In the boom and bust industry which is mining, financially preparing for and addressing mine rehabilitation has historically been neglected.
New mine rehabilitation reforms seek to remedy this, thereby improving the public image of the industry. In Queensland, mining reform with new legislation has been implemented to ensure mine rehabilitation is financially accounted for in future mine closures and to assess the risk and future of abandoned mines.
Andrew Grabski (DNRME) discussed the new mining reforms addressing changes to the Mined Land Rehabilitation Policy and the Mineral and Energy Resources (Financial Provisioning) Act 2018 with regard to mine closure provisioning. A financial assurance framework has been developed based on 7 discussion papers to manage the financial risk to State and to the holders of environmental authorities. The reforms incorporate a payment requirement to an accumulative fund to be attributed to abandoned mine clean-up. However, if the mine’s corporate risk is too high (e.g. $100, 000 < estimated rehabilitation cost (ERC)) then the mine will be unable to participate in the scheme. Rehabilitation of abandoned mines is currently government funded but through the new financial assurance scheme provisioning will be made for their clean-up. The attitude towards mine rehabilitation has been undergoing reform through the incentivising of mine rehabilitation for commercialisation such as mine repurposing for future uses. For example, the mining of potential metals from abandoned mines.
Only approximately 100-120 mines of the estimated 15,000 abandoned mines in Queensland are considered to require maintenance and rehabilitation. This is because the 15,000 abandoned mine figure is derived including small historic mineral occurrences that are not considered to be a risk to society or the environment. There is an aim to understand, quantify and prioritise which of the mines are high risk and require the most immediate attention. The risk and prioritisation framework is set to be released for public consultation in February of 2020 and published on the abandoned mines environmental management website in July of 2020.
In recent years, there has been a shift of global opinion towards an ‘anti-mining’ view, due to its significant environmental impact. Changing these views has driven the developments in the mine rehabilitation industry. Stuart Richie (AARC) discussed how regulators require a transparent whole-life mine plan with annual updates and notice of all changes to the mine plan. In response to the poor mine rehabilitation performance of the past, new regulations and regulatory changes have been introduced. For example, the ERC policed by the Department of Environment and Science (DES) and the introduction of the progressive rehabilitation and closure plan (PRCP) regulations, which requires a plan describing and pre-empting continual rehabilitation after five years or less of operation. A transitional authorisation period may be permitted for final voids when appropriate land outcome documentation and notices of insufficiency are present.
There is a drive towards rehabilitation for alternative land-use futures for mine sites and under the PRCP there is an obligation to show evidence of meeting milestones for such rehabilitation with penalties for non-compliance. Julian Power (Golder Associates) recognised the challenges of rehabilitation in Queensland such as climate, soil quality, legacy sites (erosion and ponding), acid mine drainage, access to appropriate supplies of rock and capping material. He identified how rehabilitation is moving towards geomorphic covers which replicate natural slopes through the utilisation of rip-line technology evolved for soil type variability. PRCPs require the submission of a final landform design utilising such technologies and demonstrating quality control. Such plans also require fate of contaminants and residual contaminant damage plans to prove that the future land use for the site is suitable, safe, stable and does not cause environmental harm. But with adaptations for changing future land uses and climate change it may be challenging to provide long-term designs. Overall, the reforms to mine rehabilitation have been a collaborative effort across departments and their application will be highly advantageous to promote a more balanced perspective of the mining industry.
21 November 2019 report by Lauren Reynolds, WSP
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