Backflow/Cross Connection Program

Cross Connection/Backflow – F.A.Q.

As a City of Forest Grove water customer, you expect your drinking water to be safe. We are committed to providing you healthy, high quality water, but we need your help to prevent contamination through backflow to keep our water safe throughout the system. Customers who have cross connections are responsible for preventing contaminants from entering the public water system through their individual plumbing system by installing and maintaining approved backflow prevention assemblies. Plumbing permits are also required for new installations of backflow assemblies.  The following is a list of the most frequently asked questions about cross connections and backflow prevention.

What is a cross connection?

A cross connection is any connection between piping that carries drinking water (also known as potable) and the piping or fixtures that carry other types of water or substances that are not safe to drink (also known as non-potable), and any matter that may change the color, taste, quality, or odor of water.

What are some common examples of residential cross connections?

Examples include residential fire systems, wells or auxiliary water systems, lawn irrigation systems, boilers, and swimming pools and hot tubs that are hard piped for filling purposes.

What is backflow? Why is backflow protection necessary?

Drinking water normally flows in one direction (from the meter to the house), although under certain circumstances it can flow in the opposite direction, or ‘backflow’. A backflow incident can happen at any time. All that is needed is a water pressure drop in the public water system main line, most commonly caused by fire fighting, hydrant flushing, flow testing, a water main break, or extreme high usage on the water system. Any connection to a non-potable source not protected could be siphoned back into the public water system, which can pollute or contaminate the water system.

Backflow protection is necessary because we assume that when we turn on the water tap, we have safe drinking water. This is a luxury we enjoy, but not without very strong regulations and considerable expense. Our drinking water is among the safest in the world. Water protection and conservation requires the effort and cooperation of everyone.

What is a backflow assembly?

Backflow assemblies are devices placed on cross connections to prevent water from backflowing into the water system. The most common type of backflow assembly is a double check valve assembly, which consists of two independent check valves, two resilient seated valves and test cocks.

What is the legal basis for a cross connection control program?

The federal Safe Drinking Water Act (SDWA) 42 U.S.C. 300f to 300j-26 has jurisdiction over the public health aspects of the drinking water supply. The Oregon Health Authority regulates public water systems in our state, including cross connection control, through Oregon Administrative Rules (OARs). One such rule is OAR 333-61-0070, which requires water districts to administer a cross connection control program that will protect the potable water supply and the City of Forest Grove has passed an ordinance on cross connection control, City Code 50.25 to 50.31.

Do I currently have adequate backflow protection? How can I find out?

If your irrigation system, boiler, fire system, swimming pool or spa was permitted through our local building department, adequate backflow protection was required. If you installed or had the fixture installed without proper permits, or you are not sure if you have adequate backflow protection, please contact the Backflow Program Specialist at (503) 992-3115 and they will perform a survey for you. There are no fees for this survey.

What is the responsibility of a building owner, property manager and water supplier?

Legally the water supplier is responsible for water quality and for implementing and maintaining a cross connection control program to prevent pollution or contamination of the public water system. The water supplier’s responsibility ends at the outlet side (the customer’s side) of the water meter. Once the water is on the outlet side of the water meter or service connection, responsibility and liability falls to the owner.

How often do backflow assemblies need to be tested?

Backflow assemblies must be tested at the time of installation, annually (once a year) after installation, after repairs and after relocating or replacement. When Forest Grove customers test their backflow assemblies, a test report will be submitted to the City of Forest Grove Program Specialist by the tester.

How do I know when my assembly needs to be tested?

The City maintains a database containing all the permitted backflow assemblies in Forest Grove. When your device is due to be tested, the Program Specialist will send out a notice and a list of certified local testers. It is then the customer’s responsibility to schedule the test and make payment arrangements. Upon completion of the test, the customer will be given a copy and the tester will submit the results to the City.

What are some ways that I can help prevent contamination of the public water system due to backflow?

You Can Help! Fortunately, there are many things you can do to prevent contamination of the public water system due to backflow.

  • Irrigation Systems:  Ensure an approved backflow assembly is installed, is in good working order and is tested annually.
  • Swimming pools and hot tubs:  Ensure that if a water hose is used to fill these units, it is protected with a hose bib vacuum breaker installed on the faucet.
  • Residential boilers:  Ensure an approved backflow assembly is installed, is in good working condition, and is tested annually.
  • Private wells:  Ensure that well systems are not connected to the public water system. If it is connected, it must have a backflow assembly at the meter, be in good working condition, and is tested annually.