Adoption of Health Canada’s guidance document on Corrosion Control in Drinking Water Distribution Systems as a procedure in Ontario

Decision on policy

Ontario’s drinking water is among the best protected in the world due to the province’s comprehensive protection framework that safeguards Ontario’s drinking water from source to tap.

In 2007 and 2009, the ministry incorporated relevant approaches, principles, and science from the federal guidance into ministry guidance, procedures and regulations, as part of a provincial Lead Action Plan.

The Lead Action Plan is based on recognized scientific research and expert advice and was developed to reduce the risk of exposure to substances such as lead that are known to be harmful to children. The highlights of the Lead Action Plan are below:

• in summer of 2007, Ontario announced the Lead Action Plan and passed Regulation 243/07 and followed up with amendments to O. Reg. 170/03 to include community lead testing and corrosion control plan requirements for drinking water systems owners
• as part of the government’s Lead Action Plan, new regulatory requirements were introduced under the Safe Drinking Water Act, 2002 to ensure that children were being protected in day nurseries and schools and to collect better information about lead levels in drinking water in communities throughout Ontario. The new regulatory requirements introduced were:

1. O. Reg. 243/07 (Schools, Private Schools, and Day Nurseries) requiring:

• annual lead testing at schools, private schools, and day nurseries, except at day nurseries with newer (post-1989) plumbing, and daily flushing of plumbing for all facilities with older (pre-1990) plumbing and weekly flushing of plumbing for facilities with newer plumbing

2. Amendments to O. Reg. 170/03 (Drinking Water Systems) requiring:

• bi-annual community lead testing at taps in homes and non-residential facilities, to be conducted by the owners of residential systems, and development of corrosion control plans for large municipal residential systems that exceed a prescribed threshold of poor lead test results

In 2009, further amendments were made. In cases where test results clearly indicated that there was no concern with lead, the sampling requirements could be reduced to better reflect lead test results history.

The ministry also published the "Guidance Document for Preparing Corrosion Control Plans for Drinking Water Systems" for use at systems requiring corrosion control planning due to regulatory amendments or where guidance was sought for corrosion control. The ministry’s guidance document incorporated the major elements of Health Canada's guidance document. The ministry's document can be downloaded from: https://archive.org/stream/guidancedocument00snsn21738#page/n19/mode/2up .

Due to the recent (2019) release of a revised, more stringent Health Canada Drinking Water Quality Guideline for lead, Health Canada is expected to revise the guidance on corrosion control. To ensure Ontario continues to take action to protect the province’s drinking water and water resources as part of our Made-in-Ontario Environment Plan, Ontario will work with Health Canada on this guidance and will look at how it will incorporate the revised guidance and further implementation requirements moving forward.