The first phase of the Tweefontein Water Reclamation Plant is now fully operational, providing 9 MLD of clean drinking water.
Located 8 km east of the small town of Ogies in Mpumalanga, Glencore Operations South Africa has established the Tweefontein Water Reclamation Plant, which treats mine-affected water to potable standards for the surrounding community.
The first 9 MLD phase of the plant is fully operational, and produced its first water in November 2018. Glencore is now in discussions with the eMalahleni Local Municipality (ELM) on the possible upgrade of the plant in order to increase the throughput to 14 MLD.
“There is potential to increase the capacity further depending on all the governing variables, including excess water in the mines and demand increase from ELM,” explains Shivani Chetram, head: Communications, Glencore Operations South Africa.
Supporting the community Prior to the establishment of the Tweefontein Water Reclamation Plant, the surrounding community was often without running water for extended periods of time, largely due to growing demand and lack of capacity.
Although initially conceptualised as a way to manage mineaffected water in Glencore’s Tweefontein, Goedgevonden and iMpunzi complexes, the plant also offered the opportunity to provide potable water to the Phola Township, north of Ogies.
The fully fledged reverse osmosis plant treats the mine-affected water to drinking water standards, complying with SANS 241-2015. Water is extracted from mined-out underground workings used for the storage of mine-affected water.
Typical of water emanating from coal mining activities, the water entering the reclamation plant has a high sulfate level. This said, with the current process, the plant recovers approximately 96% clean water from the feed. With a further technological introduction, the plant will soon be recovering in excess of 99% clean water from the contaminated body of water, says Chetram.
“The process to clean mine-affected water is very similar for all plants recovering water from old mine workings. Unfortunately, the water from different mining areas can differ significantly in respect of composition, making every water reclamation plant different from the next. The difference between the Glencore plant and other plants in the area exists not in the technology employed, but rather the manner in which the process was designed, resulting in the lower use of chemicals in the recovery,” she continues.
Significant infrastructure investment The by-product of the treatment process is highly concentrated brine, which is stored in an evaporation brine pond.
Established solely by Glencore Operations South Africa, this pond had to be constructed along with the entire infrastructure necessary to make the plant a reality.
This included boreholes and pumps, electrical infrastructure, reservoirs, transfer pump stations, pipelines, lined storage ponds for plant feedwater, sludge and brine, as well as the complete reverse osmosis plant. Associated support infrastructure – such as fencing, offices, security, operations and maintenance – was also necessary.
A 16 km pipeline was established between the water reclamation plant and Phola Township, where a potable water treatment facility, together with a reservoir and pump station, was established on the site to supply water to the area.
“We can now supply 9 MLD that was not available for consumption prior to the establishment of this plant, contributing to the overall water security of the area,” says Chetram.
“At the same time, the Tweefontein Water Reclamation Plant will assist in reducing our water usage footprint from other water sources such as dams and rivers, while providing an effective solution for our current mining operations as well as the long-term management and treatment of water decant at eventual mine closure.”