Defining post-mining land uses is an essential part of mine closure. Properly selected, the post-mining land use will guide the operator’s closure vision and objectives, and inform the selection of closure methods and technologies.
The 2019 International Council on Mining and Metals guidelines tell us that the closure vision should be aspirational. But when selecting a post-mining land use, we should also ensure that it is both productive and sustainable.
Sustainable post-mining land use must also be practical and – if possible – bolster socioeconomic transition and create opportunities for current and future stakeholders. However, a productive post-mining land use does not necessarily mean that the site will return direct economic benefit – not every closed mine site can be a recreational resort, an alternative energy facility, a research center, or prime agricultural land. Sometimes, the best solution is to stabilise a site physically and chemically, and restore it to a sustainable environment capable of supporting local biota and restoring, enhancing, or creating wildlife habitat.
A preliminary selection should occur early in the mine life cycle. It should be reviewed periodically to consider what is feasible, and incorporate a number of factors including location, pre-mining and surrounding land uses, local environment, proximity to population, land tenure, regulatory requirements and corporate requirements, and, most importantly, stakeholder input because some of these factors may change during the mine life.
The site environmental, social and legal context will ultimately determine feasible post-mining land uses, and a number of questions should be addressed during the closure planning. What site infrastructure could contribute to socioeconomic transition? What site conditions could limit potential land uses for some areas of the site? What technical and economic constraints could affect land use? What are the perceived and real long-term risks to the environment and public health and safety? What would local stakeholders like to see?
Although critical to the process, stakeholder engagement has its limitations when it comes to mine closure. The first challenge is that, early in the mine life cycle, it is difficult to get many stakeholders, especially local communities, to envision future land uses that may not be realised for years if not decades. Second, even when the engagement process does identify selections that reflect the aspirations and expectations of local communities, some may not be practical, economically viable, or sustainable. For example, a large, flat area like the top of a tailings impoundment might seem like an ideal place for agricultural use, but the chemistry of the tailings could risk livestock and human health. And, the permanence of closure means that the needs of future stakeholders should also be represented in selecting the post-mining land use. Therefore, assessing post-closure land use risks should consider the types of unplanned land uses that could occur because some potential future uses may not be compatible with the closure actions taken and could place the environment at risk. For example, if artisanal miners migrate to the area, the performance of engineered closure measures, such as mine waste covers, could be compromised.
In conclusion, it is imperative to begin an early discussion with local and regional stakeholders including the government and communities, regarding closure and post-closure land uses, maintaining these discussions throughout the lifecycle of the mine, adapting closure plans as needs of the local and regional stakeholders change while identifying changing post-closure land use risks.
Jeff Parshley: jparshley@srk.com
