Expanded use of treated greywater

Changes made in 2006

In 2006 the Plumbing and Drainage Act 2002 (PDA) was amended to allow the the diversion of bath, basin, laundry or shower greywater (kitchen greywater is not permitted) to lawns and gardens by subsurface or surface irrigation is permittable by means inclusive of:

• manual bucketing
• connecting a flexible hose to a washing machine outlet
• seeking Council approval for the installation of greywater diversion devices and treatment plants by licensed plumbers.

However, in sewered areas council approval for the use of greywater was limited under the PDA to premises:

• upon which a class 1a buildings (i.e. single detached dwellings) is constructed
• which generate less than 3000 litres per day.

Changes as of 1 January 2008

On 1 January 2008 amendments to the PDA commmenced to remove the reference to class 1a buildings and open the way for use of greywater in all other classes of building.

The restriction on the volume of greywater generated will be lifted to 50,000 litres per day. Applications for 50,000 litres per day will be handled by local government under existing arrangements in the PDA and applications for use of greywater over 50,000 litres per day will be handled by the Department of Natural Resources and Water (DNRW) on a case by case basis.

Removing the building class and volume restrictions will provide commercial premises with the ability to re-use greywater for the first time. It is expected to have a significant impact on the preservation of existing water resources. For example, hotels and motels will be able to treat and re-use greywater where, at present, they are unable to do so.

Combined with proposed changes to the Queensland Development Code (made under the Building Act 1975) the impact of greywater re-use could be most significant in commercial premises. The re-use of greywater in commercial buildings may also be more attractive where there is limited space for large water storage tanks. Particularly, a small roof catchment area will not generate significant capture of rain water for storage.

Also, where there is limited space for the placement of water storage tanks and the use of these tanks under trafficable areas can increase the cost of installation, e.g. where the tank needs additional bracing, support and tie-downs. In addition to expanding the classes of building and volume of greywater that can be used, the potential end uses of the greywater will also be expanded. This will be effected by changes to PDA and the Queensland Plumbing and Wastewater Code (QPW code). The PDA and QPW code amendments will permit the use of treated greywater for:

• Sanitary flushing
• Laundry use (cold water source to washing machines)
• Vehicle washing
• Path/Wall washdown
• Lawn and garden spray irrigation

The QPW code will be amended to provide the effluent quality criteria that must be satisfied for particular end uses. The potential end use will vary according to the standard of treated effluent.

All greywater treatment plants require approval under the PDA and must undergo stringent testing prior to approval being granted for greywater re-use.