Cornwall’s very own china clay mining industry is playing a big part in the construction of National Highways’ major A30 Chiverton to Carland Cross upgrade.

Sustainability and reducing the carbon footprint are reportedly key drivers behind construction of the 8.7-mile dualling scheme and, to that end, contractors Costain Jacobs and supply chain Aggregate Industries are tapping into natural Cornish materials and a significant investment in local companies.

Larger infrastructure projects typically use millions of tonnes of aggregate – representing a large carbon footprint – but as with other modern-day road building schemes, the A30 project is utilising a by-product from the china clay mining industry.

The residue, known as stent, would normally have no use and be left in white spoil heaps, scarring the local landscape.

Instead, the material from the Littlejohns Pit near St Austell is being processed into sustainable secondary sand and aggregate for construction use.

And just down the road, this is now being used as an engineering alternative across the A30 project, not only reducing the embodied carbon but also saving on the transport carbon cost.

Compared to the 5kg CO2e per tonne carbon emission of virgin aggregate, the locally imported material is around 2kg CO2e per tonne, representing a reduction of around 3kg CO2e per tonne of aggregate used.

Roads Minister Baroness Vere said: "The A30 Chiverton to Carland Cross upgrade will reduce congestion, improve journey times and provide much-needed connection for local businesses.

Falmouth Packet: Stent would normally have no use and be left in white spoil heaps, scarring the local landscape. Stent would normally have no use and be left in white spoil heaps, scarring the local landscape.

"By using natural Cornish materials, we are also ensuring the scheme has a much lower carbon impact and provides a further boost to the local community, which is exactly the kind of innovation we want to see as we strive towards a net zero road network."

Nick Simmonds-Screech, National Highways Project Director for the A30 scheme, added: "We’re already really proud of our environmental and ecological work – we’re forecasting a net biodiversity gain in the region of 20% – and this greener way of working also spreads to our construction methods and material supply.

"We all have a part to play in reducing our carbon footprint and adapting to climate change, and modern road building methods are certainly playing a part in this.

"The move towards warm mix asphalts allows us to not only achieve huge efficiency savings but also reduce carbon as we strive for net zero by 2040.

"Carbon reduction, along with ensuring our roads provide smooth, safe, and efficient journeys for motorists, are key and something we are constantly striving to improve for generations to come."

The cost of developing the scheme is being partly funded by an £8 million contribution from the European Regional Development Fund, with an additional £12 million for the construction phase.

The remainder of the cost of developing and delivering the scheme is being funded by central Government.