Organic contaminants of coal-waste dump water in the Lower- and Upper Silesian Coal Basins (Poland)

Organic phases in the waters of permanent- and temporary reservoirs located on and near coal-waste dumps in Upper- and Lower Silesia, Poland, include recent compounds of biogenic origin, geochemical compounds (biomarkers), dissolved products of coal-waste self-heating, and anthropogenic markers. Due to their adverse environmental- and health effects, the concentration levels of two compound groups were assessed, namely, polycyclic aromatic hydrocarbons (PAHs) and organic phosphates (OPEs). Their occurrence depends on whether sampling sites were thermally active or not. The predominant source of organic compounds in coal-waste dump water at thermally active sites is organic matter from coal waste. Products of self-heating dissolved in water include phenolic compounds, light ketones, organic acids, and PAHs showing the highest concentrations. OPEs are present only at thermally active sites where firefighting operations had taken place recently. These most probably derived from pump lubricants and/or the diesel engines of heavy-duty equipment such as excavators and bulldozers as no fire retardants were used. Biomarker- and PAHs ratios indicative of air particulate contamination prevail at sites where any thermal activity had ceased long ago. Traffic emission from nearby settlements seems to be the main source of organic compounds at such sites as the biomarkers indicate a crude-oil related source.