Commonly Used Residential Backflow Prevention 

While the City of Santa Ana works hard to deliver the safest water possible, there are common problems, once this water enters your property, that may arise due to improper changes in plumbing or misuse of your plumbing system. 

Cross-connections are dangerous if no protective measures are taken. Cross-connections are when a water supply line is connected to equipment or systems containing a non-potable (unsafe to drink) substance, like a hose submerged in polluted water, a heating boiler with treatment chemical added to prevent internal corrosion, an underground lawn sprinkler system or fountain that has a direct connection with your home’s water system for filling. 

Here are the most common devices you can easily install to prevent contaminants from entering into your drinking water system as well as the public water distribution system.

Air Gap:

Air gaps can be found on bathroom sinks, dishwashers. and in countless other applications. Air gaps are effective in preventing backflow. 

An air gap is the vertical separation between the supply line and the overflow rim of the receiving vessel, such as a sink. It should measure at least twice the diameter of the supply line and under no circumstances less than one inch. Fill lines to water troughs or tanks must also be physically separated or “air-gapped.” If there is no air gap, then the contents of the sink, tub, or tank may be sucked or “backsiphoned” into the water line during a loss of water pressure. 

Hose Bibb Vacuum Breaker:

Hose bibbs (spigots) are part of our everyday life. They allow us to hook up a garden hose to water the plants, apply pesticides, wash the car or fill the fountain. However, every time you connect a garden hose to a hose bibb, there is the risk that harmful materials from outdoors can seep back into your home’s drinking water system. 

A vacuum breaker is a simple device that attaches to a spigot and then your garden hose. It prevents water from flowing backward with a spring-loaded check valve, which opens and closes based on the water pressure. When you turn off the water, the pressure against the spring on the valve decreases, the valve closes, and air flows into the space around the valve, preventing backflow. 

Atmospheric Vacuum Breaker:

Irrigation systems make outdoor watering easier, but if not properly constructed, contaminants may backflow into your drinking water. For example, water pooling around sprinkler heads may be contaminated by chemicals, fertilizers or animal waste. 

Using an atmospheric vacuum breaker (AVB) can help protect against backflow. It has an air inlet valve that is normally closed when the device is pressurized, preventing potentially contaminated water from entering your home’s water system and Santa Ana’s water mains.