The information listed here provides answers to FAQ’s regarding Backflow Prevention/Cross Connection Control in Ontario, including your responsibilities and how to safeguard your property.

What is a cross-connection?
The connection between a potable water system (our drinking water) and a source of contamination (liquids, gasses or solids).

What is backflow?
The unwanted flow of water in the reverse direction, usually caused by back siphonage or back pressure, allowing contaminants to enter the potable water supply.

What is a backflow preventer?
A device or assembly installed at strategic locations in the plumbing system to prevent backflow from occurring.

Why is a cross-connection control/backflow prevention program necessary?
As explained on the Ontario Water Works Association’s website, In Chapter 7 of the Report of the Walkerton Inquiry, A Strategy for Safe Drinking Water, the Hon. Dennis O’Connor states that “as part of their comprehensive distribution system program, water providers should have active programs, working together with building inspectors and public health agencies, to detect and deter cross-contamination”. Justice O’Connor goes on to state “Infrastructure is also vulnerable to amateur cross-connections and their attendant risks of contamination”. Poor backflow conditions have the potential to contaminate the public’s water system which poses a health risk to consumers who drink water from the system and can result in serious illness including death.

Who is responsible for water protection in Ontario?
Quite simply put, it is everyone’s responsibility. Water protection in Ontario is enforced through the Ontario Safe Drinking Water Act, the Ontario Building Code Act and municipal by-laws.

Responsibilities of individual municipality or water purveyor (authorities) include establishing and monitoring cross-connection control/backflow prevention programs. Visit our Helpful Links page to view all active programs. Please note, if you have properties in different municipalities, requirements may vary for each municipality.

Responsibilities of the Owners of Industrial, Commercial and Institutional (ICI) and Multi-Residential Properties include providing water that is safe to drink under all foreseeable circumstances. In order to ensure this happens, a proper backflow preventer must be installed and maintained at the connection to each system or premises that poses a hazard to the public water system. This includes annual testing and repair when needed to ensure the device is functioning properly. Some facilities may also be required to have zone protection designed to protect facility users. Property owners must ensure only qualified persons are hired perform surveys, installations, testing, maintenance and repairs. Municipal backflow programs may have an authorized functions list that identifies which qualified person can do what with respect to testing, installing, repairing, and relocating backflow preventers.

Journeyman plumbers and registered apprentices working under the direction of a journeyman plumber are the only persons permitted to install plumbing, including installing and repairing backflow preventers as required by the Trades Qualification Act of Ontario. Property owners must ensure only qualified persons are hired. Qualified persons are responsible for ensuring their work is to code and complies with all by-laws.

OWWA Accredited Cross Connection Control Specialists are the only people qualified to perform backflow testing and cross-connection surveys in Ontario. The OWWA Cross Connection Control Committee establishes and maintains the training program for testers. Individual municipalities may have a registration program for testers.

Municipal Plumbing Inspectors are hired by the municipality to ensure work is completed to code.

Who is liable if a backflow situation occurs, causing contamination to the public water system? This depends on a number of factors. One or more of the following parties could be found liable:

  • the owner of the property where contamination originated
  • the plumbing contractor who installed the cross connection and or backflow preventer
  • the OWWA Certified Cross Connection Control Specialist hired to survey, install, test or repair any devices on the premises
  • the municipal inspector (and Municipality) responsible for ensuring work is performed to code
  • The water purveyor who owns the water system

It is important to note that as the property owner you will need to prove that you have fulfilled your responsibilities with by-laws and applicable legislation which includes hiring qualified persons, installing the appropriate backflow preventer devices, ensuring devices are inspected annually, performing regular repair and maintenance, submitting and keeping copies of all required documentation.

Why should I choose EOS Mechanical Inc. to provide service for my property?
Backflow prevention is all we do. Our purpose is to assist property owners in safeguarding their properties to ensure compliance with applicable by-laws and legislation regarding backflow prevention.We are qualified OWWA accredited testers and experienced plumbers. We focus on remaining current with changes in the industry. Our services extend beyond surveys, installs, testing and repairs; we help to educate our clients and maintain all records to help safeguard your business from penalties, fees, and liability issues.

What steps are taken during a Cross-Connection Survey, Installation, Backflow Test or Repair?
Click on the link below to view detailed information about that service.