Legacy Mines

Legacy mine sites often pose challenges for people and the planet. Degraded lands impact ecosystems and biodiversity, and communities near these sites want solutions.

We believe in giving legacy mines a second chance. We extract minerals and metals from mine waste to provide responsibly sourced materials, and use the earnings to restore the sites, creating ecological and community assets.

What are legacy mines?

Legacy mines that are abandoned, orphaned, or in company portfolios, are sites where mining has finished and the waste is left behind. Abandoned mines are where the owner is unable or unwilling to remediate the site, and the company responsible has closed their doors. Orphaned mines have no legal owner. In both cases, these sites are often a legacy from a time before environmental regulations existed or the rules were less stringent, and post-mine planning was not considered.

More recently, mining companies can have a portfolio of sites that are closed or in the processes of closing that need to be managed, in some cases these are legacy mines inherited through acquisitions.  These can be a mixture of historic and more recent sites. The environmental conditions can depend on the age of the site.

There are also examples of more modern mines where the government holds the environmental liability and doesn’t have the funding to clean up the site.

How many legacy mines are there?

It’s difficult to know exactly how many abandoned and orphaned mines exist globally because definitions vary between jurisdictions, and in many countries no formal data exists. The US government, for example, measures individual mine features, such as shafts or waste piles. Others measure mine sites; however, the mines can vary widely in size and impact. Not all legacy mines are the large, open-cut operations common today. Many include historic sites that are smaller, less sophisticated ventures with a single underground shaft, or placer gold mining sites like those we work with in our SalmonGold project.

Where data exists, the number of abandoned mines and mine features is estimated to be:

·      US: 1.8 million hardrock abandoned mine land features¹

·      Canada: 10,000 abandoned mines²

·      South Africa: 6,000 abandoned mines²

·      Australia: 80,000 abandoned mines²

While the number of legacy mines in mining company portfolios is not reported, the estimated environmental reclamation and site restoration costs for 24 major mining companies was $72billion in 2023³.  

 What problems can legacy mines create?

Legacy mines can pose health and safety risks for people, damage local environments, impact the cultural traditions and practices of communities and Indigenous Peoples, and leave behind social and economic problems.

Safety risks on legacy mine sites can include unstable slopes, uncapped mine shafts, and ground subsidence. Often, a bigger, more insidious problem is contamination from waste rock and tailings that have been partially remediated, or not at all.

Depending on what was mined, tailings and waste rock can contain contaminants like heavy metals and chemicals used during mining and processing. One of the biggest issues is acid mine drainage (AMD), which occurs when waste rock and tailings containing sulphide-bearing material, like pyrite, are mixed with oxygen and water. These materials occur naturally in the environment but are normally isolated within rock underground. The mining process brings them to the surface, exposing them to oxygen and water to create a chemical reaction. AMD is highly acidic and can contain high concentrations of heavy metals and other toxins. When waste rock and tailings aren’t properly remediated and stored, contaminants can leach into soil, surface water and groundwater.

On top of the health and environmental issues, there’s also the social and economic cost of legacy mines. Large tracts of land are left unusable – a blight on the landscape with no social or economic benefit for neighbouring communities. Many are located on or near Indigenous land and communities, impact on cultural traditions and practices.

And there’s also the opportunity cost of leaving these degraded sites, when they could be transformed into ecological and community assets. The book ‘102 things to do with a hole in the ground’ offers many examples of where restored mine sites have reestablished critical habitats and brought new life to communities.

How much will it cost to fix?

Globally, the costs of mine rehabilitation and closure liabilities run into billions of dollars⁴.  And, in the case of abandoned mines, the cost largely falls on governments and taxpayers.

Today, many mining companies undertake progressive rehabilitation – when areas are restored directly after mining has finished – rather than waiting until the mine is closed. And governments may require bonds or financial sureties.

However, legacy mines still represent a multi-billion-dollar global problem to be solved and funding to identify and restores these sites is inadequate.

How can reprocessing waste help?

One solution to reduce the impact of legacy mines is to remove and reprocess waste – which is often a source of pollution – to help fund restoration of the sites.

At legacy sites, past mining efforts often left behind valuable economic and critical minerals in waste rock, tailings and wastewater that could be reprocessed to extract useful minerals and metals. TheInternational Council on Mining and Metals (ICMM) estimates that more than 9 billion tonnes⁵ of tailings were produced worldwide in 2018 alone across the six traditional commodities of alumina, gold, coal, iron ore, nickel, and copper. While no data exists on the total amount of tailings and waste at abandoned mines, the ICMM figure shows the potential scale of mine waste currently sitting at old sites. In the US, it is estimated that almost all the critical mineral needs could be met from 90% recovery of by-products(waste) from existing metal mining operations⁶.

Regeneration’s model, which combines reprocessing with restoration, can transform legacy mines into assets. For example, a reprocessing project could be set up to extract platinum group metals from tailings in a historic mining district. Reprocessing the waste helps cleanup and the site and could supply critical minerals useful for catalysts, fuel cells, and green hydrogen production, and then earnings reinvested to restore habitat at the site. This is the model we’ve used successfully for the past 8 years at our Salmon Gold project and our recent site in Hedley, BC.

What do we need to tackle the problem?

One of the biggest challenges is the lack of readily accessible data about abandoned mines and their contents. So, we need to build a bank of information including:

·      Site inventories, as many abandoned mines are not recorded or mapped

·      Waste characteristics, including mineralogy and geochemistry

·      Environmental baseline data on water, habitat, and other conditions.

Even though these sites have already been mined, any previous development approvals and agreements no longer apply. We need to take time to talk with neighbouring and Indigenous communities to understand their vision for each site and then work together on land-use planning.

Technology will also play a critical role. Waste rock, tailings and wastewater typically hold lower-grade and smaller amounts of minerals and metals than the original orebody, so special technologies are needed to assess and then extract these materials in a cost-effective way. The good news is that there are many new and emerging technologies currently underdevelopment that will make reprocessing waste possible. These are all things we’re working on with our technology and site partners.

Progressing the remediation of abandoned mines may also require policy changes in some jurisdictions to reduce barriers to reprocess waste and clean-up sites. In the US, for example, liability rules have in the past left NGOs and volunteers seeking to clean up abandoned mines legally responsible for all the pre-existing pollution from a mine. To address this, new legislation, known as the Good Samaritan Remediation of Abandoned Hardrock Mines Act, will allow the US Environmental Protection Agency to issue permits to remediate abandoned hard rock mine sites without assuming liability underspecified environmental laws. In essence, these Good Samaritans, including Regeneration, are liable for their actions, rather than past actions.

What’s needed is a paradigm shift, like the industrial brown fields program in the US, that supported the economic revitalization and cleanup at old industrial sites by incentivizing new, responsible partnerships.

About Regeneration

Regeneration is an international, social enterprise that converts mine waste into responsible minerals and turns degraded lands into ecological and community assets. We work in partnership with local and Indigenous communities, governments, sustainable brands, and strategic business partners in the mining, technology, and remediation and restoration sectors.