Backflow FAQ

 

What is cross-connection?

What is a backflow?

What is back siphonage and its causes?

What is a back-pressure backflow?

What is a backflow device?

What kind of protection do I need?

Why do backflow prevention assemblies have to be tested?


What is cross-connection?

      A cross connection means any actual or potential physical connection between a public water system or the consumerís water system and any source of non-potable liquid, solid, or gas that could contaminate the potable water supply by backflow.

What is a backflow?

      A backflow is an undesirable reverse flow of a substance through a cross connection into the drinking water system. A backflow can contaminate either the customerís drinking water system within a building or the public water system. Backflows can be caused in one of two ways: back- siphonage or back-pressure.

What is back siphonage and its causes?

      Back-siphonage can occur when reduced pressure in the water main allows a siphon to start and contaminants to enter the main. Back-siphonage can be created when there is an interruption of the water supply due to nearby fire-fighting, repairs or breaks in water supply mains.

What is a back-pressure backflow?

      Back-pressure backflows can occur when a system operating under a higherpressure than the pressure in the water main forces the contaminants into the drinking water. Back-pressure backflows can be caused by high pressure pumps,temperature increases in boilers, elevated tanks or other pressure producing systems.

What is a backflow device?

      A backflow device is part of a plumbing system that will not allow any water or fluids to travel in the reverse direction.

What kind of protection do I need?

      A Double Check Valve backflow assembly is installed for low hazard (non-toxic) conditions.
      A Reduced Pressure Zone backflow assembly or Air Gap is installed for high hazard (toxic) conditions.
      Typical backflow assembly installations are located at your water meter connection or property line. This includes water service to domestic, irrigation, or dedicated fire systems.

Why do backflow prevention assemblies have to be tested?

      Mechanical backflow preventers or assemblies have internal check valves, seals, springs and moving parts that are subject to wear or weakness over time. †These assemblies need to be tested annually to ensure that they are working properly in protecting the water supply.

 

 

Please contact James Freeman, Cross Connection Control Specialist at our office with any questions and prior to any installation.