What is a Backflow Prevention Assembly? Why does my house have a backflow preventer?

As we move into the summer months, it’s good to know how different aspects of your yard and lawn maintenance can impact our water system.

If your home has an irrigation system, it is required to also have a backflow prevention assembly. A backflow prevention assembly is typically part of an irrigation system or commercial property.

This is an important step to protect the drinking water supply in your neighborhood. A backflow prevention device ​prevents hazardous substances (i.e. chemicals used for lawn improvement or soil borne bacteria and parasites) from inadvertently being drawn into the drinking water system and contaminating it. 

If you have any questions or if we can assist you, please call 311 or 704-336-7600. Thank you for your cooperation.

Commonly Asked Backflow Questions

How often do I need to have my backflow tested?

Annually. A list of approved testers is listed on our website.

How do I know when is my backflow test due?

It is due the same time each year unless a deferment is granted. We check the last time it was tested and provide that information in the annual “Test Letter.” We can provide that to the customer by phone.

Is backflow testing performed by Charlotte Water?

Charlotte Water only performs an initial installation inspection and any follow-up required. It is the responsibility of the water customer to get the backflow assembly tested. For a list of approved testers, please see a list on our website.

How much does a test cost?

Charlotte Water does not set pricing for backflow assembly testing. Customers need to ask individual vendors what their charge is for testing their backflow assembly.

My residential irrigation system backflow is due for testing in December, can I delay testing until the spring?

Yes, please contact Charlotte Water for a deferment on the testing date. We recommend you have your assembly tested in the spring once the irrigation system is reactivated following winterization.

I have a backflow and so does my neighbor, however, my neighbor has never received a testing notification letter, why?

Your neighbor installer may have not contacted Charlotte Water about the installation of the irrigation system.

Where is my backflow?

It is the responsibility of the water customer to know the location of the backflow prevention assembly for their water system. Charlotte Water has locations based on initial inspection details.

My backflow needs repairs, do I need to hire a licensed plumber to make the repairs?

Yes, a licensed plumber is required per the N.C. Plumbing Board. You should hire a licensed plumber or professional who has expertise in repairing backflows. 

What is the difference between a backflow inspection and a backflow test?

A backflow inspection is an onsite visit by a Charlotte Water Backflow Inspector, making sure the assembly is installed properly.  A backflow test is to make sure the assembly with working properly. Charlotte Water does not perform backflow tests for its customers.

I understand backflows are for high hazard facilities such has hospitals and mortuaries, however, why do I need one on my residential irrigation system?

Irrigation systems can encounter contact with fertilizer, pesticides, and feces, which are high hazards.  A Reduced Pressure Principle Assembly (RP) backflow is used for high hazards.

I have a double check valve assembly (DCVA) backflow that needs replacing for my lawn irrigation system, can I replace it with another DCVA?

No, per Charlotte Water ordinance, the correct backflow preventer for irrigation must now be an RP(Reduced Pressure Principle Assembly). This applies to new installation and replacing a backflow on an irrigation system.

My irrigation system is no longer in use, do I have to test it?

Annual testing is still required until a licensed plumber has capped off your water service at the connection and removed the backflow prevention assembly. An inspection by a Charlotte Water Backflow inspector is required.

Installation Questions and Answers

Do I need a plumbing permit when installing a backflow?

Yes, please contact the Mecklenburg County Code Enforcement at (980)314-2633, You will also need to complete a backflow service application.

Do I qualify for a branch of my irrigation system from my domestic service without a separate water meter?

The Plat date determines if you qualify. The property must be platted prior to 2009. Research and provide the information with the Meter Deferment application.

Where do I send the Backflow Service Application? What is the fee for a new irrigation meter?

Please send backflow/meter applications and fees to:

Charlotte Water

C/O (NAME OF DEPT)

5100 Brookshire Blvd,

Charlotte, NC 28216.

Please contact New Services at (704)336-7600 for any questions regarding fees for water taps and meters.

I have a building project under construction and just had my backflow tested, however, I still have a project hold, did I do something wrong?

You need to contact the backflow inspections department at (704)391-5188 and see if there are additional holds for a backflow inspection.  Inspector needs to ensure the installation of the backflow. Ten days after the backflow inspection the backflow assembly needs to be tested by a Charlotte Water Backflow Approved Tester.

The meter and backflow were installed, and the installer left the meter cover open, so I wanted to know do we close it or is somebody else coming back to close it?

Please call the backflow inspection department for the inspector needs to ensure the installation of the backflow.