Our brief was to move two large stands of Japanese knotweed and contaminated soil to stockpiling locations outside the construction footprint, prior to construction works starting.
What we did
We began by clearing scrub and trees within the contaminated areas, being careful not to spread any fragments of Japanese knotweed.
We installed Heras fencing, signage and foot washing stations which would act as bio-security measures for anyone entering or leaving the site.
We excavated the Japanese knotweed into stockpiles using two 30 tonne 360° excavators. This was done under the supervision of a Japanese knotweed clerk of works, who ensured that excavations continued to a point where rhizome fragments were no longer visible.
Two 25t articulated dumper trucks hauled over 12,000 tonnes of the contaminated material to designated stockpiling locations, outside the construction footprint.
Contaminated material was stockpiled onto membrane which prevented it contaminating the ground underneath. The stockpiles were fenced off in order to ensure that contaminated material could not be reached and spread around the site.
The Japanese knotweed in the stockpiles was then allowed to grow and the Japanese knotweed was subject to a spray regime.
The Japanese knotweed areas were successfully moved and stockpiled outside of the construction footprint.