Annual Backflow Testing Requirements
Per Oregon Administrative Rule (OAR) 333-061-070 and District Rules and Regulations, all approved backflow prevention assemblies must be maintained and tested at least once per 12-month period to protect the public water system. Protecting the public water system from the risk of contamination is a serious matter for Tualatin Valley Water District and the State of Oregon.
Frequently Asked Questions
Tualatin Valley Water District and the State of Oregon, Oregon Health Authority require the public water system be protected from non-potable water sources. Examples of non-potable source include, but are not limited to: irrigation systems; fire suppression systems; wells; swimming pools/hot tubs. Testable backflow assemblies prevent the flow of water in a direction other than its intended path. They are, in a sense, a one-way valve.
Using irrigation systems as an example, there is a risk that your sprinkler system may be exposed to: the glue and primer used to join the PVC pipes; chemicals and/or fertilizers commonly used to maintain your lawn and other plants; animal urine or feces which may collect around or come in contact with an outlet of your sprinkler system.
A typical backflow assembly for an irrigation system would contain two check valves. The check valve on the side of the irrigation system is under constant pressure preventing the water from entering the water supplying your home. Should this check valve fail, the second valve is present to provide the safety barrier. Research has shown, and the State and TVWD agree, annual testing is an ideal timeframe to test the backflow assembly to ensure it is properly protecting the public water system. More frequent testing would not be beneficial, however the risk of backflow failure increases greatly if testing did not take place annually.
Typically, once per calendar year.
The State and TVWD actually require backflow assemblies be tested under five circumstances:
- At the time of installation
- After any repairs to an assembly
- If the assembly is relocated
- Annually (once per calendar year)
- After a backflow incident
Backflow assemblies which are not tested annually pose a greater risk to the customer's home and the public water system. Due to the seriousness of this risk, the State authorizes water purveyors to discontinue water service until it is determined the risk is no longer present.
Only individual, apprentice plumbers, or journeyman plumbers who have satisfactorily completed a State of Oregon, Oregon Health Authority approved backflow assembly tester training course and hold a current and valid State certification may test backflow assemblies.
Yes. During a typical year, we will mail backflow testing reminder letters to residences who we do not have record of a passing annual backflow assembly test report. First notices are mailed in March. If needed, second notices are mailed in May and third/urgent notices are mailed in August.
As long as a backflow assembly is installed, it is required to be tested annually. The longer non-potable water sits in an irrigation system, or any other non-potable water source, the greater the risk of pollutants or contaminants being introduced to those systems. Water in dormant sprinkler system may sit for years. During a backflow event, that water would be introduced into customers' homes as well as the public water system.
The State and TVWD require all non-potable water sources, such as irrigation/sprinkler systems, have backflow protection.
Atmospheric Vacuum Breakers (AVBs) provide backflow protection (when installed properly to code) and are not subject to annual testing requirements. AVBs do however, require regular inspection to ensure they are functioning properly.
In some instances, TVWD does not have record of a customer's backflow assembly and we are unable to send reminder letters to those customers about the annual testing requirements. In addition, the customer may not familiar with backflow protection and its importance.
Per Oregon Administrative Rule (OAR) 333-061-070 and Tualatin Valley Water District (TVWD) rules and regulations, TVWD is authorized to discontinue water service to premises for:
(A) Failure to remove or eliminate an existing unprotected or potential cross connection;
(B) Failure to install a required approved backflow prevention assembly;
(C) Failure to maintain an approved backflow prevention assembly; or
(D) Failure to conduct the required testing of an approved backflow prevention assembly.
This conveys the seriousness the State and TVWD place on the safety of the public water system.
This is not a simple question to answer. At a minimum, a hose bibb should have a hose bibb vacuum breaker or Atmospheric Vacuum Breaker (AVB). A hose bibb vacuum breaker is a threaded device that screws onto the spigot mouth. It prevents water from flowing backward into your pipe with a spring loaded check valve. This valve opens and closes based on the water pressure.
When the water flows, the pressure of the water pushes open the check valve in the hose bib backflow preventer. When you turn off the water, the pressure against the spring on the valve decreases, the valve closes, and air flows into the space around the valve. The air pressure and the spring keep water from seeping back into the spigot from the outside.
AVBs are the simplest and least expensive of devices intended to keep water from flowing back into the water lines. They operate by using the outside air pressure to close a check valve. When you turn on the water, the water pressure pushes open the water valve. When the water is off, the air pressure pushes down on the valve and blocks the pipe.
There are installation requirements for AVBs. Atmospheric vacuum breakers require that they be installed at least 6-inches above all downstream piping and outlets. This is to eliminate the potential of backpressure. If the downstream piping or outlets are above the vacuum breaker then the resulting backpressure may flow back (backflow) through the vacuum breaker. In addition, there should not be any valves (shutoff valve or timers) downstream from the vacuum breaker.
Laying a hose on your lawn and attach a rotating or oscillating sprinkler head to the end of the hose is not a concern. However, if your hose bibb is connected to an in-ground irrigation system or drip system piping, these are more permanent examples of an irrigation system and should be properly protected from backflow. Our staff may discuss the details of your particular irrigation system and provide recommendations.
As a public entity, we are unable to recommend one company over another. We suggest searching the internet and reading online business reviews. Family, friends and neighbors may also be good source for finding a backflow testing company.
The State of Oregon, Oregon Health Authority offers a listing of certified backflow assembly testers, however the list is very extensive and does not provide business information for each tester.
If you have paid a testing company to perform your annual backflow assembly test, you should not be receiving our reminder notices. Before contacting TVWD:
- Verify the test took place in the current year. Annual tests are required once "per calendar year" not once every 12-months.
- Contact your testing company to make sure they electronically submitted the passing test report to TVWD.
- Testers/Testing companies may not be aware of who your water provider is. They may have sent the test report to neighboring water providers (the cities of Beaverton, Hillsboro, Portland, Tigard, or Tualatin).
- Your backflow assembly may have failed and follow up (with your testing company) is needed.
- Your testing company may not have the ability to electronically submit test reports to TVWD.
If your HOA or Property Management company coordinates your annual test, you may need to reach out to them to ensure the test took place.