REGENERATION experts who have overcome chemical dumps, blast zones and gas works are facing one of their toughest challenges to date – from a weed.
Waterfront Edinburgh Ltd is one of three landowners involved in the £1billion regeneration of Granton Waterfront, a 15 year project to deliver 8000 homes and thousands of jobs.
That involves cleaning up a polluted site once best known for its print factories, chemical plants and gas works and so reconnecting the city with a stretch of coastline lost to the community for decades.
Now bosses at the joint venture are tackling another recently discovered hazard – Japanese Knotweed.
David Maggs, Development Engineer at Waterfront Edinburgh, said: “It is a particularly voracious and invasive plant with little or no ecological value.
“In fact, it provides virtually no benefits to birds, mammals or insects and it grows at an incredible rate. Not only is it considered a threat to the environment, but disposal of the material is not straightforward either, as it is regarded as hazardous waste and requires specially licensed facilities.”
When it was discovered on Waterfront Edinburgh’s 120 acres of land in August, experts from the Scottish Agricultural College were called in. Now a three year containment and eradication scheme is being put in place and is likely to prove a model of good practice for the future.
The affected sites have either been completely fenced off to create a seven metre exclusion zone or are already inaccessible to the public and the weeds will be sprayed twice a year for the next three years in a treatment proven to eradicate the plant.
One site where more imminent development is anticipated will require a more direct approach. Specialist contractors are to be employed to dig up the weed infestation – roots and all.
The entire root structure and surrounding soil will then be specially transported to an unused site at West Shore Road, where it will be carefully laid out in a secure area and then treated with herbicide twice a year until no regrowth is recorded.
David Maggs added: “The plant is so aggressive that even when you dig it out roots and all you still have to take special care to ensure it has no opportunity to take root elsewhere. People can be very surprised by the lengths required to eradicate the plant.
“Certainly, the irony hasn’t escaped us that on a site with a legacy of so many problems to overcome, one of the toughest should come from a weed.”
Japanese Knotweed was introduced to the UK as an ornamental plant during the 1800s. It can grow as much as 2cms per day in any type of soil, no matter how poor, with a root network extending several metres.
New plants grow from fragments of root as small as 0.8 grams, crowd out native plant species and provide a poor habitat for wildlife. When it dies back between September and November, it can cause further environmental problems by choking waterways.
Dr Ken Davies, weed and vegetation consultant with the Scottish Agricultural College, is overseeing the project. He said: “Waterfront Edinburgh should be commended for its responsible approach.
“We suspect many people are unaware of the legal requirements, or deliberately ignore them to avoid the landfill charges. They may be dumping Japanese Knotweed and contributing to its spread across Scotland.
“Where possible we prefer to treat it on site, since there are obvious risks of transporting plants to landfill. Fragments of plant can get stuck in boot soles, vehicle wheel treads and spread that way, or simply get spread in transit.”
Colin Hunter, chief executive of Edinburgh Waterfront Ltd, said: “The regeneration of Granton Waterfront is about social inclusion and creating a welcoming destination – but that doesn’t extend to Japanese Knotweed.
“Joking aside, I am delighted that we are taking such a sensible, well-coordinated approach to dealing with this problem to underline, yet again, how this regeneration scheme aims to be a model of excellence and good practice.”