When decommissioning is required
Decommissioning is required by law when:
- When the property is being demolished,
- There is a change in use of the premise, or
- Within 60 days of change of ownership of a property, or
- Extensions to the property encroach on setback requirements for the systems.
- When mains sewage becomes available to a property, the owner has five years to disconnect the onsite disposal system and connect to sewer.
This is to ensure that the tank does not cause any future public health or environmental problems.
How to decommission a septic tank
Steps involved in decommissioning
- All effluent and sludge is to be removed from the tank by an approved contractor. The tank, leach drains or soak wells must be completely emptied.
- After pump out/cleanout, the tank is to be treated with Ag lime or hydrated lime to disinfect the tank. Care should be taken when using lime. It is recommended that appropriate precautionary steps be taken such as using personal protective equipment (skin protection, eye protection and respiratory protection). Only qualified persons should be employed to use chemicals.
- After treatment with lime, holes for drainage are to be provided to the bottom of the tank. The concrete lids and portion of the tank walls are to be broken to below ground level. Alternatively – the whole tank can be removed.
- The tank is to be filled with solid, clean fill with the ground surface made good. If settling of the fill material occurs over time it may be necessary to make good with further fill.
- The following must be provided to Council as evidence that decommissioning took place:
a. Receipt from the approved contractor for removal of the effluent and sludge; and
b. A statement/letter from a plumber stating that the works were conducted in accordance with these instructions.
Only licensed and approved personnel can decommission septic tanks. Refer to the Yellow Pages.
More information and contacts
For more information please contact us.