Greywater regulations

There are several important regulatory requirements to ensure the effective installation and use of greywater in WA.

State government greywater regulations

The ‘Code of Practice for the Reuse of Greywater in Western Australia’ (latest edition 2010) published by the Department of Health sets out the regulatory requirements for the responsible reuse of greywater in WA. Key requirements and guidance from the Code are detailed throughout this document.

The design, construction, installation, replacement, repair, alteration and maintenance of a non-drinking water service must be in accordance with all relevant Australian Standards (AS/NZS 3500) and the Plumbing Code of Australia. All installations require the services of appropriately licensed persons as required by the Plumbing Licensing Boards regulation of 2000 and the Health Act of 2016.

Local government greywater regulations

Local Government is responsible for greywater system installation and operation approvals. This approvals process is typically administered by Environmental Health Officers in each Local Government Authority, in accordance with compliance to the Code.

Technical standards and specifications

There are a number of resources available regarding greywater standards, building codes and the Residential Greywater Ready Plumbing Guidelines (JBA 2013).

Greywater system designers and installers should be fully aware of the requirements set out in the Code and relevant plumbing regulations to ensure the installation of a compliant greywater system. Greywater systems should be designed and installed by an experienced greywater professional². It is illegal to install a system not approved for use in WA and certain steps in the installation process must be undertaken by a licensed plumber.

Non-sewered areas

The Code details regulations for greywater in non-sewered areas. To summarise:

Primary onsite wastewater systems should be sized to receive the total wastewater flow.

Primary systems must be able to operate efficiently with the separation of greywater.

Greywater diversion devices must have an overflow pipe to ensure greywater is fed back to the primary system if there is a filter blockage.

Specific rules apply for those with composting toilets.

Both the greywater system and the primary system must be one approved by the Department of Health³ and their installation and the operation approved by the relevant Local Government Authority.

For more information please refer to the Perth Hills retrofit case study.

The Greywater and Wastewater Industry Group

The Greywater and Wastewater Industry Group (GWIG) is the peak industry group representing greywater and wastewater suppliers, installers and service technicians in Western Australia. Formed in 2010, GWIG is a non-profit organisation made up of industry professionals such as designers, manufacturers and installers of greywater systems, as well as consultants, researchers and service organisations to the plumbing trade. The expertise and experience of its membership enables the industry to rapidly respond and address current and emerging issues in water re-use, as well as to provide advice on industry best practice. GWIG actively promotes the responsible installation of greywater reuse systems through legislative change to achieve greater water savings in our community.

About The Author


Greywater & Wastewater Industry Group. We are a group of water industry professionals who are active in the design, research, manufacture, installation and servicing of greywater and wastewater treatment systems. GWIG is a non-profit organisation which was formed in late 2010 in order to provide a united voice for a WA industry that is largely unsupported and under-acknowledged for the important work that it does.