A well-known housing developer was due to commence with the build of approximately 75 brand new homes on their site based in Barrow Upon Humber, before becoming acquainted with problem species, Japanese knotweed. Historically, the land earmarked for development had been used as farmers fields from as far back as 1888, before most recently becoming an area of scrubland overrun with dense ground covering vegetation.
Over the years, Japanese knotweed has become notorious for its habit of causing serious environmental issues, negatively affecting ecosystems and damaging property. Listed on schedule 9 of the Wildlife and Countryside Act, this invasive non-native species has the ability to grow at an alarmingly fast rate and is extremely challenging to eradicate without the help of an invasive vegetation expert. Japanese knotweed is one of the key issues residential and commercial developers face and mismanagement can now become a criminal offense.
Ebsford were called in to survey the land, identifying any potential risks and advise the most effective methods of eradication, keeping in mind the clients tight development timescales. Our surveyor was greeted with seven separate knotweed stands all undisturbed, totalling almost 700m². An eighth area was identified containing raspberry canes from last season’s growth, these are commonly mistaken for dead knotweed canes.
On-site burial was chosen as being the best course of action, offering an immediate solution and no requirement for importation of material. An open space area not due for development was identified as an ideal burial area and would give the client immediate access back into the proposed development once excavations were complete.
The works began in June 2021, taking an initial scape to establish the extent of the Japanese knotweed rhizomes before excavating the area. Over 1,200m3 of material was excavated and buried in a mammoth 40x35x3m pit. This project formed the largest cell burial Ebsford had ever undertaken and was quite a challenge, however the site team were able to draw upon past experiences to complete the task swiftly and successfully despite the heatwave. Over 3,500m² of root barrier was handled in order to line the burial pit and fully encapsulate the contaminated material inside, which was then heat-sealed shut.
Whilst works were being undertaken, a member of the public contacted the Environment Agency with concerns about the infestation issue. The team took it in their stride and worked with the EA to keep them informed on the project, as ever the works were professional and in line with all relevant legislation and best practice guidance.
The project was successfully completed in just under two weeks, allowing the client to move forward with their development, with peace of mind the risks posed by the Japanese knotweed were fully mitigated.
