Cross Connection & Backflow Prevention Program
Backflow is a term used when the water flows in the opposite direction from its normal flow. This can happen when the supply is somehow interrupted and pressure drops and in fact goes negative, drawing water back from the end user. This water could contain chemicals or be otherwise contaminated and end up contaminating the entire building, block or City water system.
See the Cross Connection and Backflow Prevention Program Specifications for several acceptable assemblies, devices and methods to help prevent BACKFLOW.