Yes. Common-area irrigation is a cross-connection, and Arizona requires each backflow assembly on it to be tested at least once a year by a certified tester. The duty falls on the water customer, which for common-area meters is usually the association. Failed tests must be repaired and retested.
Does the rule apply to an HOA, or just businesses?
It applies to the HOA. Arizona's rule doesn't carve out common areas. The state rule, R18-4-215, lets a water system require the assembly. A public water system "may make installation of a required backflow-prevention assembly a condition of service." If a user does not comply, that "shall be sufficient cause for the public water system to terminate water service." The rule also says: "Each backflow-prevention assembly required by this Section shall be tested at least annually, or more frequently if directed by the public water system or the Department."
Phoenix puts the duty on the customer. Section 37-143 of the city code says the customer "shall properly locate, install, test and maintain each backflow prevention assembly in good working condition." Its exemption is narrow: the backflow requirements don't apply "to single-family residences used solely for residential purposes" unless a cross-connection problem is identified. A community's common-area irrigation system isn't a single-family residence. Outside Phoenix, the state rule still applies, and your water provider, whether a city or a private water company, sets the reporting steps.
Who exactly has to schedule and pay for it?
The customer, meaning whoever holds the water account for the meter feeding the irrigation. Phoenix's customer responsibilities are specific:
- Get a city permit to install a backflow assembly or modify the plumbing.
- Test every assembly at least once a year, using a certified tester.
- Submit the test results on the city's approved forms by the date the city sets.
- Keep records for at least three years.
- Repair a failed assembly to the city's satisfaction and retest it.
- Notify the city and the County health authority if a cross-connection contaminates the water.
Arizona requires the tester to hold a current general tester certification. It can come from the American Water Works Association's California-Nevada Section, the Arizona State Environmental Technical Training center, or another authority ADEQ approves. Landscape contractors who "also do backflow" should be able to show current certification.
A management company usually books the test, but the association carries the obligation. Put the due date on the board's calendar and ask for the filed report, not just an invoice.
Which assembly does common-area irrigation need?
The type depends on the system. Phoenix's required-methods list for irrigation reads:
| Irrigation system | Assembly |
|---|---|
| Uses a chemical injection system | Reduced-pressure principle (RP) assembly |
| Has elevated areas or multiple services | RP |
| Not subject to backpressure | Pressure vacuum breaker (PVB), installed above ground |
State rule R18-4-215 also permits a PVB on a landscape irrigation system only when criteria are met, including that fertilizer and pesticide injection (chemigation) is not used. If your landscaper injects fertilizer through the irrigation lines, that changes the assembly you need. Our page on RPZ vs. double check assemblies explains the difference between the types.
What happens if a test is missed?
Phoenix's rules give the city several tools, and the HOA is the one on the hook. The city can end water service for several reasons. These include failing to install, test or maintain a required assembly, removing or bypassing one without approval, and allowing a cross-connection. Late test and repair records count too. It normally gives ten days' written notice before shutting service off. If the city decides the system could be a health hazard to the public water supply, it can shut service off at once and without notice. Service comes back only after the problem is fixed to the city's satisfaction, and all costs, fees and penalties have to be paid first.
There are money penalties too. The Water Services Director can impose a civil penalty of up to 1,000 percent per billing period on the water charges from the date corrective action was required until it is done. The city can also install an assembly at the point of service and bill the customer for it. It may publish a notice naming customers in violation during the past twelve months.
For an association, the practical result is losing irrigation to the common areas in the middle of a Phoenix summer, when landscaping dies in days, plus a possible penalty on the water bill. The better outcome is the routine one: test, repair what fails, file the report.
### Why does the rule exist?
The EPA's Cross-Connection Control Manual defines a plumbing cross-connection as an actual or potential connection between a potable and a non-potable water supply, and calls it a serious public health hazard. Its list of places to check for cross-connections includes irrigation outlets, and it lists the lawn sprinkler system among fixtures whose inlets can be submerged. If pressure in the main drops, water from the irrigation side can be pulled back into the drinking water pipes. The manual's examples include a private well used for lawn sprinkling that was tied to the city supply and pushed contaminated water into the main when pressure dropped. A working backflow assembly is what prevents that.
### What does the annual test involve?
Phoenix requires the test to be done by a certified tester, following the procedures in the University of Southern California manual that the city's code incorporates. The tester checks that the assembly holds and opens the way it should, and records the results on the city's form. The customer, meaning the association, has to submit the results, and has to repair or replace any assembly that fails and have it retested until it passes. If anyone learns between annual tests that an assembly is defective, the same duty to repair and retest applies. Keep the reports for at least three years.
Fire sprinkler lines are a separate case. Phoenix requires the initial and annual test of a fire line's backflow assembly to include a full flow test by a certified tester, and those lines are handled by fire protection companies. This page covers landscape irrigation only.
### What about wells and reclaimed water?
Some communities irrigate from a private well or a reclaimed water line, sometimes alongside a city meter. Any connection between a non-drinking source and the drinking water pipes is a cross-connection. The EPA manual describes a case where a private well used for lawn sprinkling was tied to the city supply through a valve, and contaminated water was pumped into the main when pressure dropped. If your community has more than one water source, ask your water provider how each one must be protected, and never leave a valve connecting the two systems.
What should the board do this year?
- 1List every irrigation meter and every backflow assembly on the property, including the ones inside meter boxes.
- 2Confirm which are due and who the water provider says the customer is.
- 3Book a certified tester, and get failed assemblies repaired before the deadline.
- 4File the results the way the provider requires and store the reports for three years.
For the single-property versions of this question, see backflow preventers for sprinklers in Arizona and commercial backflow testing requirements. HQ is licensed and insured and gives free estimates on backflow work.