Common SBR Designs for Reduced Project Delivery and Procurement Costs

Grampians Wimmera Mallee Water Corporation own and operate 26 Water Reclamation Plants (WRPs) in the state of Victoria, Australia. St Arnaud and Warracknabeal WRPs are two such sites which were identified as having business cases for renewal in 2009. The triggers for renewal were the age of the WRPs, ongoing maintenance issues, and growing uncertainty about reuse scheme availability. In 2010 AWT Water developed a preliminary and then detailed design to upgrade the two sites with a common sequencing batch reactor (SBR) design.

Because there are a number of similarities between the two catchments, and they are located approximately 100 km apart, a common design approach was selected. This article provides a summary of the design process for the two SBRs, and highlights the benefits and pitfalls of developing a common design for different WRPs.

The key benefits identified included:

• Lower design fees;
• Better equipment purchasing power;
• Reduced construction costs;
• Improved learning from design and construction changes;
• Simplified operation; and
• Performance benchmarking.

However it is important that sites are carefully assessed for commonality. This project highlighted the need to carry out detailed assessments of influent characterisation data, and network flow conditions, as these play a major role in selecting common designs.