As mine closure evolves into a more structured and regulated phase of the mining lifecycle, independent peer reviews have emerged as an essential tool for stress-testing closure plans. Done well, they can identify significant risks, uncover strategic opportunities, and ultimately lead to better environmental, financial, and social outcomes.
Drawing on IEMA – Integrating Sustainability, Business & Community experience developing and reviewing closure plans across coal, hard rock, and industrial mineral sites, this article explores key technical areas where peer reviews can add tangible value.
Peer Review: Beyond Compliance
Peer reviews are sometimes perceived as a final gate in the regulatory process — a checkbox before submission. But at their best, they are a collaborative interrogation of closure logic, aimed at strengthening assumptions, validating risk treatments, and unlocking better outcomes.
Common peer review triggers include:
- Independent assurance for regulators or boards
- Pre-submission review of closure plans or cost models
- Change in closure scope or post-mining land use vision
- Periodic review under internal assurance frameworks
The following technical insights highlight where reviews often yield the greatest benefits.
Cost Models: Where Strategic Value Can Be Found
Closure cost estimates are a central component of a mine’s liability profile, yet they are often based on layered conservatism, outdated assumptions, or generic rates. Through independent review, we routinely uncover opportunities to refine these models.
Common Costing Pitfalls Identified in Technical Review
- Underestimated Monitoring Durations
- Redundant or Duplicated Rehabilitation Phases
- Missed Opportunities for Early Works
- Inaccurate Earthworks and Haulage Assumptions
- Oversimplified Revegetation Models
- Incomplete Demolition and Decommissioning Scope
- Regulatory Delay Risk Underestimated
- Holding Costs Post-Closure
- Tailings and Water Management Facilities
- Contractor Management and Mobilisation
By reviewing these assumptions in detail, we help clients not only meet regulatory expectations but improve internal decision-making and funding efficiency.
Hydrology, Voids, and Uncertainty
Final voids and water infrastructure often carry the greatest long-term environmental risk. Reviews frequently challenge:
- The robustness of water balance models
- Final void fill timelines and geochemical behavior
- Surface infrastructure integration with rehabilitated catchments
These issues often benefit from multidisciplinary scrutiny by hydrologists, hydro geochemists, and geotechnical engineers to ensure performance-based closure.
Tailings, Waste, and Landform Transitions
Tailings dams and waste rock facilities require significant scrutiny. We often find:
- Closure timeframes that underestimate tailings drying or cover material placement
- Incomplete costing of seepage barriers or revegetation performance
- Untapped opportunities to remove or rehandling waste early in the closure cycle (or better during operations)
Technical reviews in this space can drastically change the long-term liability trajectory and improve the safety profile of the final landform.
Post-Mining Land Use and Stakeholder Alignment
Closure success is increasingly judged by its social and legacy outcomes. Independent reviews often identify:
- Failure to assess high value beneficial landuse options
- Weak connections between closure objectives and stakeholder aspirations
- Underdeveloped integration of community land use preferences or cultural values
- Gaps in documentation to support future access, signage, or co-use arrangements
Reviews supported by social performance and cultural heritage experts can transform these elements from afterthoughts into drivers of closure success.
Delayed Relinquishment and Residual Liability
Even technically successful sites can face years of residual holding costs due to incomplete regulatory closure. Peer reviews help:
- Misalignment between approved completion criteria and the monitoring that delays the sites ability to demonstrate that the rehabilitation is on the trajectory for success.
- Failing to capture and record evidence that demonstrates effective processes in all phases (ITPs)
- Identify missing documentation or evidence for sign-off
- Recommend early actions that target lingering uncertainty and potential residual risk aspects
- Cost the full spectrum of post-closure obligations — not just physical works, but legal, social, and governance processes
Why IEMA’s Peer Reviews Add Value
At IEMA – Integrating Sustainability, Business & Community we approach peer reviews with the same depth of care we apply to closure planning itself. What makes our approach unique is our ability to bring together diverse technical specialists — from hydrologists and geochemists to social scientists and cultural heritage professionals — into a coherent, structured review process.
Because we’ve developed closure plans ourselves, we know where things often get overlooked — and how to build defensible, cost-efficient strategies that regulators, communities, and boards can trust.
Final Thought
Independent Peer Review is more than due diligence — it’s an opportunity to elevate closure planning, challenge embedded assumptions, and ensure mine closure delivers value well beyond compliance. As expectations grow for transparency, ESG outcomes, and relinquishment readiness, technically robust reviews will play a critical role in delivering success.
If you’re in the middle of a closure review, preparing a cost model, or developing a relinquishment roadmap — we welcome the chance to connect and contribute to better closure outcomes across the sector.