City of Subiaco - Greywater systems
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Greywater systems

Installation of a greywater system requires written approval. This page contains information on the approval process, incentives and rebates, types of greywater systems, and details on the installation, use and care of your system.
Greywater is the term that is used to describe the waste water we generate from our bathrooms, laundries and kitchens, but does not include toilet waste water. It is generally of sufficient quality that it can be treated and reused on the garden through the use of a greywater system. Although most households won’t produce enough greywater to supply the entire garden’s needs, reusing greywater on gardens should make a significant contribution.

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Approvals required

The installation of a greywater system requires local government approval and, in the case of greywater reuse systems where there are more than ten occupants in a building, approval from the executive director of Public Health is required. An application to construct an effluent disposal system fee and an application to use  an effluent disposal system fee apply. Please see link to fees and charges.

Choosing a greywater system

A range of locally designed and manufactured greywater systems are available in Western Australia. It is recommended that you consult a waterwise plumber when choosing a greywater system for your home.

New homes

It is much easier to install a greywater system when it is designed into a new home. If designing a home, request that the plumbing from your shower, bath and hand basins be isolated from the rest of the plumbing. This will enable the addition of a greywater system in the future. 

Existing homes

The type of home you own will determine the ease with which you can retrofit a greywater system.

For example, in some houses it can be difficult to retrofit a greywater system that recycles water from the shower, bath and hand basins, although it may be relatively simple to recycle greywater from the washing machine.

Other questions to consider:

  • How will I dispose of the greywater?
  • Will it be retained on my property?
  • What maintenance is required? How often?
  • What happens if the system fails?
  • Can the system be diverted to sewer is needed?
  • How will my garden receive water when I am on holidays?
  • What products/chemicals do I use in the home?
  • Will these affect the system in any way?

Installing a greywater system

The Code of Practice for Reuse of Greywater in WA (PDF, 351KB) outlines acceptable greywater reuse practices to ensure the conservation of ground and surface water supplies and protection of health standards. The installation and operation of all greywater systems must comply with the code. 

Step 1 - Getting approval

To apply for the installation of a greywater system you must submit the following:

  • an application form (PDF, 364KB) with the relevant fee
  • two copies of your site plans (PDF, 33KB) 
  • two copies of your proposed plumbing layout 

Please note the City of Subiaco will reimburse your application fee once the system has been approved and a permit to use apparatus certificate has been issued. To find out more about rebates please see claiming a rebate.

Step 2 - Assessment

Once your application is received, an officer will carry out a site inspection to ensure the conditions are suitable for the greywater system. If satisfied with the application, the officer will issue an approval.

The assessment process is outlined in a flow chart format.

Step 3 - Installation and notification

A licensed plumber can now install the greywater system. Make sure you provide the plumber with a copy of the approval to ensure that all conditions are complied with. Visit the Water Corporation website to locate a waterwise plumber in your area.

Once your system has been installed, you (or your plumber) must advise the city that the installation has been completed. One of the city's officers will conduct an inspection to ensure that the installation complies with the approval. You will be required to supply the city with an ‘as constructed plan’ which your plumber can provide. The city will then issue a Permit to use the apparatus certificate and you can start using the greywater system. Please note the operation and maintenance of the greywater system is the responsibility of the householder.

Claiming a rebate

Rebates are available to encourage residents to install greywater reuse systems.

Once you have a Permit to use apparatus certificate for the installation of your greywater system, you are eligible to claim the City of Subiaco Greywater Use Incentive Program Rebate form (PDF, 109KB), a rebate of the application fees paid when you lodged your application.

Use and care

Greywater recycling systems must be operated and maintained in accordance with the manufacturer’s instructions. Depending on the system that you choose, you may need to undertake:

  • regular cleaning or periodic replacement of filters
  • periodic de-sludging of treatment tanks
  • manual diversion of greywater to sewer in winter
  • flushing of sub-surface irrigation lines
  • occasional replacement of pumos and the periodic testing of soil pH.

Consult the manufacturer for more guidance on the operation and maintenance of their greywater recycling systems.

Greywater must be contained entirely on your property and must not be discharged on to your neighbours’ property.

Appropriate products

Users need to be mindful of the products that are used in the home. Products that you use inside will be distributed on to your garden and may affect your soil and plants. To minimise harming micro-organisms and worms in the soil, avoid the use of:

  • bleaches and softeners
  • detergents that advertise whitening, softening and enzymatic powers
  • detergents with ingredients which include boron, borax, chlorine or bleach
  • sodium perborate and sodium trypochlorite (salts), sodium tripolyphosphates (STPP), phosphorus, phosphates, polyphosphates, phosphate builders, acids
  • porducts used to clean drains.

If you sell your home

If you decide to sell your home, the people who purchase it may not be as committed to the environment as you are. Make sure the greywater system is diverted to a sewer or decommissioned.

If the new owners are happy to recycle their greywater, provide them with instructions and guidelines for care, maintenance and operation.