Onsite Waste Water Management Systems

What is domestic waste water?

Domestic wastewater is generated from domestic sources such as:

  • Kitchen
  • Bathroom (sink, bath, shower)
  • Toilet
  • Laundry (washing machine, sink)

Within this are two types of wastewater – blackwater and greywater. Blackwater is human excreta and water grossly contaminated with human excreta. Greywater may still be contaminated with human excreta to a small degree. It includes kitchen, bath, shower, and laundry wastes.

An on-site system is a miniature sewage treatment plant. If it is misused, overworked, or incorrectly maintained it will fail. A system that is working will have an active bacteria culture. This breaks the sewage down through metabolic activities. Once the water leaves the system it is further purified by soil micro-organisms.

Problems can arise with these systems. Beneficial bacteria can be killed and soil absorption/filtration capabilities can be degraded over time. These problems combined with unsafe disposal activities can result in serious public and environmental health risks.



History of the tank

Septic tanks have been in use since the 1920’s. These became more popular over time and were initially designed as a treatment for rural areas where there was a lot of space for treatment and disposal. However, they were also installed into urban areas as a method of treatment until a centralised system was installed. In many cases the centralised system has not eventuated and many systems have not been maintained. This has led to serious drainage issues and has in many instances posed a major risk to public and environmental health.

Why Council will be inspecting your system

Legislation introduced in the late 1990’s (Local Government Act S.68 Part C, Items 5 & 6) made it mandatory for Councils to monitor the operation of all on-site sewage management systems and ensure those systems complied with environmental and public health performance standards.

This new legislation was introduced as a result of an incident where 400 members of the public became severely ill after consuming contaminated foods. Faulty on-site septic systems were suspected to be the source of virus which caused the illness.

All Councils who have un-sewered properties in their local government areas must implement an inspection regime and issue an “Approval to Operate” (license) for all on-site wastewater management systems. In addition to this, Council’s must develop an on-site management strategy and keep a database of all on-site sewage management systems.

As part of the SepticSafe Program, Council will be undertaking inspections of septic and other wastewater management systems within the Lithgow City Council Local Government area.  The inspection program is part of Council’s commitment to the long-term protection of public health and the environment.  The inspection process will vary depending on the type of system you have.  For example, an inspection for a conventional septic talk with absorption trenches will involve checking the sludge and scum levels within the septic tank and assessing the condition of the absorption trenches.  For an aerated wastewater treatment system the focus will be on the irrigation system/area and to ensure the system is being serviced adequately.  AWTS service provider reports will be monitored to ensure services are being conducted as required by legislation. 

Water Saving Tips

The minimisation of wastewater is important:

  • To prevent overload to the installed wastewater treatment device
  • To conserve water as a valuable resource
  • Can also save you money into the future in savings on your water bill

The following can assist in conserving water:

  • Dual flush cisterns
  • Water conserving shower heads
  • Water conserving dishwashers
  • Water conserving washing machines

For each of these products, the higher the WELS or AAAAA rating the more efficient the system.

Other water conserving strategies include

  • Taking shorter showers
  • Turning off the tap while cleaning your teeth
  • Fixing dripping taps
  • Use dishwashers and washing machines only when there is a full load

Unsafe Discharges

Some materials must not enter your septic system, otherwise problems will almost certainly arise.  These include

  • Stormwater from downpipes or rainwater tank overflows
  • Backwash water from pools or spa pools
  • Solid materials such as paper (depending on the system), plastic, sanitary napkins, tampons, nappies or nappy liners
  • Trade waste from commercial or industrial premises
  • Paint, petroleum products or other solvents, strong alkaline, acid or bleaching agents
  • Antibiotics and some other prescription medicines.


Types of Systems

A number of factors need to be looked at when choosing a system that will best suit your site and your needs. The system you choose must be approved by NSW Health. The system must be installed by a licensed plumber/drainer. You should also take into account environmental and human health issues as well as considering ongoing costs of maintenance. Refer to the NSW Health website and conduct some research into the various options or combination of options.

If you are looking to install a system or alter an existing system, you will need to seek approval from Council. Please contact Regional Services Development Section of Council for further information.



