Commercial Compliance 2025-06-02 · 5 min read

Backflow Preventer Testing in Tolleson: Annual Compliance Calendar for Commercial Properties

Backflow preventer assembly with test ports and valves for Backflow Preventer Testing in Tolleson: Annual Compliance Calendar for Commercial Properties

The valves and test ports show the hardware used during backflow certification. It fits the Backflow Preventer Testing in Tolleson: Annual Compliance... section.

Annual backflow preventer testing is a legal requirement for commercial and industrial properties in Tolleson, not a recommendation. The Arizona Department of Environmental Quality's cross-connection control program requires that all backflow preventer assemblies on commercial water services be tested annually by a certified tester, with results submitted to the applicable water authority. For properties within Tolleson's incorporated city limits, that authority is the City of Tolleson Water Utilities. Understanding what the requirement covers, when the deadline applies, and what happens when certification lapses is essential for any facility manager or commercial property owner in Tolleson.

Which Properties and Devices Are Subject to Annual Testing

The annual testing requirement applies to any commercial or industrial property with a backflow preventer assembly on its water service connection. This covers the majority of commercial properties in the Tolleson Industrial District and the Van Buren commercial corridor, including warehouses, food distribution facilities, restaurants and food-service operations, retail properties with irrigation connections, and any commercial property with a fire suppression system. The specific device type present at each property determines the test procedure required.

RPZ (reduced pressure zone) assemblies: required for high-hazard connections including fire suppression systems, irrigation connections with fertilizer injection, and industrial process water connections
DCV (double check valve) assemblies: common on lower-hazard commercial water connections
PVB (pressure vacuum breaker) devices: used on some irrigation connections

Each device type requires specific test procedures and calibrated equipment. A facility with multiple assemblies needs each one tested and certified separately.

The Testing and Reporting Process

The annual test must be performed by a licensed backflow tester using calibrated pressure gauges. The test evaluates the differential pressure performance of each check valve or air inlet in the assembly and documents pass or fail for each test point. Results must be submitted to the City of Tolleson Water Utilities in the required format on or before the facility's annual certification due date.

The due date for each facility is typically tied to the date of the original installation or the last submitted certification. Facilities unsure of their current due date can request the information from the City of Tolleson Water Utilities. We maintain testing records for each assembly we have certified and send annual scheduling reminders to Tolleson facilities we service, which removes the administrative tracking burden from facility management teams.

The valves and test ports show the hardware used during backflow certification. It fits the Backflow Preventer Testing in Tolleson: Annual Compliance... section. The repair area is visible from a closer angle.

What Happens When Certification Lapses

A lapsed backflow certification creates a documented non-compliance condition with the City of Tolleson Water Utilities. The typical enforcement sequence begins with a notice of non-compliance, followed by a compliance deadline. If the deadline passes without a completed test and submitted certification, the City of Tolleson has authority to interrupt water service at the property until compliance is achieved.

For a food-service or food-distribution operation in Tolleson's industrial corridor, water service interruption is an immediate operational shutdown. The simplest avoidance strategy is scheduling the annual test at least 30 days before the certification due date and confirming that the report has been received by the city before the deadline. Many facility managers running multiple Tolleson properties find that a single certified tester managing all assemblies and handling direct submission to the city removes the most common point of compliance failure: administrative oversight during busy operational periods.

When a Device Fails the Annual Test

If an assembly fails the annual test, it must be repaired or replaced and retested before a certification can be issued. Common failure modes in Tolleson commercial assemblies include check valve seats that no longer hold differential pressure, relief valves opening below or above the required threshold, and shutoff valves that cannot be fully isolated for testing. We carry repair components for common RPZ and DCV assemblies and complete most repairs in the same visit, retesting and issuing certification immediately after the repair is verified. When a device requires a replacement part not in our standard stock, we document the failure with the city per the required notification protocol and schedule the return repair promptly.

What Happens During the Annual Certification Test

A backflow preventer certification test takes 15 to 30 minutes per assembly. The tester attaches a differential pressure gauge kit to the test cocks on the device and measures pressure readings across the check valves and relief valve. For a reduced pressure zone (RPZ) assembly, the test verifies that the first check valve holds to a minimum of 3 psi net closing differential, the second check valve holds at a minimum of 1 psi net closing differential, and the relief valve opens before the differential across the second check falls to zero. These thresholds are not arbitrary: they represent the minimum margin at which the device can be expected to prevent backflow under the pressure conditions it will encounter in normal operation.

Double check valve (DCV) assemblies undergo a similar pressure test but without the relief valve component. The tester verifies that each check valve holds independently across a range of downstream pressure conditions. A DCV that passes both checks is confirmed capable of preventing backflow in low-hazard applications. For high-hazard connections at Tolleson commercial facilities, an RPZ assembly is required regardless of DCV performance.

Common Failure Modes and What They Mean

The most frequent failure finding in annual testing is a first or second check valve that fails to hold its differential pressure threshold. This typically means a check valve disc or seal has been compromised by debris, mineral scale from Tolleson's hard water, or mechanical wear. In most cases, the assembly can be repaired on the same visit using replacement internals. Check valve seat replacement is the most common repair, taking 30 to 60 minutes for standard RPZ and DCV assemblies. A complete assembly replacement is required when the body itself is corroded or the internals are no longer available for the device's age and model.

Relief valve failure in an RPZ assembly, where the valve opens prematurely under normal differential conditions, requires replacement of the relief valve module. An RPZ with a failed relief valve is not functional as a cross-connection control device and must be repaired before the city will accept the test report. When a failed assembly is repaired and retested in the same visit, the tester can submit a passing test report for the calendar year without requiring a separate test appointment. This is why having repair components on hand matters: a passed test in one visit closes the annual compliance cycle without follow-up.

Submitting Results to the City of Tolleson

The City of Tolleson Water Utilities tracks certification status by assembly and by property. After a test, the licensed tester submits the field test report to the city using the state-approved form, and the city updates the tracking record for each certified assembly. Property owners and facility managers receive confirmation from the city when the submission is accepted. If a test report is not submitted, the city will issue a compliance notice. In some cases, repeated non-compliance leads to a water service interruption notice. Keeping the prior-year test report on file at the property simplifies the process when the city requests documentation during any inspection or permit application.

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