To satisfy municipal plumbing codes and protect your property’s drinking water, annual backflow assembly testing must be conducted by a certified technician who measures pressure differentials across internal check valves. Because compromised backflow preventers allow contaminated irrigation water, fertilizers, or industrial chemicals to siphoning backward into domestic water lines, certified annual testing is required for Sioux Falls area homes and commercial facilities.
Summary of Backflow Prevention
- Certified annual testing satisfies local city water compliance mandates
- Pressure differential testing verifies internal check valve seat closure
- Backflow preventer installations block fertilizer siphoning from irrigation lines
- Master-level backflow repairs eliminate hazardous cross-connection risks
The Role of Backflow Prevention Devices
At PrairieSons, we know that keeping clean drinking water safe across Sioux Falls and Brandon requires certified plumbing expertise. A backflow prevention device is a specialized mechanical valve assembly installed on your water line that permits water to flow in only one direction, preventing non-potable liquids from reversing course and entering your fresh water supply.
Without a properly functioning backflow assembly, sudden drops in municipal water pressure, caused by local fire hydrant use, main line breaks, or heavy irrigation demand, can create a suction effect known as backsiphonage. This vacuum pressure can draw stagnant water, lawn chemicals, pesticides, or industrial waste from irrigation systems and commercial equipment directly back into your home’s drinking water taps.
Definition: Backsiphonage
Backsiphonage is a phenomenon where negative or sub-atmospheric pressure in a municipal or private water distribution system pulls contaminated water backward through cross-connections into the clean drinking water supply.
Signs Your Backflow Preventer Needs Certified Service
Recognizing mechanical assembly failure early keeps your water supply safe and prevents unexpected city compliance fines. Visible water leaking constantly from the relief valve port on a reduced pressure zone assembly indicates that internal check valves are failing to seal properly against supply line pressure differentials.
Fluctuations in water pressure at nearby fixtures or discolored, foul-tasting water coming from domestic taps indicate that cross-connection contamination may be occurring. If local municipal water authorities send an official annual backflow testing notice, or if your sprinkler system’s double check assembly shows physical corrosion, immediate certified service is required.
What to Expect During an Annual Backflow Test
Our certified backflow technicians follow strict American Backflow Prevention Association testing protocols during every annual inspection. Using calibrated differential pressure gauges, our master plumbers connect test cocks on the backflow assembly to measure exact pressure drops across first and second internal check valves.
We test the relief valve opening point to guarantee that non-potable water vents safely to the drain during pressure fluctuations. Once testing confirms that all internal components meet state and local safety standards, PrairieSons completes and submits the official compliance documentation directly to your local water utility department on your behalf.
Backflow Preventers vs Standard Check Valves
| Performance Category | Certified Backflow Preventers | Standard Plumbing Check Valves |
| Primary Function | Blocks hazardous cross-connection contamination | Prevents simple gravity backflow in drainage lines |
| Testing Requirement | Requires certified annual differential testing | Non-testable mechanical valve without test ports |
| Relief Protection | Features automatic pressure relief discharge ports | Lacks pressure relief discharge mechanisms |
| Code Compliance | Mandated by municipal laws for irrigation and commercial | Used for basic domestic plumbing applications |
Frequently Asked Questions
Why does the city of Sioux Falls require annual backflow testing?
Municipal plumbing regulations mandate annual backflow testing to protect the public water supply from contamination caused by backsiphonage. Because backflow assemblies contain mechanical seals that wear out over time, certified annual testing ensures these protective devices function reliably.
Who is authorized to test and repair backflow devices in South Dakota?
Only plumbers holding official certification from recognized organizations, such as the American Backflow Prevention Association, are certified to inspect, test, and repair backflow prevention assemblies. PrairieSons owner Frank Howe and our master technician team hold these essential certifications.
What happens if a backflow preventer fails the annual test?
If a device fails testing due to worn rubber seals, debris, or weak springs, our certified technicians can clean, rebuild, and re-test the unit using factory repair kits. Once the assembly passes testing, we file the passing report with your city water department to keep your account compliant.
Where are backflow preventers typically located on a property?
Backflow preventers are installed on water lines where cross-connections exist, such as outdoor lawn irrigation connections, commercial boiler feed lines, fire sprinkler systems, and main domestic water service entrances for commercial buildings.
How long does a typical backflow test take to complete?
A standard backflow test usually takes thirty to forty-five minutes to complete per assembly. Our technicians complete the entire process efficiently, shutting off water briefly to conduct differential pressure gauge tests before restoring full service.
Can a backflow preventer freeze and burst during South Dakota winters?
Yes. Outdoor backflow assemblies on irrigation systems can easily freeze and crack if not properly blown out with compressed air during fall winterization. We recommend winterizing outdoor lines before the first severe freeze to protect expensive backflow assemblies.
The PrairieSons Commitment
Your trust is our livelihood, and we take public water safety seriously. Whether you need an annual backflow compliance test for your commercial property, an irrigation backflow valve repair in Brandon, or a new backflow installation in Sioux Falls, our certified technicians deliver prompt, predictable results. Ensure your drinking water remains pure and your property stays fully compliant by partnering with local plumbing craftsmen who get the job done right the first time.
By Frank Howe, Owner & President
Last Updated: October 2026
Frank Howe holds American Backflow Prevention Association Certification and master plumbing licenses across South Dakota, Minnesota, and Iowa, leading the PrairieSons technician team.