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Cross-Connection Control and Backflow Prevention


​Learn about Halton's cross-connection control program and required backflow prevention devices.

About the Cross-Connection Control Program

Do you worry about the quality of your drinking water? Are you aware of the steps that Halton Region has taken to ensure all residents have access to clean, safe drinking water?

Halton Region, in accordance with the Safe Drinking Water Act, introduced The Cross-Connection Control Program (CCCP) to protect the municipal water distribution system and prevent contamination from non-drinking water sources. It is the responsibility of all industrial, commercial and institutional (ICI), and multi-unit residential property owners to do their part to install the proper water backflow prevention devices and have these tested annually by an accredited tester.

As part of this program, Halton Region:

  • Identifies cross-connections where potential contamination of drinking water may occur
  • Enforces the installation of backflow prevention devices
  • Maintains database of locations with backflow prevention devices installed
  • Ensures testing of installed devices on an annual basis
  • Ensures compliance of the Drinking Water System By-Law 71-19 (PDF file)

Backflow prevention devices

Installed at or near the water meter, backflow prevention devices allow water to flow in only one direction by preventing what is known as backflow. Backflow occurs when a backsiphonage or back pressure condition is created in a water line and causes water to flow in the opposite direction.

Types of accepted backflow prevention devices


Reduced Pressure Principal Assembly (RP)

reduced pressure valve for backflow prevention device
  • Two independently acting check valves separated by a reduced pressure zone
  • Installed between two shut off valves
  • Each check valve is fitted with a test cock for periodic testing
  • Used for health hazards and severely hazardous connections (i.e. hospitals, medical/dental facilities, industrial or chemical plants)


Double Check Valve Assembly (DCVA)

DCVA valve for backflow prevention device
  • Two internally loaded check valves, force-loaded or internally weighted
  • If one check valve fails to close the other will prevent backflow
  • Each check valve is fitted with a test cock for periodic testing
  • Can be used for all non-health hazard connections (i.e. fire sprinkler, irrigation systems)

Step-by-step process for cross-connection control

Have you received a letter about Halton Region's Cross-Connection Control Program?

  • No backflow prevention device
    • Documents required:
      • Completed Survey
    • Administration Fee
      $112.20 + HST
  • Existing backflow prevention device
    • Documents required:
      • Completed Survey
      • Testing & Inspection Report
    • Administration Fee
      $56.10 + HST (per device)

Frequently asked questions

  • Halton Region will advise the type of device required after reviewing the completed survey submitted by the OWWA accredited tester.
  • Any connection between the municipal drinking water system and any source of contamination
  • Created when a source of pressure, such as a pump, creates pressure greater than the water distribution system
  • When water flows in the opposite direction caused by a negative pressure in the water line
  • Caused when there is a reduction or stoppage of water pressure because of nearby firefighting, power outages, repairs or breaks in watermains
  • Using a backflow prevention device to isolate the main municipal water supply and prevent drinking water contamination caused by backflow, backpressure, or backsiphonage
  • Multi-unit residential (greater than three stories)
  • Industrial, commercial, and institutional buildings
  • Installed at entrances to buildings for new sprinkler services and on customer's side of the water meter for domestic services
  • Moderate hazard - any minor hazard connection with low probability of becoming a severe hazard
  • High or severe hazard - any type of Cross-Connection involving substances considered dangerous to health