Backflow Prevention

Under certain circumstances, the flow of water can reverse in a water service line and may contaminate the City’s drinking water supply. This is known as backflow. The City of Brantford has implemented the Backflow Prevention By-law to prevent this from happening.

This by-law applies to the following properties:

  • industrial
  • commercial
  • institutional
  • multi-residential (buildings with four or more storeys)

Annual test requirement

As a property owner or occupant, you are responsible for installing and maintaining backflow prevention devices. These devices must pass performance tests annually by a plumbing contractor with backflow prevention certification. Annual testing is mandatory for all types of backflow prevention devices.

Survey forms

Below you will find our required forms:

Submitting reports

A copy of your report must be submitted within 14 days of testing to the City’s Compliance Division located at 324 Grand River Ave., Brantford, ON. Alternatively, your report can be scanned and emailed for review.

Survey requirement

The Canadian Standards Association (CSA) B64.10 Standard requires that you must perform a follow up survey every five years and submit the results to the City within 14 days of testing.

Survey exemptions

You are exempt from the survey requirement if:

  • The premise is protected with a reduced pressure principle assembly (RP) backflow prevention device.

If you fail to submit test reports and/or surveys, you may face fines. A list of all Backflow Prevention By-law policy violations and associated set fines are outlined below.

Set fines for violations of the Backflow Prevention By-law
ViolationOffence Creating ProvisionSet Fine (includes cost)
Fail to perform a survey within 30 days of making a process or operational changes that may increase the hazard level 649.4.8 $350
Fail to provide a survey to the City within 14 days of completion 649.4.8 $350
Fail to perform a follow-up survey every 5 years 649.4.9 $350
Fail to follow the CSA Standard for installation, maintenance or field testing 649.5.1 $500
Failure to ensure a device is in proper working order 649.5.3 $500
Fail to test a device annually or after repair, replacement or relocation 649.6.1(a) $350
Fail to repair or replace a malfunctioning device immediately as per backflow testing results 649.6.1(c) $500
Make a connection to the City’s potable water supply which may allow wastewater or a non-potable water source to enter 649.8.1 $1000

By-law violation enforcement process

Properties found in violation of the by-law will receive an Action Order letter detailing the nature of the infraction(s) and a 30-day grace period to comply. The Action Order letter will be sent by registered mail to the occupant, and a duplicate letter will be mailed to the registered property owner(s) if applicable.

If evidence of compliance hasn’t been submitted within the 30-day grace period, the Backflow Prevention Inspector will schedule a site visit to provide the occupant with the opportunity to explain why they have not complied with the by-law. A compliance timeline will be provided. If the occupant exceeded the timeline to comply after the site visit or failed to meet with the Backflow Prevention Inspector, a Part I Offense Notice as per the Provincial Offenses Act R.S.O. 1990, c. P.33, detailing the specific infraction(s) and corresponding set fine(s) will be served. Part I Offense Notices shall be issued no less than 30 days apart and in more serious non-compliance cases, a Part III Information as per the Provincial Offenses Act R.S.O. 1990, c. P.33 will be served until the occupant is in full compliance with the City’s Backflow Prevention By-law

More information

Find forms and more information about backflow prevention, issues and solutions:

Backflow terms defined
  • A cross-connection is any connection or potential connection between any source of pollution or contamination and a drinking water system.

Backflow Preventer

  • A device that prevents backflow from occurring. Please note that backflow preventer need to be tested annually to make sure that they will work as intended


  • Caused by negative pressure, backsiphonage is backflow in a public water system. Low water pressure can cause suction on the public water supply side and can actually pull contaminants into the water system.


  • Backpressure is pressure that is greater than the municipal water system supply pressure. This can also force contaminants into the water supply line if the pressure is greater than the City’s water pressure.
How to comply with the Backflow Prevention By-law

There are five steps in order to comply with our by-law:

  1. A qualified plumbing contractor, engineering consultant or in-house professional engineer in a related field will determine the degree of hazard posed by a given facility by performing an initial cross-connection inspection and completing the initial cross-connection survey. This inspection is needed to determine what level of protection is required to isolate the premise, (premise being at the location where a municipal water supply first enters the property or building, i.e. near water meter), in the form of a backflow prevention device.
  2. Where the highest level of protection is already in place at the premises or if the owner chooses to install a Reduced Pressure Principle Assembly (RP) backflow prevention device to isolate the premise, a cross-connection survey is not required.
  3. Once the survey is completed, the property owner will be required to install the appropriate backflow prevention device(s) to isolate the premise, as recommended by the results of the survey. A building permit would be required prior to this installation.
  4. Once a backflow prevention device is installed and tested, it must continue to be tested on an annual basis to ensure compliance with the by-law. A test report for each backflow prevention device must also be submitted to the Compliance Department.
  5. A follow-up cross-connection survey will be performed once every five years for each backflow prevention device, unless the highest level of protection is already in place to isolate the premise i.e. an installed Reduced Pressure Principle Assembly (RP).
Backflow protection and the Ontario Building Code
The Ontario Building Code (OBC) does require backflow protection devices to be in place wherever a potential cross-connection has been identified on a property. The OBC does not give authority to plumbing inspectors to re-enter a building for the purposes of inspecting their backflow prevention devices to ensure they are being tested annually. Furthermore the OBC does not give the inspectors authority to inspect existing buildings to ensure that adequate backflow protection is in place. However, the City’s Backflow Prevention By-law does give the Inspectors this authority.
Who can perform a cross-connection survey?
  • Professional engineer with tester's licence (an in-house Professional Engineer in a related field may perform survey at their own facility without a tester's licence)
  • Certified engineering technologist with tester's licence (must be under the direction of a Professional Engineer)
  • Licensed master plumber with contractor and tester's licence 
  • Journeyman plumber with tester's licence (must be employed by a licensed plumbing contractor)
Who can install, repair, relocate or replace backflow prevention devices?
  • Licensed master plumber with contactor and tester’s licence
  • Journeyman plumber with tester's licence (must be employed by a licensed plumbing contractor)
  • Apprentice plumber with tester's licence (must be employed by a licensed plumbing contractor and under the direct supervision of a journeyman plumber or master plumber)
  • In-house maintenance staff is permitted to do repairs if they have a tester's licence
Who can test backflow prevention devices?
Anyone with a tester’s licence as per CAN/CSA-864.10-94 (as amended) is permitted.
Install an RP device and avoid the requirement to submit a survey
If you plan to install an RP, the requirement to perform the cross-connection survey will be waived. Please notify us of your decision by the applicable survey deadline. Please Note: this device will cause a drop in your usual water pressure by approximately 10 psi. In addition, RP devices may not be installed in a pit and require adequate drainage capacity. In order to make an informed decision about choosing to install an RP device, it is strongly recommended that you consult with a plumbing contractor or engineer with a tester’s licence.