Technician: Richard Peach
Author: Elle Walton
Location: Stafford
Size covered: 11 m2
Techniques: Excavation
Costs: Approximately £10,000
BACKGROUND
Knotweed Services (UK) Ltd were contacted by a Tree Surgeon (who was working on a Bellway development Site in Stafford) to organise a site survey. The site was previously owned by the police and had houses and various buildings dotted around. The site was being cleared due to it being purchased by Bellway. Knotweed Services were informed some early ground works had started but 2 potential zones of JKW had been found.
SITE SURVEYS
Due to redevelopment, recommendations were that the JKW infestation was to be excavated by mechanical diggers and all controlled waste removed from site to specialist landfill.
At time of survey, 2 zones of JKW were identified within 2 areas of the site. Access was granted and no water sources were observed nearby.
My report stated that the excavation would take approximately 2 days to complete and that we would require a 8t machine and operative as well as approximately 3x 8 wheel tippers for disposal of 53 tonnes of controlled waste.
Before works begin, all excavations and plant would be clean/sprayed and we would Isolate area – install temporary fencing – and check again in 8 weeks’ time. Knotweed Services would monitor for 2 years, create a management plan with all plans , images and Issue the warranty.
A quotation was prepared and sent to out client as well as the site survey report, terms and conditions and our company brochure.
MAPPING
The mapping stage of our plans is crucial to identify the location of the infestation. This not only helps to indicate the proximity to boundaries/habitable space & outbuildings and the associated RICS classification, but also identifying the possible migration (7m buffer zone).
See Site Map below:
TREATMENT
Before arriving at site, a report identified there were no immediate risks of services within the excavation zone. A gentle scrape (approx. 6” at a time) using the mechanical excavator was used to remove the JKW from both areas.
Following the excavation and my assessment of the JKW rhizome system, I conclude that we were successful in removing all visible signs of Japanese Knotweed, including canes and rhizomes which were removed from site. However, as is the case with Japanese Knotweed, the site must be closely monitored for any regrowth.
As stipulated in the management plan, X1 technician is to carry out further inspections during building works at 3 proposed stages. I recommended inspections are conducted at the footings & damp installation stages and post completion of groundworks (3 visits Inc in original quotation).
Should regrowth occur and be identified within the monitoring period, the client will be contacted and consulted about the implementation of further treatment.
As per request, our client can now backfill the excavated zones. Contaminated soils have been removed and sent to landfill and the site has now been handed back to the client.
INSURANCE BACKED GUARANTEES (IBG’S)
The customer was provided with information regarding the IBG and went ahead with Knotweed Express Policy. A booklet was also provided to the customer regarding what the Express IBG covers.
WHAT IS GPI’S KNOTWEED EXPRESS IBG?
The general principle of our Knotweed Express IBG is simple. It will honour the terms of the written guarantee, originally issued to you by your contractor, where that contractor has ceased to trade and is, therefore, unable to meet their guarantee obligations by carrying out or meeting the costs of any re-treatment works that may be required during their written guarantee.
