A backflow preventer is a valve that keeps water from flowing the wrong way. Whether your house needs one tested depends on the rules that apply to you, and there's no one rule for the whole Valley. The fastest way to find out is to call your water provider and ask.
What does a backflow preventer do?
Water normally moves one way: from the public supply, through your meter, into your home. Backflow is when it moves the other way. That can happen when pressure in the system drops, for example during a water main break.
A backflow preventer is a valve that blocks that reverse flow. The point is to keep water that was never meant to be drunk, such as water from an irrigation line, from getting back into the water you and your neighbors drink.
At a home, you're most likely to find one on the irrigation system. Look near where the irrigation line branches off your water line. It's often an above-ground pipe assembly with small test fittings and shutoff handles. Sometimes it sits inside a ground-level box.
Who sets the rules in Arizona?
Rules can come from more than one place. Both the state and your water provider can set requirements, so ask your provider what applies to you before you book anyone. You'll also see the term cross-connection. That's any point where drinking water could meet water that isn't safe to drink.
Your water provider may run its own backflow program, whether it's a city water department or a private water company. Providers can differ on who has to test, how often, and which forms they want.
That's why we don't give one answer for the whole Valley. Start with your provider, and follow what it tells you.
Do home irrigation systems need testing?
It depends on the rules that apply to you, so ask your provider. Your provider may require it for homes or it may not, and you can't tell by looking at the device.
Commercial water connections and fire sprinkler lines fall under their own requirements. This post is about homes.
If you're having a new water line or irrigation connection installed, ask the installer how backflow protection will be handled. Our water line installation page describes that kind of work. Installing or replacing a device may also involve a permit in some cities, so ask your city.
How do I find out if my home needs testing?
It takes one call or a few minutes online.
- Find your provider's name on your water bill.
- Go to its website and search for "backflow" or "cross-connection control." Or call its customer service line.
- Ask whether your device must be tested.
- Ask how often, who may perform the test, and which report form to use.
- Ask when your next test is due, and what happens if it's late.
Write down the answers and the name of the person you spoke with. If your provider sent you a notice, keep it. The notice usually spells out what it expects and by when. If your provider says no test is required, ask for that in an email or letter, and keep it with your home records.
Who is allowed to test one?
The same two layers apply here: the state and your water provider. Testers work with a gauge kit that checks whether the device is holding. Where testing is required, ask your provider which testers and report forms it accepts.
Then, before you book, do two things. Ask the tester for proof of a current certification. And confirm with your provider that it accepts that tester's report. It's one phone call, and it can save you from paying for a test twice.
How often is testing required?
The schedule depends on the rules that apply to you, if testing is required at all. It may be a set cycle, or your provider may send a notice when a test is due. Ask when your next test is due, and how the report gets turned in.
A device can also be worth checking between tests. If it leaks, spits water, or looks damaged, tell your provider or have a licensed plumber look at it.
What if my backflow preventer fails the test?
A failed test means the device isn't doing its job. Ask your provider what it expects next, and ask a licensed plumber what the fix involves.
Get two answers from your provider: what the deadline is, and who sends in the report, you or the tester. Don't assume. A report that never gets sent can look the same as a test that never happened.
A licensed plumber can repair or replace the device. You get the price before the work starts, and you approve it first.
When should I call a licensed plumber?
Call when your provider has sent you a notice, when a test has failed, when the device is leaking or damaged, or when you're not sure what you have. Bring the notice and your water bill.
Repairs and replacements that involve your water lines are plumbing work, so a licensed plumber should do them. Our plumbing repair page explains how that works. Questions about the device in your yard? Contact us, and have your provider's requirements handy when you do.
Common Questions
It is a valve that stops water from flowing backward. It helps keep water that was never meant to be drunk, such as irrigation water, from getting into the drinking water supply.
That depends on the rules that apply to you, and the rules can differ from one provider to the next. Call your water provider and ask if your device must be tested.
Rules can come from both the state and your water provider, so ask your provider what it requires before booking anyone. Ask any tester for proof of a current certification.
It depends on the rules that apply to you, so ask your provider. Ask when your next test is due and how the report has to be turned in.
A failed test means the device is not doing its job. Ask your provider what it expects next, including the deadline and who sends in the report, and ask a licensed plumber what the fix involves.
