Which devices are recognized methods to prevent cross-connection between potable and non-potable water?

Prepare for the American Water Works Water Treatment Plant Operator Test. Study with multiple choice questions, each with hints and explanations. Get ready to excel!

Preventing cross-connection between potable and non-potable water relies on backflow prevention devices that stop water from flowing backward into the supply. The devices listed—vacuum breaker, double-check valve, and reduced pressure zone—are all recognized methods used to provide that protection, each serving different situations.

A vacuum breaker lets air into the line to break a siphon and prevent backflow, but it must be installed where it will not be subjected to continuous pressure and must be located above the highest downstream outlet to function properly. A double-check valve assembly uses two checks and springs to block reverse flow and works well for many non-hazardous cross-connections, provided it is regularly tested and maintained. A reduced pressure zone device creates a deliberately maintained low-pressure zone with a relief vent; this offers the highest level of protection and is used for high-hazard cross-connections where contamination could pose the greatest risk.

Because any single device may be inappropriate for certain conditions, the option that lists all three reflects that multiple recognized methods exist to prevent cross-connection.