Backflow Prevention Program

Frequently Asked Questions

 

What is backflow?
Backflow is the undesired reversal of water flow against normal direction, which can cause contaminants to enter into the drinking water supply system. There are two causes for backflow: Back-pressure and Back-siphonage.

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What is back pressure and back siphonage?
Back-pressure occurs when the pressure in a private water system is greater than the pressure in the City’s water supply system. If this happens, water from a private water system can force its way into the water supply system. This can be caused by a pump, elevated tank, temperature increase in boiler systems, or other events causing an increase in local pressure.

Back-siphonage is the reversal of normal flow. This is caused by a reduction in the pressure in the local water supply system which can be caused by nearby fire-fighting or a water-main break. Back-siphonage can cause contaminated water to be pulled into the water supply system.

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What is an Air Gap?
 Air gapAn air gap is the unobstructed vertical distance through air between the lowest point of a water supply outlet and the flood level rim of the fixture (e.g. a bathtub faucet) or vessel into which the outlet discharges. The separation shall be at least twice the diameter of the water supply outlet and never less than one inch (1"). In theory, a well-designed and properly maintained air gap is considered the best means available for protection against backflow. However, it is not always practical and is vulnerable to easy bypass.

 

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What is the Backflow Prevention Program? Why is it important?
Toronto Water delivers safe and clean drinking water through the distribution system. The Safe Drinking Water Act and Ontario Ministry of the Environment and Climate Change (MOECC) regulations mandate water purveyors to protect the water supply to the point of delivery. In order to protect the public, the Water Supply Bylaw includes a program for backflow prevention to ensure the safety of drinking water. The program involves the isolation of private water systems from the public waterworks through the installation of a backflow prevention device immediately after the water meter. This is called premise isolation.

The Backflow Prevention Program focuses on Industrial, Commercial, and Institutional (ICI) properties, as well as multi-residential properties of five or more units, where there is a greater potential for backflow and contamination to the water supply.

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When did the Backflow Prevention Program begin?
The City of Toronto’s Water Supply Bylaw (Municipal Code, Chapter 851) was enacted on October 22, 2007 and came into effect on January 1, 2008. This bylaw is a consolidation of all similar bylaws enforced by the former municipalities. Section 8 of the bylaw addresses backflow prevention to ensure the safety of drinking water. The Backflow Prevention Program standardizes and enforces backflow prevention across the city.

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What is a water supply cross connection?
A water supply cross connection is any connection or potential connection between the drinking water system and any contaminant that could enter the water distribution system as a result of backflow. This could include a bypass, jumper connection, removable section of pipe, swivel or changeover device, and any other temporary or permanent connecting arrangement.

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How can contaminants enter into the water distribution system?
In order for contaminants to enter the drinking water system, a number of factors must be present: a cross connection must exist, a source of contamination must be present, and a backflow event would have to occur as a result of Back-pressure or Back-siphonage.

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Who is affected by this bylaw with regard to backflow prevention?
Industrial, Commercial, Institutional (ICI) and Multi-residential Properties (five or more units) that have the potential to contaminate the City’s water supply system, must install backflow prevention devices on all connections coming off the City’s water supply line. Different industries have different hazard classifications, i.e. a car wash facility or a hospital would be rated as a severe risk, a restaurant or a school would be rated as a moderate risk.

Compliance dates for industries, based on their risk level, are listed in Schedule 5 of the bylaw.

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Why are there various compliance dates?
The City would like to protect the water supply from the most severe hazard first, followed closely by those sites that pose a lower hazard.

The implementation of the program is spread out so that the work is manageable for the City, consultants, and the installation contractors.

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Why are homes not covered by this bylaw?
Single family homes generally pose the least threat for contamination of the water supply. They are considered a low hazard and no protection is required in the bylaw. However, homeowners can help to protect our water supply and the water within their own homes by installing backflow prevention devices on their garden hoses. They are called hose bibs and they can be purchased from hardware stores. Using a hose bib is not a law, but it is good practice in protecting homeowners and their families from contaminated water. Everybody has a role to play in protecting the health and safety of our drinking water.

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What is premise isolation?
Premise isolation is the separation of a property's private water system from the City's drinking water supply. In order to accomplish this separation, a testable backflow device is installed immediately downstream of the property's water meter and by-pass piping. By completing this, the water located within a building, structure, or property is no longer able to flow back through the City water meter and is contained within the property's private plumbing system.

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Is a building permit required to install a backflow prevention device? 
Yes, the Water Supply Bylaw Chapter 851 requires a building permit for projects involving new or altered plumbing, including backflow prevention devices.

A permit can be obtained at one of the four Civic Centres, depending where the property is located. Contact information for Toronto Building.    

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Does thermal expansion within the private plumbing system need to be addressed?
The building code requires that thermal expansion is addressed within the private plumbing system whenever there is an installation of a backflow prevention device. During the Building Permit process thermal expansion will have to be dealt with by the applicant within their submission.

