Please refer to the following terms and definitions to gain a better understanding of cross connection control and backflow prevention.

Backflow means the undesirable reversal of flow of water or a mixture of water and other substances into the potable water distribution pipes from any source.

Backflow Prevention is a means to prevent potentially contaminated water from entering the potable water supply of a building or municipality. This can be achieved by the proper installation of an air gap or a backflow prevention device.

Backflow Protection Devices is an effective device used to prevent backflow into a potable water system.

Backpressure is when downstream piping pressure is greater than the water supply pressure, which may result in the reversal of the normal direction of flow.

Backsiphonage a form of backflow resulting from a reduction in system pressure which causes a sub-atmospheric pressure to exist at a site in the water system that may result in water being drawn into the system from an external source.

Carbonator is a system where carbon dioxide gas and potable water are mixed and pressurized, producing carbonated water to support various types of beverage dispensers.

Certified Backflow Tester is an individual who maintains a valid backflow preventer test specialist certificate with both a certification number and an expiration date.

Contaminant is a substance that causes illness or death if ingested; for example, sewage, hazardous chemicals, radioactive waste.

Cross-Connection means any actual or potential connection between a potable water system and any other source through which it is possible to introduce an unintended substance into the potable water system.

Downstream Flow means the intended direction of water flowing through a piping system.

Pollutant is any substance that affects the color or odor of the water, but does not pose a health hazard; for example, food coloring.

Potable (Domestic) Water is simply water that is safe to drink. Potable water is free from pollutants and contaminants and is provided to a location by a water purveyor (i.e. Las Vegas Valley Water District) or a private well.

Potable (Domestic) Water Line is the piping system that carries potable water throughout a facility on the downstream side of the water meter, up until the point of a physical cross-connection.

Test Document is a document that records test results of the backflow prevention device, normally generated in three copies, one for each customer, testing company, and health district.

Test Tag is a certificate physically attached to a backflow prevention device verifying the device successfully passed required testing parameters. The minimal information required on a test tag by the health district is the company’s name; individual tester’s name and certification number; company’s telephone number and date the device was tested. Test tags should be made to withstand moist conditions to ensure the readability of the required information is not affected.