Common examples of cross-connections include a potable water feed to boiler or chill water systems for makeup purposes, the garden hose dropped into a water trough for livestock, fire systems and equipment hookups, and a potable water feed to an irrigation service. The list of cross-connections is a long one which is why identifying them is a tedious and challenging task at times. Taking it one step further and as the name implies, the managing aspect of all of these cross-connections is called a cross-connection control program
On the other hand, backflow is an action, or verb. Looking to USC FCCHR again, backflow is defined as:
Caused by backpressure or backsiphonage, backflow is simplified as potable water flowing in the direction it is not intended to flow.
So, the next time you are trying to decide if you should be using “cross-connection” or “backflow”, try thinking in terms of either a noun or a verb. Now you know.