Mine Name: Mary Kathleen
The Mary Kathleen uranium deposit was discovered in July 1954 and set off a prospecting frenzy – although other deposits were discovered, they proved uneconomic and Mary Kathleen remained the prize. It was rapidly explored and developed with production beginning in June 1958. The project was majority owned by then Rio Tinto Zinc (‘RTZ’), ut closed in 1963 due to no renewal of export contracts to
the UK. In this 5 years production was 4,082 tonnes of uranium oxide (U3O8) and the project was then mothballed. The site was re-developed and began operations again in 1976, producing a further 4,802 tonnes of uranium oxide (U3O8) by closure in October 1982. The mine underwent rehabilitation and was formally handed back to the Queensland government in 1986. The work was considered of such a high standard that it won a national engineering excellence award in 1986.
Recent site visits by independent researchers has shown that long-term environmental problems were under-estimated, including:
– significant seepage from the tailings dam affecting nearby surface ecosystems;
– acid mine drainage in the tailings seepage;
– uptake of radionuclides and heavy metals into vegetation sufficient to raise concerns over cattle now freely grazing across the site.
Clearly, despite promises, the Mary Kathleen site has not been adequately rehabilitated and remains a pollution legacy.
B G Lottermoser, 2011, Colonisation of the rehabilitated Mary Kathleen uranium mine site (Australia) by Calotropis procera: Toxicity risk to grazign animals. Journal of Geochemical Exploration, 111 (1-2), pp 39-46.
B G Lottermoser, M T Costelloe & P M Ashley, 2005, Contaminant dispersion at the rehabilitated Mary Kathleen uranium mine, Australia. Environmental Geology, 48 (6), pp 748-761.