In 2014, the City began to add phosphate to the drinking water treatment process. Phosphate forms a protective coating inside all pipes and household plumbing fixtures, which helps to reduce the potential for lead to enter tap water.

Corrosion control is mandated and approved by the Ministry of the Environment and Climate Change (MOECC) under the Safe Drinking Water Act.

Toronto’s Corrosion Control Plan was adopted by City Council, and is supported and endorsed by Toronto Public Health as a safe way to reduce the amount of lead in tap water and the associated health risks.

About the Plan

  • The City began to add phosphate to the water treatment process at its four plants in 2014.
  • It was estimated that it could take up to two years for a protective coating to form inside all pipes.
  • The City is evaluating the effectiveness of corrosion control and is adjusting the phosphate dose accordingly.
  • Early lab results from homes with suspected lead pipes show that lead levels are decreasing.

About Phosphate and Public Health

  • Phosphates are naturally found in many foods, including milk, beef and nuts, and are required for normal cellular function.
  • The phosphate being used at the City’s water treatment plants is a food grade additive derived from a natural source of mineral rock.
  • It represents less than 1% of what a person typically consumes each day.
  • It has no impact on the taste or odour of drinking water.