Backflow is the undesired reversal of water flow against normal direction, which can cause contaminants to enter into the drinking water supply system. Backflow prevention devices, or assemblies, are used to protect potable drinking water from contaminants and pollutants. There are two causes for backflow: back-pressure and back-siphonage. Having a backflow program protects our water supply.


There are several types of backflow assemblies. Marana Water requires a Reduced Pressure Assembly (RPA) because it provides the most protection. These assemblies contain two check valves separated by a reduced pressure zone. When properly operating, the pressure between the check valves is maintained lower than the pressure of the water supply. However, if either of these check valves leaks, water will be released from the relief valve. When this happens, maintenance or replacement of the assembly is required.


Example of an installed backflow assembly

Backflow assemblies are typically found in commercial and industrial buildings, buildings three stories or more, multi-family residences, and homes where there is more than one source of water like untreated well water.

Marana is unique in that there are some neighborhoods in Gladden Farms and Rancho Marana where non-potable irrigation water is provided by the Cortaro-Marana Irrigation District (CMID), which requires a backflow assembly to prevent irrigation water from entering the potable drinking water system. These assemblies require annual testing to ensure the community water system is continually protected.

What are the customer responsibilities for the backflow?

The backflow must be tested annually by a certified backflow tester that is registered with Marana Water. The link above includes all registered testers. Failure to have the test completed could result in disconnection of the potable water until the test is done.

Who is responsible for having the backflow assemblies tested?

The person or company who is listed as the responsible party for the water service with Marana Water is responsible for the annual testing of the assembly by a certified tester. This person is also responsible for maintaining records of maintenance and backflow prevention requirements. All tenants should contact the landlord to see if backflow testing is covered in the lease agreement. Regardless of the rental/owner status of the home,  if the backflow assembly is not tested properly, it could lead to disconnection of the POTABLE water supply until the assembly is in compliance.

Be sure to check the chart below for the timing of each neighborhood's testing. For customers needing to get a backflow assembly test, click the link below for a list of testers certified with Marana Water.


The dates listed to the right are general time frames. please wait for your letter from the town of marana with further instructions before scheduling to have your backflow assembly tested

how can i tell if my backflow test passed?

Customers who have contracted with a tester should be notified immediately, by the contractor, if their backflow passed. If there is a question as to the status of the test, please call our office at (520) 382-2570.

What to do when a backflow assembly fails.

If a failing test is received, the assembly should be repaired or replaced within 7 days of the failed test date. Contact a backflow tester to inquire if they provide repair services. The Tester Link above has all testers certified with Marana Water. If replacement is the only solution, a permit is required from Marana Water. The permit can be found by clicking here.

Permits must be submitted at least 24 hours prior to the new assembly installation to schedule the required staff inspection. There is a $35 permit fee, and a passing test is required upon installation.

Is a backflow assembly always required?

Yes, for commercial and industrial customers, multi-family residences, and buildings over three stories. Additionally, connections to the system where an alternative water source is present, such as an untreated well water. Installation of a new backflow assembly requires the permit found by clicking here, and payment of the $80 new backflow assembly fee.

Residential disconnection of a backflow assembly.

Homes that are currently receiving non-potable water from CMID may have the backflow assembly removed upon disconnection from the non-potable system. The following conditions need to be met:

  • Complete the disconnection permit found here.

  • Contact the Development Services department to acquire the appropriate building permit.

  • Schedule two inspections with Marana Water - one to disconnect the system to allow for construction to be completed, and a second to inspect the completed work. There are two fees associated where these inspections, $52.50 for the disconnection, and $35 for the inspection. All scheduling can be done by calling (520) 382-2570.

  • To meet inspection requirements, 3-5 feet of non-potable plumbing line needs to be removed to prevent any potential cross-contamination.

In the event the customer wishes to reconnect to the non-potable system, the following steps must be taken:

  • Complete a new backflow assembly permit and pay the $80 fee.

  • Contact the Development Services department to acquire a building permit to re-plumb the connection to the service line to the non-potable system.

  • Receive a passing test from a tester certified with Marana Water.


information for BACKFLOW assembly TESTERS

Marana Water uses an online portal for entering backflow assembly tests. Follow the link below to access the site and enter your information. Should you have any questions, contact the office at (520) 382-2570.