Case Study - Dungannon Castle, Northern Ireland

Japanese Knotweed Solutions were called to survey a site of Historical Interest in Dungannon, Northern Ireland. The boundary of our client's land was the historic castle wall which was in desperate need of repair. Our surveyors provided a full breakdown of works to ensure that firstly, the Japanese Knotweed on site was not spread whilst the wall was being rebuilt and secondly to eradicate the knotweed to prevent further problems.

The programme of works began with an in situ chemical treatment to the Japanese knotweed. The most viable parts of the plant which included the crown material and tap root were then separated and located in a securely fenced off area within the site confines. Here, these parts of material were drilled, injected with chemical and then plugged to ensure the chemical had effect.  The whole area was blanket sprayed with chemical prior to the rebuilding works.

A clerk of works was appointed and a clean site policy drawn up to ensure that there was no cross contamination and further spread of the weed.  The wall was dismantled, stones cleaned up and then re-used, rebuilding the wall to it's original glory. A vertical barrier was installed between the wall and the sheet piles which had been installed to prevent any future infestation from disturbing the wall and a surface barrier was installed on the lower tier - again to prevent any new growth emerging.  Top soil and turf was imported and a garden was formed making the area fit for use by local residents. The top area of site was re-graded and sprayed and will be monitored and sprayed again during the summer of 2009.

The material that was separated out was further divided down using a sifting method. The rhizome was taken to landfill and other material retained on site to be monitored. 

These works were highly complicated and labour intensive. Time was not an issue on this site - the priority was to rebuild the wall whilst retaining it's historical status and deal with the problem of Japanese Knotweed. This was achieved and significant savings were made for our client by using this method.