When it's needed
A tank usually needs decommissioning when a property connects to sewer, or when an old system is replaced with a new one.
What's involved
Typically the tank is pumped out by a licensed liquid waste provider, then made safe (for example removed, or filled) so it can't collapse or hold water. The exact method should follow council requirements.
Approvals and licences
Toowoomba Regional Council covers decommissioning in its on-site sewerage information, and the work generally needs a licensed plumber. Check with council before work starts. See council approvals.
Related
Sources: Toowoomba Regional Council – On-site sewerage facilities · QBCC – Home Owners Guide to Plumbing Matters. General guidance only; check with council or a licensed provider for your property.