Sector reacts to removal of guidance on knotweed

The Environment Agency's withdrawal of best practice guidance for the removal of Japanese knotweed has come under fire as a booming market means more companies are taking on knotweed control than ever before.

Japanese knotweed: companies offering control services are reporting booming business and a buoyant market
Japanese knotweed: companies offering control services are reporting booming business and a buoyant market

The agency withdrew its Japanese knotweed code of practice, written by its senior technical adviser on invasive species Trevor Renals, in July and has asked industry bodies Invasive Non-Native Specialists Association (INNSA) and the Property Care Association (PCA) to take over the role. Both are currently writing their own versions.

However, this has led to concerns that having two standards will lead to confusion and allow unscrupulous operators to more easily avoid detection. Former INNSA chairman Mike Clough, who is writing the INNSA code of practice, pointed out that his concern is that the PCA code and the INNSA code will not specify the same level of qualifications needed, thus leading to a lack of clarity for operators and clients alike. He added that giving responsibility for overseeing best practice to industry is an unfortunate cost-cutting measure.

John Moverley, chairman of the independent Amenity Forum, said: "Withdrawl of the code by the Environment Agency is unfortunate and is causing confusion in the marketplace. The forum is speaking to the organisations involved to try and find the best way forward." The PCA was unavailable for comment.

Despite the withdrawal, an Environment Agency spokeswoman said its approach to tackling knotweed remains the same. "We encourage developers to minimise the waste they generate and seek effective management options to avoid the need to dispose of knotweed off-site. When knotweed is taken off-site it must be disposed of at a licensed landfill or incinerator. We continually work with industry to encourage new ways to treat knotweed and avoid excessive disposal costs."

She explained that the agency has a new position statement and consent is required from the Environment Agency if herbicides to control knotweed are to be sprayed near water. The police are responsible for any potential offences under the Wildlife & Countryside Act 1981. Under part II of schedule 9 of the act, it is an offence to plant or otherwise cause Japanese knotweed to grow in the wild. Failing to remove the debris to a registered landfill site may constitute "otherwise causing it to grow in the wild".

She declined to confirm whether the change is because of cost-cutting but Defra, which runs the Environment Agency, has lost a significant proportion of its budget since 2010 and agreed to a further 30 per cent budget cut last year.

Meanwhile, Japanese knotweed business is booming, according to operators. Japanese Knotweed Control (JKC) managing director David Layland said: "JKC is growing all the time. With the housing market as it is, land is very precious. It makes it more viable to remediate land. The market is buoyant at the moment."

Layland said JKC's turnover is up by 20 per cent this year compared with 2015. "There is a movement along the lines of developers with land banks acting proactively," he added.

The Council of Mortgage Lenders requires Japanese knotweed removal be undertaken by either an INNSA or PCA member before it will lend to property buyers on any land where the invasive weed is found.

Guidance - Requirements on landowners when knotweed is found

Current Environment Agency guidance on Japanese knotweed specifies that landowners must:

- Prevent Japanese knotweed spreading into the wild from their land. Allowing it to do so could lead to a fine of up to £5,000 or a jail term of up to two years.

- Make sure anyone spraying holds certificate of competence for herbicide use or works under supervision of a certificate holder.

- Carry out a Control of Substances Hazardous to Health assessment.

- Get permission from Natural England if the area is protected (site of special scientific interest).

- Get permission from Environment Agency if plants are near water.

- Dispose of chemicals through a registered waste carrier to a permitted waste disposal facility.

- Check with the Environment Agency before burying non-native invasive plant waste underground as this is only allowed on landfill sites with permits.

- Only approved herbicides can be used on the plant. Expect to respray as it usually takes three years to treat Japanese knotweed until underground rhizomes become dormant.

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