Understanding the Different Options for Preventing Contamination

Plumbing codes require the use of devices meant to ensure backflow prevention in certain situations. They’re not always required in residential properties, except if there’s an irrigation system on the property or a large boiler or fire suppression system in the building. There are several types of devices you can choose from:

• Air gap: A space between the water outlet and the flood level of a plumbing fixture.
• Double Check Valve Assembly (DCVA): Consists of two valves placed in different places along the plumbing system. It works well to prevent back pressure and back siphonage.
• Pressure Vacuum Breaker (PVB): Often used in irrigation systems, a PVB keeps non-potable water from contaminating potable water sources within the system.
• Reduced Pressure Zone Device (RPZ/RPZD/RPV): Constructed with two spring-loaded check valves, three vertical test cocks, and two shut-off valves. These can be installed outside only if the location is always above freezing.

How To Prevent Backflow Issues

• Make sure that connections for the garden hose have some sort of backflow prevention.
• Don’t let garden hoses create puddles that can contaminate the hose itself.
• Ensure that there’s an air gap when appliances like water softeners are plumbed.
• Frequently change filters, as they can grow bacteria as they decompose with use.
• Get your annual backflow inspection from Water Doctor of Washington.