Paul Stewart Member Name
Principal Geotechnical Engineer
Garrett Hall Member Name
Principal Environmental Scientist
Increasing population growth and urbanisation around the world are creating enormous and ever-growing demand for the building materials we rely on to construct our homes, cities, roads and other infrastructure. For much of the community, it’s easy to ignore the issue of where these materials come from. The extraction industry, though very valuable, is often out of sight, out of mind. But that’s going to have to change.
Many more quarries, or extensions to existing quarries, will be needed to supply the sand, stone and gravel our growing cities and towns will require. The high cost of transporting materials is a good reason for these quarries to exist near where the material will be used, which means being sited close to population centres.
A case in point is the state of Victoria, Australia, which has a capital city of nearly five million people. The population is currently growing at about 2.3% per year and is forecast to double by 2050. Over the same period, demand for materials is expected to double from 50 million tonnes to 100 million tonnes per year. However, it is expected that by 2050 supply will come from only 44% of Victoria’s existing 535 quarries.
This presents a challenge: just like in Victoria, growing population centres will need many new quarries to service increasing demand for materials – but where will we put these holes in the ground? Ideally, quarries need to be as close as possible to the centre of demand. Transport costs can comprise up to 40% of the cost of materials, so proximity is a critical factor in keeping construction costs under control (and minimising carbon emissions too!). However, vacant land close to population centres is valuable, its uses are highly contested, and a range of concerns may make it challenging to gain community acceptance.
For proponents of new quarries, success will depend on identifying an optimum site, building trust and acceptance with the local community, negotiating a successful regulatory outcome, and planning beneficial uses for the site beyond its active life.
Identifying an optimum site
Finding the best location for a new quarry is a complex process. The first prerequisite is the necessary geology of sufficient volume to provide the desired materials. On top of that comes a range of other considerations: the location of current quarries and resource volumes, projected urban expansion areas, adequacy of separation distances to potentially sensitive receptors, statutory planning constraints, existing local and arterial road or rail supply networks, and the location of future resource demand, including resource-intensive infrastructure such as future roads and railway networks, and so on.
With such a range of factors in play, it will be helpful to take advantage of digital engineering capabilities such as geographic information systems (GIS) and other tools to overlay these considerations, identify preferred resources and supply areas to meet projected demand, and then pinpoint potential quarry sites that satisfy the myriad of possible siting criteria.
Negotiating a successful regulatory outcome
Once a potential site has been identified, the process begins of negotiating (or getting the best support to negotiate) all the required statutory processes for bringing the quarry to life in a challenging environment. This usually involves several approval processes, such as obtaining planning permission from local councils and work authorities, or extractive licences from state government regulators under appropriate mineral extraction legislation.
These processes may lead to ongoing licence conditions such as requirements for monitoring air quality and water discharges. In some circumstances, quarry sites may host rare or endangered species, which will require referral under the appropriate biodiversity legislation. Approval may also be required for the extraction of groundwater. If environmentally sensitive, large greenfield sites will require a full impact assessment.
Early and proactive engagement with decision-makers, regulators and the various statutory referral agencies is essential to identify, and then assess and manage potential project risks, which can otherwise present significant delays to approval processes. Being clear on the information expectations of these stakeholders at the outset will substantially expedite the approval process and reduce the risk of refusal.
Nonetheless, however thorough and appropriate the project assessment and approval process, objections may still arise and could derail planning and statutory permissions. In these cases, quarry proponents may need to defend their interests in court or a tribunal. This highlights the need to build trust and acceptance with local community stakeholders. In most instances, the risk of objections and appeals can be reduced through early and proactive engagement with community stakeholders that seeks to understand and address their potential concerns.
Building community trust and acceptance
Communities want good roads and solid infrastructure, and most people would love to get their stone kitchen benchtop or polished concrete floor at a good price. But do they want to live or work near a quarry? Community trust and acceptance can make or break a project, and it is essential to a proponent’s reputation and to paving the way towards further successful projects.
Communities may be concerned about heavy vehicle movements and truck speeds, noise and vibration from blasting and operations, dust, overall visual amenity and environmental impacts such as adverse consequences for fauna, flora and water.
The earlier engagement begins with affected community stakeholders, the better. Identifying their concerns and communicating how those concerns will be addressed is a vital part of the planning process. There are many different ways to work with communities, and the choice of methods will depend on a range of factors, but ultimately the best chance of building a positive relationship will come through honesty, transparency, being proactive, listening actively to the community’s concerns, and responding quickly and respectfully to worries or complaints.
Designing for safe and efficient operations
Gone are the days of a quarry plan being simply a two-dimensional line on a map. Modern extractive industry and mining regulators expect detailed assessment and management of geotechnical risks in the quarry plan and for these understandings to be applied and advanced through the life of the operation.
Regulators are rightly focused on safety, both of site workers and neighbouring communities, and this assessment and management of geotechnical risk is justifiably important. But the geotechnical assessment can also drive efficiency in site operations. It can inform the quarry design and resource extraction plan, minimising potential safety risks, but also improving the efficiency of the operation through detailed staging plans, minimising double-handling of materials, and enabling progressive rehabilitation in parallel to operations.
It is important that quarry operators ensure a holistic assessment of geotechnical risks that considers site operations and safety in the here and now but is also mindful of life of the site post-extraction. The quarry assessment and planning should consider designing and shaping the landform to support and expedite rehabilitation of the site and to maximise the value of future land uses.
Planning future uses of a quarry site post-closure
Returning to our example of Victoria, it is expected that about 300 quarries in the state will close over the next three decades. All will require rehabilitation or transformation into alternative land uses. If designing a quarry on a greenfield site, it will be necessary to consider the longer-term scenarios at the outset of the project and negotiate with various stakeholders about plans for the site’s rehabilitation post-closure, despite the timeframe of potential decades of intervening operations.
In the past, old quarries were most often used as landfill, or simply made safe and effectively abandoned. But now, many other more appealing, innovative and potentially higher value solutions are emerging for incorporating disused quarries into urban landscapes. Given the expansion of the urban footprint, with clever design and landscaping, these sites can become valuable and appealing residential or commercial properties or recreational areas.
Incorporating creative future planning for community and environmental benefits is likely to encourage community acceptance of a quarry project as well as contribute to a successful planning process and an improved overall value proposition.