In 2007, the Ontario Ministry of the Environment and Climate Change (MOECC) implemented a Regulated Lead Testing Program under which Toronto Water is required to collect, analyze and submit the results of water samples taken in areas suspected of having lead water service pipes. Under the original program, twice a year, Toronto Water had to collect and report the results of samples from:

  • 100 residential water service connections
  • 20 connections from within the distribution system
  • 10 non-residential water service connections

In 2009, the MOECC directed Toronto Water to implement a Corrosion Control Program to reduce the amount of lead in drinking water. After a comprehensive study of different methods and a review of other municipalities that have implemented corrosion control, the City of Toronto decided to enhance its drinking water treatment process by adding phosphate, which forms a protective coating inside pipes and household plumbing fixtures.  This coating reduces the potential for lead to enter drinking water.

During the design and implementation of corrosion control (2009-2017) the MOECC required the City to collect and analyse 20 samples from the water distribution system twice a year.

In March 2017, Toronto Water resumed a more fulsome sampling program, which includes taking annual samples from:

  • 55 samples from residential and non-residential taps
  • 10 samples from the distribution system

Results will be posted in 2018.

View the Regulated Test Results

Ontario Drinking Water Qualtiy Standard for Lead = 10 ug/L (micrograms per litre)

Results with “<” means less than the Method Detection Limit