On-site treatment and greywater
  • Last updated:
  • 09 Sep 2020

If your property is not connected to public sewerage infrastructure, you will need an on-site sewerage facility (OSF). This facility stores, treats and disposes of your domestic sewerage on your property. An OSF consists of two components; the treatment plant and the land application area. For a more comprehensive guide refer to council's what is an OSF fact sheet.

Image shows three icons in a row with a horizontal line dividing the top and bottom of the image. The line depicts ground level. From left to right there is a building icon above the ground level, described as a typical house. In the centre there is an underground box described as a waste water treatment plant. On the right there is an icon of a spray or sprinkler above the ground level. It is described as the land application area. The house has an underground connection to the waste water treatment plant. The waste water treatment plant has an underground connection to the spray or sprinkler in the land application area.

 

All OSF's need a plumbing permit (approval) from council before installation. You need to apply for a permit if you are installing a new OSF or altering an existing system.

To apply for a permit, use form 1 permit work application for plumbing, drainage and on site sewerage work.

 Once approved, you will receive a copy of the permit and approved plan. Then a licensed drainage contractor can install the facility. It is the responsibility of the contractor to:

  • install the facility correctly
  • ensure completion of inspections and certifications
  • provide a final inspection certificate to the owner.

Before selecting an OSF, you must have a licensed site and soil evaluator visit the property. They will conduct an investigation and recommend the level of treatment required. There are three common levels of treatment:

  • primary treatment
    breaks down solid material into liquid waste, then disperses it below ground
  • secondary treatment
    breaks down organic material to wastewater suitable for surface or subsurface irrigation
  • advanced secondary treatment
    reduces suspended solids to wastewater suitable for release into sensitive ecosystems.

Factors to consider when choosing a system include:

  • soil type of the property
  • size and slope of the property
  • quantity of water to be treated
  • amount of water available
  • proximity to waterways
  • spread of load throughout the day
  • initial cost of system and land application area
  • ongoing maintenance requirements
  • budget
  • Queensland approved treatment plants.

For more information refer to Queensland approved treatment plants.

Below are videos to help you understand the different types of onsite sewerage facilities.

 

Types of onsite sewerage facilities

View the full transcript.


Primary treatment level

Septic systems

View the full transcript.
For more information see council's septic systems fact sheet.


Composting toilet systems

View the full transcript.
For more information see council's waterless composting toilets fact sheet.


Secondary or advanced secondary treatment

Aerated wastewater treatment systems

View the full transcript.
For more information see council's aerated wastewater treatment systems fact sheet.

Other types of OSF systems include:

  • activated sludge
  • split black and grey water treatment
  • holding tank with pump out
  • recirculating sand filter.

A land application area is the area of your property where your treated wastewater is disposed. The design, installation and maintenance of your land application area is important. Each step protects the environment and the health of your family and neighbours.

There are three types of land application areas:

  • trench based systems - transpiration to large flat areas with absorbent soils
  • surface irrigation systems - disperses using sprinklers, may not be suitable for sloping land
  • sub surface systems - disperses using pipes beneath a layer of suspended soil.

OSFs need regular maintenance to ensure they operate in a safe and effective manner. Poorly maintained and malfunctioning systems can impact public health, the environment and property value.

Responsibilities of owners of the OSF:

  • make sure the system is well maintained and works properly.
  • you may need a service agent agreement to service the OSF. Depending on the system, servicing frequency can vary from quarterly to yearly
  • take reasonable steps to keep all plumbing and drainage on the property in good condition
  • ensure the system does not create a nuisance or pose a health risk to the surrounding area.

Servicing may include:

  • measure sludge and scum levels
  • ensure adequate chlorine supplies
  • ensure pumps and blowers are operational
  • clean filters
  • test chemical levels
  • check for evidence of bacteria die-off
  • check for ponding of wastewater in the land application area
  • check mechanical components
  • ensure plant is in operational condition
  • submitting a service report to council (eServices or manual).

You can further ensure safe operation of your system by:

  • avoiding anti-bacterial products and using only septic safe products
  • preventing ponding of wastewater in the land application area to avoid spread of sickness
  • being alert to any failure of the electrical components of the system
  • taking note of any leaking water or broken pipes
  • acting on any change in odour coming from the plant
  • listening for the correct operation of the system.

Some medications may inadvertently compromise the OSF. For example, chemotherapy medication. Please consult a treatment plant manufacturer or service agent for advise about the potential impact on your OSF.

OSFs, including septic tanks must be correctly decommissioned. This is to ensure the tank does not pose a future risk to public health or the environment. A plumbing permit is required prior to any works associated with decommissioning an OSF.

For more information refer to council's septic tank decommissioning procedure fact sheet and sample holding tank installation.

Service reports provide important information on the performance and maintenance requirements for your OSF. Services reports allow monitoring of your OSF discharges. This ensures it doesn't pose a risk to the environment, or health of the community.

Council offers several ways to submit your service report:

OSF eServices

OSF eServices enables you to directly integrate with council's register. This means we can receive and review your service reports instantaneously.

More information

Contamination of waterways should be reported to council immediately.

Reports of odour problems are also investigated as odours can indicate system failure. 

For more information refer to council's OSF responsibilities and complaints fact sheet[456KB].

To report a problem contact council's development services.

Fact sheets:

Videos: