Septic Tanks

The Shire of Dandaragan no longer offers this service unless in the event of an emergency where a individual or property owner is unable to engage a licensed controlled waste contractor to undertake the pump out.

Residents who require a septic tank pump out can contact the following organisation or business to make arrangements:

  • Green Head Plumbing and Gas - 0429 966 700

  • Shire of Moora - 9651 0000


When a developed property is connected to sewer, usually under the infill sewerage program, any on-site effluent disposal systems such as septic tank and leach drain/soak well systems will eventually require decommissioning. This entails that the contents of the tanks are pumped out by an approved contractor and the system either removed or backfilled. If the system can't be removed, the tanks should be pumped out, the bottom of the tanks broken up and the system backfilled with sand.

As there are costs involved in both, the decommissioning of the septic tanks and connecting to sewer, householders are not automatically required to decommission tanks when they connect to the sewer. Under the Health (Treatment of Sewage and Disposal of Effluent and Liquid Waste) Regulations 1974 decommissioning is required when:

  • The property is sold
  • The use of the development changes; e.g. from a residence to a child care centre
  • Building extensions that may encroach on the minimum setback requirements for the system

Septic tanks which have not been decommissioned must not be paved or built over without approval from the Shire.

The Shire requires notification to be forwarded when a system has been decommissioned. Please forward a letter to the Shire with a copy of the certification from the liquid waste contractor.

Septic tank application and decommissioning

One of the Shire's Environmental Health Services' function is to ensure that onsite wastewater treatment systems do not pose environmental or public health threats. To achieve this we attempt to ensure that all on-site effluent disposal systems are installed, operated and maintained in accordance with legislative requirements to prevent the transmission of disease and to deliver the best possible environmental outcomes, particularly with respect to our waterways.

System installations or changes to an existing system are only permitted with the approval of the Shire of Dandaragan, or for commercial premises of the Department of Health, WA. This includes both combined effluent disposal systems at premises where the sewer is not available, and also greywater re-use systems which may be installed in either sewered or unsewered areas.

The Shire of Dandaragan can only consider applications for the installation of an on-site effluent disposal system where that system has been approved for use in Western Australia by the Department of Health.

To download an Application to Construct or Install an Apparatus for the Treatment of Sewage click here

Septic tank pump-out service

Septic tanks are an effective part of your on-site waste water disposal system. The major function of a septic tank is to separate solids, grease and oils out of the wastewater before it enters the drainage receptacles.

When a septic tank system is correctly installed and maintained, it should work effectively for many years. If the septic tanks accumulate too much sludge and scum, the effective volume of the tank is reduced which in turn reduces the time for separation to take place. When septic tanks experience problems, it can disrupt the entire septic system.

The desirable frequency of desludging is dependent on the number of people contributing to the wastewater load. As a guide, every eight years for a two-person household, every four years for a four-person household and more often for households with greater numbers is recommended.

Alternating drainage receptacles should be switched regularly (annually). This requires that the diverter box be opened and the effluent flow handle turned to the appropriate position.