What is the difference between point of use, zone and wholesite backflow protection?

Point of use protection is backflow prevention provided at the point where water is being used. For example, at a tap, washing machine, WC or trough

Zone protection is a backflow prevention device or arrangement installed in addition to all existing point of use backflow prevention within a premises. Its purpose is to prevent backflow from one part of a plumbing system to another part of a plumbing system in the same property. For example, between different installations on one site. These are commonly found on farms, manufacturing sites and hospitals.

Whole site protection is a backflow prevention device or arrangement installed in addition to all other existing backflow prevention within a premises. Its purpose is to provide an additional level of protection to safeguard public water supplies to neighbouring properties.

Please note: the provision of zone and/or wholesite backflow prevention does not relax the requirement for any other required backflow prevention provision within premises.