In every Division of Compliance Assistance-administered drinking water certification class, Certification and Licensing staff cover a chapter on cross-connection control. Cross-connections appear in all three disciplines and have caused more disease outbreaks than any other factor, which demonstrates the importance of this topic.
A cross-connection is a physical link between a potable water supply and one of unknown or questionable quality. We classify cross-connections into three levels of hazard––low, medium and high. A low hazard is typically a nuisance, while a high hazard can cause death.
Backflow is what occurs at a cross-connection that can endanger the health of customers. Backflow is the flow in the opposite direction to the normal flow, or the flowing back of a substance toward its source. It can occur in two ways––back pressure or back-siphonage. Later, we will look over all the different type of devices you can use to stop backflow.
Listed below are some locations and hazards of common cross-connections: