Heavy metals

Emissions of heavy metals are currently not regulated, but mercury has been highlighted in the South African 2007 National Framework as a pollutant that may be included in the list of criteria pollutants in the future. Some of the heavy metals contained in coal and, following combustion, in the ash and flue gas are removed to a certain degree by the existing particulate removal devices. Eskom conducts ongoing research into heavy metals in coal and their related impact on the environment. The mercury content in coal and ash is analysed regularly.

Fugitive emissions

The South African 2007 National Framework for Air Quality Management requires that best-practice control measures be established or a fugitive emission management plan be put in place for significant fugitive dust from ash facilities and other sources such as coal stockyards. Eskom will undertake fugitive emission monitoring at some power stations. Fugitive emissions are reduced through wetting and ongoing rehabilitation programmes.

Volatile organic compounds (VOCs), dioxins and furans

Benzene is currently the only VOC for which ambient air quality standards have been proposed, but according to the South African 2007 National Framework, other VOCs may be included in the list of criteria pollutants in future. VOCs are mainly associated with combustion of hydrocarbon fuels that are not coal based, for example, at gas turbines. Eskom will continue to keep abreast of international trends and research.