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Who can apply for a building permit? 
The property owner can apply for a building permit, however in many cases; the plumbing contractor will do it on the owner's behalf. For more information, please refer to Toronto Building's website.

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How do I know what type of backflow prevention device my facility requires?
The type of device required for your facility will depend on the hazard level your facility is classified as based on Schedule 5 of the Water Supply Bylaw (chapter 851). The hazard level is determined by the industry sector and the property usage at your facility. Facilities classified as a 'moderate hazard' require the installation of a Double Check Valve Assembly (DCVA) device. Facilities classified as a 'severe hazard' require the installation of a Reduce Pressure Principle (RP) device.

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What is a Double Check Valve Assembly (DCVA) device?
A Double Check Valve Assembly (DCVA) is a mechanical backflow prevention device that consists of two internally loaded check valves. It includes two shut-off valves and four test cocks. With the two check valves in series, a DCVA prevents backflow even if one check valve fails to close tightly. It can be used to prevent backflow due to both Back-siphonage and Back-pressure where a minor or moderate hazard exists. Since no visible warning is given of a failure of check valves, a DCVA must be tested at least annually to ensure proper operation.

DCVA Image

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What is a Reduced Pressure Principle Backflow Prevention Assembly (RP)?
A Reduced Pressure Principle (RP) is a mechanical backflow prevention device that consists of two independently acting, internally loaded check valves, separated by a reduced pressure zone. During normal operation, the pressure between the two check valves is maintained at a lower pressure than the supply pressure. If either check valve leaks, water will discharge from the relief port. When this happens, maintenance is required. Due to the discharge of water, an RP must be properly installed in an area that has adequate drainage.

A Reduced Pressure Principle includes two shut-off valves and four test cocks. It is designed to isolate severe hazards and must be tested at least once a year.

Typical RP Image

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How often do backflow prevention devices need to be tested?
In order to ensure the proper operation of a backflow prevention device, it must be tested upon installation, repair, relocation or replacement, and at least once a year thereafter. To ensure that backflow prevention devices are functioning properly, a certified tester must test them annually.

Test reports can be submitted to Toronto Water:

by fax: 416-696-3641
email: backflow@toronto.ca, or
by mail: 275 Merton Street, Toronto, ON, M4S 1A7
Attention: Backflow Prevention Program

There is a fee to process each backflow device test report, which is determined by Toronto City Council as part of the annual budget process. The fee for 2017 is $52.44. Property owners will be charged this fee on their utility bill.

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Will water pressure be reduced within the private plumbing system of a facility due to the installation of a premise isolation backflow device?
Yes, the installation of a backflow device will reduce the water pressure within the facility. Please consult with the plumbing contractor that you selected, to ensure that there will be adequate water pressure after backflow device is installed. 

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Why do backflow prevention devices need to be tested? 
A backflow prevention device may not show visible signs of failure. Backflow prevention assembly devices contain internal seals, springs, and moving parts that are subject to fouling, wear, or fatigue. A backflow prevention assembly device, such as Double Check Valve Assembly (DCVA), or Reduced Pressure Principle Backflow Prevention Assembly (RP), must be tested by a certified individual as listed in Schedule 6 of the bylaw (chapter 681) with a properly calibrated test gauge.

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Who is responsible for the installation and annual testing of premise isolation backflow prevention device?
The owner of the property or building that currently has a service connection to the City's water supply or has applied for a new service connection is responsible for the installation of the premise isolation backflow prevention devices, as well the annual testing of the device by a certified tester.

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Who is qualified to install backflow prevention devices?
Before hiring an installer or maintenance contractor, ensure that he/she has proper certification.

Backflow prevention devices shall only be installed by an individual with the following accreditation:

  • Ontario Water Works Association (OWWA) or equivalent certification (within five years from date of issue) as a Cross Connection Control/Backflow Prevention Specialist; and
  • A Master Plumber with a City contractor licence; or
  • A Journeyman plumber employed by a City-licensed plumbing contractor; or
  • An Apprentice plumber who is employed by a City-licensed plumbing contractor and under the direct supervision of a Journeyman Plumber or Master Plumber;

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Who is qualified to test backflow prevention devices?
Backflow prevention devices shall only be tested by a certified tester with the following qualifications:

  1. Ontario Water Works Association (OWWA) or equivalent certification (within five years from date of issue) as a Cross Connection Control/Backflow Prevention Specialist; and
  2. A Current calibration certificate for the test equipment (traceable to N.I.S.T.) for one year; and
  3. Must be one of the following:
    • Licensed master plumber with a City contractor licence;
    • Journeyman plumber, employed by a licensed plumbing contractor;
    • Apprentice plumber employed by a licensed plumbing contractor and under the direct supervision of a journeyman plumber or master plumber;
    • Professional engineer;
    • Certified engineering technologist under the direction of a professional engineer;
    • Fire system sprinkler fitter;
    • Industrial millwright;

Do test reports need to be submitted on a specific form? 
Yes, test reports for back flow prevention devices must be submitted on a City of Toronto Backflow Prevention Device Test Form. Access the backflow forms and tag templates

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I have an old Test Report template form from a previous year; can I continue to use that for annual tests and/or new installations?
No. The old test reports are missing important information that has been added to the newer test reports. Please check our website for the most recent test report version, and use it for any tests conducted.

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Do the test tags have specifications? 
Device tags may be any size, colour, and made of a moisture resistant material. Section 8, D, (9) of the bylaw only requires that:

"The owner shall cause to be displayed a legibly marked record card on the premise isolation backflow prevention device that indicates the address of the property, the location, type and date of installation of the device, manufacturer, serial number and size of the device, the test date, the tester's initials, the tester's printed name, the printed name of the tester's employer and the tester's certificate number."

Download the backflow forms and tag templates.

These tags are meant to be used as Templates only; a facility should have its device tags customized without losing the original information.

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Do fire protection systems require a backflow prevention device?
In terms of fire protection systems, the Backflow Prevention Program only addresses existing facilities. Only fire systems that contain anti-freeze, foam injection, or other chemical additives or are connected with a private water supply require a Reduce Pressure Principle (RP) backflow prevention device to be installed.

Any changes to a fire protection system shall be done under the direction of a professional engineer who specializes in fire protection systems.

New construction is addressed by the Building Code and § 851-5-M of the Water Supply Bylaw (chapter 851).

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What are the fines for non-compliance? 
Pursuant to the Sections of Offences and Penalties specified in the Water Supply Bylaw, Toronto Municipal Code Chapter § 851-8:

  • A person who is convicted of contravention of Section 8 of the Bylaw (Schedule 3) can be fined up to not more than $100,000 for a first offence and any subsequent offence.
  • In addition, a corporation that is convicted of contravention of Schedule 3 can be fined up to not more than $100,000 for both a first offence and any subsequent offence.

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Are new buildings constructed with backflow prevention devices in place? 
All new buildings must conform to current bylaw requirements.

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If a business changes from a moderate risk to a high risk, what is the process for compliance?
It is the property owner’s responsibility to notify Toronto Water if there is a change from moderate to high risk. Please send your information to: email: backflow@toronto.ca, fax: 416-696-3641 or
mail: 275 Merton Street, Toronto, ON, M4S 1A7, attention: Backflow Prevention Program.

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What is a backflow prevention survey? 
If an existing facility has more than one water service connection, or has the potential to contaminate the City’s water supply system, the General Manager of Toronto Water may require the owner, at the owner's expense, to conduct a backflow prevention devices survey to evaluate potential risks and cross connections that may allow backflow contamination to the public water supply. The survey shall be conducted and signed by an authorised person as well as the facility owner, and a copy must be submitted to the City by the date specified in the General Manager's notification, or within 30 days. A backflow prevention devices survey shall include:

  • Number of water service connections with the waterworks;
  • Level of hazard for each water service connection;
  • Number, type and condition of any existing premise isolation backflow prevention devices;
  • Recommended and planned corrective measure(s), if applicable;
  • Schedule of work required for any corrective measures;
  • Recommendations for appropriate premise isolation backflow prevention device or devices, if applicable, in accordance with the CSA-B64 Standard.

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Who is qualified to prepare a backflow prevention device survey? 
A backflow prevention devices survey can only be done by a certified individual with the following qualifications:

  1. Ontario Water Works Association (OWWA) or equivalent certification (within five years from date of issue) as a Cross Connection Control/Backflow Prevention Specialist.
  2. Be one of the following:

    • Licensed master plumber with a City contractor license;
    • Journeyman plumber, employed by a licensed plumbing contractor;
    • Professional engineer;
    • Certified engineering technologist under the direction of a professional engineer;

The owner of the property is required to sign the survey report before it is submitted. These documents can be submitted by email: backflow@toronto.ca, fax: 416-696-3641, or mail: 275 Merton Street, Toronto, ON, M4S 1A7, attention: Backflow Prevention Program.

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Can businesses get a reclassification to low hazard that does not require them to install a backflow device? 
Only small dry retail operations with one or two residential apartments above the retail space have been reclassified to a low hazard category. A low hazard category does not require a backflow preventer to be installed at this time. Currently, there are very few reclassifications being given out. If you are a small dry retail operation and do not fall into a category listed in schedule 5 of the bylaw, you could be considered for reclassification. Please contact the Backflow Prevention program at 416-394-8888 (Backflow Voicemail) or by Email: backflow@toronto.ca to discuss your facility with us.

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For more information: 
To learn more, or for inquiries about backflow prevention:

Call: 416-394-8888 (Backflow Voicemail)
Email: backflow@toronto.ca

You can also download a copy of the Water Supply Bylaw

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