Legislatively complex and a significant barrier to development, Japanese knotweed is the highest profile Schedule 9 species in the UK. At the forefront of the industry, Ebsford are able to offer a full consultative process with the widest range of solutions, backed up by the most comprehensive warranties on the market.
Japanese knotweed herbicidal solutions
When time and circumstances allow, herbicide treatments can be a cost-effective option. The treatment programme would take place over a 3-year period with a visit during the winter to clear the previous years' stems followed by 3 herbicide visits over the course of the growing season commencing in late May/early June.
There are a number of conditions which need to be met to allow a successful herbicidal treatment of your Japanese knotweed:
- The treatment zone should be outside of the developable area of the site and should remain undisturbed for the duration of the treatment and warranty period
- The JK will need to be in good health before treatment commences
- Unrestricted access to the area will need to be possible throughout the treatment and warranty period
If these conditions can be met a herbicide programme can commence at the earliest opportunity. Each treatment site is slightly different depending on the date of commencement and a specific treatment regime is created to insure efficacy of the programme.
Japanese knotweed off-site disposal
The process of off-site removal, often referred to as ‘Dig and Dump’ involves the physical removal of the plant and soil through excavation. The excavated material is loaded into tipper lorries and transported for disposal at a local landfill which is licensed to receive this type of contamination. Not all landfills are capable of receiving Japanese knotweed – the disposal needs to be arranged well in advance along with confirmation that there are no other contaminants within the soil that would further restrict the landfill choice.
Our consultants will assess the area of JK and provide an estimate to the volume which is likely to be removed. We provide fixed costs for this type of project or we are happy to share the risk with a per load rate for removal; whichever is the preference of our client. If required, we can take our own soil samples to enable an assessment of any other contamination so that an accurate cost can be prepared.
Our site teams undertake excavation carefully and diligently, insuring all the Japanese knotweed rhizome is excavated and removed whilst also minimising the amount of material excavated to keep costs to a manageable level. All our operatives hold Asbestos Awareness qualifications and bespoke EUSR Excavation training with at least one operative on each project also holding SMSTS qualification.
On completion of the excavation works our site teams will backfill or make safe the work area as per the client requirements.
Japanese knotweed on-site translocation or burial
Depending on the size of the Japanese knotweed area it could be possible to excavate the area, relocate the resulting contaminated material to a new area on site where it can be stockpiled and treated with herbicide or buried within the confines of the site. This process allows for an immediate solution and does not preclude any other option being undertaken at a later stage.
An initial appraisal of the JK area would allow for the estimation of the likely volume of material generated through excavation to enable accurate planning of the translocation area. Once this is confirmed a detailed method statement would be prepared detailing the route and method of transporting the contaminated material from the original location to the treatment area.
Burial of JK is covered by the Environment Agency Position Statement 178 LINK There are two options which can be taken:
- Burial with 5m of clear cover without any requirement for root barrier membrane
- Burial with 2m of cover provided the contaminated material is contained within a membrane cell.
Both options need careful consideration in relation to the proposed future use of the site as the location of the burial pits will affect the options for using the surface area and the design of buildings.
Japanese knotweed screening
The alternative to undertaking the options above would be to utilise the unique Enviroscreen 20-20 technology created by Ebsford. Click here to learn more about the Ebsford Screening solution.
Knowledge base
Ebsford Environmental have a wealth of experience in managing invasive non-native species from a wide range of situations: from residential to development sites, and on a landscape level e.g. water industry. Our specialists have varying backgrounds including construction and land remediation, water, ecology, agriculture.
