IWM were approached by the client looking to develop the site for housing. Their initial plan was to excavate the site and remove the material from site to landfill. As with every project a soil analysis report is required and unfortunately the results did not make good reading for us and the client. Ultimately, the soils were contaminated to a level which made it unacceptable for the landfill to accept.
Therefore, we had to get creative!
The Japanese Knotweed material was excavated from the infested areas and stockpiled within the site and processed and removed from the sub soils by our expert team & industry colleagues
This process is much more labour intensive but is a much more sustainable option to developers as it removes the need for haulage & Landfill. Most of the sub soils excavated were re-introduced into the site which removed the need and expense for the importation of additional backfill material, which would have been needed had it been the dig & dump method. As the Infestation of Japanese Knotweed was growing by a row of properties IWM had to install a vertical root barrier along the clients boundary with the Knotweed growing by the properties treated with herbicide for several years.
The site is now ready for residential development for much needed affordable housing.