Our society is built on sand. That may make it sound as if it was built on a weak, insubstantial foundation. The weakness is there, but not the way you might think. It’s not due to a poor foundation. Instead, our weakness is more prosaic; globally, we are literally, running out of sand!
But what of the “limitless” supply of sand in the Sahara, or the Arabian Peninsula’s dunes, or the Gobi desert? How about all the beaches out there? Oddly, our City of Barrie is built on an ancient beach; the soil under most peoples’ properties is mostly sand. Nevertheless, Barrie’s beaches are largely artificial; their sand has been imported from elsewhere. And that’s the problem. We are running out of readily available sand, of sand with the proper characteristics and at a price we are willing to pay, governed by how the sand is being used. So, what do we use sand for?
What is Sand Used For?
The sheer number of uses for this substance will surprise you. Sand is a basic component of concrete and of asphalt for paving the majority of our roads – the minority are paved with concrete . . . The basic raw material for the glass in our windows and glass bottles is silica sand (silicon dioxide, of at least 95% purity) which is melted down together with sodium carbonate. Sand exceeding this level of purity is only found in a few places. Even higher purity is needed for photovoltaic panels, and still higher purity for the silicon chips used in our cell phones and computers. Even the lower purity sand required for concrete must be “sharp” – grains of sand with sharp edges; rounded grains make weak concrete. Road asphalt tolerates more rounded grains. Sand is a vital component of the fluid mixture petroleum companies use for hydraulic fracturing (“fracking”) deep deposits of shale stone to release its hydrocarbons. After the high pressure shock which cracks the rock, sand grains prop open these cracks, allowing the oil to flow. This type of sand needs to be within a narrow band of grain size, the grains need to be rounded enough to let often viscous oil slide around them and have the strength to resist crushing by the enormous pressure encountered in deep shale oil deposits. In the USA, the best place to procure “frac-sand” is Wisconsin. Each fracking well requires uses up to 25,000 tons of sand, and in 2017 Wisconsin shipped 92 million tons of frac-sand – in one year. Where farmers have worked their land for a century, sand miners have bought up land, converting peaceful, pretty, rolling cropland into noisy industrial areas stripped of all trees and small plants!
More seriously, these operations raise dust – silica-laden dust. In an industrial setting, there are strict limits to the amount of silica which a worker can inhale due to the danger of silicosis. But apparently, these limits do not apply to people who happen to live across the highway from a sand mine . . . And then there is the huge water demand, required to wash the sand, and chemicals used to process it to the required purity, some of which are inevitably spilled.
Most environmentalists are against fracking because of its potential effects (ground water contamination, earth tremors) in the vicinity of the petroleum extraction. Very few consider the troubling effects on the lives of people in the neighbourhood of the sand mining which makes fracking possible. Then, one of the largest uses for sand is for “reclaiming” land. The City of Barrie used locally available sand to convert Kempenfelt Bay’s marshy shoreline into a beautiful municipal park plus several beaches for citizens to enjoy.
Around the World
On a much more massive scale, Tokyo’s Haneda airport was largely built on land reclaimed from the sea and one quarter of Singapore’s area consists of reclaimed land. Both relied on sand brought from elsewhere. Backed by a buoyant economy, Singapore has become the world’s largest importer of sand. In Florida’s Ft. Lauderdale beach and Palm Beach, replenishment has been necessary to replace natural erosion. In Miami Beach, sand has been brought in to raise the level of main streets by a meter or more. These main streets have become dykes protecting the town from storm surges. This sand mining has stripped Florida’s south east coast sea bed of virtually all its sand! In the past, a southward-flowing coastal current used to bring sand to the Florida coast from various river deltas to the north. Unfortunately, shore development like piers, marinas and hotel foreshores have repositioned this current just far enough away from shore to greatly reduce the natural movement of sand. Southern California’s beaches depended on rivers bringing silt (sand) in from the mountains to maintain its beaches. Many (most?) of these rivers are now dammed for hydroelectricity and irrigation, trapping the sand, but erosion continues, gradually destroying beaches which had been there “forever”. Dubai is building artificial islands which wealthy people can purchase in whole or in part to construct dream homes. These properties are gated communities, insulated from ordinary folk, yet near to the “delights” of a modern city with a busy, well connected airport. The sand for these islands was dredged from the sea bed nearby, completely destroying its coral reefs.
Moreover, the local desert sand is too fine and powdery to use in concrete; huge quantities of sharp sand must be imported. Sand suitable to make concrete tends to be found in river deltas. All over south Asia, rivers like the Mekong, Ganges and Yangzi have been mined for their sand. It turns out that this river sand had been protecting ground water along the banks of these rivers from tide-driven salt infiltration. As a result, sea water has been damaging riverbank croplands in Vietnam and Cambodia up to 100km up the Mekong River. Mining sand from Asian rivers has caused riverbank erosion. In some cases, this has been amplified by dams built upriver which now trap much of the silt which had been deposited along riverbanks. Sand mining has also undermined bridge supports threatening or actually causing collapse! Fishermen complain that sand removal; has damaged their ocean fishery nearby. These days, sand is stolen from public beaches and river bottoms at night when nobody is watching! Government
corruption often makes it easy for sand pirates to continue working despite the obvious damage they cause.
The bottom line is that the world is rapidly running out of a substance which most of us would have thought was limitless! And in many areas, its absence has caused serious environmental damage.
-By Peter Bursztyn