Backflow Information & Prevention

Backsiphonage is when the water flows backwards due to a sudden pressure drop whilst backpressure occurs when the outlet (downstream) pressure is greater than the supply pressure.

At worst, backflow can cause death. Any property that has drinking water entering it is classified with a degree of seriousness of the backflow contamination risk known as the HAZARD RATING.

High Hazard is any condition in the water supply that can cause death.
Medium Hazard is any condition in the water supply that can endanger health.
Low Hazard is any condition in the water supply that can be a nuisance.

First, it is necessary to identify the hazards within the property. Upstream from these hazards, the water is considered as non-drinking until a suitable backflow prevention device is installed. It may be necessary to install a backflow prevention device for a fixture, a zone within a building, or at the boundary of the property.

Individual protection

Backflow prevention protection is provided at individual fixtures.

Zone protection

Backflow prevention protection is provided at the connection to specific sections of the water supply system within a building.

Containment protection

Backflow prevention protection is provided at the property boundary to protect the authority’s water supply from contamination.