Contract Details

• The Cardiff City Council Lamby Way Landfill Site is located on the Severn Estuary foreshore southeast of the city.
• It covers an overall area of 50 hectares, part of which has been filled to capacity.
• In order to increase the capacity of the site and to meet current environmental standards, the Council has embarked on a programme of works to cap the filled part of the site and to open up more cells for further landfill.
• Under the Phase I Contract, a 15 hectares area of completed landfill was reprofiled and then capped with a 150mm protection layer of soil, upon which were successively laid a geotextile membrane, a 1mm thick HDPE membrane and an HDPE drainage layer. Finally, the area was overlaid with a final capping of 800mm of sub soil. At the same time, vertical landfill gas extraction pipes and leachate drains and outfalls were installed.
• Under Phase II, a separation layer was installed between the previously filled part of the site, to which it in effect formed a capping layer, and a new adjacent landfill cell. In addition to the layers provided in the capping Phase I, a 750mm-clay layer reinforced with a geogrid was incorporated in the separation layer.
• Phase III comprises of the construction of a new cell to extend the landfill capacity of the site. In addition to the installation of the separation layers, which included a 500mm thick geogrid reinforced clay layer; the work involved the excavation of 70,000m³ of material to increase the available capacity of the cell. Part of this excavated material was used in forming the reinforced clay layer.