Cross Connection / Backflow

Protecting Our Water Supply

What is a cross connection?

A cross connection is any actual or potential connection that could introduce non-potable substances into the public water system.

The most common cross connections for homeowners involve an irrigation system, a boiler, an onsite well and a fire suppression system. These cross connections still exist and must be protected against even if they are not being used (irrigation off, well not being used). Below is a link to the Oregon Administrative Rules regarding cross connection and backflow prevention and testing.

What is backflow prevention?

Backflow prevention is any effective method used to prevent backflow into a potable water system. There are many types of backflow protection including air gaps, double check backflow assemblies, reduced pressure backflow assemblies, atmospheric vacuum breakers, pressure vacuum breakers, and spill resistant vacuum breakers. Each hazard level requires different backflow prevention which will be approved by the water supplier.

Why do I have to have my backflow tested?

Backflow assemblies must be tested to show that they are properly working and, in the event of a backpressure or backsiphonage incident, they will prevent backflow into the public water system.

When do I have to test my backflow assembly?

Backflow assemblies are required to be tested at the time of installation, repair or relocation; at least annually; more frequently than annually for approved backflow prevention assemblies that repeatedly fail or are protecting health hazard cross connections as determined by the water supplier; after a backflow incident; and after an approved air gap is re-plumbed.

Who can test my backflow and where can I find them?

Backflow tests must be performed by Oregon Health Authority Certified Backflow Assembly Testers. They can be found at the following link:

What do I do if my backflow assembly fails the required testing?

A backflow that fails testing must be repaired and tested again to show that it is in working condition, replaced with a new backflow that must be tested, or removed if the water supplier approves removal and a plumbing permit is approved through the City of Beaverton building department.

Who can repair my backflow assembly?

Plumbers can do repairs and replacements on all backflow assemblies.

Landscapers with the proper phase of professional licensing through the Landscape Contractor’ Board can install, repair or replace assemblies for irrigation systems with the additional requirement of certification through the Oregon Health Authority as a Certified Backflow Assembly Tester.

Employees can repair or replace assemblies on their employer’s property.

Homeowners can repair or replace their own assemblies.

Anyone can do repairs or replace assemblies that are protecting stand-alone fire systems. Stand-alone means that the connection is only for the fire system.