Return to Home Page
Call us at 615-628-0237

Backflow Prevention/ Cross Connection

Mallory Valley Utility Districts Cross Connection Control Program protects our community’s drinking water supply by preventing backflow contamination

Backflow can occur when a change in pressure in the water system causes water in the pipes to flow in the reverse direction. This change in pressure has the potential to pull contaminants into the drinking water distribution system.

A cross-connection can occur when non-drinking water is unintentionally able to mix with drinking water.

Our Cross Connection Control Program regulates and inspects both commercial and residential buildings for conditions that could put our community’s drinking water system at risk for contamination.

Your participation in the Cross Connection Control Plan is critical in helping the District to protect the public water system from cross contamination and ensure safe drinking water for all its customers. Thank you for your efforts.

Required Annual Inspections

To meet state requirements, every backflow device must be inspected by Mallory Valley Utility District annually. We schedule inspections geographically.

Annual Program and Inspection Cost

  • Each service requiring a backflow device is charged $5 per month.
  • Backflow inspection charges will appear monthly on your water bill.
  • Failed inspections
  • If the backflow assembly fails inspection, we give the customer a timeline to address the issue.
  • The timeline will range from immediate disconnection to ninety days, depending on the level of hazard.
  • Re-test visits will continue until the customer has taken all corrective action to ensure backflow protection.

Commercial Backflow Requirements and Inspections

The District inspects commercial locations and classifies them as either high hazard or low hazard.
Depending on the level of hazard, the District may require

  • immediate protection,
  • immediate disconnection,
  • or customers may be given a certain amount of time to comply with regulations.

 Residential Backflow Requirements and Inspections

Potential cross connections concerns at homes include:

  • swimming pools,
  • hot tubs, and jacuzzies,
  • alternative water sources,
  • underground irrigation systems,
  • fire protection systems.

Any residence where a cross connection exists will be required to use proper backflow prevention measures. The District will inspect and test the backflow device every twelve months.

Note: Commercial residential buildings (i.e. triplex or apartment complex) are considered commercial properties.

Installation of Backflow Devices

All backflow installations installed for the protection of a public water system must meet the minimum District and  State of Tennessee installation standards.

Location of Backflow Devices

Backflow prevention devices should be placed directly behind the meter so that any connections are past the backflow and therefore protected.

If your device must be placed inside a building and its location has been approved, it must be placed in an area with:

  • Proper drainage
  • Proper head clearance
  • Must be installed at least 12” off floor and no higher than 5’.
  • Proper lighting
  • Easy accessibility
  • 3 feet clearance in front of device
  • No connections between meter and backflow are allowed.

If an existing backflow device requires replacement, it must be relocated to meet current District standards for installation and access requirements. This would apply to any installation of a backflow device which had previously been inspected by the District. Any remodeling project to the premises that adversely effects the access to the mainline backflow device would not be permitted and result in enforcement action for the customer connection.

 Customers Responsibility

Cross-connections created and maintained by the customer for his or her convenience endanger the health and safety of all who depend upon the public water supply.  Therefore, the customer who creates a cross-connection problem shall bear the expense of providing necessary backflow protection and for keeping the protective measures in good working order.  This includes repair, testing, installation, etc.

Cross Connection Hazards in the Summer

Over the next few months, the warm weather will bring people outdoors to work in their yards and gardens. And, many will begin getting their swimming pools ready. Mallory Valley Utility District would like to ensure that our customers are aware of the potential dangers associated with cross contamination when engaged in these activities.

A garden hose submerged in any liquid or attached to certain devices used to spray pesticides or herbicides will form a cross connection. A cross connection is a situation where a possible source of contamination is directly linked to our public water system. If the end of your garden hose is connected to a chemical container, swimming pool or other contaminant during a water main break or fire, the substance can be siphoned back into the water system. This condition, known as cross connection, could cause a public health hazard. Devices are available to prevent this problem. And, the best solution is to always be careful when using your garden hose.

Please help us provide a safe supply of drinking water to all of our customers. For more information on cross connections and how to protect against them, please call our office at 615-628-0237.

Backflow Testing Rate Change 

Special notice for commercial and residential customers that are required to have a backflow device. Cross Connection Program Backflow Testing Fee

Mallory Valley Utility District’s Cross Connection Program protects our community’s drinking water supply by preventing backflow contamination.  Generally, all commercial customers are required to have at least one backflow device and residential customers with irrigation systems are required to have a backflow device.  As required by the State of Tennessee, the District performs backflow testing for these customers each year. Beginning January 1, 2023, there will be a change in how the District charges for this service.

The District currently charges $60 per year, per device, for the testing and administration of the cross connection control program. This fee is added to your water bill during the month that we test the device. The District will now be charging the $60 fee over 12 months at $5.00 per month per active service that is required to have a backflow device. This $5 per month charge will now be added to your monthly water bill beginning January 2023.

Should you have any questions concerning this, please do not hesitate to call our Cross Connection Maintenance Coordinator, Marcella Waterston at (615) 628-0237 or visit our website



    Contact Us

    Mallory Valley Utility District serves customers in parts of Brentwood and Franklin, Tennessee.

    465 Duke Drive
    Franklin, TN 37067

    Government Websites by Municipal One ®