Install and Maintain an Effluent Disposal System

Find out how to apply for an effluent disposal system and steps to maintain its efficiency. 

Choosing an effluent system and location

The type of effluent disposal system and its location are determined by many factors including ground water depth, sewerage sensitive areas, wetlands, water courses and bores. 

Find out about the types of effluent disposal systems. You can also contact the City’s Health Services for help to determine the type of system you should install and its location.  

Approval to install an effluent disposal system

Who assesses and approves applications

• For single residential or small commercial premises (producing up to 540 litres of wastewater per day): The City of Cockburn usually handles the approval for on-site effluent disposal systems.
• For larger residential or commercial properties: The approval process falls under the Department of Health (WA). However, even for these larger properties, applications must initially be submitted to the City's Health Services. Once received, the City will forward your application to the Department of Health for assessment and approval. 

How to apply

To apply, please: 

• Complete the application form below 
• Include two scaled site plans (1:100) for the City of Cockburn’s Health Service* 
• Add three identical site plans for the Department of Health (WA)* 
• Attach schematic plans detailing the proposed plumbing layout 
• Pay the application and permit-to-use fee (details are in the application form) 
• If approval from the Department of Health WA is necessary, an additional payment is required (details are in the application form). 

*Refer to requirements for site plans below.  

Requirements for effluent disposal system site plans 

• Site plans must be drawn to a scale of 1:100, be labelled with all dimensions and include: 
• The location of the effluent disposal system and all drains and pipe work 
• Distance of the system from all buildings, boundaries, trafficable areas, bores, waterways, and water bodies 
• Site contours or spot heights in Australian Height Datum 
• Volume of spa if relevant (if the spa volume exceeds 350 litres, a separate septic tank and effluent disposal system are required). 

Maintaining an effluent disposal system

Responsibilities of property owners 

Tank pumping: 

• For a four-person household: Pump out tanks every four years. 
• For a two-person household: Pump out tanks every eight to nine years. 

Leach drains: 

• If your system was approved from 1990 onwards, it has two leach drains and an alternating device. 
• Alternate between the leach drains each year to allow systems to rest. 

Alternative treatment systems: 

• These systems need regular servicing by a qualified agent. 
• After servicing, the agent must submit a report to the City. 

What property owners should avoid 

• Do not dispose of non-biodegradable items: Such as plastic bags, kitchen sponges, sanitary napkins, tampons, and disposable nappies. 
• Limit chemical disposal: Refrain from disposing of old medicines, large amounts of disinfectants, or other strong chemicals into the septic system. Moderate use of bleaches and detergents is acceptable. 

Note: Only licensed liquid waste contractors are permitted to pump out septic tanks.