//Cross Connection Terms and Definitions

Cross Connection Terms and Definitions

To understand the measures and devices used to protect our drinking water, review the cross-connection terms and definitions.

Backflow means any unwanted flow of used or non-potable water or substance from any domestic, industrial or institutional piping system into the pure, potable water distribution system.

Backflow Protection Devices is a valve or assembly that is designed to prevent backsiphonage, backpressure or both.

Backpressure is when downstream piping pressure is greater than the upstream piping pressure, which reverses the normal flow of water.

Backsiphon is a sub-atmospheric pressure loss in the water line causing the flow of water to travel along the least resistant path.

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 completed either the 40-hour backflow preventer test specialist course or the 8-hour refresher course, successfully passed both written and practical tests and has 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 a physical connection between a potable water plumbing system and any domestic, industrial or institutional piping system containing used or non-potable water.

Downstream Flow means the direction of water flowing out of the valve.

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 plumbing 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 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 device verifying the device successfully passed required testing parameters. The minimal information required on test tags by the health district the company’s name; individual tester’s name and certification number; company’s telephone number and date assembly tested. Test tags should be made of materials that can withstand various conditions of moisture so that when subjected to moist conditions the readability of the required information is not affected.

Upstream Flow means the direction of water flowing into a valve.

Contact Information

Phone: (702) 759-1549


Updated on: October 5, 2018