St. Erth Multi Modal Hub

Through collaboration with contaminated land specialists, our team were able to produce a revised Contaminated Land Remediation Strategy which was agreed with the Environment Agency and Local Planning Authority. Our solution involved the bio-remediation of contaminated soils to bring them within the limits for classification as non-hazardous waste. This in turn allowed for materials to be disposed of locally at a land recovery site 10 miles from the project. This represented a significant reduction in transport emissions in addition to strong commercial benefits.

Our team identified the potential to combine the extensive excavation operation to remediate the 120 m long adit (a tunnel used to drain mine shafts) with the requirement to deal with surplus Japanese Knotweed contaminated soils. The process of lime improvement involving mixing lime into the soils to improve their load bearing characteristics - was identified as a potential solution to the issue. This highly innovative solution involved creating an on-site containment cell into which the contaminated material was placed. The spread of the Japanese Knotweed was prevented by installing a secure membrane around the cell.

The solutions delivered drew upon a variety of expertise across environmental, geotechnical and mining remediation disciplines. The methodology applied was the first time in the UK this combination of methods was used to treat and manage contaminated materials on-site.