Beyond recycling: redefining circularity in water infrastructure

As water organisations apply circular economy principles in infrastructure, a leading waste recovery and circular economy expert recommends shifting focus from traditional recycling to a comprehensive approach to resource recovery and to think of waste as a resource.

Prioritising reuse, remanufacturing and redesign in infrastructure not only cuts landfill waste but also maximises resource efficiency across water and construction projects.

WSP Waste Management & Circular Economy Director Maree Marshall emphasises that truly leveraging circular economy principles in water sector projects requires going far beyond including recycled content alone.

"Being immersed in the fields of waste and circular economy, it's always interesting to apply circular economy thinking across various sectors – not just in property, but also in water, which is a great example," she said.

"When we’re building water infrastructure, we should consider items that can be reused, refurbished or remanufactured, not just recycled.

“This circular economy approach is as applicable in water as it is in building infrastructure. Retaining infrastructure with high embedded carbon, like concrete structures, is crucial for sustainability."

Marshall said to be truly circular, water sector infrastructure should be designed for flexibility, adaptability and not just recyclability or inclusion of recycled content.

"A crucial piece of advice: circular economy is not just about recycling,” she said.

“There’s a common theme within project briefs that the inclusion of recycled material covers the circular economy, but recycling is just one ‘R’. We advise clients to seek help with specifications to ensure a complete circular approach.

"We don’t just operate on the classic three R’s: reduce, reuse, recycle. We use what we call the 10 R’s. It’s no longer just about recycling but includes things like refusing, rethinking, and remanufacturing.

"For example, water filters don’t have to be discarded after use. The supplier can take them back, refurbish them and return them for reuse. This circular approach extends well beyond recycling to avoid waste altogether."

The 10 R’s

Considering the material demands of water infrastructure with the 10 R’s in mind reaches for a more sophisticated approach to actually realising circular economy within any project, Marshall said.

"The 10 R’s start with refuse and rethink, which are about designing out waste and increasing flexibility. Then there's reducing material usage by using lighter materials, like polystyrene for voids, similar to what’s done in building infrastructure,” she said.

"We also have reuse, which is evident in construction backfill – crushed rock and aggregate are reused in waterworks infrastructure. Another example is recycled asphalt, which can be used on-site for sealing areas after construction."

Marshall said there are a few R’s that are considered less often in infrastructure builds, but that add huge value when considered and implemented.

"The next R’s are repair and refurbish, which involve maintaining existing infrastructure instead of replacing it. This is common with pipe linings in old pipework, where we refurbish rather than replace,” she said.

“Remanufacturing means taking a component, repairing it, and reintroducing it to service with possibly a new purpose.

"Repurpose is also crucial. Shipping containers are a great example – they’ve been repurposed from storage facilities to workshops, cafes and even apartments. And, right at the bottom, we have recycle, which should be one of the last steps in the chain.”

Before recycling, all other opportunities should be exhausted, Marshall said.

"Finally, recover is about retrieving any remaining value from a material at the end of its life, whether organic or non-recyclable materials. The last step, of course, is disposal to landfill, which we aim to avoid,” she said.

Documenting details

Another key element to progressing circular economy principles and creating truly circular outcomes is to get very serious about documenting, tracking and mapping all of the aspects of applying the 10 R’s within infrastructure and construction projects.

"Documentation is key to making circular practices mainstream. AustRoads, for instance, created standards for recycled content in roads by documenting potential materials for infrastructure. This led to easier implementation of design standards,” Marshall said.

"Creating a ‘circularity score’ could also help measure how much waste we’ve avoided through design. It’s challenging to measure, but as we document more, it will get easier to apply these principles on a larger scale."

As an example, Marshall discussed the recent WSP office fit-out, highlighting some of the incredible gains that were documented effectively, thereby increasing likelihood and ease of utilising the process again in future builds.

"Our recent Sydney office fit-out shows circular economy principles in action. On a $14 million project, we saved $1 million, reduced landfill by 75 tonnes, cut upfront carbon by 200,000 kg, and saved around 630,000 litres of water,” Marshall said.

"We tracked every component. We converted standard desk to sit-stand desks by replacing the legs, we reused roller blinds, repaired chairs with new fabric, repurposed partitions and glazing and recycled the acoustic insulation into the new kitchen benchtop. These efforts have been so successful that it’s now the standard for refurbishing every WSP office globally."

Flexibility and modularity

Importantly, Marshall said it also starts with design – starting all new projects with flexibility and modularity in mind will encourage a circular approach to future works.

"We need to design for flexibility and modularity so that infrastructure can be reused or adapted instead of being discarded. Examples include using modular components that can be updated without tearing down entire structures,” she said.

"This thinking is especially relevant now, as Australia invests heavily in infrastructure to support growing populations in our cities. The water sector, in particular, can greatly benefit from incorporating circular economy principles and documenting best practices so they can be applied widely.

"If we can minimise the materials that need recycling, we’re already winning. Don’t demolish it if you don’t have to. Avoiding waste from the start is key."