BY-PRODUCT from the china clay industry is helping to reduce the environmental impact of a major road scheme in Cornwall.

The A30 Chiverton to Carland Cross upgrade is expected to be finished by winter 2023 and includes dualling of 8.7 miles of the trunk road.

Larger infrastructure projects such as this one 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. Instead, material from just up the road at the Littlejohns Pit near St Austell is being processed into sustainable secondary sand and aggregate for construction use.

Compared to the 5kg CO2e per tonne carbon emission of virgin aggregate, the locally imported material is around 2kg CO2e per tonne, says National Highways.