The pumping, treatment and release of treated acid mine drainage (AMD) for the testing of the central basin AMD treatment plant has commenced.

The treatment plant was recently launched by the Inter-Ministerial Committee (IMC) on Acid Mine Drainage and is aimed at implementing the short-term action plan in the Western, Central and Eastern Basins of the Witwatersrand Goldfields.

The IMC mandated the Trans Caledon Tunnel Authority (TCTA) to provide a short-term solution in 2011. The action plan is to prevent decant in the Western Basin and breaching of the Environmental Critical Level (ECL) in the Central and Eastern Basins.

Following the heavy rains earlier this year, approximately 30 million litres of AMD was spilling out to the surface in the West Rand every day. On 14 March Minister of Water and Environmental Affairs Edna Molewa inserted AMD pumps at the Central Basin Pump station. Molewa said her department will continuously apply regulatory mechanisms for the adoption and implementation of long-term AMD or mine water management strategies by mining companies.

Testing the plant

The testing of the plant will be implemented in two phases. One train will be operated, and water released from 9 May, and then progressively a second train will be put in operation in the following weeks.

The discharge from this plant will affect the Elsburgspruit River into which treated AMD will be released. As a result, downstream users and other interested and affected parties will remain informed of the volume of the water that will be released as well as the quality of the AMD.

The treatment plant is be pumping approximately 63ML/d until 30 March, 75% of the ultimate 84ML/d capacity.

The quality of the treated AMD will be as follows:

Water Quality Variable	Average water quality across all three Basins	HDS plant effluent standard
Sulphates	4344 mg/ℓ	2400 mg/ℓ
pH	4	6-9
Iron	768 mg/ℓ	<1 mg/ℓ
Aluminium	35 mg/ℓ	<1 mg/ℓ
Manganese	127 mg/ℓ	<3 mg/ℓ
Uranium	0.2 mg/ℓ	0.05 mg/ℓ