Cross-Connection Backflow Control

USEPA Cross-Connection control Manual

Water line breaks or a sudden use of large amounts of water, e.g. during firefighting, can cause low pressure in the buried pipes that supply water to consumers' property. When this happens higher pressure water in a consumer's plumbing could be sucked backward drawing contaminants into the public water system.

The Division of Water is responsible for ensuring that the public water system is protected from this back siphoning of water from consumers' private water systems.

The Columbus Building and Zoning Department also has a role in ensuring that the consumer's plumbing system is protected from potential contamination from on-site hazards.

Backflow Preventor Certain plumbing installations pose a higher risk of contamination than others. When a sufficient hazard exists, a special device, known as a backflow prevention assembly, must be installed by the consumer. This device prevents the consumer's water from flowing backward in the supply line and maintains a one-way system.

Some typical examples of plumbing installations where backflow prevention assemblies are required include: irrigation systems, commercially leased property, full service restaurants, medical facilities, mortuaries, convalescent homes, laboratories, car washes, automotive shops, industrial sites, swimming pools and any property that has a second source of water available such as a well, pond or other auxiliary water storage.

When backflow prevention is required, the consumer must provide and maintain the assembly or assemblies at their own cost. Failure to do so poses a risk to the public, and may necessitate the Division of Water shutting off water to the property with the unprotected service line.

Annual Testing of Backflow Prevention Assemblies

Backflow prevention assemblies are mechanical devices. Like any mechanical device, they are prone to malfunction due to age, use, manufacturing defects, vandalism, etc. When a backflow prevention device is required, it must also be tested by an approved plumber or contractor at least once every 12 (twelve) months to ensure that it continues to function within accepted ranges. For listings of testers approved to test backflow prevention assemblies within the Division of Water service area refer to the Consumers' Page.

The Backflow Compliance Office (BCO)

The BCO administers the Division's backflow prevention program and assists the Building and Zoning Department in tracking the installation, maintenance, and testing of devices under their purview. The primary duties include:

  • track nearly 35,000 backflow prevention assemblies that protect the water system
  • ensure consumers comply with regulations
  • inspect new plumbing installations for conformity to codes
  • perform periodic surveys of consumers' property to identify potential hazards to the water system
  • establish minimum credentials required to be approved to test backflow prevention devices within our service area and monitor testers for compliance
  • ensure that the City is compliant with Ohio EPA's backflow prevention requirements for public water systems

Properties with Backflow Prevention Assemblies

If your property contains a backflow prevention assembly refer to the Consumers' Page for more information.

Backflow Prevention Assembly Testers

If you are a Certified Backflow Tester by the Ohio Department of Commerce Division of Industrial Compliance and wish to test backflow prevention assemblies at properties served by the Columbus Division of Water, refer to the Testers' Page.

Well Conversion

Properties with an auxiliary water system on or available to the property need to comply with backflow prevention codes and complete the Well Conversion form(PDF, 113KB).

  • Call 614-645-8276 for questions regarding the fee.
  • Call 614-645-6674 for more specific questions on backflow and the device.

Regulations Related to Backflow Prevention