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Auxiliary Water Sources

I have an auxiliary source of water on my property for irrigation and want to keep it. What do I need to do?

  • Residences and other buildings or facilities that use an auxiliary water supply, such as a private well, a rainwater harvesting system or a pump in a lake, must install a Reduced Pressure Backflow Prevention Assembly (RPZ) at the meter. The existence of an alternate auxiliary water source onsite creates the potential of a cross connection between two water sources. The Texas Commission on Environmental Quality requires the highest level of backflow prevention protection, an RPZ, be installed to protect the public water supply from actual or potential cross contamination in situations where a secondary (or auxiliary) source of water that is outside the sanitary control of the public utility is available to a property.

  • The installation of the RPZ creates a closed water system in your home. Without an expansion tank, pressure build up in the water heater is released back through the meter. The RPZ prevents this release through the meter. That is why an expansion tank is required. This is installed on the cold water piping to the water heater.

  • You have the option to not install a backflow preventer (RPZ) on your water service, but that is contingent on abandoning the well, plugging it and providing the plugging report to the Water Department. Visit the Abandoned Wells page for more information on how to plug an abandoned well.

  • If you decide to keep the well and use it for irrigation purposes, you must install an RPZ on the water service and meet TCEQ Rules for Landscape Irrigation which requires that “any irrigation system that is connected to a public or private potable water supply must be connected through a commission-approved backflow prevention method.

What are the requirements for an RPZ?

  • The RPZ must be labeled as USC approved. It is installed above ground and requires 12-inches of clearance from ground level to bottom of the relief valve opening. Freeze protection equivalent to ¾-inch wall installation is required. If the RPZ is enclosed in an insulated box for freeze protection, there must be a drain to daylight.

  • Assemblies shall be installed at the point of delivery of the water supply, before any branch in the line, and on private property located just inside the boundary of the city’s right-of-way. An inspector may specify other areas for installation of the assembly.

Do I need any permits for this work?

  • Yes, and multiple permits may be required. City ordinances require that any structure connected to the Fort Worth water system meet city plumbing standards. Fort Worth cannot connect you to the water system if you do not comply. Fort Worth has adopted the 2015 International Plumbing Code and the 2015 International Residential Code with local amendments.

How much do the permits cost and how do I obtain them?

  • Permit applications can be completed online, once registered in the system, or in person through the City of Fort Worth Development Services Department, located on the lower level of City Hall, 200 Texas St. You will need at least two permits – one plumbing backflow permit and one plumbing permit for the thermal expansion tank. If the irrigation system is new, is having zones added or modifications to over 20 percent of an existing system, a lawn sprinkler permit is required. Each permit has a $25 application fee in addition to the permit cost. The plumbing backflow permit cost is $31.31, and the lawn sprinkler permit is $58.69. Visit the Development Services Department fee schedule to determine the plumbing permit cost for the thermal expansion tank or call Development Services at 817-392-2222.

  • Fort Worth allows homeowners to do plumbing work on their own residences, but the required permits still need to be obtained. The homeowner must present documentation showing that the home and is his or her homestead. Permits can be obtained based on data in the Tarrant Appraisal District records. Additionally, the address on the applicant’s driver’s license must match the address of the home for which the permit is being obtained.

Who performs the inspections?

  • A residential inspector from the Fort Worth Development Services Department will inspect the thermal expansion tank installation. A certified backflow inspector from the Water Utility will inspect the RPZ installation and lawn sprinkler system, if necessary. The RPZ requires an annual inspection by a registered backflow tester on Fort Worth’s list of Registered Backflow Testers. The annual inspection is not performed by Fort Worth staff.

Can I have my house connected to both the city water supply and an auxiliary water supply?

  • No. Connections of a public water supply and a private water supply are prohibited by City of Fort Worth Plumbing Code. The connection of both a public water supply and an auxiliary supply is considered a cross connection and is not allowed even an RPZ backflow assembly in place.

Contact Information

Backflow/Cross Connection Control Section