Backflow Testing in St. Cloud

Backflow Prevention Device Types

Backflow occurs when a sudden drop in water pressure causes water to reverse direction in the supply line, potentially drawing contaminants back into the potable water supply. A backflow prevention assembly stops that reversal. The type of device your property requires depends on the hazard level of the cross-connection: the point where your plumbing connects to the public water supply.

RPZ Valves

An RPZ valve provides the highest level of protection and is required for high-hazard connections such as irrigation systems with chemical injection, boilers, and fire suppression systems. RPZ devices must be tested annually under the Minnesota Plumbing Code, and the City of St. Cloud requires those results to be filed through BSI Online.

Pressure Vacuum Breakers

A pressure vacuum breaker (PVB) is the most common backflow device on residential lawn irrigation systems in Minnesota. It’s a simpler assembly than an RPZ valve, but still requires annual testing if it was installed or replaced on or after January 23, 2016, per state code.

Double Check Valve Assemblies

A double check valve assembly (DC) is used for lower-hazard connections. Under Minnesota Plumbing Code section 603.5.10, a double check valve is also recognized as an option for boiler protection alongside RPZ valves, depending on the system’s hazard classification.

What Happens During a Backflow Test

A certified tester uses calibrated equipment to verify that your backflow prevention assembly is holding pressure and functioning as required. The process is straightforward from the property owner’s side: the tester accesses the device, runs the test, and records the results. Afterward, the device is tagged with the testing date, the tester’s signature, and their certification number. Written records must be submitted to the administrative authority and the community public water supplier within 30 days. For St. Cloud properties with RPZ devices, that means electronic submission through BSI Online.

If the device fails, it must be repaired or replaced by a licensed plumber before it can be certified as compliant, and a follow-up test is then required. Because Neighborhood Home Services handles both testing and plumbing repairs, we can move from a failed test to a completed repair without adding another scheduling step.

Backflow Testing Questions St. Cloud Property Owners Ask

How often does backflow testing need to happen?
Minnesota Plumbing Code requires annual testing for all testable backflow prevention assemblies. For most St. Cloud properties, that means once per year.

Does my home need a backflow test?
Homes with lawn irrigation systems, certain boiler setups, or other cross-connections to the public water supply are most likely to have a testable device. If you aren’t sure whether your property has one, our technicians can assess it during a visit.

Who is qualified to test backflow devices in Minnesota?
Testers must hold ASSE 5110 certification and be registered with the Minnesota DLI as a Backflow Prevention Tester. That certification covers all testable assemblies, including RPZ valves.

What happens if my device fails the test?
The device must be repaired or replaced by a licensed plumber before it can pass certification. A follow-up test then confirms compliance. We handle both steps so you don’t have to coordinate between two contractors.

How does the City of St. Cloud handle report submission?
The City of St. Cloud requires RPZ test reports to be submitted through BSI Online within 30 days of the test date.