Excavation & Disposal
If Japanese knotweed cannot be dealt with effectively on site, it must be disposed of at a suitably licensed waste management site.
Disposal to landfill should be considered a last resort due to the expensive nature of disposal. Great care is required to ensure that no material is lost when the excavated material is being transported (a licence to transport the material must be granted by NPWS).
The material must be disposed at licensed waste facility where:
the facility have been informed in advance of the nature of the waste material;
the facility is licensed to accept this material; and
the facility is prepared to accept the material.
At least two weeks prior to excavation, the IAPS shall be treated with a non-persistent herbicide (certain plant protection products containing glyphosate are non-persistent).
The herbicide must not be capable of causing groundwater contamination. Under no circumstances shall a persistent herbicide be used when excavation and containment/disposal techniques are being considered, as this would potentially cause the material to be classified as a ‘hazardous waste’.
When excavation and containment/disposal control methods are deemed necessary it is essential that good site hygiene practices are employed to reduce the risk of contaminating other areas of the site.
Measures employed may include:
fencing off and signing areas of infestation;
not using tracked vehicles in the infested areas;
pressure washing vehicles exiting infested areas in designated wash-down areas; and,
ensuring adequate supervision.