Currently these are stored in a Tailings Dam called the Tailings Retention System (TRS). This system is vast, covering more than 500 hectares and standing 10 metres in height. More than 10 million tonnes of tailings per year are added to this massive reservoir.

The TRS does not isolate the toxic wastes from the environment or the nearby township of Roxby Downs. They are subject to erosion by rain and wind, blowing across the mine site and township, where radioactive dust particles settle on roof tops, in gardens, gutters, streets, playgrounds, or are in the air the community breathes.

In 1994 a massive leak from the TRS was reported. Over four years, three million cubic metres of liquid leaked through the aquifer. The highly acidic liquid (pH 1.3) which leaked through limestone deposits contained a toxic mixture of heavy metals and dangerous radionuclides. The retention system did not comply with the designs outlined in the original Environmental Impact Statement (EIS).

A report by the Environment, Resources and Development Committee (a State Parliamentary Committee) reinforced concerns that then operator WMC cannot be trusted to assess and regulate its own activities. The report found that in regard to the leak from the TRS :

“...there were deficiencies in monitoring and reporting systems in place at Olympic Dam...”

“...the operators were reluctant to accept that a leakage from the tailings retention system was occurring despite mounting evidence to that effect.”

“The Committee finds that it was only when the leakage was too big to ignore or to explain away and only in response to hard prompting from the regulatory agencies that ad hoc operational changes were converted into radical remedial action to alter the original defective design concept.”

The tailings will be radioactive for tens of thousands of years, yet BHPB claim they have made provision for maintaining the TRS for only 200 years.