Backflow Preventer Testing

Backflow prevention devices are used to protect potable water supplies from contamination or pollution.  In water supply systems, source pressure is maintained at a high enough pressure to enable water to flow from the tap, shower, or other fixture in your home or business.  In the event of a water main break, pipe freeze, or an unexpectedly high demand on the water system (for example, when several fire hydrants are opened) water pressure can fail or be reduced.  When that situation occurs, the reduced pressure in the pipe may allow contaminated water from the soil, from storage, or from other sources to be drawn back into the main supply system.

The backflow preventer is designed to keep water from being drawn back into the system.  There are multiple points where a potable water system connects with a non-potable water system which are called cross connections.  These connections occur naturally in appliances such as clothes washers and dishwashers, but they are carefully designed and installed to prevent a backflow condition.  In the fire protection industry we are focused on the connection of a fire sprinkler system to the water main.  A backflow preventer is used at this connection to prevent pressurized water in the fire suppression system from flowing into the public water supply.

Backflow prevention assemblies are required by law, and must be installed in accordance with plumbing or building codes.  A typical backflow assembly must be tested when installed, if relocated or repaired, and also on a periodic basis.  The Environmental Protection Agency (EPA) holds local water suppliers responsible for maintaining a certain amount of purity in potable water systems.  Laws vary from state to state, and depending on your local municipality, you will be required to test this device annually.