Commercial Japanese Knotweed Removal

Commercial knotweed excavation involves the physical excavation and removal of contaminated soils from your site. It is the preferred method where the discovery of Japanese knotweed has halted a property development or construction programme, as it allows development to resume as quickly as possible once remediation is complete.

Excavation must be carried out by a recognised and experienced specialist to ensure compliance with legislation and that contaminated soil is disposed of at a licensed landfill facility. Following successful excavation and off-site disposal, a 10-Year Insurance Backed Guarantee is provided from a leading insurer. The guarantee becomes valid once the excavation works and monitoring period have been completed on-site. Development can then proceed as normal.

During herbicide treatment, herbicides are applied to the top and underside of the knotweed leaf. The herbicide is absorbed and carried into the plant, where it takes effect and kills the plant at its base. The time taken varies depending on site-specific factors, taking effect from as little as four days up to a few months.

Repeat applications cause the plant to become stunted and reduce its capacity to photosynthesise and regenerate. Over the course of a 3-5 year treatment programme, you can expect full control over the infestation. This method also provides an Insurance Backed Guarantee, valid once the treatment programme has been completed.

Soil screening involves the excavation and removal of Japanese knotweed material from the ground. A selection of different-sized metal screens and conveyors are then used to separate the knotweed rhizome (root material) from the soil. This method allows the cleaned soil to be reused on-site, reducing disposal costs and the volume of material requiring off-site removal.

If your site has the space available we are able to excavate the infested soil and encapsulate it within a heat welded geo-textile membrane. A large burial pit is created (up to five meters deep) which is lines with a geo-textile membrane.

The clean soil is stockpiled while the infested soil is placed into the burial pit. The seams of the geo-textile membrane are heat welded to create a fully sealed “cell” with a minimum of two metres clean soil being placed on top of this cell.

Following successful excavation and on-site cell burial, our clients are provided with a 10-year Insurance Backed Guarantee, from a leading insurer, which becomes valid once we complete the cell burial works. Development and landscaping can commence within previously affected area/s, as soon as TP Knotweed Solutions have completed the cell burial works.

Where space is available on a client’s site, contaminated soil containing Japanese knotweed can be excavated from the affected area and relocated to a different part of the site to be stockpiled. The stockpiled material is then treated on-site using herbicide treatments over a period of five years to kill any existing plants. This method requires a large site and clients should contact Zirkon early in the development process so that the appropriate approach can be advised and planned.

Zirkon’s CAD Technicians create detailed site plans showing the affected areas, proposed stockpile areas, and supporting information to assist with decision-making.