Effluent waste is treated or untreated liquid sewage. It is also referred to as wastewater and includes trade/commercial effluent and domestic/household effluent.
Onsite effluent disposal involves the treatment and disposal of sewage on a property. In areas of the Shire where connection to reticulated sewerage is not available, an approved onsite effluent disposal system is required.
What types of systems are available?
The most common type of effluent disposal system installed historically throughout Western Australia is a septic tank and leach drain system. Today there are many different types of systems available to cater for varying site and operational requirements. The Department of Health WA maintains a list of product approvals on their website that can be applied for installation approval:
Approved Wastewater Systems (Health WA)
The system type and size will depend on several factors including location, development size, wastewater produced, land gradient, soil conditions and depth to groundwater. Many areas in the Shire are characterised by sloping land, heavy soils and perched water tables, which can pose challenges for onsite effluent disposal. Within areas where these conditions are present there can be restrictions on what type of system is permitted.
Do I need to install an onsite effluent disposal system?
All buildings that produce wastewater are required to be connected to reticulated sewer where available, or apply for approval to install an onsite effluent disposal system.
To check if a property is connected, or is able to be connected, to reticulated sewer, please contact the Water Corporation. An online search tool is available on their website:
www.watercorporation.com.au
If reticulated sewer is not available to your property, an onsite effluent disposal system will be required.
What approvals are required?
Before an onsite effluent disposal system can be installed, altered, extended or upgraded, an application for approval must be made to the Shire, or Department of Health WA, in accordance with the Health (Treatment of Sewage and Disposal of Effluent and Liquid Waste) Regulations 1974.
- For proposed systems servicing a single dwelling occupied by not more than 8 persons and is the only dwelling on the lot, or is for a proposed system treating less than 540 litres of sewage per day, application can be made to the Shire.
- For proposed systems servicing development other than the above, approval must be obtained from the Chief Health Officer, Department of Health WA. These applications are to be first submitted to the Shire for issue of a Local Government Report.
Once an application is received along with applicable fees and supporting documentation, it will be assessed by the Shire’s Environmental Health Services to assess compliance with legislative requirements.
How do I apply?
To apply for approval to install an onsite effluent disposal system, please complete an 'Application to Construct or Install an Apparatus for the Treatment of Sewage'. Fees are applicable as specified on the Application form (available below).
Obtaining a permit to use
Once your effluent disposal system has been installed, the installer must contact the Shire's Environmental Health Services to organise an inspection. Please allow a minimum 24 hours notice and ensure that prior to the inspection:
- All aspects of the system, including pipework, are left exposed;
- All Conditions as specified on the issued Approval have been completed, and;
- The septic tanks are filled with water prior to inspection.
Subject to compliance with requirements, a 'Permit to Use' will be issued by the Shire. It is important to note that it is an offence to use a system without being issued a 'Permit to Use'.
Desludging / Pumping out of septic tanks
Over time, septic tanks will accumulate sludge and scum and will need to be pumped out or desludged. As a guide, pumping out / desludging is required as follows:
- Two-person households: every eight (8) years;
- Four-person households: every four (4) years;
- Four+ person households: more often is recommended.
Pumping out / desludging requires a licenced liquid waste contractor. Contractors are listed in commercial business directories typically under a Septic Tank Cleaning category.
Looking for existing system plans?
The Shire may have records of existing approved effluent disposal systems. If you are the owner of a property, or have the written consent of the owner, we can provide you with available records. Please note fees apply.
Contact Us
An 'Application to Construct or Install an Apparatus for the Treatment of Sewage' form is available from the Department of Health WA website: