What Is Backflow?

Backflow is the undesirable reversal of water flow or mixtures of water and other substances into the distribution of pipes of any potable water supply or source.

A Backflow situation can happen in back siphonage or back pressure condition. Back pressure condition(superior pressure) is a condition in which the pressure in a non potable system is greater than the pressure in the potable distribution system. Superior pressure will cause non potable liquids to flow into the distribution system through unprotected cross connections. Back siphonage on the other hand is the reversal of liquids caused by a partial vacuum in the potable distribution system.

What Is A Cross Connection?

Any temporarily or permanent arrangement of pipes, fittings, fixtures, or devices that somehow connects a non potable water system to a potable water system. Bypass arrangements, jumper connections or any other connection in which backflow can occur are considered to be cross connections.

Who Is Responsible For Preventing A Backflow Condition?

Federal and State laws require that Water Purveyors protect their system from cross connections and backflow conditions. Counties like San Diego and Riverside spend millions of dollars each year to insure the safety of our drinking water. They have put together Backflow prevention programs in which they work closely with consumers, architects, contractors and engineers.

Backflow Prevention Assemblies:

Atmospheric Vacuum Breaker - A mechanical device consisting of a float check valve and an air inlet port designed to prevent back siphonage

Pressure Vacuum Breaker - A device consisting of one or two independently operating, spring-loaded check valves and an independently operating, spring-loaded air-inlet valve designed to prevent back siphonage

Double Check/Double Check Detector Assembly - These two types of Backflow prevention assemblies consists of two check valves, test cocks, and shut offs valves design to prevent backflow.

Reduced Pressure/Reduced Pressure Detector Assembly - These two types of Backflow prevention assemblies are mechanical devices consisting of two independently operating, spring-loaded check valves with a reduced pressure zone between the checks designed to protect against both back pressure and back siphonage

Spill Resistant Pressure Vacuum Breaker - A device consisting of an independently operated, spring-loaded check valve and an independently operating, spring-loaded air inlet valve with a vent valve designed to prevent back siphonage.