This case concerns the management of a former industrial landfill over two decades to the final implementation of a “nature based” solution. In 1975, about 140.000 m3 of industrial waste was moved from on site storage to a nearby former sand & gravel pit. It was covered with a recultivation layer of about 1 meter. Increased environmental awareness in the 1990’s resulted in a first investigation. Simultaneously, legislation evolved from fixed value to site specific risk assessment.
The management project changed accordingly from a “classical” capping case to ultimately the implementation of a “nature based” solution. Over time, the location use had changed from agriculture, sand/gravel pit, and landfill to landscape & nature development, hence introducing a new and important stakeholder: the Landscape Foundation, responsible for managing the area.
Unexpectedly, the Land trust agenda and objective proved to be a positive driver to move towards a less intrusive management than initially proposed, i.e. drainage of free water from the cover layer in order to limit contaminant leaching from the landfill through water infiltration. The presence of natural attenuation of the contaminants (chlorinated solvents) and the absence of
risk for the open water receptor in the present situation helped convince the authorities to accept another approach, satisfying the Landscape Foundation by limiting disturbance of the actual use.10 A one-year study demonstrated that during vegetation growth there was no freestanding water at the interface between the landfill and the cover layer, hence no percolation. Nowadays one can find Galloway cattle and Konik horses roaming freely in this unique nature reserve.
Nature based remediation: From a landfill to a landscape nature reserve.