Water treatment

Water management is a key part of Energy Resources of Australia Ltd's (ERA) operational activities. Water is managed according to the quality.

Water that falls as rain outside the mining operational areas is directed away from the mine site. Rain that falls within the mine site is diverted, collected and retained. Water used in processing operations is directed to a specially constructed tailings dam.

The upgrade of the lime softening circuit and the completed retrofit of the process water treatment plant in 2009 enables ERA to treat water used in processing operations to extremely high standards.

The retrofitted water treatment plant has a capacity of 1.1 megalitres per day. Treated water can be released into ERA's wetland water polishing systems.

Tailings dam

After uranium is leached from crushed ore, the resulting slurry residue, called tailings, is currently transferred by a closed pumping system to the tailings dam for temporary storage. 

The handling and storage of tailings is carefully controlled to ensure that there are no health risks to people, wildlife or the environment. 

Ultimately, the tailings will be returned to the mined out pits for secure containment and rehabilitation.

During 2009 ERA invested $43 million to ensure world class water management systems capable of managing existing and proposed uranium production activities, in line with ERA's water management strategy.

Part of this investment included the tailings dam wall lift, and expansion of water treatment capacity. Both projects were completed in 2009.

The tailings dam continues to outperform the original design parameters. The dam's performance and integrity is closely monitored, with boreholes, electromagnetic surveys and visual inspections.

The performance of the tailings dam is regularly reviewed by ERA and stakeholders to ensure operation within optimal design parameters.

The Federal Government's Supervising Scientist, stated in his 2008/2009 annual report that the "extensive monitoring and research programmes of the Supervising Scientist Division confirm that the environment has remained protected", and that "there is no evidence of seepage extending from the base of the TSF (tailings dam) into Kakadu National Park."