Revised EA advice on disposal of Japanese Knotweed
On 26 March 2019, the Environment Agency issued its revised Regulatory Position Statement (RPS) Treatment and disposal of invasive non-native plants: RPS 178. As we noted last year, religious organisations own a substantial amount of land – and some of it, no doubt, will infested with Japanese knotweed. This post reviews the new EA position statement and its implications for faith groups at local and national level, and others.
Japanese Knotweed – the basics
The RHS states that
“Japanese knotweed…is a weed that spreads rapidly. in winter the plant dies back to ground level, but by early summer the bamboo-like stems emerge from rhizomes deep underground to shoot to over 2.1m (7ft), suppressing all other plant growth”. Phlorum, the organization which was an expert witness in the Network Rail case, infra, indicates that only the female plant has been recorded to date in the UK, therefore even where Japanese knotweed seeds are produced, they have not been fertilised by the same species, and are sterile and unable to produce new plants. Hybridisation with the two related UK species is rare, requiring both species in the same area for cross pollination to occur, and when produced these hybrid seeds rarely survive due to a lack of hardiness; it therefore appears that wind dispersal of Japanese knotweed seed is quite rare.
“The main culprit in the spread of Japanese knotweed is the inadvertent transportation of soils containing rhizome fragments”; “Japanese knotweed exhibits vigorous growth through the soil from a fibrous rhizome (creeping root system, much like underground stems). Soil can be contaminated with reproductive knotweed material up to a depth of 3m and a radius of over 7m (or wider in certain instances) from the main clump of stems”.
Organizations and individuals must prevent Japanese knotweed from spreading from their land into the wild. Soil or plant material contaminated with non-native and invasive plants like Japanese knotweed can cause ecological damage and may be classified as controlled waste. Whilst it is not obligatory to remove Japanese knotweed from one’s land, an organization or individual could be prosecuted or given a community protection notice for causing a nuisance if they allow it to spread onto anyone else’s property. The presence of Japanese knotweed can give rise to common law nuisance, where it results in an unlawful interference with the use and enjoyment of another’s land and results in loss of enjoyment and property damage. Furthermore, there is an associated cost of eradication and potential ongoing liability for re-infestation.
In England and Wales, the primary statutory provision relating to knotweed is s14(2) and Schedule 9 Wildlife and Countryside Act 1981 (WCA). In Scotland, this has been amended through the Wildlife and Natural Environment (Scotland) Act 2011 and subsequent provisions. The Scottish Environment Protection Agency (SEPA) has no statutory duty to control Japanese Knotweed; however it does have an alliance with the police and Local Authorities for enforcement under the WCA in the case of a waste offence being caused. Whilst not wishing to initiate a discursus on causation – Alphacell Ltd v Woodward, & seq, it should be noted that section 14(2) of the 1981 Act makes it an offence for persons “planting or otherwise causing to grow in the wild”, whatever that might mean, [but see reference 1].
Local authorities have enforcement powers to require clearance of knotweed under s215 Town & Country Planning Act 1990 and any failure to comply can lead to prosecution, a fine and remedial costs. A community protection notice under the Anti-social Behaviour, Crime and Policing Act 2014 also contains powers which might be used against an occupier failing to clear knotweed.
In addition to the revised RPS discussed below, other government guidance is available:
- Prevent Japanese knotweed from spreading, which indicates how to identify, prevent spread and dispose of Japanese knotweed. [Published 30 March 2016, Updated 18 January 2018].
- Prevent harmful weeds and invasive non-native plants spreading, provides further guidance, [Published 23 September 2014, Last updated 30 March 2016].
A landowner could also face an action in nuisance in common law as we noted last year: the Court of Appeal ruled that two householders in Wales were entitled to damages from Network Rail because it had failed to control the Japanese knotwood on its land, which had been infested for fifty years. In Network Rail Infrastructure Ltd v Williams & Anor  EWCA Civ 1514, the Court upheld the ruling of Cardiff County Court – though on rather different grounds – and concluded unanimously that there had been an unlawful interference with the claimants’ enjoyment of the amenity of their properties because of the impairment of their right to use and enjoy those properties. It dismissed Network Rail’s appeal.
Revised Regulatory Position Statement
Regulatory Position Statements (RPSs) apply to circumstance in which the Environment Agency does not require a permit to undertake certain activities. If the review date in a RPS issued by the Environment Agency has passed, the RPS remains in force and can be relied upon until it is removed from GOV.UK or marked as withdrawn. If the RPS says that it expires on a certain date it cannot be relied upon and does not apply after that date.
With regard to Japanese knotweed and other invasive non-native plants, the Regulatory position statement 178, May 2016 was revised on 26 March 2019; in the new version Treatment and disposal of invasive non-native plants: RPS 178: a paragraph is added in section 1.3 on the disposal of the dead brown canes; there is also new section 1.4 on the reuse of sieved or screened soils; and the review date has been extended until 30 June 2021.
The addition to section 1.3 provides that the dead brown canes of Japanese knotweed may be disposed of at green waste disposal facilities or by composting on-site, provided they are cut (not pulled) a minimum of 10cm above the crown.
Section 1.4 indicates that the quantity of Japanese knotweed in soil may be reduced by screening or sieving, although this is unlikely to remove all propagules. Screened or sieved soils must not be taken off-site, except for disposal to landfill or incineration. This material may be reused on the site of production, but only in a restricted area – not spread across the site.
Comparison of the new RPS with that of 2016 indicates that the recent change are relatively small; nevertheless, they add an important degree of flexibility to the on-site treatment of this problematic plant. Since the main problems arising from Japanese knotweed are associated with its spread below-ground and the use of contaminated soil, the EAs revised RPS provides a pragmatic relaxation of its controls which extend the options for on-site treatment of the above-ground material.
. D N Pocklington, Polygonium cuspidatum – A knotty problem of causation?’, Environmental Law, 1997, 11, 9.
At L&RUK we do not give legal or technical advice, or purport to do so. This post summarizes the issues arising from the recent Environment Agency position statement on the treatment and disposal of invasive non-native plants. For specific queries on the application of the legislation and the practical issues associated with the treatment and disposal of these plants, professional advice should be sought from the competent authorities and practitioners in this area.