Where a Wastewater Treatment Plant (WWTP) is to be decommissioned, appropriate actions must be undertaken to ensure that environmental harm on-site or off-site is avoided during and after the decommissioning phase. Land uses allowable under the relevant zoning of the land must not be prejudiced by residual pollutants on the land.
For Level 2 WWTPs as defined in the Environmental Management and Pollution Control Act 1994 (EMPCA), environmental conditions of the Land Use Permit or Environment Protection Notice usually require a Decommissioning and Rehabilitation
Plan (DRP) to be submitted to the Director, Environment Protection Authority prior to decommissioning of the WWTP. The Guidelines – Decommissioning of Wastewater Treatment Plants Nov 2010 provide information to assist with the preparation of a DRP.
Where a WWTP is not classified as a Level 2 plant under EMPCA, the responsible council should be consulted about requirements under the relevant planning scheme. In this case, the above guidelines can be used as a reference document.
Wastewater treatment storages classified as ‘dams’ under the Water Management Act 1999 may require a permit from the Assessment Committee for Dam Construction
prior to decommissioning or for alterations to the storage. Further information can be obtained from the Water Management Branch, Department of Primary Industries, Parks, Water and Environment.