Since 2002, the Tweelopiespruit has been an ‘emergency’ waste pipe for acid mine drainage – toxic water polluted by heavy metals, including uranium, from old mines on the West Rand.
However, unlike in a lined, properly managed slimes dam, water in the Tweelopiespruit cannot be contained. The stream flows through the Krugersdorp Nature Reserve and into a tributary of the Crocodile River, upstream from Hartbeespoort Dam.
Water from the stream is also finding its way towards the Cradle of Humankind (a UNESCO World Heritage Site). It has also polluted borehole water.
In January 2011 the Department of Water Affairs estimated that about 42 million litres (Ml) of mine water was flowing every day into the Tweelopiespruit. Of this only 12 Ml is partially treated by the mining company Rand Uranium. The partial treatment process does not remove the heavy metals from the river system.
As it flows through the Krugersdorp Nature Reserve the stream flows through two dams. The first of these, the Hippo Dam is being used as a settlement pond for the partially treated mine water.
On 3 February 2011 the pH of the water in the Hippo Dam was about 3.5. Just before it flowed out of the Aviary Dam it had a pH of 2 – as acidic as lemon juice (measurements taken by an Earthlife Africa volunteer). In a healthy stream a pH of about 7-8 would be expected. This indicates further problems with the neutralisation treatment process being used, which is currently advocated as a simple and quick solution by the Inter Ministerial Committee on Acid Mine Drainage, see: Ministers catch up with AMD? and Inadequate treatment of acid water flowing into the Tweelopiespruit
The Department of Water Affairs has classified the Tweelopiespruit as a Class V river – a very high acute hazard.
See also: Stream of acid, the Tweelopiespruit
Water flowing from old mine shaft towards wetland near Tweelopiespruit (30 Jan 2010)
Acid mine drainage into Tweelopiespruit, just before it flows into the Krugersdorp Nature Reserve (3 Feb 2011)
Tweelopiespruit flowing out of Aviary Dam, Krugersdorp Nature Reserve (3 Feb 2011)
Tweelopiespruit, Krugersdorp Nature Reserve (3 Feb 2011)
Animals at risk from the polluted water in the Krugersdorp Nature Reserve (3 Feb 2011)
Tweelopiespruit waterfall, distant mine dumps, Krugersdorp Game Reserve (3 Feb 2011)