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Eastern Selwyn Sewerage Scheme

Cost saving design solutions cater to a growing population

  • 70%

    Sludge Conversion

  • Selwyn, New Zealand

    Selwyn, New Zealand

This municipal waste biosolids drying facility in New Zealand is helping to alleviate the wastewater demands of three communities

The towns of Prebbleton, Lincoln, and Rolleston in Selwyn, on New Zealand’s south island, had commissioned the Eastern Selwyn Sewerage Scheme (ESSS) to help them cope with a continuing increase in population. Our team was brought in to develop the ESSS to convey and treat wastewater flows for the projected population. However, after the devastating Canterbury earthquakes in 2010 and 2011 resulted in more population spikes (as people moved away from the affected areas), we also needed to fast-track the project.

To overcome the large operating cost in handling and disposing of sludge, our team developed its most innovative feature yet—the design of solar, air-drying halls to manage sludge biosolids. As the first municipal waste biosolids drying facility of this scale in New Zealand, the redesigned plant now converts sludge to 70% dry solids using a natural process. Disposal of sludge is far less frequent than before, and alongside treatment efficiencies, that means significant ongoing cost savings.

Not only did our team keep the existing system operational while the expansion took place, but by reusing existing infrastructure, costs were kept low which avoided burdening ratepayers and ensured that past investments were not put to waste. Now, these communities can rest easy knowing that even as the population grows, their wastewater system can rise to the challenge.

At a Glance

Water New Zealand Project Award, 2016
Water New Zealand Ronald Hicks Memorial Award, 2015
Institute of Public Works Engineering Australasia, NZ Division, 2014
Meet Our Team

Janan Dunning, Group Leader, Planning

There are many moving parts to much of what we do as planners, and I enjoy the unpredictability of each day.

Shane Bishop, Principal Water Engineer

My contribution has a direct bearing on the direction of a community, providing the building blocks that set our clients up for success.

Simon Todd, Senior Mechanical Engineer/Project Manager

The work I do has a material benefit for the communities we live in and provides secure sources of clean drinking water.
Simon Todd Senior Mechanical Engineer/Project Manager Read More

Rico Parkinson, Canterbury Regional Delivery Lead, Water

I love that my water industry skills and knowledge are universal, allowing me to provide help around the world.
Rico Parkinson Canterbury Regional Delivery Lead, Water Read More

Chris Baddock, Electrical Discipline Leader

With innovative engineering, we can upgrade our water infrastructure to turn waste into resources and achieve better outcomes for everyone.
Chris Baddock Electrical Discipline Leader Read More

Janan Dunning

Group Leader, Planning

Shane Bishop

Principal Water Engineer

Simon Todd

Senior Mechanical Engineer/Project Manager

Rico Parkinson

Canterbury Regional Delivery Lead, Water

Chris Baddock

Electrical Discipline Leader

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