How Often Should Backflow Preventers Be Tested?

In Rochester, MN — and throughout Minnesota — backflow prevention devices must be tested at least once per year. This annual requirement is mandated by Minnesota state plumbing code (Chapter 4714) and enforced locally by Rochester Public Utilities (RPU).

The annual testing requirement applies to all types of backflow preventers, including Reduced Pressure Zone (RPZ) assemblies, Double Check Valve Assemblies (DCVA), and Pressure Vacuum Breakers (PVB). No matter what type of device you have, it needs to be tested every 12 months by a state-certified tester. If you're unsure what backflow testing involves, our complete guide walks you through the entire process.

This annual requirement isn't arbitrary — it reflects the reality that backflow preventers are mechanical devices with internal components (springs, seals, check valves, and O-rings) that wear out over time. Even a device that passed with flying colors last year could develop problems within 12 months due to normal wear, mineral buildup, or environmental factors.

RPU typically assigns testing windows based on when your device was installed or when your last test was performed. Most property owners receive a notification letter from RPU reminding them when their test is due. Your compliance date is essentially 12 months from your last successful test.

Best practice is to schedule your test 1-2 months before your deadline to allow time for any repairs if the device fails. This prevents last-minute scrambling and potential lapses in compliance. If your device needs repair, having that buffer time is invaluable.

Many property owners find it convenient to schedule their backflow test in the spring (April-May) for several reasons:

• Irrigation systems are being activated for the season and need their backflow preventers tested before first use
• Weather is comfortable for outdoor testing, which is important since most devices are installed outside
• It's easy to remember as part of an annual spring maintenance routine
• Testing companies tend to have more availability before the busy summer season
• Spring testing gives you the full irrigation season with a confirmed-working device

That said, backflow testing can be performed year-round. Some property owners prefer fall testing after their irrigation system is shut down for winter, combining testing with winterization services. Commercial properties often schedule during their annual maintenance windows regardless of season.

While annual testing is the minimum requirement, some situations may warrant more frequent testing:

• After a repair — Any time a backflow device is repaired or has internal components replaced, it must be retested to verify it's working correctly. This retest establishes a new baseline and resets your compliance clock.
• After a new installation — New devices must be tested before being placed into service, and then again within 12 months. The initial test confirms proper installation and that the device meets specifications.
• High-hazard facilities — Some commercial and industrial properties with high contamination risks may be required to test more frequently. Hospitals, chemical manufacturing plants, and wastewater treatment facilities often test semi-annually or quarterly.
• Recurring failures — If a device has a history of failing tests, more frequent monitoring may be recommended by RPU or your testing professional. This helps catch developing problems before they compromise water safety.
• After a backflow incident — If backflow is suspected or confirmed, immediate testing is required to determine if the device failed and to restore protection as quickly as possible.
• After freeze events — Minnesota winters can damage backflow preventers, especially if they weren't properly winterized. If your device was exposed to freezing temperatures, testing after the thaw is strongly recommended.
• After water main work — If RPU performs work on the water main serving your property, the resulting pressure changes could affect your backflow preventer. Testing afterward confirms it still functions properly.

While all devices require annual testing, different types of backflow preventers have different reliability characteristics that property owners should understand:

RPZ (Reduced Pressure Zone) Assemblies: RPZ devices are the most complex backflow preventers and provide the highest level of protection. They have more internal components (two check valves plus a relief valve), which means more potential failure points. RPZ devices should be tested annually at minimum, and regular maintenance between tests is especially important.

Double Check Valve Assemblies (DCVA): DCVAs are simpler than RPZ devices with fewer components, but they still require annual testing. These devices are less likely to have catastrophic failures, but worn check valve seals can gradually allow backflow without obvious external symptoms.

Pressure Vacuum Breakers (PVB): PVBs are commonly used for irrigation systems and must be tested annually. Because they're typically installed outdoors, they're more susceptible to weather damage and should be inspected carefully each spring before the irrigation season begins.

Regardless of device type, the testing process is similar and typically takes 15-30 minutes. Our guide on what happens during a backflow test provides a detailed walkthrough of the process.

Skipping your annual backflow test is not worth the risk. The consequences escalate progressively:

• RPU notification — You'll receive reminder letters, followed by warning notices with firm compliance deadlines
• Final warning — A certified letter giving you a final deadline, typically 10-14 days, to complete your test
• Water service disconnection — RPU can and does shut off water service for non-compliant properties. This happens more often than you might think.
• Reconnection fees — Getting your water turned back on involves additional fees ($50-$150) plus the cost of the backflow test itself
• Health risks — An untested device could be malfunctioning, putting your family and community at risk of contaminated water
• Liability — If a backflow incident occurs due to a malfunctioning device that wasn't tested, the property owner could face legal liability for any resulting harm or cleanup costs
• Property transaction issues — When selling your home, an expired backflow test can complicate the closing process and give buyers leverage to negotiate

The cost of annual testing ($75-$200) is minimal compared to these potential consequences. Learn more about Rochester's compliance requirements and deadlines to understand the full enforcement process.

Here are practical strategies to never miss a backflow test and stay permanently compliant:

1. Set a recurring calendar reminder — Add an annual reminder 60 days before your test is due. Set a second reminder 30 days out as a backup. Use your phone's calendar so you get push notifications.
2. Bundle with other maintenance — Schedule backflow testing alongside spring HVAC tune-ups, irrigation system startups, or fall winterization. This makes it part of your regular property maintenance routine.
3. Choose a reliable testing company — A good tester will proactively remind you when your next test is due. Many companies maintain client databases and send automated reminders. Learn what to look for in our guide to choosing a backflow tester.
4. Keep records accessible — Store your test reports where you can easily find them and reference the dates. A dedicated folder (physical or digital) for utility compliance documents makes this simple.
5. Don't wait for RPU's letter — While RPU sends reminders, don't rely on them as your only trigger. Proactively schedule your test rather than waiting for the reminder.
6. Consider a service agreement — Many backflow testing companies offer annual service agreements that automatically schedule your test each year. This eliminates the need to remember entirely.
7. Coordinate with neighbors — If multiple properties in your area need testing, some companies offer group discounts. This saves money and ensures your whole neighborhood stays compliant.

Ready to schedule your annual test? Contact us to get on a regular testing schedule for your Rochester, Byron, Stewartville, or Kasson property.