THE IMPORTANCE OF MINE REHABILITATION

By Christopher Allan, Journalist, Mining Magazine

Mine rehabilitation is a restoration process ensuring that land used in mining is made available for economic activity, conservation, and diverse community uses. Rehabilitation projects can range from restoring forest ecosystems, native vegetation and agricultural land, through to the development of ecotourism experience centres. Here we consider why mine rehabilitation represents a critical obligation for the mining industry and an integral component of a mining company’s sustainable development strategies, before taking a look at some major rehabilitation projects from around Australia.

At its simplest, mine rehabilitation is about restoring landscapes for future use after mining activity.

This restoration can range from simply making a mine site safe and stable, through to a best-practice approach that works progressively towards the intended future use of the land.

The final land use of a rehabilitated mine site can vary greatly: from restoring major forest ecosystems to repopulating the land with native revegetation and fauna; from agricultural use in crops and grazing, to the development of major ecotourism centres.

At a practical level, the rehabilitation of a coal mine could involve flattening the steep sides of the mine, covering exposed coal with soil and clay, and revegetating the area with trees and grasses.

Although the rehabilitation of a mine site might be associated with its closure, best practice in industry has evolved to integrate rehabilitation during the planning and operational stages of a mining project – referred to as progressive mine rehabilitation.

Best practice rehabilitation also implicates community consultation; communities are often the future users of land rehabilitated from mining, and should be meaningfully engaged in any discussion regarding land restoration.

In a report considering industry mine rehabilitation responses, the Minerals Council of Australia (MCA), said, “The industry’s approach to land rehabilitation has improved significantly over past decades.

“This evolution has been driven by sustained investment in land rehabilitation techniques, evolving corporate values, community expectations and government regulation.

“While much progress has been made, the industry is continuing its efforts to improve rehabilitation methods to ensure mining’s compatibility with current and future land uses.”

Why is mine rehabilitation important?

Australia’s mining sector is evolving, and an emergent priority is making sure that capital investment is better aligned to environmental, social and governance considerations.

Indeed, industry leaders are now faced with an opportunity to demonstrate environmental stewardship across all mining activities, and responsible environmental practice is particularly significant given the finite nature of mining projects in a landscape.

Mine rehabilitation also reflects the important social obligations facing mining companies, who are socially licensed to operate on the condition that their actions support future land uses, community economic prospects, and public safety.

The 2014 Hazlewood mine fire in Victoria perhaps demonstrated a failure from part of the mining industry to adhere to its public safety obligations, with major repercussions.

Described by Environment Victoria as “one of the worst environmental and public health disasters in Victoria’s history”, the Hazlewood mine fire was estimated to have a total financial cost exceeding $100 million.

Importantly, the Hazlewood Mine Fire Inquiry found that the fire was entirely preventable, and even heard that mine rehabilitation can be an effective way of preventing coal mine fires.

The financial obligation for mine rehabilitation

Beyond social and environmental obligations, mining companies also possess a financial stake in mine rehabilitation – with closure planning and rehabilitation enshrined in statebased regulatory approvals.

According to the MCA, companies are required to progressively rehabilitate mined land “where practical” and report annually on their progress.

Furthermore, all jurisdictions require that previously mined land is made “safe, stable and non-polluting”.

To guarantee these outcomes, mining companies must deliver some financial surety – such as a rehabilitation bond – before any mine’s approval or lease.

These funds can be directed into mine rehabilitation, often through covering third party costs, should a mining company default on its approved obligations.

While financial obligations do incentivise mine rehabilitation, environmental groups such as Environment Victoria have also speculated that rehabilitation bonds can be “too low to provide sufficient incentive for mine operators to fulfill their obligations”.

The world of mine rehabilitation projects

Mine rehabilitation projects can vary greatly, from lengthy revegetation programs to the conception of new experience centres. The MCA has identified ten key stages of mine rehabilitation, spanning the full lifecycle of a mining project.

These stages are: ♦ Environmental investigation ♦ Post-mining land use planning ♦ Rehabilitation security bonds ♦ Species and habitat protection ♦ Site preparation ♦ Progressive rehabilitation ♦ Mining and landform design ♦ Topsoil and revegetation ♦ Monitoring ♦ Sign-off and relinquishment

Here we explore three different mine rehabilitation projects that reveal both the potential for success and the depth of effort involved when restoring landscapes used in mining.

Native vegetation: Ginkgo Mineral Sands Mine

Situated on semi-arid land in the Murray-Darling Basin, western New South Wales, the Ginkgo Mineral Sands Mine stands as a testament to the benefits of progressive rehabilitation when re-establishing native vegetation and fauna.

Owned and operated by Cristal Mining, the Ginkgo mine faces highly challenging environmental conditions for restoration – the MCA reports that the site receives around 270mm of annual rainfall, with summer temperatures exceeding 40 degrees.

The value of a proactive rehabilitation strategy for Ginkgo mine has been evident throughout the project’s operation, given the high levels of diligence and monitoring required to restore native vegetation in such a challenging environment.

