Potential Groundwater Contamination from Pulverised Fuel Ash (PFA)

Abstract

In coal-fired power stations the ash produced either falls to the base of the furnace (furnace bottom ash, FBA) or is carried through the combustion chambers as fine-grained particulate matter (pulverised fuel ash, PFA). Approximately 80% of the ash produced is PFA. Both FBA and PFA are used in the construction industry but there is an excess production of PFA necessitating disposal in lagoons, land-fill sites and mounds. In 1990 48.6 x 106 tonnes of coal were used in UK. power stations (Central Statistical Office 1992) producing about 10 x 106 tonnes of PFA, just over half of which was not marketed. In the future there may be less PFA in the UK. to be disposed of and disposal sites are carefully engineered to reduce the risk of groundwater contamination. However, on older disposal sites there is the possibility of long-term weathering reactions influencing groundwater composition. It is this aspect which has been of particular interest to us. Furthermore, elsewhere in the World the production of coal for power generation is rapidly increasing, particularly in China and India, and there is the threat of both short and long term weathering reactions adversely influencing