Water plays a vital part in the mining process - let's find out why...

As the mining industry moves towards a more sustainable future, there are concerns about one of our most important and often taken-for-granted renewable resources – water. Whether it’s over management, contamination, consumption or supply, more and more companies are striving to improve their relationship with water.

This was prevalent in our Metals and Mining Innovation Forecast 2022/23, where improving water use was cited as a top-three business priority in the next one to three years.

We spoke to Dr Joe Huddart, Business Development Manager at NatureMetrics, to further understand the relationship between water and mining, the challenges faced and how the industry can address them.

Q. Why do you believe water is making an appearance as a trend now, despite it being an issue for a while?

A. Context is everything; the extraordinary heatwave experienced across Europe over the summer placed enormous pressure on water infrastructure. Depleted aquifers, empty reservoirs, disappearing rivers, and shrinking water supplies demonstrated the extreme weather patterns and shifts to rainfall that come with climate change. Conversely, this includes flooding; a third of Pakistan has been underwater, and eastern Australia has also been inundated this year. We need to rethink water use and infrastructure; with efficiency, quantification and capacity being the triptych required to maintain water security and infrastructure through increasingly frequent and severe weather episodes.

It's is not only a capacity and supply issue; water quality and its impact on society and the environment, namely biodiversity, are becoming hot topics in the press and social media. These also get impacted by extremes; drought conditions cause sewage and contaminants to concentrate in the environment, whereas floods cause treatment and containment facilities to overflow. The public is quite rightly outraged by declines in water quality that make it unsafe to drink or bathe.

In addition, the recent Living Planet Index report has again shown that freshwater biodiversity is vanishing at a much faster rate than in marine and land combined, with population declines averaging more than 86% since the 1970s. We can visualise this by thinking of a pond that used to have 20 fish, now only having three! While there are many causes, declines in water quality due to pollution and contamination rank among the highest. The focus on water is, therefore, not a zeitgeist but here to stay.

Q. How can mining companies improve water usage?

A. Industries are embracing a ‘systems-based’ revolution to understand their environmental impact. Supply chains are being assessed to ensure they are ethical and efficient; water is no different. ‘Where is the water we are using coming from, are we using it as efficiently as possible, what condition is it in afterwards and where is it going to end up?’ Should be at the front of water management plans for mining companies.

Water is, of course, a critical component of many mining operations. Mines need to tackle water usage based on efficiencies that reduce demand; ensuring sources are sustainable and do not deprive surrounding ecosystems or local communities of water; but most importantly, that water is treated to remove contaminants effectively before being released back into the environment. Vitally, this includes closure and post-closure.

Water managers need to break down and quantify the primary uses of water throughout their operations, from mineral conveyance, mineral processing and separation, mineral extraction, cooling, tailings dams, cleaning machinery, and dust suppression, to name a few. These all vary from mine to mine. Then they can work on efficiencies in each process.

So, in essence, improving water usage is split between sustainable sourcing, efficient use, and effective treatment - the three key areas to evaluate water usage. We have also been promoting a collaborative catchment approach, where different mining operations and other watershed stakeholders collaborate and communicate, sharing knowledge and data to benefit water and the environment. This can allow for the mapping of pollution and contamination entry points, alongside areas of ecological value that need to be protected.

Q. How should we evaluate water risk in mining?

There is a growing demand for water globally. And with uncertainties concerning changing weather patterns meeting the demands of mines, while not impacting water availability (and quality) to surrounding communities and ecosystems, this makes it critical to evaluate water risk. So, there is a supply risk. How much demand will the mine place on the local watershed? Is this sustainable? How long can the asset function in drought conditions?

Contamination is another massive risk. The contamination potential to the wider environment is largely due to the passive (and even active) movement of contaminated water from the mine operation via groundwater and surface waters into the wider environment. This risk increases with extreme rainfall and flooding, which can overwhelm tailings dams and other infrastructure. We are talking acid mine drainage, heavy metals, lead, cadmium, and even arsenic and mercury. These can leach out of the site, transcending the footprint of the mine and entering human water supplies and food production systems, removing sensitive but important species such as salmonids from ecosystems. The sheer range of potential contaminants makes measuring all physicochemical parameters particularly challenging. Missing any pollution incidents and the resulting declines in biodiversity is a widely recognised risk for which the company is directly liable.

Effective water containment, treatment and monitoring at the mine site and surrounding areas using physicochemical and, most importantly, biological indices throughout an asset's life cycle and afterwards, will be critical to monitoring risk. Even with hundreds of water chemistry measurements, we still rely on aquatic invertebrates for detecting contamination as these will respond to sudden pollution surges that otherwise might not get detected between testing intervals. Our biomonitoring tool is specifically focused on species detection and quantification- and it is ironic that the best way of knowing the impact of a mine on biodiversity is by directly monitoring aquatic animals in the waters draining from mine sites over time.

Q. How can innovation/transformation impact issues around water in mining?

A. New technologies for treating mine water are evolving rapidly, some of these are even using algae biofilters to strip heavy metals and other contaminants. As the field develops, these will continue to be adapted and commercialised, with uptake becoming standard for mining operations as threshold levels of pollutants continue to be reduced and enforced. Many other treatments are being developed to decontaminate soils too using bacteria for bioremediation.

Water testing is also becoming increasingly sophisticated, i.e., more compact and automated; probes can be deployed that remotely measure at the minute, 30-minute, or hourly intervals and send their data over the internet. This is a huge advancement when compared to the old-school field collection, with scientists filling hundreds of test tubes and sending these miles for analysis within very short time windows.

The electric vehicle and battery revolution are also gathering momentum in the sector. This will continue to reduce the risk of petrochemical spills in mining sites as power and transport continue to be less dependent on generators and other combustion engines using hydrocarbons.

Innovations with environmental DNA are also revolutionising aquatic and riparian biodiversity sampling and monitoring, we need to play catch up to incorporate these tools into biodiversity monitoring frameworks.

Q. Are you seeing a pattern in the types of companies investing the most in water solutions? 

A. We are finding that there is a transformational shift in how mines want to be perceived and how they are being scrutinised. This might result in negative PR leading to fines delicensing, closure and divestment.

We find our tools are being adopted not because they are required by regulators, but because companies want to demonstrate they are going the extra mile, rather than box-ticking and kicking the regulatory can down the road. So, we are finding that large companies, in particular, want to safeguard against reputational risk, but also demonstrate their ESG credentials and commitments.

Given the opposition faced by many mines, there is a need for companies to have the best possible data on which to manage their assets and base decisions on, and we offer that. They can even have the community collect the water samples, which offers an additional level of objectivity to the data collection.

Q. Are enough organisations understanding and taking water usage as seriously as they should?

A. Currently no, there is a lot of indiscriminate and unsustainable use of aquifers and groundwaters; dirty entities and businesses need to be regulated and made to get better. This also largely depends on where they are operating and how they are being scrutinised; companies operating in water scarce areas are far more conscious about water usage by necessity. In some cases, desalination plants are even constructed to provide water for these operations. There is also differing regulatory framework between countries and types of mining operations; for instance, Europe has stringent regulations which are tightly enforced, but emerging economies often lack these.

The perception that mining is a ‘dirty business’ that can contaminate water supplies and lead to health implications for neighbouring communities is a huge reputational risk, this awareness provides a powerful incentive where regulations and enforcement are lacking. The increasing ability to sample water in remote locations and record on mobile phones has also made water monitoring accessible to everyone, with global citizen science water monitoring projects further empowering local communities with the means and platforms to detect environmental pollution and hold polluters accountable.

There will always be ‘dirty’ entities, attracted by maximising profits without a thought to the environment, these give the sector a bad name. However, supply chains are becoming increasingly traceable, from pit-to-product, so tracing their material through supply chains to end-products and suppliers can allow for more ethical purchasing. The energy transition is a huge opportunity for mining, but we need to ensure we aren’t robbing Peter to pay Paul in the process, i.e., trashing our freshwater resources, biodiversity and ecosystem on the road to clean renewable energy.

What is without question, is that with variations in weather patterns and water availability, water usage and treatment will only grow in importance for mining operations.