

Water treatment is key to both the multi-barrier approach and to protecting public health. The safety of Canada's drinking water is largely due to the introduction of disinfection at the start of the 20th century which eradicated serious and life-threatening diseases such as cholera and typhoid fever. That said, the safety of Canada's drinking water supplies is still challenged by microbiological pathogens and chemical substances found in source waters.

In order to safeguard public health, it is important that treatment systems be designed and constructed based on the results of source water assessments. They should be regularly reviewed and upgraded as necessary. Items to consider in designing effective treatment systems include the treatment processes required, treatment components (including redundancies), equipment design, chemicals used, treatment efficiency, and monitoring procedures. In assessing these components, potential hazards and their causes should be identified along with their associated health risks so priorities for risk management can be established.

Comprehensive, scientifically defensible, and achievable performance standards - based on recognized principles - are essential to ensuring the effectiveness and reliability of treatment technologies. Decision-makers must balance the need or desire to use the latest technologies against economic realities. Public health goals should be at the forefront of any treatment-related decision.

Criteria for the design and operation of the treatment system should be established to ensure public health protection objectives are met. Alternative approaches may be used if these have been demonstrated to be equivalent or better ways of achieving the same objectives.

Only certified products (such as chemicals, plumbing materials or water treatment devices) that meet recognized health-based performance standards should be used during treatment and distribution. For consumers who use treatment devices in their homes, the proper selection, operation and maintenance of off-the-shelf products is important to reducing the risk of illness.