Case Study


St Oswald’s Park, Gloucester

Client: Herbosch-Kiere Marine Contractors Ltd

Location: Pounds Quay, Portsmouth, UK

Contract Value: £90,000

Dunton Environmental’s eradZion8, rapid Japanese Knotweed treatment technology successfully eradicates Japanese Knotweed contamination from large volumes of soil stockpiles within 4 weeks.

This reduced the client’s overall cost risk by 70%.



  • During the redevelopment of a former industrial site for new residential housing, several stands of Japanese Knotweed were inadvertently spread across the site and later excavated and placed in a stockpile on site by the Client.
  • Given the presence of Japanese Knotweed rhizomes within these soil stockpiles, the cost for the disposal off site to landfill would have exceeded £200,000.00.
  • In addition the Client needed fill material to raise the site levels. The challenge therefore was to provide a solution which could rapidly remove any Japanese Knotweed contamination from the 6,000 tons of site soils to enable these soils to be reused safely on site as general fill. The Client’s site and therefore an in-situ eradication programme was required for those stands.

Building around 14,500 beautifully-designed new homes a year in more than 400 prime locations nationwide, Persimmon is proud to be the one of the UK’s most successful house builders, committed to the highest standards of design, construction and service.

Our Solution –

  • Dunton Environmental safely relocated 6,000 tons of Japanese Knotweed contaminated soils to a treatment area on site.
  • Dunton deployed their specialist eradZion8 rapid treatment solution into the site soils and within 4 weeks released treated knotweed free soils, which the Client could safely reuse these soils on site as backfill.
st oswalds

“Dunton are specialists in the remediation sector and have successfully delivered innovative solutions to overcome remediation challenges on a number of our developments past and present.”

Alex Vicary MRICS
Associate Director – Technical
Crest Strategic Projects