Redcliffe Sewage Treatment Plant Rehabilitation Works


The rehabilitation works aim to:

  • renew assets to ensure the STP has the capacity, serviceability and performance to meet the needs of the Redcliffe Peninsula communities

  • ensure the STP operation allows us to continue to meet our environmental obligations 

  • maintain treatment capacity equivalent to a community of 70,000 people until at least 2030.

In conjunction with these aims of the rehabilitation works, Unitywater has a major focus on reducing the odour emissions associated with the STP.

While TRILITY Pty Ltd will operate and maintain the STP, Unitywater remains the holder of the Environmental Licence.



Original sewage treatment plant at Redcliffe constructed


Most recent upgrade carried out by Redcliffe City Council as part of a design, build and operate contract which used a contractor to construct the upgrade with the intention to then operate the STP until 2016

2000 – 2012

STP operated by contractor engaged by the former Redcliffe City Council

June 2012

Unitywater commences operating the plant and begins replacing and refurbishing elements of the plant to ensure the long-term reliability of equipment

September 2012

Unitywater submits a draft Transitional Environmental Program to the Department of Environment and Heritage Protection documenting the actions being completed on site and committing to undertake detailed odour monitoring and assessment as well as developing an upgrade strategy to ensure long-term compliance

January 2013

Department of Environment and Heritage Protection approves the Transitional Environmental Program

February 2013

Unitywater begins a program of works to clean and refurbish major process units including the primary clarifiers and bioreactors

March 2013

Comprehensive odour sampling is carried out at the STP to be used as the basis for odour dispersion modelling and determining the odour control infrastructure required as part of the rehabilitation works

June 2013

Unitywater engages with the community on the rehabilitation works

December 2013

Unitywater Board approves the rehabilitation project. Unitywater holds industry briefing session to highlight the project expectations

April 2014

Prequalified tenderers selected

November 2014

Tenders received

January 2015

Redcliffe STP rehabilitation contract awarded to TRILITY Pty Ltd

November 2015

TRILITY Pty Ltd begins construction works on site


 257 Duffield Road, Clontarf


 January 2015


 Late 2020




 Estimated $28.6 million in capital works



Redcliffe STP timeline

Jan 2015
Contract awarded to TRILITY 
Nov 2015
Commenced construction and rehabilitation works
Mid 2018
Construction of odour control facility to be complete
Late 2018
Inlet works to be commissioned
Late 2018
Aerobic digester to be commissioned
Late 2018
Odour control facility to be fully commissioned and operational
Late 2018
All new facilities to be complete and operational
2018 - 2020
Ongoing refurbishment of existing concrete structures