Any actual or potential connection between a drinking water system and any other source or system through which it is possible to introduce any used water, industrial fluid, gas or substance other than intended for drinking water. Category: Public Works
A connection between a drinking (potable) water system and an unapproved water supply. For example, if you have a pump moving irrigation water from a pond and hook it into the drinking water system either to augment the sprinklers, or even just to supply potable water for the irrigation pump seal, a cross connection or mixing between the two water systems can occur. This mixing may lead to contamination of the drinking water system.
"Cross connection" means any connection or arrangement, physical or otherwise, between a potable water supply system and any plumbing fixture, or tank, receptacle, equipment, or device through which it may be possible for nonpotable, used, unclean, polluted, or contaminated water or other substance to enter any part of such potable water system under any condition.
Any physical connection or arrangement between two otherwise separate piping systems, one of which contains potable water and the other either water of unknown or questionable safety or steam, gas, or chemical whereby there may be a flow from one system to the other, the direction of flow depending on the pressure differential between the two systems. (See Backflow and Back siphonage.)