Cross-connections are connections in your plumbing that could allow contaminated water from your home or business to flow backward if there is a loss of water pressure and enter the drinking water.

You may introduce a risk of a cross connection if you directly attach something that uses chemicals, an alternative water source, or anything that could potentially add contaminants to the drinking water system to your water pipes, fixtures, or even a hose. Unprotected cross-connections introduce potential public health risks.

You can eliminate these risks by leaving at least a two-inch air gap between the water source and anything that contains dangerous or objectionable materials, such as a bucket of soapy water or a container of fertilizer.

If you cannot leave an air gap, a backflow prevention assembly or portable water meter is required to prevent your water from flowing back into the public water supply

Residential homes need a backflow assembly if they feature a lawn irrigation system, swimming pool, water treatment system, or fire protection system. Alternative water sources, like wells, springs, and harvested rainwater can also pose a risk if connected to your home’s plumbing.

Most businesses need a backflow device. Some examples of businesses that need backflow protection include but are not limited to: industries, restaurants, car washes, hospitals, dry cleaners, and salons.

A list of facility types susceptible to cross-connection can be found here.

To confirm with KUB whether or not you need a bakcflow assembly, call 865-594-8333.

If your water use introduces the potential for a cross-connection, you must install a reduced pressure zone backflow (RP) assembly following manufacturer’s instructions, local plumbing codes, and KUB specifications. 

If you are installing the device at a property within the City of Knoxville or in Knox County, you may need a permit and inspection. You can call 215-4311 in the City or 215-2325 in the County for more information.

If you are installing the device in Sevier or Jefferson county, please contact your County office to determine its requirements and call KUB for an inspection after installation.

Permits and inspections are only required on new installations. They are not required for maintenance or testing.

You are responsible for the installation, testing, and verification that your contractor submits a passing test report for all backflow prevention assemblies on property, which you may do using KUB's backflow prevention assembly portal. 

Backflow assemblies can only be removed if an air gap is installed in its place, or if the use of water has changed so that the risk of cross-connection is eliminated. For example, if your device is installed outside on an irrigation system, you can remove the assembly if it has been tested and cap the water lines while the system is not in use.

You may not remove or bypass backflow assembly and continue to connect potential risks to the water system. If in doubt, call KUB at 865-594-8333 before removing your backflow assembly.