The demand for sustainable mining practices has intensified the focus on mine remediation in recent years. This shift is not merely a trend; it is becoming a fundamental aspect of the industry.
According to world market research, the environmental remediation sector is projected to grow at a compound annual growth rate of 7.5 percent, with an estimated value of $152 billion by 2025.
In Australia, where mining plays a crucial role in the economy, significant changes are underway.Western Australia, the country’s largest mineral producing state, is set to update its mine closure procedures to emphasise effective project rehabilitation and remediation.
Late last year, the Department of Energy, MinesIndustry Regulation and Safety (DEMIRS) released a framework outlining the procedures for the forth coming mining development and closure proposals (MDCP)alongside existing mine closure plans (MCP).
The updated Mining Amendment Act 2022 will mandate that a compulsory MDCP includes explicit environmental outcomes throughout and following a project’s life.
This legislation is expected to take effect in August, further aligning the state’s environmental policies with those of the Environmental Protection Authority.The MDCP will encompass closure designs for key mining activities, identify knowledge gaps, and establish schedules for addressing them.
It will also outline opportunities for progressive rehabilitation, ensuring that environmental outcomes are integrated into a robust monitoring framework.
Importantly, while a standalone MCP will no longer be required at the approval stage, it will still serve as a vital planning tool throughout the mine’s operationa life.
This document will demonstrate that projects remain on track for successful closure.DEMIRS said: “As a condition of approval, tenement holders will need to provide an environmental report to DEMIRS demonstrating compliance with environmental and closure outcomes.”
Such reports will include standard conditions related to environmental monitoring and reporting, ensuring progress towards closure outcomes are transparent and accountable.
The rehabilitation and remediation of abandoned mines are pivotal elements of the revised regulation, addressing a wide array of environmental and safety considerations.
A process that includes the design and construction of landforms and the establishment of sustainable ecosystems, rehabilitation is a core component of sustainable development strategies in mining.
It is a regulatory requirement and a key performance indicator to evaluate a mining company’s environmental performance.
Failure to adequately rehabilitate mines can result insignificant legacy issues for governments, communities, and the corporate sector.
Early planning and initiation of rehabilitation efforts are crucial; without these, mining operations risk hindering the development of the necessary knowledge and capacity for sustainable outcomes.
As highlighted in a 2016 federal government report: “Following mining, there is typically a regression in structural and functional complexity.”
Thus, rehabilitation aims to restore ecosystem functionality and land productivity, albeit often with different land uses and species compositions compared to the original ecosystem.
Contrastingly, restoration seeks to re-establish the original ecosystem’s structure and function, aiming for a landscape that mirrors its pre-disturbance state.
Over time, as ecosystems develop, their definitions may also evolve. A rehabilitated ecosystem might transition towards a near-natural restored ecosystem, while those labelled as restored may fall short due to inadequate management, resembling mere rehabilitation instead.
Several factors define the business case for effective mine site rehabilitation. Gaining access to land increasingly necessitates a demonstrated commitment to land stewardship. In this context, rehabilitation becomes a crucial performance indicator.
DEMIRS said: “Regulatory trends are such that achieving leading rehabilitation practice will, in the short to medium term, be a competitive advantage.“Failure to demonstrate a strong commitment to land use stewardship, particularly successful rehabilitation, can lead to approval delays and, in the worst case, total loss of development opportunities.”
Therefore, over the longer term, it may well become the minimum requirement for acquiring land access. The implications of poorly planned rehabilitation efforts are significant.
Initiating closure operations without the necessary skills, equipment, and technical knowledge can lead tos ubpar outcomes, resulting in costly remediation and an increased likelihood of unfavourable closure.
“Successful rehabilitation requires a continuous improvement focus, based on site-specific knowledge, research, and monitoring,” DEMIRS said.
“Opportunities and threats should be identified early so operations do not reduce rehabilitation options.”
“Thus, delayed investment leads to delayed relinquishment beyond the operational life of a mine,a dding to cost and, in some cases, the retention of liability for years longer than necessary.”
Rehabilitation, inherently a costly endeavour, must be meticulously planned and executed.
Successful rehabilitation practices should involve stakeholders, including community members and government representatives, to ensure transparency and shared objectives.
Meanwhile, mine remediation addresses the need to make abandoned mines safe for human habitation or use.
This process may involve treating or removing contaminated soil, sediments, and water. It can also encompass removing tailings dams and rectifying damages caused by mining activities.
Additional remediation efforts might include removing hazardous materials, stabilising structures, demolishing unused infrastructure, capping mine shafts, and implementing soil stabilisation measures to prevent erosion.
Moreover, remediation could entail upgrading dams to mitigate the risk of tailings spills, managing acid drainage, and enhancing biodiversity through engineering upgrades to water systems associated with tailings ponds and waste rock piles.
Each of these efforts contributes to a broader commitment to environmental stewardship and responsible mining practices.
As the mining industry continues to evolve, robust rehabilitation and remediation strategies will be essential for maintaining a social licence to operate, securing regulatory approvals, and ultimately ensuring the sustainability of mining operations.
