Robert Sarsby, author of a new ICE Publishing book title Environmental Geotechnics in Practice, discusses ways of improving land-based waste disposal.
For centuries mankind has been dumping all manner of waste materials (both toxic and non-toxic) on land, usually in an uncontrolled, haphazard manner. During the last 150 years, across the globe, there has been unprecedented rapid industrialisation and urbanisation. These developments, coupled with population explosion, have led to disposal and dumping of huge volumes of wastes on land. Inevitably this means that an increasing number of people are living in the 'influence zone' of sites potentially containing landfilled refuse, ground contamination, tips and lagoons.
Past, well-known disasters resulting from on-land dumps of wastes include;
Examination of case histories (especially where serious loss and damage has occurred) indicates that there are several factors that play a major role in the failure of waste dumps:
Global climate change is now causing increased frequency and severity of extreme weather events, elevated ambient temperatures and rising sea levels. Not only do these changes act to destabilise dormant non-engineered waste deposits, but they also mean that current design standards for engineered waste disposal sites will become inadequate. In future, we are going to see 'failure' of more and more waste dumps, with associated movement of large amounts of materials and contaminants and concomitant harm to humans and the environment.
Recent examples of serious events involving on-land waste deposits include:
Brasilian tailings dams (National Geographic, 2019)
Moscow's landfill problems (BBC News, 2019)
Radioactive waste flowing into an aquifer in Florida via a sinkhole (BBC News, 2016)
Erosion of the cover over toxic landfill (The secret life of landfill, BBC 4, 2019)
Large-scale on-land disposal of wastes is not, and never has been, a sustainable practice because it blights large tracts of land for an indefinite period of time and poses a permanent threat to the surrounding area. Failures of tips and lagoons are causing environmental disasters way beyond their boundaries - the red mud that escaped at Kolontar (in 2010) flooded 8km2 of land and caused Hungary's greatest environmental crisis ever. Mankind has been able to get away with dumping wastes on land for centuries because the waste facilities were comparatively small and isolated. But, due to exponential population growth, land, water and natural resources have become ever more precious commodities. Construction is a major consumer of natural resources and can make itself more sustainable and make disposal of wastes less damaging by re-using such materials wherever possible. This will require a big commitment from the sector as it will need to adapt and develop waste processing methods, material specifications and working practices, as well as convincing clients to pay significantly more for their projects.
To forestall even greater, and more prevalent, problems with waste dumps and repositories in the future, we need to install measures such as;
Find out more about realities of land-based waste disposal in Environmental Geotechnics in Practice : Introduction and case studies, available in both print and digital format.