Backflow Prevention Program
A program to minimize potential drinking water contamination

Markham’s Backflow Prevention By-law, passed by Council in 2007, is designed to minimize potential contamination of Markham’s drinking water. The program involves identifying and removing cross connections between customer connections (deemed a risk) and Markham’s drinking water system.

The current Backflow Prevention Bylaw applies to:

• All industrial and commercial properties in Markham.
  
  
• Residential buildings and structures which are individually serviced from the municipal drinking water system through a single connection greater than 50mm in diameter.
  
  
• Residential properties with connections to fire protection or lawn sprinkler or any other potable systems.

Contracting Testers and Insurance

Property owners will have to contract (and pay) a Certified Tester for the required survey and testing of their backflow prevention device(s).

Any testers who are hired must meet the specific technical requirements indicated in the Backflow Prevention By-law (see the Backflow Preventer Device Tester Application Form below).

We also suggest that customers check appropriate insurance coverage and discuss costs before proceeding with any work.

How does the program work?

• Markham will monitor compliance with the Bylaw and identify (through survey reports) cross-connections (between customer’s plumbing and water supply system) where potential contamination of Markham’s drinking water system may occur.
  
  
• We’ll maintain a convenience list of Certified Backflow Prevention Device Testers for customers to reference
  
  
• Waterworks will maintain a backflow prevention device database
  
  
• Cross-connection surveys will be required to be conducted by affected customers every three years
  
  
• Testing of backflow prevention devices will be required to be conducted by affected customers annually

What are the property owners’ responsibilities?

Cross-Connection Survey: The property owner (for which the By-law applies) is required to have a certified tester carry out a cross-connection survey of all plumbing in each building or structure every three years and submit a report to the Town.

Backflow Prevention Device Testing: The property owner (for which the By-law applies) is required to have a certified tester perform backflow prevention device testing every year and submit a report to the Town.

How do I locate a Certified Tester?

Markham maintains a list of certified testers below. SEE RELATED DOCUMENTS FOR UP-TO-DATE LIST.

I’m a tester. How do I have my name added to the list of certified testers?

A Backflow Preventer Tester Application Form is available below for those interested in applying for consideration. SEE RELATED DOCUMENTS FOR APPLICATION FORM.  

The Backflow Preventer Tester Application Form must be submitted to Markham’s Waterworks Department with all required certificates.

Contact Information

For more information contact Markham Waterworks
Telephone: 905-475-4862
Fax: 905-479-7772
Email: backflow@markham.ca