Ontario Regulated Lead Testing Program

In 2007, the Provincial Government implemented a Regulated Lead Testing Program under which Toronto Water was 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 collected and reported 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, Toronto Water began developing a Corrosion Control Program as mandated and approved by the Province under the Safe Drinking Water Act.

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

In 2014, the City implemented corrosion control by adding phosphate to the drinking water treatment process at the four water treatment plants. Phosphate forms a protective coating inside all pipes and household plumbing fixtures, which helps to reduce the potential for lead to enter tap water. Recent results indicate a reduction in lead levels.

In March 2017, Toronto Water resumed the regulated sampling program, which includes taking samples throughout the year from at least:

• 55 residential and non-residential tap locations
• 10 distribution system locations

These results are submitted to the Ontario Ministry of the Environment, Conservation and Parks (MECP).

In 2020, due to COVID-19, the MECP granted regulatory relief for the collection of regulatory samples due to the limited access to plumbing samples.

Regulated Test Results

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

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