Water is a critical input in mining, used to process ores, suppress dust and cool equipment – but in Chile’s Atacama Desert, one of the driest places on Earth, fresh water is scarce and heavily contested. The country faces high water stress, particularly in its central and northern regions, where demand often exceeds supply. A prolonged mega-drought, now more than a decade long, has drastically reduced water availability, while challenges around water governance and competing demands from mining, agriculture and communities have intensified the crisis.
With local resources prioritised for human and agricultural use, the mining sector is turning to the Pacific Ocean. Desalination offers a viable solution for long-term water access but comes with high energy costs and environmental trade-offs.
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In this Q&A, Ilya Epikhin, principal at Arthur D. Little, talks to Alejandro Gonzalez, a financial services editor with GlobalData, Mining Technology’s parent company, about how mining companies are balancing operational demands with sustainability goals in one of the world’s most water-stressed regions.
Alejandro Gonzalez (AG): How are mining companies in Chile addressing water scarcity at a strategic level, and how do government regulations and environmental, social and governance (ESG) commitments influence their long-term water management plans?
Ilya Epikhin (IE): Mining companies in Chile are responding to water scarcity with a multi-layered strategy shaped by environmental regulations and ESG commitments. We have identified three key focus areas: water stewardship, regulation and ESG-driven transformation.
First, water stewardship is becoming a core part of operations. Companies like BHP and Antofagasta Minerals already use desalinated water for 30% of their needs, and that is expected to reach 50% by 2030. BHP’s Spence mine, for example, has a 1,000 litres per second desalination plant. Others, like Hot Chili, are using shared infrastructure models to distribute water more efficiently. There is also growing use of untreated saltwater – Antofagasta’s Nuevo Centinela project is a case in point.
Closed-loop systems and advanced recycling achieves 76% water reuse in mining operations. Anglo American’s El Soldado facility recovers 80% of tailings water through hydro-dewatering and Mantos Blancos uses energy-efficient processing circuits to cut losses.
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By GlobalDataTailings innovation is also a focus topic. We see dry stack technologies replacing conventional methods, with BHP’s cell-designed tailings deposits at Spence, for example, cutting evaporation by 30%, and Anglo American’s hydraulic stacking method achieving 80% recovery of processed water.
Second, regulation is pushing these efforts forward, but challenges remain. Chile’s Mining Policy 2050 limits the use of continental water to 10% by 2025, accelerating desalination adoption. Upcoming amendments to the Mining Code (Bulletin 9.185-08) will require desalination for projects exceeding 150 litres per second. However, permitting remains a bottleneck – some projects face six-year approval timelines, prompting operators like Hot Chili to partner with specialists such as Stantec to speed up delivery.
Third, ESG pressures are reshaping water strategy. Investor support now depends heavily on sustainability, with 64% stakeholder approval for mining hinging on sustainability. Collaborations with companies like Veolia have reduced the sector’s water use by 16 million cubic metres annually. Renewable-powered desalination – such as solar installations at Codelco – and floating photovoltaic panels at Los Bronces’ tailings ponds are also helping reduce emissions. Programmes like Veolia’s Proof Not Promises are setting standards for performance, and Anglo American’s 80% recovery at El Soldado is one of the industry benchmarks.
Although desalination is still costly – typically between $0.50 and $2 per cubic metre – and subject to regulatory delays, investments in circular systems and renewables are starting to lower those risks. If permitting and technology scale up as planned, Chile’s mining sector could cut fresh water use to just 5% by 2040.
AG: What are the biggest operational challenges Chilean mining companies face due to water scarcity, particularly in the Atacama Desert and other arid mining regions?
IE: Chilean mining companies face significant operational challenges due to water scarcity in the Atacama Desert and other arid areas, driven by environmental, technical and socio-political factors.
The Atacama Desert, among Earth’s driest regions, holds vast copper and lithium reserves, yet faces severe aquifer overexploitation. Mining operations in areas like Salar de Atacama consume water at rates quadrupling domestic use, depleting resources critical to indigenous Lickanantay communities and ecosystems. Lithium extraction alone has driven localised water table declines of up to 2m, exacerbating conflicts with agriculture and traditional livelihoods.
Groundwater overuse is a widespread issue. The Pampa del Tamarugal aquifer, critical for mining in the north, has seen usage rise nearly 1,900% over the past three decades. Surface water is also limited – only 28% of mining’s water comes from rivers or lakes – and climate variability is making these sources less reliable.
Desalination offers a partial solution, but it comes with its own challenges. Transporting water from coastal plants to inland and high-altitude mines requires long pipelines, often at elevations above 2,000m. These systems are energy-intensive and expensive. Antofagasta aims to meet 66% of its copper sector’s water needs through desalination by 2031, but this will require major infrastructure investment.
There are also technical and geological challenges. Declining ore grades mean more water is needed to process the same amount of metal. In addition, outdated geological databases make it difficult to manage water resources effectively across regions.
Climate change compounds the situation. A prolonged 13-year drought has already cut reservoir capacity to 30%, forcing miners to make more efficient use of water. Rising temperatures – Chile has warmed by 0.15°C per decade since 1961 – are also increasing evaporation rates. Since 2011, Chile has experienced 12 consecutive warmer-than-average years, with eight of the ten warmest years occurring since 2000.
In response, companies are focusing on desalination, recycling, groundwater monitoring and community engagement to balance resource use with social and ecological concerns.
AG: How do mining operations in Chile adapt to the high costs and logistical complexities of transporting and storing water, especially when moving desalinated water over long distances and high altitudes?
