Landfill lining on a steep slope

The slopes of the Lostallo landfill site were levelled before a foundation layer was applied by a bulldozer.

SHOWCASING its abilities to work in steep and difficult conditions, WALO UK recently completed a project to produce a lining system at a 30,000m2 landfill site in Lostallo, a village in the district of Moesa in the Italian area of Switzerland.

The company, a specialist in the field of hydraulic asphalt engineering, produced the lining system for a cell of approximately 10,000m2. At 1:1.5, the slopes here are extremely steep, requiring the use of specially-adapted machinery and operators trained to work in these conditions, according to WALO UK.
Groundwater at landfill sites is always vulnerable to contamination from leachate and methane, which are found in most solid waste landfill deposits. WALO’s dense asphaltic concrete, formulated to a design mix unique to the project, is said to offer a highly robust barrier lining system, impermeable to both of these contaminants.
The base and slopes of the cell were levelled by an excavator and a foundation layer was then placed by a bulldozer, which was secured for working on the extreme slope by one of the company’s 60-tonne winches. Next the clay liner, also known as the geological barrier (k>5×10-8 m/s), and some 7 to 800 mm thick, was placed in two layers by an asphalt paver and main winch. Two bituminous layers – an asphaltic binder layer and a dense asphaltic concrete layer – were also installed by the main winch and paver and compacted by rollers on winches. Work commenced in May 2013 and was complete by autumn 2013. The client was CRER Corporazionedei Comuni del Moesano.