Waste dumping in Sharpeville (Emfuleni Municipality) : an investigation of the characteristics and the potential impacts on air quality

Abstract

Waste management is of significance as poorly handled waste can have detrimental effects on both the environment, and the public health. Open burning of domestic waste is a common practice in developing countries, particularly in relatively poor areas with minimal or infrequent waste services. The emission contribution of uncontrolled waste burning to air quality issues is known to be immense. Uncontrolled burning of domestic waste is a source of various emissions such as black carbon, particulate matter, volatile organic compounds (VOCs), polychlorinated dibenzodioxins and dibenzofurans (PCDD/F), polycyclic aromatic hydrocarbons (PAHs) and other toxic pollutants. It is important to understand the actual composition of waste that is being burned, since the composition of the waste determines the type of emissions that was formed. The primary aim of this study was to investigate the extent of waste dumping and burning in Sharpeville, within the context of the fact that waste burning may contribute to air pollution. A pilot study was done to identify the illegal waste dumping sites throughout the township. Thirty-three waste dumping sites were identified during the pilot study. Most of the sites had evidence of historic waste burning, and some of the waste was being burned at the time of the site visits. A second site survey was done where evaluation and cataloguing of the thirty-three illegal waste dumping sites was undertaken. The sites were evaluated based on their location, waste-related activities, size, level of waste burning activity and a visual estimation of the waste composition. One of the thirty-three sites (the largest and most active of the sites) was then selected for further detailed assessment, where waste (composition) characterisation was performed. It was discovered that the waste consisted mainly of organic waste (29%), other wastes such as rock, ceramics, etc. (27%) and paper and cardboard (19%), while other wastes such as plastic film, nappies, polystyrene packaging and burned tyres were also noted. Only small amounts of glass were encountered. The small amount of glass was due to the frequent collection of glass bottles by waste pickers for an incentive. One important factor which determines the composition of emissions is the chemical constitution of the material being burnt. Based on the composition of waste, the formation of greenhouse gases and some persistent organic pollutants, such as dioxins, furans, polychlorinated biphenyls (PCBs) and PAHs are expected. However, a large fraction of the waste that is being dumped is inert (and non-flammable) and minimal emissions are expected during burning activities.