On-site Treatment System - Noosa Shire Council

A large number of properties on the Sunshine Coast 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.

On-site sewerage facilities

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.

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 EP would also require approval and further monitoring from the Environmental Protection Agency.

Types of on-site sewerage systems

Treatment systems for household wastewater include:

conventional domestic sewage treatment plants (secondary treatment or better) activated sludge system biological trickling filter system extended aeration system aerated/aerobic sand filter system 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) 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 grey water 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).

The type of land application area will depend on the level of treatment the wastewater has received prior to disposal.

On-site sewerage forms