Backflow Prevention Program logo

The Town of Aurora will be implementing a mandatory Backflow Prevention Program, under Backflow and Cross Connection By-law 6213-19. To comply with the Bylaw, all industrial, commercial and institutional, and multi-residential property owners have to install a backflow preventer on the water supply line to their property. Multi-residential properties are those that have more than six units sharing a single water service.

The purpose of the Program is to ensure that the Town continues to provide safe and high-quality drinking water to our community by decreasing the chance of backflow.

Backflow happens when water from private properties flows back into the municipal water distribution system. These properties may have internal connections (called cross connections) to water used for non-potable purposes. This can create unsafe situations because of the potential for contaminants to flow back into the drinking water system.

Customers will receive information about the program by mail followed by Notices to Comply with the Backflow and Cross Connection Bylaw.

The bylaw will require industrial, commercial, institutional, and multi-residential property owners to undertake the following at their properties: 

Conduct a survey

  • The property owner will receive a Notice to Comply when the a Cross-Connection Control Survey is required at the property.

  • Select a qualified contractor.

  • Have the selected contractor survey the property to identify potential or existing cross connections within the plumbing.

  • As part of the survey, have the contractor classify the degree of hazard of your property.

  • Submit the completed Cross-Connection Control Survey to the Town.

  • Conduct a survey of the property every 5 years thereafter or whenever there is a change in use or ownership of the property

Install and/or test the backflow prevention device


  • The property owner will receive a Notice to Comply as a reminder if a backflow preventer(s) needs to be installed based on the survey report.

  • If the property does not have a backflow device, have the selected contractor install the required device and test it.

  • If the property already has the appropriate backflow preventer, have the selected contractor test the backflow prevention device.

  • Testing of the device is required at installation, after repair or relocation, and yearly thereafter.

  • The contractor must attach a test tag to the device.

  • The property owner must submit the Cross-Connection Control Test Report to the Town.

  • Owners must maintain the devices and address any corrective actions identified in the Cross-Connection Control Survey or Cross Connection Control Test Report.

  • Keep copies of the reports on-site

  • Notify the Town of any change to a property use (due to operational or tenant changes)

It is the responsibility of the selected contractor to determine the degree of hazard and type of device to be installed. These must be done according to the Canadian Standard Association  - CSA B64.

The program will be rolled out in three (3) phases:

  • Phase 1 – Properties classified as a severe hazard

  • Phase 2 – Properties classified as a moderate hazard

  • Phase 3 – Properties classified as a minor hazard. Devices would not be required at these properties unless the property use and hazard level changes.

Learn more:

 How Does Aurora's Drinking Water System Work?

The Town of Aurora distributes clean, safe drinking water through the local distribution system to individual customers.

York Region supplies treated drinking water to the Town. The drinking water supplied by the Region is a blend of water sourced from Lake Ontario and ground water wells.

Aurora's Water System

Under certain rare conditions, water from a private property could flow back into the Town’s drinking water system, creating an unsafe situation.  Here’s how:


  • Backflow happens when the normal flow of water reverses. Backflow may occur if there is a large pressure difference between the drinking water system and the customer's private system. This could happen if there is a break in a watermain, during use of a hydrant, or if pumps on private property increase pressure at the site. 

  • Cross connections is a connection between the drinking water pipes to another water source or to a source of contamination, like process water.

Before Backflow Prevention

After Backflow Prevention

Backflow Prevention By-Law

The Town of Aurora is taking steps to ensure that our drinking water continues to be clean and safe. 

The Town is legally responsible under the Safe Drinking Water Act, Section 19, Standard of Care to do its due diligence. Installation of backflow preventers is required under Section 7 of the Ontario Building Code and is considered to be industry best practice. 

Property types

To comply with the Bylaw, Industrial, Commercial and Institutional and multi residential property owners will be required to:

  • Conduct a cross connection survey of the private water plumbing and send the Town the Cross Connection Control Survey by fall 2019 and every five years after that.
  • Install backflow prevention devices at each property by 2020.
  • Test backflow prevention devices and send the Town the Cross Connection Control Test Report annually beginning in Spring 2020.
Residential property owners will not be impacted by this bylaw at this time.  However, a residential property may be subject to the bylaw if it poses a high risk for contaminating the water supply.


Get Involved


Take a look at the full by-law and the associated forms below to see how you may be affected.

Property owners of all IC&I and multi-residential (6 or more units) please complete the Information Request Form and to submit it to the Town by January 31, 2020.

Property owners must undertake a Cross Control Survey using the services of a qualified person and submit the reports to the Town by March 31, 2020. A list of qualified persons to conduct the surveys and perform the testing is available below in the downloads section.

Share your thoughts on the Backflow Prevention Program by visiting the comments page or email us at

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