Arizona Administrative Code R18-4-215: Backflow Prevention and Annual Testing

In Short

Arizona Administrative Code R18-4-215 requires public water systems to guard the drinking supply from backflow through cross-connections. It makes owners install an approved backflow-prevention assembly where a hazard exists, have it tested by a certified tester, and keep records of each test.

Primary Source

Arizona Administrative Code R18-4-215 (Backflow Prevention)

This is a government work (Arizona statute, administrative rule, or city ordinance) in the public domain. Always confirm the current official text at the source before relying on it.

Drinking water flows one way by design: from the utility to your tap. Backflow is when that flow reverses and pulls water from a building back toward the public main. If that building water has touched irrigation soil, chemicals, or a fire-sprinkler line, the reversal can contaminate the drinking supply for a whole neighborhood. Arizona Administrative Code R18-4-215 is the state rule that forces water systems to prevent it.

What this rule requires

R18-4-215 puts the duty on the public water system to protect its supply from cross-connections, and it does that by requiring backflow-prevention assemblies where a hazard exists. The rule states the core duty plainly:

A public water system shall protect its system from contamination caused by backflow through unprotected cross-connections by requiring the installation and periodic testing of backflow-prevention assemblies.

A few specific requirements follow from that. The assembly must be installed as close as practicable to the service connection. It is required wherever a substance harmful to health could enter the system, which the rule lists as chemicals, process waters, deteriorated water supplies, and water that has entered a fire sprinkler system. Testing must follow the procedures in the Manual of Cross-Connection Control and be done by a certified tester. The assembly itself must carry a certificate of approval from the USC Foundation for Cross-Connection Control and Hydraulic Research or another approved certifying body. And the water system must keep records of installations and tests.

When this comes into play

This rule reaches almost every commercial property and many homes with irrigation. Picture an office building with a lawn-sprinkler system tapped off the domestic water line. That is a classic cross-connection hazard, so R18-4-215 requires a backflow assembly on it, an annual test by a certified tester, and a test report on file. The same applies to a restaurant with a carbonator, a warehouse with a fire-sprinkler system, or a car wash. In practice, the water provider passes the state rule down to the property owner, who pays for the assembly, the yearly test, and the reporting.

What this means for you

If your property has a backflow assembly, put its annual test on a calendar and use a certified tester, because a missed test can mean a shutoff notice from the water provider. If you are not sure whether you need one, the trigger is a cross-connection hazard, not the size of the building. Phoenix carries out this state rule through its own Chapter 37 cross-connection program. For how Phoenix tracks and enforces this locally, see do I have to register my backflow assembly with the City of Phoenix, and for the commercial testing cycle, see commercial backflow testing requirements in Arizona.

Full text and source

R18-4-215 is part of the Arizona Administrative Code, a public record of the state's rules. Read the current text on the Cornell Legal Information Institute mirror: Ariz. Admin. Code R18-4-215. The state's program is administered by ADEQ.

This page explains a state rule in general terms and is not legal or compliance advice. Local water providers add their own requirements on top of the state rule, so confirm the current rule text and your provider's rules before you rely on them.

Sources

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