Backflow prevention - Definition of terms

Term

Definition

AS/NZS 3500

See Australian New Zealand Standards 3500

Australian New Zealand Standards 3500

The Australian New Zealand Standards 3500 provides the guidelines for installing and maintaining a backflow prevention device and is consistent with Sydney Water's Backflow Prevention Policy.

Back pressure

The difference between the pressure within any water service and a higher pressure within any vessel or pipework to which it is connected. For example, a customer is using water at a higher pressure than the pressure supplied by Sydney Water.

Backflow

Flow in a direction contrary to the normal or intended direction. The unintended flow of water from a potentially polluted source into a potable water supply.

Backflow Prevention Device

A device to prevent backflow. There are a number of different devices including a reduced pressure zone device, a registered air gap and a testable double check valve.

Backflow Prevention Device Inspection and Maintenance Report

The form, which backflow accredited plumber completes to certify the correct commissioning and function of the backflow device.

Backflow Prevention Policy

Sydney Water's Backflow Prevention requirements, for all properties both new and existing, where there is a risk of contaminating the water supply.

Backsiphonage

Backsiphonage occurs when the water supply pressure falls below atmospheric pressure.

Containment device

A backflow prevention device installed at the water meter(s) on the property boundary, to prevent backflow from within the property.

Contaminant

Any solid, liquid or gas with potential to enter or pollute the potable water supply.

Cross connection

Any connection or arrangements between the drinking water supply system connected to the water main or any fixture, which may under certain conditions enable non-drinking water or other substances to enter the drinking water supply system.

Individual backflow protection

A backflow prevention device installed at the water connection to a fixture or appliance.

New South Wales Code of Practice Plumbing and Drainage

Government legislation to provide uniform administration and technical requirements for the installation of plumbing and drainage in New South Wales.

Non-drinking water

Water is deemed non-drinking if there is potential for contamination from an unprotected source.

Drinking water

Water which is suitable for human consumption.

Standpipe

A rigidly supported vertical length of pipe emerging from the ground with a tap or valve, serving as an outdoor water supply point.

Sydney Water Customer Contract

The Customer Contract is a legally enforceable document that clearly spells out the rights and responsibilities of customers and of Sydney Water. It also introduces Sydney Water's policies for handling your complaints and giving redress, that is, a rebate on your service availability charge, and compensation in the event that we fail to provide our services at agreed standards.

Sydney Water's Operating Licence enables Sydney Water to undertake water, wastewater and stormwater activities in the Sydney, Illawarra and Blue Mountains region.

The Operating Licence sets quality and performance standards for Sydney Water in relation to:

Customer rights

Drinking water (health and aesthetic), environmental and other water quality

Systems performance, water continuity and pressure and sewage overflow

Water conservation and demand management

Environment indicators and plans

ESD indicators, energy management, pollution reduction and; trade waste

Zone backflow protection

A backflow prevention device installed at the connection to specified sections of a plumbing system within a building or facility.