Types of Effluent Disposal Systems

When a connection to a sewer is not available, an effluent disposal system must be installed. Find out about the different types of systems available. 

Approved types of effluent disposal systems 

The following effluent disposal systems can be installed in the City of Cockburn subject to approval: 

Conventional septic systems 

  • Comprise two septic tanks and either two leach drains or four soak wells. 
  • Septic tanks digest all solid and liquid wastes into an effluent, discharged into the ground via leach drains or soak wells. 

Nutrient retentive leaching systems 

  • Utilise septic tanks to process solid and liquid waste. 
  • Liquid waste flows to leach drains with an amended soil column to bind phosphorus before disposal into the ground. 

Aerobic treatment units 

  • Use an aeration chamber to aid in the breakdown of bacteria. 
  • Effluent is further treated and disposed of either by surface irrigation, sub-soil dripper, or leach drain system. 
Note: Surface irrigation is not a preferred method of disposal within the City of Cockburn. 

Applying for approval 

For guidance on the application process to install one of these systems, please refer to Install and Maintain an Effluent Disposal System

More information and contact 

For more details on types of effluent disposal systems, contact the Health Services team on 08 9411 3444 or email [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)

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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 and present.