Soil Treatment Success Story

Our new soil treatment unit, which launched last year, has been out on site in South Wales to treat invasive plant-infested soils with impressive results.

We were asked by Morgan Sindall Infrastructure to treat Japanese Knotweed contaminated soils on a landscaping bund at a Welsh Water Treatment Works site in Trebanos. Morgan Sindall Infrastructure is delivering a wider scheme to deliver new, critical wastewater treatment infrastructure and this formed part of the works.

With South Wales having a high prevalence of Japanese Knotweed, a hugely invasive species, the need for effective, chemical-free treatment, particularly at sensitive sites such as this is of great importance.

The alternative would be to send this contaminated soil to landfill which is both bad for the environment and costly.

Our soil treatment unit was deployed to site to process materials, enabling the treated soil to be re-used on site, reducing the project’s environmental impact.

Scope of Works

In total, we treated over 1,700m³ of Japanese Knotweed-infested soil with our thermal soil treatment technology which uses controlled, high-temperature steam to neutralise invasive plant materials within soils.

The work was carried on site with full monitoring and compliance with invasive species and waste regulations. Our soil treatment unit is fully mobile, allowing us to take it directly to site where treated soils can be reused within the project footprint.

Results

Our soil treatment technology is highly effective. Following robust testing, it was shown to have eliminated viable knotweed rhizomes from the soil, enabling it to be reused rather than being sent to landfill. This also removed the need for vehicle movements associated with its removal, reducing carbon emissions in the process.

Environmental Impact

Our work on the Welsh Water Treatment Works site resulted in significant diversion from landfill, sustainable on-site soil reuse and improved biodiversity through the removal of invasive species.

The project created a total estimated carbon saving of 55-60 tonnes CO₂e. This approach has contributed to both Morgan Sindall Infrastructure and Welsh Water’s environmental and carbon reduction objectives.

Next Steps

If you have a need for either soil testing or full remediation works and would like to find out more about our soil treatment solutions please call us on 01792 795 829 or email enquiries@griffiths-group.co.uk