On-site Waste Management

If you are proposing to build on land that cannot be connected to Council’s reticulated sewerage system, then it will be necessary for you install an on-site sewage management system. This is likely to be the case if you are building outside of the Cowra Township in a rural area or in one of the Shire’s villages. 

An on-site sewage management system is a general term used to describe a device used to treat domestic sewage and may include a septic tank, an aerated waste treatment system or composting system for example. The end product, which is referred to as effluent, is then gravity-fed or pumped to an effluent disposal area. In some cases, the effluent disposal area is absorbed into the land, irrigated onto the land, or directed to a holding well and collected later by a tanker.  

In NSW, on-site sewage management systems must be designed, operated and maintained in a manner that will:

  • Prevent public health risk.
  • Prevent environmental damage (particularly to land, soil, groundwater and surface waters); and
  • Protect community amenity (e.g. odours).

It is also important that an on-site sewage management system is designed, installed and operated so that it works well into the future. 

To find out more about on-site sewage management systems and the requirements for your next building project, explore the FAQ’s below. 

Frequently Asked Questions

What are the approval requirements for OSSM's?

Existing Systems

All applications to install, modify existing, operate existing and/or register existing On-site Sewage Management System must be applied for via the NSW Planning Portal.

For existing systems, by lodging this application, you are granted interim approval to operate the system until such time as Council inspects the system. If the system is not satisfactory, you will be advised what needs to be done to gain approval and to operate. 

For all new systems, this application must be applied for, inspected and approved by Council prior to occupation of your new home.


How much does it cost to lodge an application with Council?

Please refer to the list of fees and charges for "Onsite Sewage Management Systems" in Council's Revenue Policy for all current application fees.

Does Council require me to install a particular type of OSSM?

Council does not require specific types of on-site sewage management systems to be installed. 

The type of system that is suitable for your property will depend on a number of factors. Site characteristics including soil type, soil depth, slope, proximity to water and water balance will determine the most appropriate type of on-site sewage management system for your land. 

For this reason, Council recommends you to engage the services of a qualified Geotechnical Engineer to investigate the site characteristics and recommend the most appropriate type of on-site sewage management system for your land. The Geotechnical Report will form part of your application to Council. 

What information must be submitted with my OSSM application?

The following information must be submitted with your application on the NSW Planning Portal.


Your application must be accompanied by a plan, drawn to scale, showing the location of:

  • The sewage management facility
  • Any related effluent application areas
  • Any existing or proposed buildings on the land
  • Any environmentally sensitive areas within 100 metres of the sewage management facility.
  • Any related drainage lines or pipework (whether natural or constructed).


Your application must be accompanied by full specifications of the sewage management facility proposed to be installed or constructed on the premise concerned. This information can usually be obtained from the manufacturer or supplier of the chosen system. 

Site Assessment

Your application must be accompanied by details of the climate, geology, hydrogeology, topography, soil composition and vegetation of any effluent application areas, together with an assessment of the site in light of those details. 

Council recommends that you engage the services of a qualified Geotechnical Engineer to prepare a suitable site assessment report. A search in the yellow pages for ‘Geotechnical Engineer’ will return results for a number of consultancies operating in the local area that are capable of preparing a suitable report.


Your application must be accompanied by a statement of:

  • The number of persons residing, or probably number of persons to reside, on the premises.
  • Such other factors as are relevant to the capacity of the proposed on-site sewage management system.

Operation and Maintenance

Your application must be accompanied by details of:

  • The operation and maintenance requirements for the proposed on-site sewage management system.
  • The proposed operation, maintenance and servicing arrangements intended to meet those requirements.
  • The action to be taken in the event of a breakdown in, or other interference with, its operation.

Is there someone at Council who can help?

If you would like further information about on-site sewage management systems, please contact Council’s Environmental Services Department on (02) 6340 2040.