Clay Barriers in Landfills

This chapter presents a practical review of the use of clays as environmental barriers around waste disposal (landfill) sites. Clay barriers are generally used as liners and capping materials for landfill sites. In each case they isolate potentially polluting wastes from the surrounding environment such that the environmental impacts attributable to a landfill are minimised. This review initially discusses the hazards associated with waste disposal sites which necessitate the containment of wastes and describes why natural clays are so often used as barriers around landfills (Sect. 6.2). The physical and chemical properties of clays which render them suitable for use in landfills are then discussed (Sects. 6.3 and 6.4). A description of the practicalities involved in clay liner construction is then presented, including investigation and testing required prior to construction, and details of appropriate construction methods (Sect. 6.5). Construction quality control (CQC) and construction quality assurance (CQA) procedures to be followed during construction are then considered in detail in Section 6.6. Finally, some of the ‘aftercare’ problems which can occur on landfill sites following their development are described (6.6.5), with particular emphasis on those concerning any clay materials used.