Backflow Prevention and Air Gaps

Backflow is the reverse flow of dirty water into the potable supply. The exam tests the two devices that prevent it and where each belongs.

Key points:

An air gap is the only absolute protection and is required between a drain and the potable supply.
A vacuum breaker is the common mechanical device for hose bibs and threaded faucets.
Never leave a hose submerged in a sink, bucket, or mop water.
Report any cross-connection or backflow event to the regulatory authority.

The exam rarely asks for a definition. It asks what you would do at 2 p.m. on a Friday with a full walk-in and a delivery at the door.

Free practice bank: FoodSafe Prep.