Between a rock and a hard place
Opinion By Rob McCann, South Pacific Sustainability.
The proposal
If approved, the Stony Ridge Quarry is expected to produce approximately 1.5 million tonnes of hard rock per annum, largely to supply the construction industry. Indeed we need materials for construction projects, although we need to be smarter about how we use these materials, and where we mine for them. Though I couldn’t believe my eyes when I saw the proposal to construct this quarry within the Wallaroo State Forest, I won’t dwell on the environmental impacts here, as there is plenty of information on this website for you to make up your own mind about this project. I want to address the sustainability of such projects, how we have got ourselves in this position, and how we may lessen the problem.
It’s the economy, stupid
The proponents of this project have correctly stated that the current supply of materials is not going to keep up with demand. This statement piqued my interest and is already true, and they have partly used this as justification for pursuing this project. While acknowledging this, they are also placing themselves in a position where they will be able to supply materials to a burgeoning construction market, no doubt for a handsome and fairly low-risk profit (owing to the supply being less than the demand) over the lifecycle of the project. Good for them.
But from a sustainability perspective, is the quarry (the supply) the key problem? Or is it the unsustainable demand of the market?
But from a sustainability perspective, is the quarry (the supply) the key problem? Or is it the unsustainable demand of the market?
What is going on with commodities for construction at the moment has parallels to the social catastrophe that is the Australian housing market. A state-backed frenzy and subsequent demand for a particular thing will continue to outstrip supply, thus increasing scarcity, in turn ensuring that prices will continue to rise unabatedly, or so the narrative goes. A shortage here, a boom there, a spike in prices, and great tax revenues and GDP figures to show on paper. Such is the nature of resources like aggregate, sand and so on – take your pick.
A quick refresher on first principles of economics. For many, where you want to be is that sweet spot on the curve that sits somewhere in between the demand and supply. The rule of thumb says that too much demand and prices go up, too much supply and you have a glut; prices go down. This is good or bad, depending on which side of the ledger you sit on. If you own or invest in a quarry, despite your stress levels increasing dramatically, i.e.“we have run out of truck drivers and our clients are going to our bigger competitors, help!!”, so long as its managed and planned for, your profits will be handsome to say the least, and as an industry we will continue to be in the position where we are digging up large swathes of land to hock materials to construction projects, and concrete and aggregate manufacturers. This is where we are now. We are experiencing a once in a generation construction boom, backed by the state and federal governments, the scale of which cannot be overstated.
The amount of fill material, road base, VENM (Virgin Excavated Natural Material), sand, gravel and rock being used by, and produced by a project like Sydney Metro (pick any of the sections), is extraordinary. On a planetary scale, we have altered our environment and moved so much rock and soil that we have created a new geological era. All this blasting, digging and hauling has extraordinary environmental impacts. Roads and houses are a necessity, to be sure, but again – how are we going to supply all this in such a short amount of time?
Some practical, project-level solutions
There are some things which may help. I wrote about this in April 2022. Some more in depth examples are below.
Put simply, when you dig a big hole, presumably you have a surplus of material which can meet the shortage of this material (i.e. fill a hole) elsewhere. This is called cut-to-fill. Believe it or not, I have a front row seat to this in my profession and it is not common practice on projects, for reasons I won’t go into here. So long as the material is not contaminated, you can pick up the phone to another project in the area and say “G’day ****, I have 400m3 of clean material you can have. Just cover haulage, provide your VENM paperwork and we’re square”. Both projects save money this way.
…when you dig a big hole, presumably you have a surplus of material which can meet the shortage of this material (i.e. fill a hole) elsewhere. This is called cut-to-fill. Believe it or not, I have a front row seat to this in my profession and it is not common practice …
I was once on a rail project where we excavated a significant amount of perfectly good ballast which was no longer needed. We had a huge surplus just sitting there, so I picked up the phone to a nearby project which needed ballast in a couple of months’ time for an upcoming track recon. Curiously, they declined. I had to go to this particular site a week later to chat to some of the Project Managers, having still not found a home for all this ballast. When I arrived on site, my first words were “what the **** is this?”. I saw a mountain of freshly quarried, brand-spanking new ballast which had only just been purchased. Believe me, this happens all the time.
A project may also choose to hire a crusher and recycle bricks, concrete, rock or other materials on site so you can use it again and not buy more. You also save a motza by reducing haulage of materials to and from site, and you’re also not paying a disposal fee (which is usually a fee paid to a recycling company who will be paid to collect it, and will on sell it and get paid twice for that same material). By lessening haulage, you are saving fuel and emissions, and the community doesn’t have to listen to trucks down gearing for days on end.
What about sand, which is used in concrete, asphalt, pipe bedding, backfill and many other aspects of construction? Not only is usable sand for engineering becoming extremely scarce globally (which I have written about before on this website – there is much literature on this), it’s expensive. Again, this is purely because this resource is mismanaged. If it’s managed properly (i.e. sustainably), there are no shortages. So long as it meets the spec, you can use materials like recycled glass, which is readily available on many projects, and at times is extremely cheap per tonne (I have used it on several projects in the past to the delight of parsimonious construction managers). I was recently involved with a company in Western Sydney who is collecting used solar panels, crushing them and selling the glass to construction projects.
At one point in 2020, Western Sydney was swimming in so much sand from all the tunnelling (for Sydney Metro) that they were struggling to find a suitable home for it.
At one point in 2020, Western Sydney was swimming in so much sand from all the tunnelling (for Sydney Metro) that they were struggling to find a suitable home for it. I believe much surplus material ended up at the new runway in Badgery’s Creek – a great recycling solution for materials. I worked on projects at the time which needed clean fill, so we picked up the phone, joined the dots, and saved a pretty penny, as well as reducing environmental impacts and the need for quarrying virgin materials.
Conclusion
There are so many ways we can reduce demand and thus reduce the frenzy of quarrying, at least so we aren’t at the point where we are clearing natural habitat in areas like Wallaroo State Forest.
Whether you are planning a major construction project, a small home renovation, building a retaining wall, or batching concrete, you can do your part and make sure your recycled materials are maximised. Get it in your drawings, ask your supplier, advertise your surplus material online, and ask “where does this aggregate come from?” before your purchase. A bit of thought gone into how we plan for and purchase materials, and we can lessen this problem, and perhaps in the future avoid this absurd situation we find ourselves in.