Frequently Asked Questions

What is an aerated wastewater treatment system?
Lithgow City Council and Oberon Council are seeking expressions of interest from appropriately qualified, independent persons to become a member of the Lithgow-Oberon Audit Committee.
AWTS treat wastewater to a higher level than septic systems through an aeration process, clarification, and finally disinfection through chlorination or exposure to ultra violet light. It is important to have these systems regularly serviced to ensure pumps, air blowers, and other mechanical components are operating correctly and to replace chlorine tablets or to clean the ultra violet lamp. For systems that are used infrequently (such as holiday homes) it is very important that servicing occurs as your service technician may need to “feed” the system to ensure it operates effectively. These systems are commonly referred to as their brand names such as Envirocycle, Biocycle, and Bioseptic etc.
Why do I need warning signs and need to keep humans and animals away from the irrigated wastewater?
Because legislation requires signage for safety reasons.
What is an “approval to operate”?

Operating a system of sewage management is a prescribed activity under section 68(F10) of the Local Government Act 1993 and clause 45 of the Local Government (General) Regulation 2005. This means that an approval to operate a system of sewage management must be obtained from the local council.

Approval to operate a system of sewage management requires the landowner to take all reasonable steps to minimise transmission of disease, pollution of water and degradation of land as a result of sewage management activity and requires that the landowner inform the Council about those activities and pay fees to contribute to the Council’s costs of managing the cumulative impact of sewage pollution.

Why should on-site sewage system owners have to pay council for an approval?

Most of the costs of operating an on-site sewage management system are borne by the landowner or resident, but the Council is responsible for supervision and environmental management. Residents in sewered areas pay for supervision and environmental management through sewerage charges, which include load based EPA licence fees and other environmental management costs. This program, known as Septic Safe, provides monitoring and assurance of water quality, better control of effluent discharge, supervision of plumbers and service agents, education programs and practical support to assist landowners.

Is Council approval required for existing systems?

Landowners with any type of on-site sewage management system are required to obtain a council approval to operate. Councils are entitled to charge a fee to cover the cost of registration and assessment. In some environmentally sensitive areas Councils will also be conducting function checks to confirm the performance of systems considered high risk. Please refer to Council’s Onsite Wastewater Management Strategy for further information on requirements.

What will Council do if it does not receive a service report?

Council will send a letter reminding the resident of the need to have the system serviced. If a service report is not received a penalty infringement notice for $330.00 may be issued. It must be noted that it is the responsibility of the owner or licence holder to ensure that the service technician provides council with a service report. This is particularly relevant after the first letter has been sent.

How can I improve my irrigation system and irrigation field?

Ideally treated wastewater should be irrigated over an area of approximately 1000m 2. This is considered a large enough area for the soil and vegetation to or utilise wastewater without any adverse effects. The larger the area the less likely it is that wastewater will run off into bushland, creeks, and neighbouring properties when it rains. This can also be helped by diverting stormwater away from the disposal area with the use of diversion mounds or drains.

To spread the wastewater over such a large area it maybe necessary to divide the irrigation system and area into 2 or 3 zones with the use of manual or automatic valves (indexing valves). This is necessary as there is generally only enough wastewater in the irrigation chamber of the AWTS to irrigate approximately 300 m 2 at a time. A good example of an irrigation system is attached to the end of this document.

Your irrigation system will also work better if you install filters at the start of the irrigation system and you use pipes and fitting designed for wastewater reuse. These can be identified through their Lilac colouring or striping. Where sprinklers are used these should be coarse droplet that throw no more than 2 metres at a height of 600mm. This is to avoid the wastewater becoming aerated or windborne.

Are AWTS still allowed to be installed in the greater Lithgow area?

Yes, but these days they can only be installed on larger properties and where it can be demonstrated, through a site and soil assessment, that the land can sustain the system without any risk to public health and the environment.

What would Council do if they found a person discharging wastewater directly into a creek, bushland, or a stormwater service, or other water body?

These are offences under the Protection of the Environment Operations Act 1997 for polluting water. Council would consider a prosecution or issuing penalty infringement notice (fine). Minimum fines for such offences are $750.00 for individuals or $1500.00 for corporations.

Will council be inspecting my AWTS?

Council will be randomly inspecting AWTS within the local government area. This is to ensure that the service technicians are servicing systems within the Local Government Area to a satisfactory standard. Council must receive quarterly service reports from service technicians and will be monitoring this through the database system. It is your responsibility to ensure your service technician is forwarding your service report to Council. If these reports are not received, Council may inspect your AWTS at a cost to you of $70 and you may be issued with a penalty infringement notice (fine).

Further information

Onsidte Sewage Management Strategy

This Management Strategy has been developed to help Lithgow City Council assess, regulate and manage the selection, design, installation, operation and maintenance of on-site sewage management systems.

The easy septic guide

If your home is not connected to the sewer, this booklet is for you.

Septic Tank and Absorption Trench

A guide to looking after your septic tank and absorption trench.