AngloGold Ashanti continues its engagement with all stakeholders with regard to heavy metal contamination of the Wonderfontein Spruit. At issue is the suggestion that higher than acceptable levels of uranium and other heavy metals are present in the spruit, which has been the focus of research to determine the risk to informal settlements, formal townships and subsistence farmers who use the water in an untreated form.
The Wonderfontein Spruit, which lies to the north of the West Wits operations, is part of the Mooi River catchment area. This catchment extends from the Far West Rand with the upper section in the Gauteng province to the lower part of the North West province. The headwaters of the Wonderfontein Spruit originate from the Donaldson Dam located to the south of Randfontein, where residue deposits (tailings storage facilities and rock dumps) from several old and abandoned mines are generally believed to have contributed to its contamination. Active mines in the Far West Rand Basin have also been accused of continuing the contamination of the spruit through continued water discharges.
“Our West Wits operations currently operate essentially a water negative or zero discharge system, but we acknowledge we may have contributed in the past to the sediment that now exists in the river,” says Harry Rex, manager for environmental issues in Southern Africa. “The challenge is determining the extent of the pollution and proportionality of responsibility, bearing in mind that this problem dates back 100 years and obviously some of these companies don’t exist any more, and then, more importantly, deciding on how to deal with the problem responsibly.”
Since 2001 AngloGold Ashanti has spent about R10 million to improve its West Wits water management system through upgrading the storage capacity of its facilities and ensuring the separation of storm water from process water. Overflows are a rare occurrence when heavy rainfall incidents occur.
AngloGold Ashanti participates in the Mining Interest Group (MIG), which draws together a number of interest groups, including municipalities, mining companies, private individuals and organisations, regulatory bodies, industry and service providers.
Over the years, a number of scientific studies have been conducted by various industry bodies and NGOs to establish the extent of sediment deposition. The most recent is a study commissioned by the National Nuclear Regulator (NNR) to determine the potential radiological impacts of mining on the Wonderfontein Spruit, by analysing concentrations and assessing to what extent humans, flora and fauna are affected by consumption of its water.
“The report found that, based on conservative assumptions, there is a possibility that 50% of the sampling sites would result in exposures above the NNR dose limit of 1mSv/l per annum, predominantly as a result of the consumption of sediment by animals,” says Jozua Ellis, AngloGold Ashanti’s environmental manager for systems and radiation, who adds that, although the findings could potentially be serious, there remains debate around whether the report is consistent with scientific best practice.
Both the Department of Water Affairs and Forestry (DWAF) and the NNR have stated that the water in the spruit is fit for industrial and agricultural use, at the same time cautioning individuals that no untreated water is potable.
A challenge going forward, says Rex, is to ensure there is no ongoing pollution of the water system before cleaning up the spruit. “Cleanup, if decided on as the way forward, could be achieved in a variety of ways, from establishing wetlands to creating river diversions and then physically removing the sediment,” he suggests. AngloGold Ashanti will maintain its involvement with the MIG and the regulatory bodies, at the same time engaging with pressure groups. Adds Rex, “As a responsible corporate citizen, AngloGold Ashanti continues to be part of the process to find solutions and will take the necessary steps to ensure compliance with DWAF and NNR directives in terms of its certificate of registration. In summary, our short-term objectives are to maintain and, where possible, improve our on-site water source control and, in the long-term, to remain involved in the mitigation of the historical impact of pollution in the Wonderfontein Spruit.”
AngloGold Ashanti Annual Report 2007 – Report to Society