Cross Connection Program

What is a cross connection?
A cross connection occurs when a water supply line is connected to a non-potable (unfit to drink) water source. If these cross-connections are not protected, it could potentially lead to a dangerous situation. By installing a backflow prevention device, these dangers are minimized.

What is a backflow?
A backflow can occur when the hydraulic conditions within a system change from their normal conditions, and cause water to flow in a backwards direction. A backflow of water in the system can be harmful because it could siphon any substance that it is in contact with into the water distribution system causing a cross connection.

What is a Backflow Prevention Device?
A Backflow Prevention Device is a mechanical assembly designed to counter any backflow that may occur. There are several different types of devices; the type required in any given situation depends on the type of backflow that may exist and how hazardous it is.

New Hampshire Department of Environmental Services requires that public water utilities take the appropriate measures to prevent the reverse flow of water into their distribution system.

These devices have been tested by the Foundation for Cross-Connection Control and Hydraulic Research at the University of Southern California. Devices that are granted approval by the foundation are extremely dependable. For further information on backflow and Backflow Prevention Devices, and a list of approved devices, please visit the University of Southern California’s website at

Pennichuck has an extensive Cross Connection Program for your reference. Please contact our Engineering Department at (800) 553-5191 extension 2321 to request a copy of the program.