Cross connections are actual or potential connections between the public water supply and a source of contamination or pollution.

Cross-connections can be identified by looking for physical interconnections between individual customer’s plumbing and the public water system. Some examples include:

• Lawn chemicals back flowing through a garden hose into indoor plumbing.
• Backsiphonage of Blue water from a toilet into a building’s water supply.
• Carbonated water from a restaurant’s soda dispenser entering a water system due to back pressure.
• Backflow of boiler corrosion control chemicals into an office building’s water supply.

The EPA established cross-connection control programs for local water authorities in an effort to reduce public health risk.

Most cities require annual backflow testing. City Backflow Testing is licensed by the state of Texas and test in compliance with the USC 10th edition for cross connection control.