A cross connection is a piping arrangement that allows a potable water system to be connected to a source of potential pollution or contamination. It is vital to control cross connections in order to prevent a backflow of contaminants into potable water. Ultimately, backflow has the potential to cause the contamination of the entire public water supply, posing a risk for anyone using the water. For examples of cross connections that require control:
Fire sprinkler systems
Lawn irrigation systems
Reclaimed water systems
If there is an incident which results in contamination of public drinking water due to improper or unprotected plumbing connections, the owner or occupant of the property can be held liable for damages.
For more information see Bylaw 2015. No. 2117 Section 4 Integrity of Waterworks System.