Backflow Testing & Prevention
Test and maintain the device that keeps irrigation and reclaimed water out of drinking water.
Plumbing guide
Backflow Preventers in Sun City West, AZ: Sprinklers & Pools
A backflow preventer is a one-way gate for your drinking water. It sits on the sprinkler line and keeps lawn water, fertilizer and reclaimed water from flowing backward into the pipes you drink from.
By the Sun City West Plumbing Co. team ·
What backflow is
Water normally flows from the city main into your house. If pressure in the main drops, because of a main break or heavy demand such as firefighting, water can flow the other way. Backsiphonage pulls water backward through a connection. Backpressure pushes it backward when a system downstream has higher pressure than the supply.
A sprinkler system is a risk because it connects to the drinking water supply and sits in the yard, where heads and valve boxes can fill with puddled water, fertilizer, pesticides and soil. Without a barrier, that water can be drawn back into the line.
How a backflow preventer works
The device contains check valves, spring-loaded gates that open to let water through and close when flow reverses. Higher-protection devices add a relief valve that opens and dumps water if the checks fail. The common types for irrigation include the pressure vacuum breaker, the double check assembly and the reduced pressure zone assembly. Which one is required depends on the hazard and on local rules.
Hose bibs have a simple vacuum breaker built in or screwed on. Fire systems, boilers and commercial buildings often need larger assemblies. A plumber can tell you what your property needs and whether it is installed correctly.
Backflow devices compared
The device you need depends on the hazard and on local rules.
| Device | Where it is used | Note |
|---|---|---|
| Hose bib vacuum breaker | Outdoor hose spigots | A simple breaker, built in or screwed on |
| Pressure vacuum breaker | Irrigation | A common type for sprinkler systems |
| Double check assembly | Irrigation | Two check valves in series |
| Reduced pressure zone assembly | Higher-hazard connections | Adds a relief valve that dumps water if the checks fail |
Annual testing
Many water utilities require backflow assemblies to be tested each year by a certified tester. The tester checks that the check valves hold and that the relief valve opens at the right pressure, then files a report with the utility. A device that fails needs repair, often a new seat, disc or spring, or replacement.
Keep the report. Ask the tester whether they file it for you. Clear the area around the device and make sure the cover opens. Water to the sprinkler line will be off for a short time during the test. See backflow testing and prevention for what to expect.
Golf courses and common-area irrigation
Sun City West is built around seven golf courses run by Recreation Centers of Sun City West, and the surrounding desert landscaping on common areas and larger lots often runs on its own irrigation system separate from a home's drinking water. Wherever an irrigation system taps into the drinking water supply, whether it serves a single yard or a larger common area, a backflow preventer sized for that connection is required.
A plumber who installs or services residential irrigation backflow devices can also tell you whether your property's setup meets current code, since older installations sometimes predate stricter requirements.
Pool fill lines need protection too
Many homes in the Sun City West area have a pool, and the line that refills it from the house supply is another place a cross-connection can form if a hose or fill valve is left submerged. A simple air gap, or a backflow device on the fill line, keeps pool water (with its chlorine and chemicals) from ever being pulled back into the drinking supply.
If you're not sure how your pool is plumbed to the house, a plumber can check the fill connection along with your irrigation backflow device in the same visit.
Cross-connections inside the house
Backflow risks are not only outside. A hose left in a bucket, a sink with a spray hose that dangles in the water, a hose connected to a chemical sprayer, or a fish tank siphon can all draw water backward. An air gap, a physical space between the faucet and the water in the sink, is the simplest protection.
Use a hose bib vacuum breaker on any spigot that you attach a hose to, and do not leave hoses submerged. A plumber can check the spigots and the fixtures for places where a cross-connection is possible.
Choosing a tester
Testing must be done by a person with the right certification, using a calibrated test kit. Ask for the tester's certification number and ask whether the report will be filed with the utility. A repair, if needed, should be quoted before it starts, and the device should be retested after the repair so the report shows a pass.
Ask the utility for a list of requirements, such as which devices need an annual test, and where the report goes. That avoids penalties and keeps the water supply protected.
Signs your device needs attention
Water spitting from the relief port, a cracked body, a handle that will not turn or a device that has been hit by a mower or a vehicle all need attention. A wet patch around the box, or sprinkler heads that stay wet, can mean a leak. After a flood, a device that was underwater should be checked, since debris and contamination may have entered.
Why this protects the neighborhood too
A cross-connection on one property can affect others. If the main loses pressure, contaminated water can be drawn back into the lines that serve the whole street. That is why utilities set testing rules and why a failed device is treated as a public health issue, not only a private repair. Keeping your device in good shape protects the people next door as well as your own family.
Winter nights and the device
The Phoenix area rarely freezes, but an occasional hard cold snap in December or January can crack an exposed assembly, so cover it or wrap it when a freeze is forecast. After any flooding from a monsoon storm, check the device for damage and debris, and have it retested if it was submerged. A landscaping crew can also knock a device off its mounting, so mark it with a stake the mower or trimmer will not clip.
What to do now
Find your device. It is usually a pipe assembly above ground near the house or the meter, or in a box in the lawn. Note the make and size and when it was last tested. If you have a notice from the utility, call a certified tester promptly, since deadlines apply.
If you are installing a sprinkler system or adding reclaimed water, plan the backflow protection from the start and ask who handles the permit and the test report. A plumber can also check the outdoor spigots, since a leaking spigot is often related. See faucet and spigot repair.
Common questions
Backflow preventer questions
Most in-ground systems do. Local code decides which type. Ask your utility or a plumber.
A lot of water providers want a yearly test from a certified tester. Your provider can confirm the schedule.
If the pool fill line connects to your house's drinking water supply, yes. An air gap or a backflow device on that line keeps pool water from being pulled back into the house.
It needs repair or replacement and a retest. The utility may set a deadline.
Related services
Commercial Plumbing
Plumbing service for shops, offices, multi-unit buildings and shopping plazas.
Faucet & Sink Repair
Repair drips, weak flow, stuck shutoff valves and leaking outdoor spigots.
More plumbing guides
Outdoor spigot leaking
Where the water appears tells you which part failed. Handle, spout, vacuum breaker or the pipe behind the wall.
Pool leak bucket test
A bucket and a marker tell you whether your pool is losing water to evaporation or to a leak.
Why is my water bill so high?
A jump in the water bill usually has a plain cause. Eight to check, from toilets and irrigation to a leak under the slab.
Backflow test due, or not sure what you have?
Call and describe the device. The dispatcher will connect you with a local contractor.