The discovery of gold was the reason for the birth and the rise of Johannesburg, long called the “City of Gold.” But a century later, those same mines, where toxic water has built up in abandoned shafts and may leak into South Africa’s water supply, now pose a serious threat. [Mentions AngloGold Ashanti]
See http://www.voanews.com/english/news/africa/Johannesburg-Threatened-by-Toxic-Waters-139219729.html.