Exploring better ways to manage water in mining

To satisfy future mineral demands, the mining industry will be forced to extract lower-grade orebodies, meaning that we will need to dig more rock out of the ground to generate the valuable minerals or metals that society requires.

When we consider water consumption in relation to ore grades, research by Professor Gavin Mudd at RMIT and his colleagues has shown that as ore grades decline, water and energy consumption increases per tonne of product.

If mining companies extract these lower grade orebodies using the same methods as in the past, they will need more water and energy to process the ores into valuable minerals. Mines of the future will therefore generate more waste material per tonne of product than their predecessors, require larger tailings dams and, potentially, create more risks through water legacy issues.

These trends mean that, unless we start doing something differently, future mining will intensify the water-related challenges that already exist today.

While on a global or national scale, the mining industry is not a massive consumer of water – in Australia for example, mining accounts for approximately 4% of national water consumption – the nature of mineral deposits mean that water use is heavily clustered in mining regions, and this increases pressure on local resources significantly. For example, in Western Australia, mining accounts for 26% of the state’s water consumption.

I wanted to better understand the complex relationship that the mining industry has with water and how management practices could potentially be improved, so asked Dr Nadja Kunz, Assistant Professor at the University of British Columbia, and Canada Research Chair in Mine Water Management and Stewardship, to join me for a chat.

CL: Have you seen a shift in the mining industry’s attitude towards water in recent years? I imagine the environmental, social and governance (ESG) movement will have triggered a lot of conversations.

NK: Yes, I’d agree that the attitude towards water has shifted in recent years, though I’d say that this has been triggered by a range of factors. The ESG movement has certainly pushed the industry to be much more aware of the ways in which its use and management of water is perceived by other stakeholders.

Water is increasingly important from the perspective of local communities and indigenous rights-holders, and there are plenty of examples of new mining proposals that have been opposed on the basis of water-related impacts.

However, the investor community has also become a powerful motivator for companies to improve water management performance. This is in part due to concerns about project delays e.g., due to community opposition, but also because water has become genuinely costly; droughts and floods have caused billion-dollar production losses in some regions.

For instance, in 2010, heavy rainfall in the Bowen Basin mining region of Queensland led to huge production losses and raised concerns about the impacts of saline mine discharge on surrounding waterways.

For other mines, the cost of sourcing water for new projects, particularly those in water scarce countries like Chile, has skyrocketed and many companies are turning to desalination to meet their needs.

Investors are very attuned to these risks. The mining sector is also especially vulnerable to increases in water-related risks due to forecasted shifts in climate variability as a result of climate change.

Alongside land, water seems to be one of the most contentious natural resources that mining intersects with. Why is this relationship so complex? 

Mining operations have a unique relationship with, and dependency, upon water.

Water is an essential input for mineral extraction and processing, but too much water can also pose production and safety risks – for example, the risk of underground mine collapse due to flooding, or tailings dam failures.

Mining operations can also interfere with natural water systems throughout the entire mine life cycle, from exploration through to operations and closure. It’s no surprise that water-related issues are a significant legacy issue at many mines after closure.

The Faro mine in the Yukon, Canada, is one example: Faro was once one of the largest open-pit lead-zinc mines in the world as well as a significant producer of silver. However, it now represents one of the most complex abandoned mine clean-up projects in Canada.

Upon closure, the mine left behind 70 million tonnes of tailings and 320 million tonnes of waste rock which has the potential to leach metals and acid into the surrounding land and water. It’s estimated that the clean-up costs will exceed half a billion dollars.

The risks that the mining industry faces due to water and land also have many similarities.

I actually have a book chapter coming out soon with two collaborators, Dr. Laura Sonter, from the University of Queensland, and Professor Chris Moran of Curtin University, where we contrast land and water risks, and identify regions in the world that are most vulnerable to either or both of these risks simultaneously.

We also illustrate the ways in which these risks can interact. For example, where a water risk can pose a land risk, and vice versa.

What is water stewardship? How does this approach differ to traditional mine water management practices?

Traditionally, the mining sector adopted an ‘in-bound’ approach to ‘water management’; an internally-oriented strategy focused on managing water issues within the company fence. This was largely the domain of technical experts in meeting operational water-supply needs and avoiding discharge volumes or qualities that exceed local regulations.

But in recent years, stakeholder pressure has pushed the industry to adopt a much more externally-oriented strategy referred to as ‘water stewardship’ which includes improved transparency and accountability in public reporting, and greater attention to community engagement.

A particularly interesting consequence is that the skills needed for mines to be effective water managers also require a shift beyond a technical focus. This open-access paper provides a summary of how I see this field evolving.

There are obviously risks attached to water in mining going forward, but there are also opportunities. Could you talk us through some of the latter?

Indeed, the flipside of a threat is an opportunity.

Given the significant importance of water to many of the mining industry’s stakeholders (communities, investors, First-Nations rights holders, and governments), there is a strong case to be made for mining companies to show leadership in the area of water.

It has the potential to increase investor confidence, improve community relations and trust, and also deliver business value through reduced costs.

I’m particularly interested in how water can generate shared value for mining companies, communities and the environment. Are there any interesting projects in the pipeline that you can highlight for us?

My colleague, Dr. Jocelyn Fraser, has done some great work on this topic, and has written extensively on the case of the Cerro Verde mine in Peru.

Jocelyn and I have also had a long-term research partnership with Erdene Resource Development Corporation, a Canadian exploration company operating in Mongolia.

In one of our recent papers, also co-authored with Bulgan Batdorj, we illustrate how Erdene’s proactive approach to water stewardship in early-stage exploration has helped to foster relationships with local stakeholders and identify opportunity to create and share value. In this case, Erdene’s hydrogeological studies helped to identify new potable water sources that could also benefit the community.

Some years ago, I also worked on a paper co-published by the International Council on Mining and metals (ICMM) and the International Finance Corporation (IFC). In it we traced a number of global examples of companies that have worked collaboratively with local communities, government and other infrastructure projects on water-related issues.

What role do you see water playing in the future of the mining industry?

There is no question that water will continue to play an important role in the future of the mining industry.

The thing that I find most fascinating about working in this area is that every mine I visit encounters different types of water challenges and opportunities, whether they be in water scarce or abundant areas, with a high or low population, or with different environmental impacts.

This keeps it an exciting space to work!