Backflow Assembly Testing Questions & Answers
What is backflow?
Backflow is the flow of water in the opposite direction than intended, due to either backsiphonage or backpressure. The things that can cause a "backflow incident" are, breaks in the main supply pipe, the water company or repair technician temporarily turning off the water pressure and decompressing the line, fire trucks drawing excessive pressure and things of that nature.
What is a backsiphonage?
Backsiphonage is backflow caused by a negative pressure (i.e., a vacuum or partial vacuum) in a public water system or consumer's potable water system. The effect is similar to drinking water through a straw. Backsiphonage can occur when there is a stoppage of water supply due to nearby fire fighting, a break in a water main, etc.
What is a backpressure?
Backpressure backflow is caused when the downstream pressure is greater than the upstream pressure in either the public water system or a consumer's potable water system. This can occur during fire fighting, water line flushing or water main breaks. It can also occur when there are pumps installed on piping systems such as car washes with soap and wax injection or residential, commercial and agricultural wells. Elevated piping such as high hillsides or tall buildings can also have booster pumps to get water to higher heights.
What is a cross-connection?
A cross-connection is any temporary or permanent connection between a public water system or consumer's potable (i.e., drinking) water system and any source or system containing non-potable water or other substances. In other words, connecting dirty piping systems to the clean drinking water pipes including things like, medical buildings, landscape irrigation, fire suppression systems, boilers, and commercial facilities using chemical injection. That sort of thing. If you stop to think for a moment, the imagination can go on and on with the sheer quantity of cross connections throughout every water district.
What can happen when backflow occurs?
When water moves backwards in closed pipes we are at the mercy of every connection in that system. Some of the case histories of backflow incidence include carwash soap and wax, red wine, pesticides and bath water getting into drinking water pipes. The list is extraordinary.
What is a backflow preventer?
The best backflow preventer to date is the gap of air from the end of our faucets to the rim of our tubs and sinks and everything else in our homes. So if concern sets in after reading this, be comforted that your house has been designed not to backflow on its own. However, we install a few things that need isolation. That is where the backflow prevention assembly comes in. There are several kinds but they all do the same basic thing. They are in essence a one way valve that allows water only to flow in one direction, that is, from the water supplier to the delivery points. Good water goes in and bad water stays out. That is about all there is to it.
Why do I need a backflow preventer?
Backflow preventers are only needed when there is a determined risk to the drinking water supply. The common household systems that require protection are, landscape irrigation, closed or isolated fire suppression systems, and Jacuzzi tubs where the shower wand can reach into the tub and potentially draw water in a backsiphonage scenario. In our newer homes you can also see small backflow preventers installed on the exterior hose bibs so hoses that are left in any kind of container of liquid, cannot draw during a backflow incident. Boiler heating systems pose another kind of threat called thermal expansion. Water overheats and overpowers the supply water pressure and again causes the water to move backwards. So you can see the need for protecting the drinking water systems of our cities and equally as important, the immediate systems of our own homes. In conclusion, backflow prevention primarily protects the health of everyone drinking water and secondly, our liabilities.
Why do backflow preventers need to be tested yearly?
Backflow preventers have seals, springs and other moving parts that wear out or break. Because of this, they need to be tested to assure they are working properly. The professionals say that there is an approximate 4 - 5% failure rate annually if these devices are properly maintained. Even though the failure rate is low and backflow incidences are rare, there are just too many cross connections and too many past incidences to ignore the protection of our water delivery systems.
Can anyone test backflow preventers?
No, there is a stringent process of training and certification required by the government before a professional is qualified to test. It involves a 40 hour class with written and hands on exams before certification is issued.
How do I know who my water company is?
To find out who your water company is, click on the following link. You will be asked to enter your zip code to determine who provides your water: http://www.regionalh2o.org/.
How do I find a backflow tester?
OHA (Oregon Health Authority) provides a list of certified Backflow Assembly Testers. Only Oregon OHA-certified testers can test assemblies in Oregon. To see a list of OHA-certified Backflow Assembly Testers, click on the following link: https://yourwater.oregon.gov/backflow.php?county=Multnomah.
Do I need to send my test report to the water company?
No! Bruton Backflow & Irrigation will send a copy of your report to the water company for you. We will also happy to communicate with your water company on your behalf for anything pertaining to backflow prevention.
Thank you for taking the time to read about backflow prevention. If you or anyone you know have any more questions in need of clarification please feel free to contact us directly, we will be happy to help.