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On-Site Sewerage Management (OSSM)

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OSSM – On Site Sewage Management Systems

Hilltops Council regulate On Site Sewage Managements Systems (OSSM) to ensure compliance with relevant legislation.

OSSM systems are designed to treat and release wastewater into the environment, which can include solid and liquid waste. If these systems are not maintained or installed appropriately, there can be serious health repercussions and environmental impacts. These can include (but are not limited to):

  • The spread of disease, bacteria, pathogens, and viruses
  • Contamination of surface and groundwater
  • Spreading of unpleasant odours
  • Encouraging vermin and insects
  • Degradation of vegetation and soil

What is an On-Site Sewage Management System?

An onsite sewage management system, or commonly known as a septic system is an on-site system that manages waste and wastewater from your property. This includes from your toilets, washing machine, dishwasher, and drains. It is important that an appropriate system is installed in an appropriate location to reduce any risk to your health and the environment’s health.

There are a few options for onsite sewage management systems, examples of the types of systems include:

  • Secondary Treatment or Aerated Water Treatment System (AWTS), and
  • Primary Treatment septic tanks

Do I need approval from Council?

Approval is required via section 68 of the Local Government Act 1993 application to install, alter, modify or to operate an On-Site Sewage Management System (OSSM). To find out more information on how to process this application online through the NSW Planning Portal system click here.

Click here for the Hilltops On-Site Sewerage Management Policy

Information to be provided with your Application

Please include the following information with the completed Application Form via the Service NSW Planning Portal

  • A copy of the NSW Health Accreditation and Manufacturer’s specifications for proposed septic tank/ system
  • Design plan of proposed effluent disposal area (i.e. absorption trenches),
  • A floor plan of the dwelling/building the septic system is to be connected to. For non-residential systems, please provide a statement detailing the proposed or current use of the building/s the OSSM will be connected to and the amount of people expected to be using the system each day (for calculation of the daily wastewater load),
  • An accurately drawn, detailed site plan drawn to scale and showing the following:
    • Proposed location of preferred wastewater treatment system and intended
    • land application area
    • Location of any existing and proposed dwellings and other buildings and structures on the property
    • Location of property boundaries, watercourses (including rivers, creeks, dams, creeks, gullies, and bores), and trees
    • Please indicate the distance the wastewater treatment system and land application area will be from all of the above (including buildings, boundaries and watercourses), ensuring NSW Health buffer setback distances are complied with

Is your land less than 1 hectare?

  • A Wastewater Management Plan, including a site and soil assessment prepared by a suitably qualified consultant, will need to be provided with your application using criteria from Australian Standard AS/NZS 1547 Onsite Domestic Wastewater Management and the Environment & Health Protection Guidelines – OnSite Sewage Management for Single Households (1998)

Please Note: Staff may request additional information including a Wastewater Management Plan depending on location and environmental sensitivity of the land, even if the property is greater than 1 hectare in area

Assistance using the Planning Portal

If you require assistance using the Planning Portal, and you were unable to find the answer within the Help and Support section of the Planning Portal Platform, contact Service NSW for assistance. Call 1300 305 695 or email

Useful Links

NSW Health Certificates of Accreditation

NSW Health Fact Sheet on Primary Treatment Septic Tanks and Collection Wells

NSW Health Fact Sheet on Aerated Wastewater Treatment System (AWTS)

NSW Health Fact Sheet on Wastewater Management and Water Recycling

Office of Local Government Website OSSM Laws and Regulations

Section 68 of the Local Government Act which lists all the activities that require Section 68 approval

NSW Planning Portal – Apply for your Section 68 application HERE

Further Information

Contact Council on 1300 445 586 or with any further OSSM related enquires.