Client / SIte: Viridor / Norlands Lane
In 2007 Viridor introduced us to their 35ha closed landfill site to recommend cost-effective land management systems that would ensure the successful establishment of the agreed restoration scheme during the five years post-closure period and fulfil the planning obligations. We undertook a full Baseline Survey of the land resource covering five-year actions to reduce costs and prioritise essential contracting work.
27ha of restoration grassland were present of which 21ha were recently restored on an active landfill. An extensive system of plastic pipes had been laid at 20-30cm depth to collect and transfer landfill gas to the electricity plant. This included 60 surface monitoring wells and surface-laid infrastructure within the sward.
The grassland in all cases was becoming overgrown and reaching 1.5m height in the summer with an element of noxious and invasive weed. Landscaping contractors were becoming less willing to take liability for damage to surface structures whilst mowing. This was as an issue for the waste planning authority in recent monitoring inspections and held negative connotations with the local public’s perception.
We prioritised demarcation of the gas field infrastructure and took forward the supervision of this work. Sourcing original layout maps has allowed us to supervise strimming and CATScan, to expose the surface lines and allow installation of 1.8m marker posts along their length. A colour coded system was agreed for power, gas, water and data lines. We incorporated the work into a 12month maintenance tender to include the subsequent 2-3 yearly mows of the site using a tractor mounted flail.
Contractors now have the assurance that vital infrastructure can be safely avoided. Five years later, the planning authorities have re-inspected and are very pleased with the standard of maintenance. 20m habitat cordons have been introduced to the grass fields to allow ground nesting birds, such as skylark, to breed successfully.
Viridor have subsequently adopted this system on a number of sites. The up-front work has allowed Viridor to maintain the site cost-effectively and secure a strong relationship with the local waste planning authority.
“Lockhart Garratt’s baseline reports have been valuable in helping Viridor prioritise the post-closure maintenance and in guiding planning liaison at the transition from operations to aftercare”.
Laurie Read, Viridor