Agenda item

Report of the Director of Environment and Neighbourhoods. To be introduced by the Cabinet Member for Communities and Civic Life.

This report seeks approval to award a contract for the remediation of the land at The Paddock in Tottenham Hale to treat the invasive plant species that are present on the site.

The Cabinet Member for Communities and Public Life introduced the report which sought approval to award a contract for the remediation of the land at The Paddock in Tottenham Hale to treat the invasive plant species that are present on the site.

It was explained that there was a mandatory duty to remove Japanese Knotweed and other invasive species. It was proposed to use a capping method which was a specialist and largely chemical free technique. The works would enable the delivery of an enhancement programme to create a new nature reserve.

In response to questions from Cllr Connor, the following information was provided:

-       It was confirmed that the proposed method of capping the Japanese Knotweed was an alternative method to chemical techniques which was largely chemical free.

Following consideration of the exempt information, it was

RESOLVED

Pursuant to Contract Standing Order 9.07.1(d), to approve the waiver of Contract Standing Order (CSO) 9.01 the requirement to obtain three competitive quotations as permitted by CSO 10.01.1a) and to approve the award of a contract to Ebsford Environmental Ltd. for a package of Japanese Knotweed remediation works at The Paddock, Tottenham Hale, for a maximum value of £545,752, subject to the further recommendation in the exempt report.

Reasons for decision

Statutory duty to treat

The Council has a statutory duty to treat Japanese Knotweed, which has been a long-standing maintenance issue at The Paddock. The Council has agreed heads of terms with Thames Water for the lease of its land at The Paddock to be incorporated into the new nature reserve, which also places a responsibility on the Council to treat the Japanese Knotweed.

Chemical-free approach

The proposed approach involves minimal use of chemical treatments, which would be unsuitable in close proximity to watercourses and in areas used by the public. Advice from invasive species remediation specialists has indicated that chemical treatment is not viable or effective long-term, and evidence indicates that a level of chemical resistance is developing within the knotweed strains on the site. Chemical treatment is therefore unlikely to provide a permanent solution and will require more extensive treatment measures within a few years.

Capping has been identified as the most effective remediation solution for the site. This methodology responds to the underlying site conditions (e.g., asbestos fibre contamination in areas of The Paddock), the ecology of the site and its use by members of the public rendering chemical treatments unsuitable, and the long-term nature of a capping solution, reducing ongoing revenue costs by undertaking one core package of capital works.

Habitat Protection

The Japanese Knotweed remediation works form the critical first phase of a capital works programme to enhance The Paddock. The Japanese Knotweed infestation risks significant damage to The Paddock’s ecosystems, reducing the biodiversity of flora and fauna by out-competing native species. A large area of The Paddock is threatened by the spread of Japanese Knotweed, so its eradication will help protect the range of habitats on site, improve biodiversity and enable implementation of the long-term management plan that is required to achieve local nature reserve status.

Alternative options considered

Chemical treatment

Chemical spraying with a glyphosate-based treatment is the only other possible treatment method. This option was rejected as such a treatment programme would take three to five years, during which time no site improvement works could take place within the treated areas. This would delay any significant enhancement of The Paddock and cause prolonged disruption.

Previous attempts at chemical treatment of Japanese Knotweed in some areas of the site have not been successful. Furthermore, spraying chemicals in a busy public area and next to a watercourse would bring risks to other plant and animal life. Capping is a more permanent and predictable solution, resulting in the Japanese Knotweed issues largely being dealt with in one project phase, and reducing the likelihood of any future recurrence.

Re-tendering

The early engagement and soft market testing undertaken by the Council with several specialist suppliers has not resulted in a strong response to the procurement exercises undertaken. It is unlikely that going out to the market again would provide a stronger response to the specification, as the works are specialist in nature and would serve only to delay the project and impact on the delivery of the programme.

Not awarding the contract

The Council has a statutory duty to treat the Japanese Knotweed on the site. These works are the critical first phase of the Paddock enhancement programme, enabling the comprehensive landscape works to be undertaken. Using an alternative chemical treatment approach would not be effective or viable long-term and would require the comprehensive landscape scheme to be re-designed. This would lead to delays in the programme and in the delivery of benefits to local communities.