On-site sewage facilities

There are two types of on-site sewerage treatment facilities:

  • a septic system (common on older properties)
  • an on-site sewerage treatment facility.

How does an on-site sewerage treatment facility work?

An on-site sewerage treatment facility produces a higher water quality output than a septic system reducing the impact on the environment.

The performance of an on-site sewerage treatment facility relies on having living bacteria in the storage tank. The bacteria break down the effluent, and along with a consistent supply of oxygen the bacteria grow and treat the wastewater to a safe water quality.

Like a septic system, what you use in your household determines the performance of your system. Too much water flowing into the system will cause the effluent to flow quickly through the tank before the bacteria have a chance to work. This can result in large particles flowing into and clogging the land application area.

Tips on maintaining an on-site sewerage facility

  • Use natural cleaning products and low phosphorous detergents in your home.
  • Using toxic chemicals will kill the good bacteria in the system, avoid chemicals like:
    • solvents
    • oils
    • paints
    • disinfectants
    • pesticides
    • household cleaning products
    • bleaches.
  • Make sure the existing house drainage system is compliant, e.g. no broken pipes or tank leaks.
  • Engage a Service Agent to conduct quarterly repairs and proactive maintenance.
  • Desludge tanks, pumps and drainage lines.
  • If applicable, maintain and protect the land application area.
  • Comply with the requirements of the Plumbing and Drainage Act 2018 and the Plumbing and Drainage Regulations 2019 to provide Council with quarterly copies of service maintenance reports.

Common Problems with septic systems

  • Full tank: If you have a septic tank the sludge level of your tank should not be more than 2/3 full. Too much sludge and scum in the tank will eventually make the system fail, resulting in untreated contaminated wastewater with heavy solids flowing out of the tank. This can lead to a failure of the land application area. Tanks should be pumped out according to the sludge and scum levels.
  • Too much water going into the system: This will cause the effluent to flow quickly through the tank before the bacteria can breakdown solids. As a result, large particles will flow into and the land application area reducing its efficiency.

Common problems with land application areas

  • Ensure they are not installed in high traffic areas, e.g. do not drive on or disturb storm water diversion mounds.
  • Do not build structures on the disposal area or plant trees that will shade the area.
  • Avoid flooding the disposal area with sprinklers or hoses.
  • Do not allow children to play in the area or animals to graze in the area.
  • Avoid covering the area with concrete or pavers.
  • Avoid storing earth material / soils on the disposal area.
  • Do not add extra soil to the disposal area, as this often causes the area to become saturated. This can affect the performance and efficiency of the land application area.

Reporting a possible non-compliant on-site sewerage treatment facility or septic system

To report any possible non-complaint systems, please call us on 07 3412 3412.

We will investigate the issue and contact you with the outcome of our investigation.

How to lodge an on-site sewerage treatment facility application

You will need Council approval to install or change an on-site sewerage treatment facility or grey water facility.

To apply, please see Plumbing and Drainage – Application forms and lodgement.