Install and Maintain an Effluent Disposal System

Choosing an effluent system and location

A number of factors can determine the type of system and location where a system can be installed on the lot.  Factors such as depth to ground water, sewerage sensitive areas, wetlands, water courses and bores must be considered.

For assistance in determining the type of system and the location you should apply for please contact the City’s Health Services.  Officers will require the address of the lot and details about the type of development you wish to apply for in order to provide you specific advice.

Onsite effluent disposal system application and approval

The City of Cockburn can approve most applications for on-site effluent disposal systems on single residential or small commercial premises (producing no more than 540 litres of waste water per day).

Application process

You must submit a completed application form (see below) with the following:

• Two copies of site plans to scale (1:100), where the application may be approved by the City of Cockburn’s Health Service
• Three copies of site plans to scale (1:100), where Department of Health (WA) approval is required
• Schematic plans of the proposed plumbing layout (please see details below)
• An application and permit to use fee (see application form for details)
• A cheque made out to the Executive Director of Public Health (if Department of Health WA approval is required).

Effluent disposal system site plans

Site plans must be drawn to a scale of 1:100, be labelled with all dimensions and include:

• 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 provided). Where the volumes of the spa exceed 350L, a separate septic tank and effluent disposal system is required.

Approval of on-site effluent disposal for all larger residential or commercial premises

Approval of on-site effluent disposal for all larger residential or commercial premises must be assessed and approved by the Department of Health (WA). These applications should first be lodged with the City's Health Services, who will forward it onto the Department. Please note that additional Department of Health fees are incurred, refer to the back of the application form for further details.   

Maintain an effluent disposal system

Property owners must:

• Pump out the tanks on a regular basis. This equates to every four years for an average four person household or every eight to nine years for a two person household
• Alternate leach drains each year. All domestic systems approved from 1990 and onwards have two leach drains and an alternating device to allow systems to rest
• For alternative treatment systems the system is required to be regularly serviced by a qualified agent.  The agent submits the servicing report to the City upon completion.

Property owners must not:

• Dispose of materials that do not break down readily (e.g. plastic bags, kitchen sponges, sanitary napkins, tampons, disposable nappies)
• Dispose of old medicines, large amounts of disinfectant or other strong chemicals down the pipes leading to the septic tank. (Bleaches and detergents are acceptable if used in moderation).

Please be advised that only licensed liquid waste contractors can pump out septic tanks. Contractors are listed in the Yellow Pages under Septic Tank Cleaning Services.