You must regularly maintain your OSD system to prevent potential problems.
If your OSD system discharges directly into a Sydney Water owned drainage system, you must enter into a formal agreement with Sydney Water which sets out your ongoing OSD maintenance responsibilities. You will need to register this agreement on the property title to ensure the information is stored on the title of the land. This prevents the details from being lost over time, especially as the property changes ownership.
If your OSD system discharges directly into a drainage system that is not owned by Sydney Water, you may be required to enter into an agreement with your local council.