The success or failure of the mining industry in supporting the decarbonization of the global economy – through the provision of essential raw materials – depends heavily on the industry to take a holistic approach to water management. This approach considers water for a mining project in its entirety, from the start of exploration and licensing through to closure and post-closure. Holistic water management improves results, minimizing project risks and costs throughout the life of the mine.
Aside from the benefits of this approach, what deserves attention in an era that has seen an increasing emphasis on environmental, social and governance (ESG) assessments and reporting is that the drivers of holistic management of water align directly with ESG objectives. Here I am sharing some ideas about these engines from the work we have done and are doing at BQE Water to support better results for water.
Social acceptability is a requirement of modern mining. Projects can tick all the boxes of subject matter experts familiar with technical and investment risk assessment and legal compliance, but unless they are socially acceptable to the public, it is unlikely that ‘they come true.
Water management professionals can commit to making mining socially acceptable by eliminating the need for dilution to meet watercourse boundaries. This requires that the end-of-pipe limits for treated water are equal to those applied to the receiving environment. Mine water treatment should also be done in a way that does not introduce new chemicals or biologicals into the treated effluent that were not previously present in the water source.
The receiving environment standards largely protect all aquatic life, and as such the limits for many metals and metalloids are ultra-low. Cadmium and selenium are good examples of constituents often present in mine water in trace amounts that require removal to even lower levels. Until recently, the industry had no choice but to accept the dilution and deal with the unexpected impacts of organoselenates produced by biological treatment systems to control selenium. This has now changed with the introduction of electroreduction applied alone or in combination with ion exchange to remove selenium at one digit per billion and without any unintended consequences of the treatment.
Mining is a global business. Although there is great diversity in the professional workforce in the industry, water opens up new opportunities for inclusiveness, increased transparency and better environmental governance.
One opportunity is to invite representatives of local communities to participate in guided tours of pilot water treatment demonstrations during the environmental assessment and licensing stages of mining projects. This was done at the Seabridge Gold KSM project in British Columbia and it not only helped clarify the management and treatment of the water, but it also enabled the mine owner to respond to issues early on. water regulators and the public.
Another opportunity is to allow communities to have a say in where treated water is discharged. During a project in British Columbia, it was the local First Nations who chose the body of water that would receive the environmental discharge. For the First Nations who hunted, gathered and fished in the region, it showed respect and allowed their historical and cultural traditions to continue.
Nor is there a better champion and custodian of drinking water than local communities who have tangible incentives to protect local environments for present and future generations. As operators of water treatment plants, we seek the engagement of local communities and provide training for those who wish to learn how to better manage and treat water. An example of this is our partnership with an Inuit community business focused on securing economic development opportunities, Nuvumiut Developments, to ensure the continued operation of several mining water treatment plants in northern Canada.
Water treatment is an essential part of any mining operation. To be sustainable, it must go beyond the immediate need to remove targeted constituents of concern. The chosen treatment system must also take into account social, ecological and economic factors.
A crucial principle of sustainable water management is the reduction or elimination of treatment residues. The waste generated by the treatment is most often in the form of solid sludge or liquid brine requiring additional treatment and / or long-term monitoring. The goals of holistic water management and ESG are to implement water treatment solutions that avoid long-term costs and liabilities by generating by-products that can be reused or by recovering the value of the waste. This raises the bar above the regulatory checkbox of generating non-toxic and non-hazardous waste.
During the last two decades, water treatment systems with simultaneous selective recovery of copper, zinc and nickel have been implemented with great success. Waste production is reduced, with the value of the recovered metals paying for the entire treatment or offsetting part of the costs. And there are new water treatment technologies that produce stable, inert solids that have been independently verified as inputs for building materials and steelmaking.
Companies that choose treatment on the basis of short-term financial criteria or that do not consider upgrading waste treatment systems or non-toxic residues are doing themselves a disservice in the long term. The reduction or elimination of waste, as well as the value generated over decades – even after primary production ceases – can be significant.
Sustainability also means a low carbon footprint. During mine production, the additional carbon footprint associated with water is relatively small compared to the fragmentation and transport of ore and waste rock. However, it can still be equivalent to a city’s carbon footprint many times the size of all local communities combined.
Once the project goes into closure and after closure, water management and treatment can become the main carbon generator. And because contact between water and sources of contamination often takes years to stop, carbon production from processing can continue for decades after mining ceases. To avoid a significant carbon footprint in the long term, the industry must choose its water management and treatment methods from a holistic perspective.
If we want the mining industry to play a positive role in transforming society and the fossil fuel economy towards a circular economy, we must go beyond the principle of ‘do no harm’. A holistic approach to water can help in this effort. Whether we are just starting out, whether we are mining companies, regulators, service providers or suppliers, we are deliberately choosing to ‘do better’ in tandem with advancements in knowledge and technology to achieve better business outcomes. mining industry and for society as a whole.
David Kratochvil, PhD, PEng is the President and CEO of BQE Water (www.bqewater.com).