Greywater Reuse Information Package

What is greywater?

Greywater is water that has not come into contact with toilet waste. It comes from the bath, shower, bathroom washbasins, clothes washing machine and laundry trough. Wastewater from the kitchen sink and dishwasher should not be reused as these contain heavy loads of organic materials, fats and caustic additives.

Choosing a greywater reuse system

Only greywater systems that have been approved by the Executive Director of Public Health may be installed. Once a greywater system is installed, it becomes the householder’s responsibility to ensure it is operated and maintained according to the manufacturer’s instructions.

Code of Practice and approved greywater reuse system list is available at the Department of Health webpage 

Issues to consider

• Some greywater systems may require weekly cleaning or replacement of filters, periodic desludging of treatment tanks, the manual diversion of greywater back to the sewer in winter, flushing of the irrigation lines, occasional replacement of pumps, and the periodic testing of the soil pH.
• Greywater must be contained entirely on the property and must not run onto neighbouring properties or be allowed to pool, which can create a nuisance.
• Greywater must not come into contact with edible plants or vegetables, and can only irrigate fruit plants where the fruit does not come into direct contact with it.
• Greywater must not come into contact with a drinking water supply or the stormwater drainage system.
• Using products with high phosphorous, sodium, or boron levels, or bleaches and softeners can affect your garden and the environment, and should be used sparingly when the water is directed into a greywater reuse system.
• The system must be designed so as to prevent mosquito breeding.
• The system must be designed to avoid pooling, blockage, leakage and overflow.

Installing a Greywater System

Application
The City of Melville is able to approve a system that can accommodate up to ten people. The fee for an application to the City of Melville is $216. The application should include two copies of a site plan, drawn to a scale of 1:100, and including the following:

• Location of the apparatus and all drains and pipework;
• Distance of the apparatus from all buildings, boundaries, bores and waterbodies;
• Greywater source and likely volume;
• Flow storage and the treatment proposed;
• Details of the proposed system;
• Details of the treatment and disposal systems, including: - proposed location of the greywater system and reuse area, including to position of the irrigation lines / trench - method of construction of surface irrigation disposal bed area, including the materials to be used; and - where a split irrigation system is used, details of mechanisms to ensure an even discharge to each area and to prevent overloading of individual areas.

For systems that are able to accommodate more than ten people, the application will need to be referred to the Department of Health.

Three sets of plans showing the above are to be included in the application. The fee for an application that needs to be referred to the Department of Health is $261. As part of the approval procedure, the Water Corporation must agree to the diversion of greywater from the sewer system, in regard to the possible negative impacts on the sewerage system.

The City of Melville will only issue approval for the use of the greywater system in a sewered location when the Water Corporation has indicated no objections to the application. All plumbing works are to be conducted by a licenced plumber, who must also obtain approval from the Water Corporation for any required connection or modification to the plumbing works connected to the sewer system.

Download application form from the Department of Health website

Further Information
For further Information, please contact the City of Melville Health Service on 9364 0275.