• A collection tank connected to underground trenches or beds.
• Solids settle to the bottom, fats float to the top, and clearer liquid flows to the disposal area.
• Septic tanks should be pumped out about every 2- 5 years (depending on tank size, use and household practices).
• Regular maintenance includes:
  • Monitoring tank levels;
  • Checking for leaks or blockages;
  • Maintaining vegetation around tanks and disposal areas;
  • Ensuring trenches/disposal areas are functioning and no surface water is noted;

In additional to septic tanks, AWTS:

• Treat wastewater using aeration and additional disinfection methods.
• Effluent is disposed of by surface sprinklers or subsurface dripper irrigation.
• Irrigation areas can be used on lawns and shrubs, but not fruit/vegetable gardens or recreational areas.
• Disposal areas must be signposted and access to the area restricted by children, pets, livestock and vehicles.
• AWTS require:
  • Electricity to run pumps and alarms;
  • Regular servicing (generally 3-month intervals) by an approved service agent;
  • Service reports to be forwarded to Council;
  • Prompt action to repair or replace pumps and parts as required.

• Council approval is required for any new system or modification of an existing system.
• Applications must be submitted through the NSW Planning Portal.
• When applying, ensure you have all required supporting documentation. For further information see:
  • Fact Sheet – Installing or Altering OSSM
  • On-Site Sewage Management System Application Guide
  • OSSM Checklist 

Council’s Application Guide

All OSSM systems must have an Approval to Operate. To request a copy or renew an approval, contact Council via:

• • Email: council@muswellbrook.nsw.gov.au (preferred)
  • Phone: 6549 3700

Note: Written permission from the owner is required before Council can release documents to a third party such as solicitors and lawyers.

If an approval has lapsed and no inspection has been carried out in the last 10 years, a Council inspection will be required.

• Inspections for renewal of Approval to Operate:
  • No fee if the system is already registered with Council.
  • At least 7 days’ notice required for inspections,
  • Owners don’t need to be home, but must provide safe access (clear vegetation, unlock gates, restrain animals)

If a system is not registered, additional fees and processing time will apply.