On-site Sewerage Facilities (OSSF)
A large number of properties in the Southern Downs are not connected to a reticulated sewerage system. The treatment and disposal of all wastewater generated on these properties must then be undertaken by an on-site sewerage facility.
An on-site sewerage facility is any system that captures, stores, treats and disposes of household wastewater on the property. The disposal of effluent (treated sewage) may occur:
- on the property on a designated area (called a land application area)
- off the premises by collection from a holding tank by a council-approved liquid waste carrier.
- off the premises by a common effluent drainage system.
A common effluent drainage system is where two or more premises have their wastewater combined (usually after primary treatment) and transported to a common land application area independent of premises where the wastewater was generated. Such systems over 20 equivalent persons would also require approval and further monitoring from the Department of Environment and Heritage Protection.
Legislation supporting on-site sewer systems
Council undertakes assessment for on-site sewerage facilities under the requirement of the Plumbing and Drainage Act 2018, the Queensland Plumbing and Wastewater Code and Council's development permit conditions.
The Queensland Plumbing and Wastewater Code sets out the technical requirements for sustainable management, site and soil evaluation, design, installation and operation for on-site sewerage facilities.
This code is to be read in conjunction with AS/NZS 1547 2000, which includes information relating to on-site domestic wastewater management.
The site and soil evaluator
One of the important aspects of the Queensland Plumbing and Wastewater Code is the requirement for a thorough site and soil evaluation to be undertaken as part of the process of obtaining Council approval for effluent disposal within the property.
It is essential for the evaluator to select the most suitable on-site effluent disposal facility for the property and engage the best environmental practices to support his or her design. The quality of effluent from an on-site sewerage facility is a key consideration to determine how sewage effluent is to be controlled and disposed of within the property.
Before lodging an application to install an on-site sewerage facility with Council, it is recommended that the property owner consult with a site and soil evaluator to discuss the options available for effluent disposal within the property
For more information refer to the Department of Housing and Public Works website.
Poorly sited or maintained on-site sewerage facilities can impact public health and the environment. The owner of the facility is responsible for ensuring the system is maintained and functioning properly. It is emphasised that maintenance is essential for the satisfactory performance of these facilities.
Newsflash 534 On-site sewerage facility requirements (PDF 3.5MB)