The mining industry uses water for mineral processing, dust suppression, cooling systems, tailings management as well as drilling and rock cutting.

“Without water, a mine will shut down, water is critical to their existence. So wherever possible, water is recycled back into a mine’s processes. They use a lot of technology to either utilise less water in their processes or recycle that water. Furthermore, many mines have surface water catchment systems and often make use of groundwater resources. Depending on a region’s hydrogeology, an underground mine may have to manage significant water inflows simply to maintain operations and often find a way to divert that water to other uses. A lot mines have embraced the principles of the circular economy,” says Bartels.

He adds that it all comes down to a water balance. “Mines will evaluate the inputs of water, the amount of water already in the system, how much water their processes consume and the volume of water that can be either recycled or added to the system again.

“Because of their reliance on water, mines have become increasingly conscious of how they use this resource.”

Large scale water reuse

Bartels believes that while many South African mines and other industries may have embraced water reuse, South Africa lags in large-scale water reuse adoption. This is compared to global leaders in water recycling, such as Singapore and Israel – where wastewater is treated and reused for industrial processes, irrigation, and even potable water supplementation.

“It is not a pleasant thought to imagine that the water you are drinking has already gone through a number of other people’s bodies, but we need to remember that the natural water cycle works the same way. There are many technologies available to treat water to potable standards, in fact, treated wastewater is often of a higher quality that the water in our rivers and dams.”

As a water stressed country with a growing population, it is shortsighted to not fully explore water reuse on a larger scale. The recharge of water is not infinite. South Africa receives significantly less rainfall than the global average. The country’s average annual rainfall is about 464 mm, which is well below the global average of approximately 990 mm. Rainfall distribution is highly uneven, with the eastern regions receiving more precipitation (up to 1 000 mm annually) and the western parts, such as the arid Karoo and Namib Desert, getting as little as 100 mm per year.

“Day Zero in Cape Town in 2018 would have been less severe if existing wastewater treatment plants had been equipped with technology to treat wastewater for reuse. Fortunately today, the city is in the process of implementing three water reuse schemes; the Atlantis water resource management scheme, the Cape Flats managed aquifer recharge scheme and the Faure new water scheme,” states Bartels.

Bartels further comments on the eutrophic conditions resulting from the discharge of poorly treated wastewater, which has led to the excessive growth of hyacinth and water lettuce in many of South Africa’s dams. “If we consider water reuse and look at our wastewater as an actual resource, our water quality would improve.”

Technology

Generally, the technology required for water reuse is expensive and has a high energy requirement. When balancing the cost of a water reuse project with the need to save water, one needs to consider both the operational, maintenance and capital expenditure of the project. There is also always an environmental trade off. For example the brines from desalination plants and reverse osmosis plants  need to be disposed of and many chemicals are used to treat effluent for reuse.

But Bartels adds that technology is progressively making water reuse more efficient and cost effective, reducing environmental impacts.

“SRK Consulting recently held a global conference where I attended a workshop on filtered tailings plants. Tailings are often made into a paste and then pumped to a storage facility. However, this process uses a lot of water. Typically, tailings are pumped into a dam, solids are settled out and the water is reclaimed through penstock lines and filtered back into the plant. Overseas, tailings go through a filtered press, removing the water and creating a filter cake that could be dry stacked or taken to a waste dump facility, improving water recovery. Furthermore, tools including artificial intelligence and digital mapping are stepping in to mitigate and manage essential tailings dam infrastructure.”

“There are cases where mines cover the cost of municipalities conveying partly treated wastewater to  facilities to use in a mine’s processes,” he states.

Legislation

Mines have also learnt to navigate a detailed legal framework and have even formed their own standards around waste and water management. The Water Act, Waste Act and National Environmental Management Act (NEMA) are three key pieces of legislation that govern the mining industry’s approach to water use and waste management.

“One would consult NEMA when developing environmental impact studies, the Waste Act when managing tailings and classifying waste as well as determining the appropriate barrier systems and management required. The National Water Act will determine how much water a mine will extract from the environment, how and where water should be stored as well as the quantity and quality of effluent that can be discharged into the environment. This is rigorously controlled by a mine’s water use license,”  explains Bartells.

Most mining houses responsibly manage their water use and are signatories to the International Council on Mining and Metals – a CEO-led leadership organisation, on the premise of improving sustainable development in the mining and metals industry. The ICMM has developed a Water Stewardship Framework, which includes practical guidance, adopts a catchment-based approach to water management.

“Then there is the Global Industry Standard on Tailings Management (GISTM) that has a huge social responsibility component around protecting the environment as well as the communities surrounding mines,” says Bartels.

“As South Africa continues to face growing water scarcity, the mining sector’s evolving approach to water stewardship offers valuable insights for industries and municipalities alike. From embracing circular economy principles and advanced technologies to navigating complex legislation and prioritizing environmental responsibility, mines are proving that sustainable water management is both possible and essential. While SRK Consulting has a strong mining division focused on mineral extraction, we also offer expertise in environmental, social and governance matters, supported by specialists in soil contamination, groundwater, hydrology, and geohydrology. Our global presence enables us to take a holistic approach and assist clients across industries with effective water management,” concludes Bartels.