Monde, Puleng, Zizipho and Khuselo play on the Riverlea mine dump near their homes. Riverlea is a new housing development on the corner of Main Reef Road and Nasrec Road, Johannesburg. This is the area where the first discovery of gold on the Witwatersrand Main Reef took place. The discovery of gold was un-earthed by Harrison and George Walker in March 1886. For decades, gold miners have been extracting residual gold from the dumps. Today chemical methods are used to enable companies to âre-mineâ the dumps, slowly changing the Johannesburg landscape once again. However, this also has beneficial impact on the environment as these large mounds of sand are being flattened. For every metric tonne of solid waste heaped in the dumps there is just 0.3 grams of gold.