Approved wastewater systems

Only approved wastewater systems can be used in WA. Premises owners who install an unapproved system contravene the Health (Treatment of Sewage and Disposal of Effluent and Liquid Waste) Regulations 1974 (external site).

The Department of Health (DoH) requires certification for all onsite wastewater treatment systems against the relevant Australian Standard as detailed in the table below:

Type of Onsite Wastewater System Capacity (L/day) Standard
Precast concrete septic tanks 6000 AS 1546.1 or *DoH approval
Glass fibre-reinforced plastic or plastic septic tanks 6000 AS 1546.1
Waterless composting toilets N/A AS 1546.2
Secondary treatment systems (Including ATUs) 5000 AS 1546.3
Greywater treatment systems 1000 AS 1546.4

*DoH approval as per Appendix 1 of Code of Practice for Product Approval of Onsite Wastewater Systems (2013)

The transitional period to obtain certification for any onsite wastewater treatment systems is due on 31 December 2020.

All onsite wastewater treatment systems with the hydraulic capacities below the volumes in the table must be approved by the DoH. The approved onsite wastewater treatment systems are listed below.

Onsite wastewater treatment systems with capacities exceeding the volumes presented in the table require engineering certification to accompany each application to install the system. It is recommended to submit an engineering certification for each system model at once so that the documentation is on the DoH records  for any future applications.

The DoH will approve and publish onsite wastewater treatment systems with capacities above volumes listed on the table that have StandardMark certification to the relevant Australian Standard. 

Approved wastewater systems include:

Last reviewed: 25-09-2019
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Public Health