By Kim Morrison, Chief Technical Officer, ATC Williams
One of the most significant shifts I have witnessed during my career is the evolution of how the mining industry thinks about closure and long-term stewardship. Early in my career, closure was viewed as something to be addressed later in a project’s life. Today, we increasingly recognise that many of the most important closure outcomes are determined by decisions made decades earlier.
Historically, considerable effort was rightly devoted to designing, constructing, and operating mining and tailings facilities safely and efficiently. These priorities remain fundamental. However, there is now growing recognition that success is not defined solely by performance during operations. Rather, it is increasingly measured by how facilities perform across their entire lifecycle, including the decades that follow mine closure.
In many respects, the industry is transitioning from designing for operations to designing for long-term outcomes. Tailings facilities are no longer viewed simply as structures that support mining activities; they are increasingly recognised as long-term landforms and infrastructure systems that must remain safe, stable, and responsibly managed long after production has ceased. This shift challenges us to think beyond the next operational phase, the next year, or even the life of the mine. It requires us to adopt a mindset that begins with the end in mind.
Closure is a Process, not an Event
Closure is often discussed as though it is a discrete phase that occurs at the end of mining. In reality, closure begins long before the final tonne of ore is processed and continues long after operations cease. The decisions made during site selection, facility layout, water management, materials management, deposition strategy, and progressive rehabilitation all influence the eventual closure outcome.
Importantly, closure outcomes are seldom determined by a single decision or activity. They are the cumulative result of decisions made throughout the lifecycle of a mine and its associated infrastructure. When closure considerations are deferred until the later years of operation, opportunities may already have been lost. When closure objectives are embedded from the outset, however, operators can often reduce long-term risk, minimise liabilities, improve environmental performance, and create more sustainable and resilient outcomes.
Responsible Closure and Long-term Stewardship
For many years, closure was viewed primarily as a technical or regulatory challenge. Today, it is increasingly understood as a stewardship challenge.
Responsible closure extends beyond physical stability and environmental compliance. It requires alignment between engineering, environmental science, governance, economics, social performance, and stakeholder expectations over timeframes that may span generations.
This evolution in thinking is reflected in the growing attention being given to closure across industry, academia, regulators, and investors. What was once often treated as a specialist discipline addressed near the end of mine life is increasingly becoming a core element of project planning, risk management, and governance.
Sharing What We've Learned
I have had the privilege of co-editing the forthcoming Society for Mining, Metallurgy & Exploration (SME) Tailings Closure Handbook: Beginning with the End in Mind, a collaborative effort bringing together practitioners from around the world to share lessons learned, leading practices, and emerging approaches to tailings facility closure. ATC Williams is proud to sponsor the Handbook, which is progressing towards publication. Drawing upon contributions from leading practitioners, the Handbook reflects the industry’s continuing evolution toward more integrated, lifecycle-based approaches to closure.
In September, ATC Williams participated in the Australian Centre for Geomechanics (ACG) Mine Closure 2026 Conference in Melbourne, where five of our practitioners presented papers addressing a range of mine and tailings closure challenges. Their contributions reflect both the breadth of expertise across our team and the importance we place on sharing practical experience and advancing industry knowledge.
The papers are now freely available through the ACG Online Repository of Conference Proceedings (Australian Centre for Geomechanics | Mine Closure 2026 – Conference Papers), providing an opportunity for clients, colleagues, and industry peers to explore the work in greater detail.
Read the papers below:
Sustainability Across the Entire Lifecycle
Sustainability is often associated with environmental performance, but successful closure requires balancing a much broader set of objectives.
A sustainable closure outcome must be technically sound, environmentally responsible, socially acceptable, and economically realistic. Achieving this requires meaningful integration between disciplines that have historically operated somewhat independently. Geotechnical engineers, hydrologists, hydrogeologists, environmental scientists, closure specialists, mine planners, and social performance professionals all have essential roles to play.
Lifecycle thinking encourages these conversations to occur earlier and more frequently. It allows decisions to be assessed not only against immediate operational objectives, but also against their implications for closure performance, residual risk, and long-term stewardship.
Preserving Value Beyond Mining
Closure has often been viewed primarily through the lens of cost and liability. I believe this perspective is increasingly outdated.
Well-planned closure preserves and, in some cases, creates value. That value may be reflected through improved environmental outcomes, reduced long-term liabilities, stronger stakeholder relationships, enhanced social licence, improved land-use opportunities, or greater confidence from investors and regulators. Increasingly, closure performance is recognised as a visible component of responsible resource development.
Put simply, closure is no longer merely a compliance exercise. It is an essential component of value preservation and long-term project success.
The Legacy We Leave Behind
Technical professionals naturally focus on solving today’s problems. Yet one of the defining characteristics of closure planning is that many of the most important outcomes will be experienced by future generations.
Mining provides the materials that society depends upon. However, from the perspective of those who inherit closed sites, closure outcomes may ultimately become one of the primary measures by which a mining operation is judged. The quality of the closure strategy, the resilience of the final landform, the effectiveness of stewardship arrangements, and the long-term protection of people and the environment all contribute to the legacy left behind.
This is why beginning with the end in mind is so important.
The decisions we make today shape the outcomes that others will inherit tomorrow. By embedding closure thinking throughout the lifecycle of a facility, we can reduce risk, support sustainability, preserve value, strengthen stakeholder confidence, and contribute to more responsible and enduring outcomes.
As our industry continues to evolve, I believe the future of mining and tailings management will not be defined solely by how effectively we build and operate facilities. It will increasingly be defined by how successfully we envision, plan for, and achieve responsible closure.
Final Thoughts
As our industry continues to evolve, initiatives such as the forthcoming Tailings Closure Handbook, the discussions and technical contributions shared at the recent ACG Mine Closure Conference, and the broader body of emerging guidance reflect a growing recognition that closure is no longer a specialist topic addressed at the end of mine life. It is becoming a central consideration in how we design, manage, and govern mining projects from the outset.
Ultimately, while mining creates value through the commodities it produces, communities and future generations are more likely to judge an operation by the legacy it leaves behind. The condition of the land, the quality of the water, the resilience of ecosystems, and the stewardship demonstrated after mining ceases often become the most enduring measures of success.
Closure, therefore, is not the final chapter of mining. In many respects, it is the chapter by which the entire story is judged.