Cross-connection
A connection between a potable water supply and another source or use can create a pathway that deserves protection.
Why it matters
Backflow protection is about direction.
Water is expected to move through a system in a controlled direction. A backflow preventer is part of the protection strategy when a connection could allow unwanted flow toward the potable supply.
Plain-language information only; this is not a site-specific code determination.
The basic idea
Think in arrows.
Supply water moves toward the point of use. A cross-connection can create a pathway in the opposite direction under certain conditions.
Backflow
Backflow describes water moving in an unintended direction. Actual risk depends on system conditions.
Protection
A backflow preventer is a physical control intended to help prevent reverse flow from reaching the protected supply.
For irrigation
The outside system changes the conversation.
Irrigation connects the water supply to outdoor equipment and conditions beyond the normal indoor plumbing environment. Appropriate protection depends on the installation and applicable requirements.
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