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How well do civil engineers reduce, reuse and recycle?

05 June 2023

This World Environment Day, Chartered Environmentalist Catherine Topliss reflects on the three Rs, the cornerstone of a sustainability professional’s work.

How well do civil engineers reduce, reuse and recycle?
Most materials we come across in construction can be reused. Image credit: Shutterstock

Most people will have come across discussion of the importance of the three Rs in education: Reading, wRiting and aRithmetic. The foundation blocks of learning.

As a sustainability professional, however, the three Rs have taken on a different meaning: reduce, reuse, recycle.

And they’re implicitly taken to be an integral consideration for all projects.

Consequently, the recent news article of plastic crisp and sweet packets from the 1960s being found on a Norfolk beach, not surprisingly, caught my eye.

My thoughts went to the knowledge that our reliance on plastic has increased substantially since the 1960s, alongside our reliance on landfills.

(I’ll just note that I wasn’t born in the 1960s but have dug trial pits through many a landfill of varying age, when undertaking ground investigations, several decades later!)

This led me to reflect on how far we’ve come on the sustainability journey since I joined the engineering profession, and a few years later became a Chartered Environmentalist (CEnv) when the qualification was introduced in the mid 2000s.

What progress has civil engineering made on reducing, reusing and recycling?

Reduction (through design)

Working in a civil and structural engineering consultancy, reducing our use of material by appropriate design has always been a fundamental principle.

Many will probably point to this being for economic reasons and that often-used term ‘value engineering’.

However, now being invited to meetings to discuss how we can assist our clients with improving their sustainability, means being able to have the conversation about better and more detailed design beyond purely financial benefit.

Design, alongside other factors, such as understanding and apportioning of risk, is often now being considered to reduce material and resource use over the lifetime of a development.

Naturally, this often brings economic benefit, so we can sell a ‘win-win’ scenario.

Reuse (of soils)

Redeveloping brownfield land and reducing our reliance on developing greenfield sites has been a key strategy throughout my career, as principally a ground engineer.

This has led to ground engineers playing a pivotal role in establishing the appropriate reuse of soil to create chemically and geotechnically suitable development platforms.

These brownfield sites often include former landfills, and, being based in Yorkshire, colliery sites.

Post-completion of projects, we’ve been asked to reflect on the sustainability aspect of some of these projects, which have been going on for many years.

This made me realise that the sustainability of these, which was something that we as the designers saw as a fundamental part of the strategy, was now coming to the attention of people in the developer’s organisation(s).

They were now seeing the sustainability of reuse of soils as a good thing in its own right.

It’s not often that we feel like we’re ahead of the game!

Some stumbling blocks

Just when we thought we were getting there, something came along to keep us on our toes.

Ground engineers have often embraced the Definition of Waste: Code of Practice (DoW CoP) to ensure the appropriate reuse of soils, as opposed to these soils being classified as waste.

The consequence of this classification would have meant taking the soils to landfill.

A couple of stumbling blocks in applying the DoW CoP have led to much healthy discussion in the ground engineering industry over the past year.

These are each significant discussion points in their own right and moving at pace, so I won’t focus on them now.

However, I’ll briefly mention two.

  1. The first is not being able to reuse stockpiled material, if production of a Materials Management Plan didn't predate the stockpiling.

    The Materials Management Plan sets out how the proposals are in accordance with the four main principles of reusing of material as non-waste.

    Stockpiled soil will often be clean topsoil and subsoil on greenfield sites, so not materials we’d wish to see going to landfill.

  2. The second is the inability to reuse colliery spoil under the current system.

    The discussions are focused on the hope that a way through is found, which continues to use a system where the sustainability of reuse of soils is not compromised.

Recycling (of waste for other uses)

Most materials we come across in construction (such as soil, concrete and bricks) can be reused.

However, a material which we often associate with recycling is plastic, something we haven’t tended to make much use of in construction to date.

The scope for the reuse of plastic, and hopefully therefore recycled plastic, is consequently possibly one which could have merit.

In the past week, I noted a contact’s social post on a 100% recycled plastic crib retaining wall.

However, our efforts don’t need to be confined to the work we produce.

For example, we had crisp and confectionary packet collection bins in our office, which were sent to make recycled plastic products, such as park benches.

This stopped during Covid, but writing this has reminded me to make sure it’s reinstated.

I recall being surprised by how many packets an office of 100 people generated!

Finally, living in Sheffield, we get to consider the benefits of a different solution for our waste, the Energy Recovery Facility, which you pass as you reach the city centre from the M1 to the east.

This takes household waste via the roadside wheelie bins and uses it in a modern incinerator to generate electricity for the National Grid, and heat for the city’s District Energy Network.

Working in design teams on schemes in the city, I’ve always been pleased to see consideration given to connecting into, or extension of, the existing system, which heats buildings including some of the city’s hospitals and universities.

Sustainability is becoming the norm

In summary, the reduce, reuse, recycle hierarchy has been the cornerstone for sustainability professionals for some time.

It’s great to see the successful use of this becoming adopted more widely, and hopefully extended.

Recent news articles that caught my eye included ones about the pitfalls of recycling plastics.

Therefore, focusing on reducing and reusing, as we currently tend to do in construction, seems the priority for now!

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  • Catherine Topliss, director at Eastwood Consulting Engineers