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Backflow Prevention

Backflow Prevention – Building Permit Requirements

On April 1, 2017, Region of Peel Council passed the Backflow Prevention By-law 10-2017. The purpose of the By-law is to prevent backflow into the Municipal Drinking Water System of The Regional Municipality of Peel for provisions of clean and safe drinking water.

Backflow prevention devices are required under the authority of the Region of Peel By-law 10-2017 and the Ontario Building Code. For further information on By-law 10-2017 and the Backflow Prevention Program, please visit

The following information is required to be provided upon applying for the installation of a backflow prevention device:

  • Site plan or key plan of the building that shows the location(s) of the proposed backflow prevention device(s), and
  • Detailed drawing(s), sealed, signed, and dated by a Professional Engineer, that indicate:
    • Installation methods of the backflow prevention device,
    • Backflow prevention device valve specification with reference to the applicable CSA B64 Standard,
    • Method of protection against thermal expansion, including sizing calculations,
  • Completed Commitment to General Review form, which can be accessed from the Forms Centre.

Note, if the backflow prevention device(s) is to be installed in a water system that serves a fire protection system (sprinkler, standpipe), submit drawings / details that show the new configuration and hydraulic calculations.

The above information must be submitted through the City of Mississauga’s ePlans system, which can be accessed from the following link: For further assistance in applying for a building permit, please call 905 615 4311.