For example, an extensive seed collection campaign put rehabilitation efforts on the right track, with seeds collected from areas up to 500km away from the site at Ginkgo to ensure progressive rehabilitation of native vegetation.

Rehabilitation at the Ginkgo site also implicates the value of community land users, with community members from the Dareton Men’s Shed contributing to the building of bat and bird boxes to provide habitat for returning animals, and local landholders also helping Cristal Mining manage incoming populations of feral goats, which can destroy native vegetation.

To gauge ecosystem development and monitor success of the project, Cristal Mining also adopted an innovative program of counting ants; abundances of ants can represent both a stable food source in the food chain as well as support the germination of plants.

The progressive rehabilitation and monitoring of native vegetation and fauna at Ginkgo, alongside ongoing operations, speaks to both a depth of commitment from the operator as well as the sensitivity required to restore a semi-arid ecosystem.

Water management: Renison Bell tin mine

The rehabilitation of Renison Bell tin mine in western Tasmania is a success story for responding to the impact of mining operations on water quality.

Re-opened in 2008, the Renison Bell tin mine is one of the world’s largest and highest-grade tin mines. The mine is currently owned by Bluestone Mines in a 50/50 joint venture between Metals X and Yunnan Tin Group.

Major rehabilitation efforts at Rension have centred around two tailing storage facilities (TSF), which were identified to have a history of discharging elevated levels of dissolved metals, sulphate and acidity into the nearby Lake Pieman.

Lake Pieman represents a highly valued trout fishing and ecotourism destination for western Tasmania.

Following innovative geochemical studies carried out in collaboration with the CSIRO, the Renison mine operator embarked on a rehabilitation strategy to cap these storage facilities, excluding oxygen and neutralising the water within.

By adopting this cap procedure and working to rehabilitate the land into a wetland ecosystem, the operator has ensured that surface water quality has rapidly improved since 2003, with acceptable discharge standards achieved – by 2014, waterbirds had inhabited the wetland ecosystem.

By partnering with the CSIRO to understand and solve water quality issues, the Renison Bell tin mine operator has ensured its legacy is a testament to both the application of good science and a commitment to solve environmental challenges.

Ecotourism: The Eden Project at Anglesea coal mine

The proposed rehabilitation of Anglesea coal mine into a world-class cultural attraction highlights how ecotourism restoration projects can offer economic prosperity, while also reinforcing the importance for the mining industry to hold true to sustainable practices.

With the Anglesea coal mine having retired operations in August 2015, the proposed Eden Project Anglesea is an ambitious plan to transform the site of Anglesea’s retired coal mine into a major environmental tourism attraction.

In a project vision statement, the Eden Project Anglesea projected that the world-class centre could create more than 1,300 new jobs, generate $350 million for the regional economy in its first ten years of operation, and deliver 750,000 projected visitors per annum.

The vision statement for Eden Project Anglesea reads, “Set within the landscape of the Anglesea Heath, it showcases a vision to transform an area within the former coal mine into a destination for immersive education and experiences which celebrate the local ecology and tells a story of sustainability.”

A large part of the $150 million ecotourism concept would see the mine void transformed into a massive water body.

Delivery of the Eden Project Anglesea is contingent on whether Alcoa, the mining company overseeing the rehabilitation plan, can fill the mine void with water to at least half of its total capacity by 2024.

Alcoa has already made existing progress in its Anglesea Mine Rehabilitation and Closure Plan, with the demolition of

the power station in October 2018, and subsequent clearing of the site.

However, the scale of the Eden Project Anglesea’s ambitious revitalisation of the mine site has been matched by environmental concerns about how the mine void is being filled with water.

For example, recent concerns reported by the ABC in March 2022 centre on Alcoa’s preference to source water from an aquifer beneath Anglesea.

The ABC reported that community and environmental groups, such as Friends of Anglesea River, believe that Alcoa’s current methodology for filling the mine void could lead to long-term harm to local ecosystems, accelerating acidification of Anglesea River and damaging fish ecosystems.

Group member of Friends of Anglesea River, Janine Strachan, said, “What we're really wanting to see is an Anglesea River rehabilitation plan that all of the regulators come together and identify and offer their expertise, and bring together a plan that we can see the life of the river brought back into its former glory.”

With Alcoa set to hand over the delivery of its mine rehabilitation strategy to the Eden Project by 2024, a full response to local environmental concerns would ensure that the Eden Project’s environmental message rings true from its inception.

Meeting rehabilitation obligations

In summary, the mining sector is environmentally, socially and financially obligated to engage with mine rehabilitation – starting from any project’s initial planning stage.

The breadth of rehabilitation projects undertaken around Australia in recent history – from semi-arid vegetation restoration in the Murray-Darling Basin to wetland introduction in western Tasmania – speaks to the values of adaptability and willingness to collaborate for operators in the minerals industry.

While there is always room to improve industry towards best-practice, the overall success of mine rehabilitation projects in Australia reflects the depth of effort taken towards returning mined land for fair use in the community.

Heritage walking track at Blue Gum Hills Regional Park. The walking track winds through a rehabilitated coal mine site, with replanted eucalyptus trees forming part of the rehabilitation plans.