Anglo American subsidiary Kumba Iron Ore is making a concerted effort to achieve a 10% to 15% water saving by 2020, the company states in its yearly social and community development newspaper, Boswa Ba Rona, released last month.

To achieve this, Anglo American’s water efficiency target tool (WETT) is being used to improve Kumba’s water management and make it more resilient during periods of water scarcity. The installation of water- quality monitoring meters is expected to be completed early next year.

The WETT is a water-balance tool that measures the company’s current water consumption against its future business production plan, enabling the company to benchmark its water efficiency, set future targets and measure its progress towards those targets.

The Anglo American water standard was rolled out to all its operations in 2011, a gap analysis was performed and gaps had to be dealt with through specific actions in the operations’ water action plans.

“Kumba’s plans include extensive stake-holder engagement, including participation in various regional forums with the Department of Water Affairs and the Sedibeng district municipality, the International Water Disclosure Project, which works with business to prevent climate change and protect our natural resources, local farmers and water-user associations, as well as other interested and affected parties,” Kumba Iron Ore states in its 2012 Sustainable Development report.

When water-management performance was measured at the end of July last year, water efficiency at the Kolomela and Sishen mines, in the Northern Cape, was found to be favourable, compared with the target of 175 ℓ/t of ore mined.

However, the water efficiency of the Thabazimbi mine, in Limpopo, had deteriorated during the reporting period, owing to a significant drop in production, Kumba states.

Meanwhile, as an extension of its water- use and management strategy, Kumba is studying aquifer recharge so that some of the excess water from its mines can be stored in compartments adjacent to mining activities where it is not used but available to replenish the original groundwater source.

“By recharging aquifers we are behaving as responsible water custodians and this is a sustainable solution to the management of excess water. Rather than releasing the water into the environment, it is stored under- ground where it cannot be contaminated or evaporate,” says Kumba senior engineer Anca Burger.

Although the Sishen and Kolomela mines operate in water-scarce regions, their activities generate significant amounts of water from groundwater inflow into the pits, which must be dewatered to enable safe mining.

Excess water pumped from the pits is supplied to local municipalities, in line with the mines’ water-use licences. However, the local municipalities do not have adequate infrastructure to deal with the water during periods of flooding, so the excess water has to be released into the environment, Kumba states in its report.

“At the Thabazimbi mine, dewatering is not necessary yet. Water is extracted from boreholes but, instead of using pristine groundwater for production processes, effluent is reused,” Kumba says.

Recycled effluent is also used in processes at the Sishen and Kolomela mines, enabling them to export even more water to the surrounding municipal areas. About 50% of all water used by Kumba’s operations has been recycled, the report states.

In addition, the treatment works at the Thabazimbi mine are being upgraded to become the mine’s sole water source, and Kumba is planning to build a potable water reservoir at the Sishen mine this year, which will be shared by the mine and the town when the facility is commissioned in 2014.

“It will ensure supply for about seven days – if the town does not receive water from the mine in seven days, it will not be in dire straits,” Burger states, adding that the reservoir will also ensure that the mine has sufficient water for its processes.