The California Code of Regulations, Title 17 mandates that water purveyors such as NWC, administer a cross-connection control and backflow prevention program. You as our valued customer, also play an important role in preserving Nuevo Water Company’s water quality. Below, we are providing information on why backflow occurs and how you can help ensure that the public water system maintains its water quality integrity from contamination.

What is Backflow?

Backflow is the undesired or unintended reversal of flow of water and/or other liquids, gases, or other substances into a public water system’s distribution system. It can be caused by two conditions:



Backflow Installation Requirements:

If you are required to install a backflow preventer, please follow these guidelines:

Install per the appropriate standard drawing that is provided.

It is the customers responsibility to install, test, maintain and assume all costs for an approved backflow prevention assembly installed at the service connection.

The customer has 30 days to complete the installation and have the device tested immediately after installation. Unless a high hazard situation exists and then an immediate installation may be required.

Ongoing Requirements:

The customer is required to have the backflow prevention assembly tested annually. This is at the customer’s cost. (In some instances, testing may be more frequent than the annual requirement).

NWC will send out a reminder with a due date of when the assembly must be tested by.

You will be provided a Nuevo Water Company test form to be utilized by the Backflow Assembly Tester that you choose from the accepted NWC Tester list.

A sheet with Nuevo Water Companies accepted Backflow Assembly Tester’s will be included in the notice. Only Testers who are identified on this sheet are allowed to test within Nuevo Water Company’s service area.

Cross-Connection / Backflow Forms

NWC Test Form

Accepted List of NWC Backflow Testers (Click here for list, updated March 2022)

Approved List of Backflow Assemblies –

If you have any questions or if you suspect that a Cross-Connection may exist, please call 951-928-1922 or e-mail