This chapter focuses on how sand, the second most used natural resource on earth after water, is facing one of the greatest environmental challenges of the new millennium. Sand is a crucial material used in all sorts of building projects, from asphalt, concrete, and glass. Globally, construction accounts for the largest portion of the 15 billion tons of sand consumed annually. Yet, sand is a finite resource and the depletion of alluvial sand used in construction is destroying the ecosystem of riverbeds, sea beds, and coastal beaches, and is contributing seriously to climate change. This chapter will discuss how these threats have developed, including coastal construction and erosion, river dredging, and sand “mafias” whereby illegal sand miners strip beaches and use sand in inferior concrete that has led to building collapses and deaths. The authors then discuss potential solutions to this crisis, including regulation and enforcement of environmental and construction standards, as well as materials substitution such as desert sand, sand created from sandstone, and recycled glass.
TopA World Built On Sand
[A] foolish man... built his house on sand. The rain came down, the streams rose, and the winds blew and beat against that house, and it fell with a great crash. – Matthew 7:26-27, Holy Bible, New International Version
After water, sand is the second most used natural resource on earth. A United Nations report estimated that in 2012, the world used as much as 29.6 billion tons of sand, or, “enough concrete to build a wall 27 meters high by 27 meters wide around the equator” (Peduzzi, 2014). Sand is a major internationally traded commodity. According to the Observatory of Economic Complexity, the world’s largest importer of sand is Singapore, which imports 13% of the world’s sand, followed by Canada (11%), Belgium-Luxembourg (9%), The Netherlands (6.2%), Germany (4.4%), and Mexico (4.4%). The top ten largest exporters of sand in 2015 were the United States, at $385 billion being more than twice The Netherlands, the next country. Germany, Belgium, Australia, Vietnam, Cambodia, France, China, and Egypt rounded out the top ten (World Atlas, 2017).
Asphalt, concrete, and glass all contain copious amounts of sand. The silicon that goes into computer chips that power our iPhones and computers is made from it. Sand even finds its way into toothpaste, cosmetics, and fast food.1 Without sand, we would be without bridges, skyscrapers, and paved roads.
Sand is the primary raw ingredient in the manufacture of silicon wafers used in computer chips and other electronics, a process that requires a highly purified form that can only be mined in specific locations. Turning sand into silicon involves a 300-step process (Marshall, 2016). Once the process is complete, the resulting crystals are the purist on earth, surpassing even the purist diamonds (McWhan, 2012).
Silicon is also a key ingredient in other forms of electronics. For instance, it is essential to the manufacture of solar panels. Despite its importance, silicon production accounts for a tiny fraction of overall sand production. In the United States, 173,000 metric tons of the nearly 30 million metric tons of industrial sand and gravel consumed annually goes toward silicon manufacturing (Dolley, 2012).
By far, the biggest consumer of industrial sand in the United States is the petroleum industry, which uses sand for hydraulic fracturing, commonly known as fracking. Sand forms part of a slurry that is injected into wells at high pressure to release oil and gas. In 2010, fracking consumed 3.8 million metric tons of industrial sand (12.7 percent of total production for that year) (Dolley, 2012). Fracking is considered a godsend to energy security advocates, as it has greatly reduced America’s dependence on imported fuel. The use of sand is also costly for fracking companies. As a result, in 2017, sand use per foot of drilling declined as oil companies deployed new methods that require lower quantities of the substance (Nair & Bhattacharjee, 2017). Aside from silicon and frac sand, industrial sand is also used in large quantities in glassmaking, in creating molds for steel foundries, and in the manufacture of water filtration systems and abrasives.
Despite these impressive numbers, industrial sand use is dwarfed by construction sand. In the United States, the construction industry consumes 443 million metric tons of sand, which is nearly 15 times the amount used for industrial purposes. In 2016, the US Geological survey estimated, that about 44% of construction sand and gravel was used as concrete aggregates; 25% for road base and coverings and road stabilization; 13% as asphaltic concrete aggregates and other bituminous mixtures; 12% as construction fill; 1% each for concrete products, such as blocks, bricks, and pipes; plaster and gunite sands; and snow and ice control; and the remaining 3% for filtration, golf courses, railroad ballast, roofing granules, and other miscellaneous uses (US Department of the Interior, 2017).
Globally, construction accounts for the largest portion of the 15 billion tons of sand consumed each year, with 10 billion tons of sand destined for cement production (Allen, Thallon, & Schreyer, 2017).