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Backflow

       🎯 PROTECT YOUR WATER SUPPLY: Understanding Backflow

🚫 What is Backflow?

Backflow is the unwanted reverse flow of water or other substances into the clean water supply. This can happen when there’s a sudden change in pressure—like a burst pipe that pulls contaminated water back into the main water supply from your plumbing system.

🛑 Why Backflow Protection Matters

  • Health & Safety: Contaminated water can carry chemicals, bacteria, or pollutants into your drinking water.
  • Legal Compliance: Local plumbing codes often require backflow prevention devices in certain installations (especially commercial and irrigation systems).
  • Backflow devices are commonly installed in: Irrigation systems, fire sprinklers, boilers, water heaters and main water lines
Brass water valve with multiple connections and handles, likely a backflow preventer.

✔️ Stay Safe. Stay Up to Code.

Backflow devices are to be tested annually by a certified backflow testing agency. Once your test is complete, your tester will submit the test reports to West Slope Water District where we maintain a database of our customers who have backflow devices on their property, as well as the device information and testing results.

West Slope Water District sends out testing reminders to ensure you have proper notification of when your test needs to be completed. To schedule a backflow test, you will need to contact an independent certified backflow tester. The link to a certified backflow tester can be found under backflow on our website at www.wswd.org.   

       

  🔧 Parts of a Double Check Valve Assembly (DCVA) & What They Do

The most common backflow device is a DCVA and is made up of two independent check valves assembled in a series, along with shutoff valves and test ports.

💧 Inlet Shutoff Valve (Shutoff Valve #1)

  • Function: Stops water from entering the DCVA.
  • Purpose: Allows maintenance and testing by isolating the device from the supply side.

🧰 Check Valves

  • Function: Check 1 allows water to flow forward (from supply into the system) but closes automatically if flow reverses. Check 2 is the same as Check Valve #1, installed downstream in series.
  • Purpose: Check 1 is the first line of defense against backflow. If water tries to move backward, the valve shuts to block it. Check 2 acts as a backup in case the first check valve fails. Double protection is what makes it a double check assembly.

🧪 Test Cocks (Usually 4 Ports)

  • Function: Small ports used to connect gauges or test equipment.
  • Purpose: Let a licensed technician test each check valve's function and pressure drop. They’re numbered #1 through #4 from inlet to outlet.

🔒 Outlet Shutoff Valve (Shutoff Valve #2)

  • Function: Stops water from leaving the DCVA and entering the protected system.
  • Purpose: Like the inlet valve, it's used to isolate the assembly for maintenance or testing.
A plumbing assembly with shutoff valves, check valves, and test cocks labeled.

Please email annual completed certified backflow device tests to backflow@wswd.org.

Visit   https://public.health.oregon.gov/HealthyEnvironments/DrinkingWater/CrossConnection/Pages/index.aspx, for a  List of OHA-Certified Backflow Assembly Testers.

Additional questions?  Please visit the Oregon Health Authority's website:  https://public.health.oregon.gov/HealthyEnvironments/DrinkingWater/CrossConnection/Pages/index.aspx

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