Cross-Connection Control

What is a cross-connection?

A cross-connection is a connection between the potable water supply and a contaminant source. Some examples include: a garden hose with one end submerged in a solution, (soapy water, fertilizer, or a pool) a supply line, a toilet, or a lawn irrigation system.

Why should I be concerned?

Cross-connections can allow the backflow of an undesirable toxic substance or contaminant into the MWRD drinking water supply. This can occur when water pressure is lower than normal as the result of maintenance or repairs. Back siphonage can also occur which is cause by negative pressure.

Cross Connection and Backflow

What are some common household cross-connection hazards? 

Hose connections are an extension of the water system. The installation of vacuum breakers on each hose connection ensures no harmful materials are drawn back into the water supply.

Boilers build-up pressure from the expansion of water and can result in the boiler water being pushed into the water supply. The installation of a backflow preventers can eliminate this risk.

If not properly installed, lawn irrigation systems can allow contaminants to enter the drinking water system. Protection can be provided by installing backflow prevention devices such as an atmospheric vacuum breaker or a reduced pressure device.

Do I need backflow prevention?

If you have any questions regarding cross-connections, please contact David Risner at the Cross Connection Control Department at 615-848-3222.

Irrigation Guidelines

  • IrrigationBackflow protection is required on all irrigation systems to ensure the safety of the public water supply. If your property has an irrigation system that does not have the required backflow protection you are not in compliance.
  • If an irrigation system is supplied by a well or river, the system must be totally segregated from the public water supply.
  • If an irrigation system is supplied by a well or river the Murfreesboro Water Resources Department requires you to fill out a Cross-Connection Control Statement. The completed form may be returned by fax or mailed with your water and sewer bill payment.
  • If you are not sure your irrigation system has the required backflow protection, please contact us and we will schedule an inspection.


Please refer to the Cross-Connection Control Procedures Manual for all cross-connection control requirements to include approved devices and installation criteria.

Cross Connection