IE: What we are seeing is that to manage the high costs and technical difficulties of transporting water – especially desalinated seawater – mining companies in Chile are turning to collaborative infrastructure, better pipeline engineering and closed-loop systems.
Transporting desalinated water up to altitudes of 2,000–4,000m requires large-diameter pipelines, powerful high-pressure pumps and corrosion-resistant materials. According to our data, around 70% of pipeline operating costs come from energy use. Improving the design and materials used can lower these costs significantly.
Joint infrastructure investments are becoming more common. Codelco’s northern operations, for example, now share desalination infrastructure across three mines. In another example, the Los Pelambres mine recently expanded its pipeline system, tripling water transport capacity. However, land rights and permitting continue to pose challenges in some areas.
Efficiency measures are also playing a key role. Facilities like Anglo American’s El Soldado are recovering up to 80% of process water, and thickened tailings help reduce overall water loss by around 10% compared with conventional tailings. Some sites are using floating solar panels on tailings ponds to reduce evaporation.
Closed-loop systems are becoming more prevalent, with some mines achieving water recycling rates of 85% or more. These efforts reduce reliance on new water sources and help manage operating costs.
AG: How is water scarcity affecting mining productivity and costs in Chile, and what strategies are companies using to mitigate these risks while maintaining output levels?
IE: Water scarcity is having a clear impact on productivity and costs in Chile’s mining sector. With below-average rainfall persisting for more than a decade, reservoir capacity has dropped to around 30%. Meanwhile, falling ore grades mean that more water is needed for processing, which drives up both cost and complexity.
This has already led to production cuts. BHP’s Cerro Colorado and Anglo American’s Los Bronces operations have reported output reductions of up to 44% because of water shortages.
Desalination is now a key part of the response, but it is costly. Desalinated water can be up to ten-times more expensive than groundwater. There is also the capital expense of infrastructure and the high energy demands of pumping water to remote, high-altitude mines.
To manage these costs while maintaining production, companies are investing in more efficient pipeline systems, improving water recycling and sharing infrastructure to cut duplication. According to our data, the copper sector’s water use is expected to grow 2.3% annually to reach 23.7 cubic metres per second by 2034. Seawater use alone is projected to increase 230% this decade.
This creates pressure to maintain output while meeting sustainability goals, particularly in a mining-dependent economy like Chile’s.
AG: What are the key technological innovations being adopted in Chile to reduce water consumption and improve water recycling in mining processes?
IE: We are seeing a clear shift in Chile’s mining sector towards technologies that reduce water use and improve recycling. From our perspective, four main areas of innovation are driving this progress.
First, desalination has become a central part of the water strategy. Reverse osmosis plants are leading the way, with total capacity in Chile projected to grow by 130% by 2031. A good example is BHP’s Spence copper mine, which operates a desalination plant capable of supplying 1,000 litres per second – meeting around half of the mine’s current water needs. The company is already planning to expand this capacity.
In mineral processing, we are seeing three interconnected innovations that are changing the way water is used. Coarser particle flotation, for instance, cuts water consumption by more than 20% while also improving metal recovery rates by three to five percentage points. At the same time, dry tailings disposal is gaining ground, enabling up to 50% water savings by using advanced filtration systems to recycle more water. Supporting all of this, AI-driven sensor networks in concentrator plants are being used to make real-time process adjustments, which helps modern facilities reach water reuse rates of 85–90%.
Resource efficiency is also improving through technologies like magnetic resonance ore sorting, which enables more precise targeting of high-grade ore. This reduces the amount of low-grade material processed and cuts water use by 15–20%. In parallel, heap leaching methods are being upgraded to reduce evaporation losses – an important development, especially in the extremely dry conditions of northern Chile.
Our benchmarking suggests that companies adopting these combined approaches are already seeing significant results, with fresh water withdrawals per unit of copper reduced by 35–45%. That said, desalination remains energy intensive – typically requiring 3.5–4.5 kilowatt-hours per cubic metre of water – which means decarbonising the process through renewable energy will be essential moving forward.
Overall, we believe these innovations position Chile’s mining industry to maintain output growth while cutting total water use by 25% by 2030 compared with 2020 levels. Achieving this balance is critical – not just for the future of mining exports but also to support the long-term security of water supplies for local communities.
AG: How are advancements in desalination technology improving the sustainability of mining in Chile, and what measures are being taken to minimise environmental impacts, such as brine disposal?
IE: Advancements in desalination technology are significantly improving the sustainability of mining operations in Chile, helping the industry address acute water scarcity while working to minimise environmental impacts.
Mining companies are increasingly relying on reverse osmosis (RO) plants, which use membrane technology that is more energy efficient and produces less waste than older thermal systems. Many large-scale RO facilities are now equipped with energy recovery systems, which further improve efficiency. These upgrades not only lower operational costs but also reduce the carbon footprint associated with water production.
To make desalination more viable at scale, we are also seeing a shift towards shared infrastructure. Mining clusters are developing joint desalination pipelines and treatment facilities. This collaborative approach helps reduce capital expenditure, limits the environmental disruption caused by building multiple systems and can improve community acceptance of mining operations.
That said, brine discharge remains a key environmental concern due to its high salinity, which can harm marine ecosystems. While Chile’s regulatory framework lacks specific brine concentration limits, certain measures have been taken to control it, with two most prominent being dilution and controlled discharge, representing mixing brine with seawater before release to minimise localised salinity spikes, as well as deep-well injection and evaporation ponds, which is an alternative disposal method reducing marine impact, although it is much costlier.
