Capping of black devon landfill, Alloa, Scotland case study
The area of contention was Black Devon, a pre legislative landfill of the old „dig and dump“ variety on the banks of the river Forth, outside of Alloa, Scotland. Alloa is situated at the foot of the stunning Ochill Hills in the county of Clackmannanshire and is close to the port of Grangemouth. The landfill had been accepting wastes over many years from neighbouring industries including 4 breweries and 3 whisky distilleries. The local council decided that the area should be sealed and restored to a condition that would reflect the current prosperity of the area and comply with the European Landfill Directive. The restoration would provide recreation parkland for the local residents, certainly a major improvement from a partially capped landfill.
Through consultation between NAUE and a regional environmental consultancy and the subsequent
appointment of a local contractor to undertake the work, Bentofix® BFG 5000 geosynthetic clay liner was chosen to cap the 220,000 m² site because of its unique self sealing properties of the entirely bentonite impregnated cover nonwoven and its very low permeability. The benefit of having a 300 g/m² nonwoven needle-punched geotextile on top also provided sufficient puncture protection from the cover material.
Current UK and European landfill legislation now requires landfills to be designed and capped to strict standards and the technical merits of Bentofix® BFG 5000 fulfil these requirements. The material provided significant cost savings due to the ease of installation; only 2 labourers and an excavator were used, deploying upto 30,000m² per week. Installation of the material took six weeks and the overall project was completed ahead of schedule and within budget.