A large number of properties in the Central Highlands region are not connected to a reticulated sewerage system. The treatment and disposal of all wastewater generated on these properties must be undertaken by an On-Site Sewerage Facility.
An On-Site Sewerage Facility is any system that stores, treats and disposes of household wastewater on the property. 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.
On-Site Sewerage Systems are governed by the Plumbing and Drainage Act 2002 Part 4 Division 2. In accordance with this act, On-Site Sewerage work must be assessed for compliance with the Standard Plumbing and Drainage Regulation, and a Compliance Permit issued prior to any work commencing.
For more information on this Act and other legislation, please see the links to the Department of Local Government and Planning website (formerly the Department of Infrastructure and Planning), and the Queensland Legislation website on the Legislation page.
For information on how to submit a Plumbing Application, please see the Checklist of requirements for submitting an application for a Non-Sewered 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 a common effluent drainage system*
- off the premises by collection from a holding tank by a Council approved liquid waste carrier
* 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 (EP) would also require approval and further monitoring by the Department of Environment and Resource Management (formerly known as the Environmental Protection Agency). For more information please see the Department of Environment and Resource Management’s Information Sheet on Greywater and Sewage in the Environmental Protection Act 1994.
Types of On-Site Sewerage Systems
Treatment systems for household waste include:
- Septic Tanks (Primary treatment)
· All-waste septic tank (all household wastewater)
· Black water septic tank (toilet, urinal and bidet wastewater only)
· Greywater septic tank (sullage wastewater only)
- Conventional domestic sewage treatment plants (Secondary treatment or better)
· Activated sludge system
· Biological trickle filter system
· Extended aeration system
· Aerated/aerobic sand filter system
- Composting systems
· Dry vault system (toilet waste only - waterless)
· Wet system (all household wastewater - may be considered a domestic sewage treatment plant
- Holding tank
· Off the premises by collection from a holding tank by a Council approved liquid waste carrier.
· Greywater treatment/diversion facility
Although Council approves the installation of an On-Site Sewerage Facility, the treatment system will require product approval from a State Government department or demonstrated compliance with a manufacturing code or Australian Standard before it is approved.
Types of Land Application Areas
The designated area on a property for application of the treated effluent is as a land application area and includes:
- Irrigation system
· Surface irrigation (spray above ground)
· Sub-surface irrigation (drippers in shallow trench – large surface area)
· Covered surface irrigation (drippers on natural ground covered by mulch, woodchip etc. – large surface area)
- Evapotranspiration-absorption trench/bed/mound
· Trench or bed (embodies the principles of evaporation, transpiration and absorption)
· Elevated sand mound (specially constructed on natural ground level)
Greywater is waste water from the bath, shower, hand basin and laundry which can be diverted for reuse on lawns and gardens. Kitchen waste water is not Greywater suitable for reuse, as grease and oil can clog irrigation systems and build up on soil surfaces.
Under the State Government’s Plumbing and Drainage Act 2002, residents in sewered areas may use Greywater by means of:
- Manual bucketing
- Connecting a flexible hose to a washing machine outlet
- Installation of Greywater diversion devices (with Council approval) and treatment plants by licensed plumbers, connected to an irrigation hose
- Surface or sub-surface system (with Council approval)
Care should be taken if reusing Greywater as it can have:
- Potential health risks to humans; and
- Potential for environmental damage to soils, ground water, and waterways caused by increased nutrient and chemical levels
Council approval is required before installing either:
- A Greywater diversion device, which diverts Greywater from the bath, shower, hand basin and/or laundry to an irrigation hose. Untreated Greywater cannot be stored
- A Greywater treatment system, which collects the Greywater and treats it to a high standard for reuse as garden irrigation
Council approval is not required for manual bucketing or connecting a flexible hose to a washing machine outlet.
Information for Plumbers/Drainers
The Greywater guidelines for Plumbers and Drainers on the Department of Local Government and Planning website (formerly known as the Department of Infrastructure and Planning) can help with assessing whether the home owner has suitable and sufficient land to distribute Greywater.
Plumbers and Drainers should use the guidelines to give advice on the purchase and installation costs of Greywater systems, prior to the home owner making an application to Council.
If you have any queries about On-Site Sewerage Systems or Greywater, please contact the Plumbing Section on 1300 242 686 or 07 4982 8378.