City of Toronto Backflow Prevention Program

As per the City’s website, to help protect the safety of the City’s drinking water, it is mandatory under the City of Toronto’s Water Supply By-law for property owners of industrial, commercial, institutional and Part 3 residential properties (as defined by the Ontario Building Code) to install a backflow prevention device on the water supply line(s) to their facility. This is done to isolate buildings from the City’s water distribution system, helping to ensure contaminants do not enter drinking water.

A complete list of sectors required to install a device can be found in Schedule 5 of the Water Supply By-law.

Water Supply By-law

Summary of Property Owner’s Responsibilities

  • Some property owners may receive a letter requesting that they complete a survey to help the City ensure adequate protection has been assessed.
  • Surveys must be updated at least every five years, unless otherwise approved by the General Manager of Toronto Water, or within 30 days of any increase in hazard level.
  • Obtain permit(s) and have appropriate backflow preventer(s) installed by a plumber licensed with the City
  • Backflow devices must be tested by a registered Cross-Connection Control Specialist:
    • at the time of initial installation
    • within 72 hours after a device has been cleaned, repaired, replaced, serviced or overhauled
    • at least once a year

Qualified Person Registry

Backflow preventer devices can only be installed by a plumber licensed with the City of Toronto. In addition to meeting this requirement, EOS Mechanical Inc. is a registered Cross-Connection Control Specialist authorized to conduct Surveys, Installs, Testing, Service & Repair.

Compliance Letters

The City of Toronto frequently sends notices requesting compliance with the by-law:

City of Toronto Backflow Compliance Letter