We were contacted by our client to carry out a survey on a former waste transfer station with areas of hazardous & controlled waste including areas of asbestos, used ammunition shells and gas canisters.
There is also an overgrown open area of land on the banks nearby covering 28 acres, which has several stands of knotweed within woodland and established reed beds.
The land was previously used as a storage facility for the petrol/chemical factory on the adjacent land.
Japanese knotweed remediation methodology
In view of the plans for the area, we had proposed two distinct options to the client. The main consideration in treating the Japanese knotweed on site is cost and the carbon footprint for the works.
Off-site disposal costs at a landfill facility incur the application of a disposal tax, which varies considerably and is dependent upon whether the material to be tipped is classified by the landfill operator as either hazardous or controlled waste.
Off-site disposal of Japanese knotweed also incurs a large carbon footprint due to the movement of large vehicles involved with both the transport of the waste and the machinery used at landfill.
The client agreed with onsite screening & incineration of Japanese knotweed, which used the following methodology.
It was essential to prevent cross site contamination and so an effective site biosecurity protocol was established and consisted of the following measures;
a) All personnel undertaking the JKW removal works and working within the works area attended the Site Task Briefing and Toolbox Talk. They also read, understood and signed the Method Statement, Risk Assessments, COSHH Assessments and JKW Management Plan before undertaking the Japanese knotweed removal and treatment works.
b) All personnel undertaking the above tasks held valid CSCS, CPCS or approved trade cards.
c) All Plant, Machinery and Tools were operated by trained personnel and were in good working order, with no defects and valid certification where applicable.
d) Appropriate signage and fencing was erected around the contaminated Japanese knotweed areas and subsequently around the stockpiled material identifying and notifying people working that there was Japanese knotweed contamination
e) Prior to screening of the Japanese knotweed contaminated materials, a protective root barrier was placed beneath stockpiles to prevent any potential for cross contamination