An On-site Wastewater Management System refers to any system that processes wastewater and disposes of the effluent by applying it to the land within the property boundary.
What is an On-site Wastewater Management System?
An On-site Stormwater Absorption System collects and disposes of rainwater (from roofs, driveways and other ground surfaces) within your property. If your home is not connected to the sewer, you may need to have an On-site Sewage Management System.
Septic tanks and trench style absorption systems are the most common type of domestic wastewater treatment systems in Australia.
Absorption trenches are usually built below ground and the bottom layer is filled with a hard aggregate such as uncompacted gravel. Either perforated piping, self-supporting arch trenching or box trenching is placed in the trench and is backfilled with gravel. A geotextile filter cloth is then laid over the pipe and gravel and under the top soil to ensure that the soil does not penetrate and block the trench.
Effluent flows into the trenches where it is absorbed through the trenching material and into the surrounding soil. The absorption process and the action of bacteria in the soil treat the effluent.
There are special regulations that apply to these On-site Wastewater Management Systems and as the owner of the property, it is your responsibility to ensure that the system is approved by your local council and is working efficiently and safely.
Types of Wastewater Around Your Home
There are 3 types of household wastewater:
Wastewater generated from toilet plumbing fixtures and is heavily and directly contaminated with human faeces and/or urine and may contain contaminated solid material, such as toilet paper. This wastewater is highly infectious.
Wastewater from non-toilet plumbing fixtures and includes wastewater from hand basins, showers, laundry and kitchens. Greywater is often contaminated with human faeces, dirt and other materials but to a lesser extent than blackwater and is therefore considered less infectious.
Wastewater from the premises (both blackwater and greywater) normally discharged to a swewer and is considered very infectious.
Stormwater is rainwater as well as anything it carries with it such as water from roofs, roads, footpaths, driveways and other ground surfaces and can include sewage from sewer overflows.
Unlike sewage, stormwater has not been treated and the stormwater pipes carry all the water that flows into waterways inhabited by fish, frogs and other aquatic animals and plants.
How can Wastewater be disposed?
Through pipes called sewers into a sewerage system and treated in a single large sewage treatment plant.
It can then be converted into a resource for selective reuse for car washing, outdoor household garden watering, toilet flushing, golf course watering and irrigation of crops.
The treated effluent may also be discharged to rivers and oceans.
Through pipes into a local community small sewage treatment plant for local community reuse.
A number of these local systems make up de-centralised sewage management.
On-site Wastewater Management System
Where stormwater, sewage or components such as greywater must be partially or fully treated for utilisation or reuse within the property boundaries.
On-site single domestic wastewater management is regulated jointly by local councils and NSW Health.
On-site systems may not be installed or altered unless approved by the local council.