Research Highlights

Pb-210 radiometric dating in sediment of three marine lakes receiving metal inputs from coal-fired power stations in Australia

In New South Wales, estuarine lakes receiving inputs from coal fired power plants have been shown to contain elevated metal concentrations which may be degrading aquatic ecosystems. This is potentially a major problem considering coal-power stations currently supply 49% of Australia’s electricity, with energy supply from coal fi red power stations projected to increase to 57% by 2040.
This project aims to investigate the history of trace metal contamination in sediments of Lake Macquarie, Lake Budgewoi and Lake Illawarra in order to evaluate the metal contamination profile of estuarine lakes receiving inputs from coal-fi red power stations. The geochronology of sediment cores showed an increase of Se concentration in the 60s for Lake Macquarie and Lake Budgewoi, corresponding to the start of power stations activities. Selenium concentrations decreased from the 70s, corresponding to the improved ash handling procedures established by the power stations in these 2 lakes.
The plot of Se concentration against the age of the sediment in the core collected in Lake Illawarra shows an increase of Se concentration in the 60s which corresponds to the start of Tallawarra Power stations activity. The time of closing the power station also correlates with the time at which Se concentrations decreased in the lake. These results show that mitigation measures taken by the power stations to improve ash handling procedures has been effective in reducing selenium inputs and should be considered at other power stations to minimize selenium contamination in Australian water systems.
This project is part of Larissa Schneider’s PhD thesis in Environmental Chemistry at the University of Canberra. Larissa is being supervised by Professor Bill Maher from the University of Canberra and Jaimie Potts from the Department of Environment and Heritage NSW.