Types of Effluent Disposal Systems

Where sewer is not available an effluent disposal system must be installed. The Department of Health is responsible for approving the types of onsite effluent disposal systems allowed in Western Australia. The City's Health Services can generally provide approval for the installation of approved types of Effluent Treatment and Disposal Systems, subject to certain conditions.

Approved types of effluent disposal systems

The following types of effluent disposal systems have been approved by the WA Health Department and can be installed in the City of Cockburn.

Conventional septic systems

These systems incorporate two septic tanks and either two leach drains or four soak wells. The septic tanks digest all solid and liquid wastes into an effluent which is discharged into the ground via leach drains or soak wells.

Nutrient retentive leaching systems

These systems utilise septic tanks to process solid and liquid waste, however the effluent is discharged through an amended soil which strips the effluent of nutrients.

Aerobic treatment units

These units incorporate aeration systems to aid in the breakdown of waste. The effluent is further treated and disposed of either by surface irrigation, sub-soil dripper or leach drain system. Surface irrigation is not a preferred method of disposal within the City of Cockburn.

More information and contact

Contact Health Services for more information on types of effluent disposal systems on 08 9411 3444 or at [email protected]



City of Cockburn
Whadjuk Boodja
9 Coleville Crescent,
Spearwood 6163

PO Box 1215, Bibra Lake DC,
Western Australia, 6965

Office opening hours:
8.30am to 4.30pm
Monday to Friday (excluding public holidays)

Language Support

Cockburn Nyungar moort Beeliar boodja-k kaadadjiny. Koora, yeyi, benang baalap nidja boodja-k kaaradjiny.
Ngalak kaadatj dayin boodja, kep wer malayin. Ngalak kaadatj koora koora wer yeyi ngalang birdiya.

City of Cockburn acknowledges the Nyungar people of Beeliar boodja. Long ago, now and in the future they care for country.
We acknowledge a continuing connection to land, waters and culture and pay our respects to the Elders, past, present and emerging.