In this article:
- Recent legislation in Australia has focused on the issue of progressive rehabilitation during an existing mine’s life cycle. However, it remains unclear what purpose these mines should serve at the end of their lives. More specifically, what can we do with the thousands of abandoned mines and quarries littered across the country?
- Victoria is in prime position to lead the rest of Australia in mines rehabilitation that can serve communities well into the future
- See what score you get for your Rehabilitation and Closure program
- Find out about Decipher’s Rehabilitation and Closure solution
Opportunities for value after closureAustralia’s abandoned mines don’t have to be a liability; instead, they can become an asset if properly managed. In fact, our national policy for old mines recommends “valuing abandoned mines”. This could include further mineral extraction via secondary mining such as reprocessing tailings; industrial archaeological heritage conservation and tourism; unique habitats for biodiversity enhancement; collaborative research into innovative solutions to contamination problems, which could guide the broader industry; and Indigenous and other employment and training opportunities for regional Australia.
Rehabilitation for flood retentionAs populations continue to rise, increasing urbanisation alters the natural hydrologic cycle, and we face more extreme and heavy rainfall events. Many communities in rural areas and along the urban fringes will face increasing flood risk. If an abandoned mine is nearby, water can potentially be redirected to it, thereby providing storage and attenuation of flood waters, reducing the vulnerability of the catchment and affected regions downstream. Retention basins provide additional benefits, such as increasing biodiversity conservation through the restoration and provision of natural areas. Our analysis highlighted two clusters of abandoned mines most suitable for rehabilitation. One is north of Melbourne’s urban fringe in Kilmore, and another is in northwestern Victoria. This is largely due to higher levels of population growth expected in Kilmore, and greater soil suitability in northwestern Victoria. (Our analysis defines greater soil suitability as areas with sandy soils that are able to more swiftly absorb water.)
Rehabilitation for water supply storageAnother use for abandoned mines is water supply storage. Such an initiative is underway in Atlanta, in the US, where an abandoned granite quarry is being rehabilitated for water storage. The quarry receives water from a nearby water treatment plant about 8km away, and will extend Atlanta’s water supply from five days to 30 days. Additionally, the project creates significant recreational space for the surrounding area, with the quarry at the centre. Closer to home, even though the most desirable mine for water supply storage is located south west of Kilmore, further investigation showed that it was too small to deliver any significant benefit to the water supply, highlighting the importance of also considering site characteristics. The second-most desirable mine is southeast of Mount Eliza, in the Moorooduc nature conservation reserve, and has a potential maximum capacity of 665 megalitres. The quarry is 9.7km away from the Mount Martha Water Recycling Plant. This plant produces Class A recycled water, and could potentially provide a stable supply to the proposed water supply storage. The rehabilitation of this quarry would also improve the damaged landform.
Rehabilitation into waste managementVictoria’s growing population also increases demand for waste management facilities. Urban sprawl places challenging restrictions on the placement of municipal landfills. Some abandoned quarries and mines could present viable opportunities for additional waste disposal sites. The Environment Protection Authority of Victoria’s publication of the “Siting, design, operation and rehabilitation of landfills” sets out a best-practice plan for the entire landfill life cycle. We examined Victoria’s abandoned mines and quarries using this framework to find suitable sites that meet the guidelines’ minimum safety requirements. Some of these included a minimum of 100 metres from all surface water, 500 metres from any building or structure, and two metres’ separation from the groundwater table. Our analysis showed a particularly high-ranking set of sites in the Kilmore region. These could be strong candidates for future landfill sites to service Greater Melbourne. As shown in the water supply storage case, additional site-specific analysis would be required to ensure the long-term suitability and safety for landfill facilities. Mine-site rehabilitation is a growing challenge that all states and territories will need to face. Our work has demonstrated how opportunities can be ranked and compared in order for better decisions to be made. However, more research is needed to better understand how we can transform these sites into multi-functional spaces that can deliver a greater suite of ecosystem services for the benefit of local communities and the environment. Suitable approaches would also lead to improvements in the current rehabilitation regulatory framework, greatly reduce the impacts of mining operations, and provide further clarity for future rehabilitation requirements and end-use planning.
How to drive progressive rehabilitation and closure
[embedyt] https://www.youtube.com/watch?v=340Weed-sww[/embedyt] Dr Yellishetty’s research team on the project includes Melissa Truong, Han Chung Chia, Thomas Richards, Dr Stuart Walsh of Department of Civil Engineering, Monash University, and Dr Peter Bach, Research Scientist, Swiss Federal Institute of Aquatic Science & Technology (Eawag / ETH). Originally published by Monash University.
Decipher’s Rehabilitation & Closure SolutionArmed with Decipher’s Rehabilitation & Closure solution, including GIS, remote sensing, monitoring and management tools means you can easily capture and analyse a wide range of environmental monitoring data, manage risks and issues around put backfilling, rapid flooding, slope instability and acid generation, and ensure you’re meeting your environmental obligations and compliance with alerts and notifications of exceedances.
Want to find out more about mine rehabilitation?
- What is mine rehabilitation and closure?
- What are some key challenges facing mine rehabilitation and closure?
- How much does mine rehabilitation cost?
- What are the advancements in mine rehabilitation technology?
- What are some best practice mine rehabilitation methods?
- How to take a macro and micro approach to mine rehabilitation
- What is CRC-TiME?
- How to become an industry leader in mine rehabilitation
- Download this free Guide to Mine Rehabilitation in Australia