Raising the Bar for Sustainable Water Infrastructure

Congratulations to Sydney Water’s Lower South Creek Treatment Program team, who were awarded an Infrastructure Sustainability Design ‘Excellent’ rating – one of the highest ratings ever achieved for an Australian water infrastructure project from the Infrastructure Sustainability Council of Australia (ISCA).

The program provides new and upgraded wastewater infrastructure to support Sydney’s North-West communities, accommodating an additional half a million people by 2040. It includes a $450m upgrade of facilities at St Marys and Quakers Hill which will see the adoption of new innovative technologies that will make water treatment more sustainable, cost efficient and effective for future generations.


The Lower South Creek Delivery Partner, consisting of WSP and UGL, used the Infrastructure Sustainability (IS) tool to benchmark the project’s sustainability performance without incurring additional capital costs. This provided insights into how Sydney Water’s policies and procedures align with IS Rating best practice, facilitated independent third-party assurance of sustainability outcomes in project delivery and has raised the bar in benchmarking future programs.


Gill Fowler, Lead Environmental Scientist at Sydney Water said, “Embarking on the IS journey provided greater incentive and opportunity to challenge current process thinking and explore new ways of operating. This helped drive sustainability benefits, reduced energy demand and our carbon footprint.


“Sydney Water has committed to obtaining a sustainability benchmarks for all its major infrastructure projects.”


Energy and carbon forecast modelling estimate the program will achieve a reduction of 870,000 tonnes or a 42 per cent reduction of total Greenhouse Gas emissions during construction and across its 50 years’ operation. This reduction includes embodied CO2 emissions from construction materials and treatment chemicals. The team used a novel approach to forecasting and benchmarking energy and carbon under the IS Rating tool. This involved comparison against robust energy benchmark data published by the Water Services Association of Australia (WSAA) from 245 Waste Water Treatment Plants (WWTP) across Australia and New Zealand.


Onsite 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 can self-supply 69 per cent of its electricity demand.


The program deployed many innovative processes and technologies delivering industry-leading sustainability benefits which resulted in a full 10/10 score for innovation. Two of these innovation points were awarded for exceeding energy and carbon reduction, and renewable energy supply benchmarks. In Australian-firsts, the program achieved the transfer of sludge for consolidated biosolids processing and installation of mechanical primary sedimentation screens. Other innovations included anaerobic digestion with Thermal Hydrolysis Pre-treatment (THP) at St Marys and the secondary treatment process was modified to a Nereda Aerobic Granulated Sludge bioreactor, after a successful pilot trial, at the Quakers Hill Plant.


Anthony Korbel, Program Director and Major Projects Executive at WSP said, “ISCA certification of the Lower South Creek Treatment Program is a further step by the infrastructure industry and in particular Sydney Water in recognising the importance of sustainability in the delivery of large capital programs. It’s been both an interesting and rewarding process for the (WSP/UGL) team and I’m delighted to see such a fantastic result in delivering outcomes for our communities to thrive.”


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