Image above: Paris, France - Governments and companies around the world are taking steps to advance circular economy development. France adopted a comprehensive anti-waste Law in 2020 (Loi relative à la lutte contre le gaspillage et à l’économie circulaire). The law encourages businesses across various sectors, municipalities, and citizens to eliminate waste and adopt more circular economy practices.
When we first spoke about advancing sustainable infrastructure at the beginning of 2023, you emphasized the need to reuse, adapt and recycle when planning and designing infrastructure to achieve net zero. How can these principles of the circular economy be applied to the built environment?
Eric Peissel: There are many ways to apply circular economy principles to the infrastructure and systems we all depend on. The COVID-19 pandemic highlighted the importance of reusing and adapting the urban realm, rather than building from scratch; as remote work took hold and online purchases increased, our cities needed to respond.
As decision-makers consider infrastructure needs in a sustainability context, adapting infrastructure is essential to reduce material use. Modern methods of construction, including modular construction, when compared to conventional methods reduces waste and results in lower environmental impacts, in addition to enabling better productivity, faster construction times and higher-quality results. Studies have shown that adopting a modular construction approach can produce about 45 percent less carbon dioxide emissions than traditional construction methods.1 On top of that, such structures tend to be more flexible into the future—they can be reused, which results in less need for raw materials.
The principle of reuse can also be understood in the context of transport infrastructure. For example, for the construction phase of Highland Spring Group’s new Blackford Rail Freight Facility in the United Kingdom, WSP’s design specified second-hand concrete sleepers2—the reuse of 1,358 serviceable concrete railway sleepers equivalent to 180m3 of concrete.
Furthermore, WSP is applying these principles to modularize and standardize the design of airport piers. We have recently delivered the tender information for eight fixed links and nodes for the new pier at Terminal 2 of Manchester Airport where thousands of components expected to come to site have been replaced by a hundred larger subassemblies created around a reusable kit of parts.
With the shift to electric vehicles, the issue of battery waste raises environmental concerns. The European Parliament recently adopted an update of the European Union’s battery directive to ensure that batteries can be repurposed, remanufactured or recycled at the end of their life.3 WSP is currently working on numerous EV-battery-related projects around the world. These include both recycling facilities and manufacturing facilities to support the need for recycling an increasing number of end-of-life cells as well as manufacturing scrap.
Often, we do not think of infrastructure as something that can be reused or repurposed, but both are ways to significantly reduce carbon footprints. For example, instead of rebuilding a bridge, rehabilitating it to extend its overall lifecycle can yield huge environmental dividends. WSP’s bridge teams inspect thousands of bridges every year and develop asset management plans using digital tools; they collect and manage data that can be used to effectively plan targeted rehabilitation programs and apply machine learning to the data to more reliably predict capacity and useful life of structures. Emerging technologies, such as carbon fibre applications to repair or strengthen bridges, are being used regularly to help maximize the life of these assets.
Of course, keeping an asset in use at high value as long as possible must be coupled with increased energy efficiency and use of renewable sources to power the infrastructure we retain and ensure that they remain resilient.
What measures are supporting sustainability choices in infrastructure projects?
Eric Peissel: Increasingly, infrastructure projects are integrating targets to reduce embodied carbon, which is giving rise to more sustainable material choices, use and reuse. Lifecycle assessments are enabling better understanding of environmental impacts, leading to more-informed material choices toward reducing embodied carbon from the design stage through construction. The City Rail Link project4 underway in Auckland, which is the largest infrastructure project in New Zealand, has achieved an IS [Infrastructure Sustainability]5 leading rating for design; the project includes a 16-percent reduction in embodied carbon, a 22-percent reduction in energy CO2 emissions, reduced waste to landfill, and reduced construction and operational water use throughout the project’s lifecycle. These reductions are baselined against tender-design quantities.
The Turcot Interchange redevelopment project in Montreal was the first project of its kind in Canada to achieve carbon neutrality, by reusing more than 90 percent of the concrete from the old interchange, planting 9,000 trees, 61,000 shrubs, all to create a much greener piece of infrastructure that is better integrated into its urban context.