Why Backflow Prevention Matters
Without a backflow preventer, a drop in water pressure (broken main, fire hydrant use) can suck irrigation water — containing fertilizer, pesticides, and soil bacteria — back into your home's drinking water supply. This isn't theoretical — backflow contamination events are documented annually across the US.
Idaho Requirements
Idaho Plumbing Code requires backflow prevention on all irrigation systems connected to potable water. This includes residential sprinkler systems, drip irrigation, and garden hose connections with fertilizer injectors. The type of preventer required depends on the hazard level. Annual testing by a certified tester is required.
- ✓ Pressure Vacuum Breaker (PVB): Most common for residential irrigation
- ✓ Reduced Pressure Zone (RPZ): Required for high-hazard connections
- ✓ Double Check Valve Assembly (DCVA): Used in some residential applications
- ✓ Annual testing required by Idaho code
- ✓ Certified tester must submit results to the water provider
Annual Testing
Your backflow preventer must be tested annually by a certified tester. United Water Idaho and most Boise-area water providers require proof of testing. If your device fails the test, it must be repaired and retested before the irrigation season. We are certified backflow testers and handle the entire process.
Schedule your annual backflow test — $75-$150.
Call (208) 555-0199 — Free EstimateWinterization
Backflow preventers must be winterized along with your irrigation system. During the sprinkler blowout, the preventer is drained and the test cocks are opened to prevent freeze damage. A cracked backflow preventer costs $200-$800 to replace — far more than the $50-$100 winterization blowout.
Frequently Asked Questions
Do I need a backflow preventer on my sprinkler system?
Yes — Idaho plumbing code requires it on all irrigation connections to potable water. If you don't have one, you're out of compliance and risking drinking water contamination.
How much does backflow testing cost in Boise?
Annual testing: $75-$150. If the device fails and needs repair: $100-$300 additional. New preventer installation: $200-$800 depending on type.
What happens if I don't test my backflow preventer?
Your water provider may require testing as a condition of service. Non-compliance can result in service shutoff. More importantly, an untested device may not protect your drinking water from contamination.
Related Services
Backflow Testing
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