Environmental contamination threat from the deposition of construction and demolition waste (CDW)

Abstract: Growing population, industrialization and infrastructure development have resulted in enormous waste generation over the past decades. The disposal of vast amounts of waste remains a major challenge. However, in the globalized world recycling has become a main option for managing wastes while in other parts of the globe, landfilling is done due to waste handling difficulties. South Africa is one of many countries where landfilling activities is high, as roughly 75% of daily generated solid waste is disposed in landfills. This includes massive amounts of construction and demolition wastes (CDW) from reconstruction and development activities. South Africa depends on landfilling as a system of waste management which in the foreseeable future would linger till feasible recycling options are initiated. As such, the generation and seepage of leachate into soil, water reserves is probable in such dump sites due to exposure of the waste bodies to rain and run-offs. A bespoke device was used in the study to investigate the impacts of disposing CDW in open dumps paying mind to an unlined site relying on the geology of the area as worst case scenario. To generate leachate, the device was coupled with CDW in a bottom chamber and de-ionized water percolated the system from a reservoir. Arsenic, Copper and Chromium from the generated leachate effluent were analyzed by full spectral method and were compared to the South African standard of drinking water. Targeted ions were found to decrease over the testing period and it was however, clear that improper disposal of CDW could have consequential impacts on human and environmental health