Exceeding energy requirements
The project exceeded the IS Rating requirements for Energy & Carbon Monitoring and Reduction & Use of Renewable Energy.
The Base Case footprint for energy and carbon reporting was calculated using a novel approach based upon the Water Services Association of Australia Wastewater Treatment Plant Energy Benchmarking Report. The project has achieved a 43% reduction in energy use against the established base case.
On-site renewable energy use is a core objective of the Lower South Creek Treatment Strategy, with the consolidated solids processing at St Marys implemented to allow for anaerobic digestion and energy recovery through a co-generation plant. With on-site thermal energy recovery and electricity generation the project is able to self-supply 67% of its electricity demand, which greatly exceeds IS benchmark requirement.
A first for the wastewater treatment industry
New process technologies have been installed to support the project’s sustainability outcomes. This resulted in the project receiving the maximum of 10 innovation points.
Mechanical Primary Sedimentation (MPS) Screens were installed at both WRPs, MPS screens are an emerging technology to replace conventional Primary Sedimentation Tanks. The MPS delivers reduced power consumption and greenhouse gas emissions due to reduced aeration requirements in the bioreactor. MPS also enables pre-sedimentation to take place in a much smaller footprint, using few materials, and odour control is more efficient, and the process is cost effective. Solids harvested in the MPS are anaerobically digested producing biogas that further enhances energy recovery. This technology is an Australian first for the wastewater treatment industry.
The Nereda Aerobic Granulated Sludge (AGS) process is a fully automated process relying on smart controllers and sophisticated instrumentation. There are no clarifiers required for the AGS process (treated effluent is decanted after a very short settling period) and therefore substantially less concrete used in construction, the foot-print is much smaller and the construction costs are substantially lower. The AGS process also uses approx. 25% to 30% less energy and a conventional membrane type bioreactor, delivering significant greenhouse gas reduction for the project. This is the first project where the AGS process has been used in NSW.
Using non-potable water
Recycled effluent was demonstrated to provide 99% of water demand for non-potable water demands over the life of the project.