Parts of the Nannup Townsite are now connected to the sewer. There is a requirement to connect to the sewerage system within a specified time in accordance with Water Corporation policy.

After a premises is connected to the Sewer, the existing septic tank system becomes redundant and there are legal requirements to decommission your septic tank effluent disposal system.

When are you required to decommission your septic tank?

• If a property is sold, the new owner has a legal obligation under the Health (Treatment of Sewage and Disposal of Effluent and Liquid Waste) Regulations 1974, to decommission the system within 60 days after settlement.
• If building extensions encroach on minimum clearances from the system.
• If the permitted use of the development changes eg. from a residence to a commercial use.

Please note there is no legal obligation to have the disused system decommissioned at the time of sewer connection unless one of the above situations exists. However, consideration should be given to decommissioning septic systems at the earliest possible opportunity as the effluent drainage receptacles may become unstable over time, which may also cause the structures to collapse.

What does decommissioning involve?

1. The pump out/emptying of all septic tanks, soakwells, leach drains or other on-site disposal systems (registered liquid waste contractor only to be used).
2. The removal of the tanks or if impractical, the breaking up of the base of the tank.
3. The backfilling of all tanks, soakwells and leach drains with clean fill.

Important

As the original system may have been extended by the addition of extra soakwells or leach drains, it is important to ensure that the whole of the system is located.