Crown Prince Mohammed bin Salman dreams of building two 100-mile-long skyscrapers in the desert, a pair of mirror-encased, parallel lines running through the sand.
The project, appropriately dubbed “the Line,” is part of the Saudi government’s planned $500 billion megacity near the Gulf of Aqaba, east of Egypt. The vision is fanciful for a few reasons. If realized, the linear, carless utopia with high-speed underground trains would generate zero carbon emissions and house 9 million people.
But there are more than a few practical considerations standing in the way, including a not-so-obvious one: While the project site is surrounded by sand — a material critical for the concrete required to fortify the structure — grittier grains would likely need to be shipped from Australia and other countries, as is often the case for construction projects in Saudi Arabia. The abundant local sand isn’t fit for the purpose.
At a much smaller scale, the paradox of the Line is playing out in regions across the globe. Many communities have access to sand, but not the right kind of sand. Sand used for constructing buildings and producing glass needs to be mined from riverbeds or beaches, quarried from open pits or blasted from rock formations. This higher-quality sand is running out.
More accurately, humanity is using it faster than it can be naturally replenished. The United Nations Environment Program estimates that between 40 and 50 metric tons of sand are consumed each year, triple what was used two decades ago. The increase has largely been driven by an explosion of construction, particularly in China and India. While shortages of construction sand are more pronounced in some parts of the world — as evidenced by the proliferation of “sand mafias” that illegally mine the material in Vietnam, China, India and other countries — cities around the globe are exhausting their resources.
Construction companies in Los Angeles are now importing sand and gravel from Vancouver Island in Canada to make concrete because local quarries are largely tapped out. Suppliers are consolidating on Long Island and turning to neighboring states as resources are depleted.
In many cases, construction managers, architects and developers are not even aware there is a shortage of sand, a material often taken for granted as a resource in endless supply. The hierarchy of a construction project means a developer is not usually privy to the intricacies of where raw materials are from unless they dramatically increase the project’s cost or timeframe. If a member of the design or development team learns of a material shortage, it is often because it is already holding things up.
“We hear about it, but the difficulty we have is it is not quantified, and the response is reactionary,” said David Shook, a San Francisco-based structural engineer with the architecture firm Skidmore, Owings & Merrill. “Disruptions happen, and they don’t see it coming.”
It’s an issue the industry will soon need to grapple with, especially as supply chain disruptions from the pandemic continue to snarl projects. The construction industry is the biggest consumer of sand and gravel, and demand for these materials is expected to grow exponentially in the next few decades.
In an August report, JLL noted that there are already “considerable disruptions” in the delivery of glass and concrete. The commercial brokerage cautioned that the sand industry is seeing “rapid price growth” and “shortages in high-quality materials that are likely to have long-term consequences.”
The depletion of local resources is causing companies to mine at new depths in river and ocean floors, further eroding coastlines, and dig deeper into the earth, disrupting natural habitats and in some cases neighborhoods. The cost of transporting sand from farther and farther away threatens to drive up prices and derail efforts to decarbonize the construction process.
“Sand is essential to economic growth and development. No matter where you are in the world, that’s a given,” said Mark Russell, the Mineral Products Association’s executive director for planning and mineral resources in the U.K. “Is it sustainable to manage sand in the way that we are globally? Absolutely not.”
Through the looking glass
In June, David Hamilton, vice president of purchasing at construction management firm Structure Tone, received a message from his glass supplier, Guardian Glass. The Michigan-based company was increasing the price of certain types of glass sheets by 40 percent.
“It came sort of by surprise,” he said, adding, however, that market volatility during the pandemic has led to sudden price hikes. Some suppliers previously gave more advance notice when they planned to increase costs, but that is no longer the case. “Nobody gives you any breathing room.”
Guardian wasn’t alone. According to the trade magazine USGlass, at least five other major U.S. glass suppliers increased prices in June, citing, among other things, “extreme volatility in raw material costs.”
Glass is typically made using silica sand, also called industrial or quartz sand, a purer form of the material that must be at least 95 percent silicon dioxide. Such sand is much more expensive than what is used for concrete and is available in fewer places.
It is not clear how much of the price increases can be attributed to silica sand shortages, but demand for the material is expected to balloon in the next few years. John Robbins, managing director and head of real estate for Turner & Townsend’s U.S. and North America division, noted that lead times for curtain wall deliveries have recently doubled. Glass is the cladding of choice for new skyscrapers, in which floor-to-ceiling windows are a selling point for both luxury penthouses and corner offices.
China is the top producer and consumer of the world’s flat glass. According to the book “The World in a Grain: The Story of Sand and How it Transformed Civilization,” while the World Trade Center’s original twin towers were made with American glass, the lower floors of One World Trade Center gleam with Chinese glass.
According to the Department of the Interior, the U.S. consumed 67 million tons of industrial sand last year, compared to 23.6 million tons in 2011. The department’s 2022 geological survey noted that local shortages are expected to “increase owing to land development priorities, local zoning regulations and logistical issues.”
For some regions, this spells a supply crisis: Vietnamese officials in 2017 predicted that the country could run out of sand in a few years. The “sand mafias” have sprung up to illegally extract the resource and sell it on the black market. These groups, in some cases, have resorted to violence to protect their business, reportedly leading to hundreds of deaths in India and other countries.
In other regions, the pressure of dwindling supplies takes on a different shape.
“In the U.S., the issue isn’t so much that we’re literally running out of sand,” said Vince Beiser, author of “The World in a Grain.” “It’s more that the sand that’s easy to get at has been largely tapped out, so we’re having to go further and dig deeper and potentially do more harm to get at the stuff that’s left.”
Take a hike
In April, the UN Environment Program released a report with key recommendations on how to “avert a crisis” by better managing global sand resources. The report called for developers to audit the availability of raw materials before beginning a project, rather than assuming they will magically show up at a site.
“To coin a ‘Field of Dreams’ phrase, if we build it, the materials needed will come,” said Russell of the Mineral Products Association, one of the authors of the report. “The supply is almost always able to respond to the market demands. But the fundamental question is whether that response is providing the most sustainable option.”
If there is any silver lining to the extensive supply chain issues wrought by the pandemic, it is that they have brought increased awareness to the availability of raw materials.
“We pivoted and started to track things a lot more,” Structure Tone’s Hamilton said, noting that this was previously left up to subcontractors. “It’s really since Covid that we have grown to understand that we need more visibility into the supply chain.”
“The Line” is part of the Saudi government’s planned $500 billion megacity near the Gulf of Aqaba, east of Egypt (Photo courtesy of Neom)
The solution for some cities has been to ship sand in, an option that increases the cost of concrete and deepens an already massive carbon footprint. Builders in Los Angeles, San Diego and the San Francisco Bay Area have increasingly had to look elsewhere, because local quarries are now bare. While more sand and gravel — together called aggregate — sit under these cities, residents do not want new pits or the noise that accompanies them.
As a result, sand and gravel are shipped more than 1,400 miles from Canada, according to the Los Angeles Times. The sand is scraped from a quarry on Vancouver Island, which provides grains rough enough to bind together when mixed with cement, rather than smooth and rounded like desert sand.
SOM’s Shook said regional shortages tend to affect smaller projects disproportionately, because concrete companies will prepare in advance for larger, high-paying jobs. But major projects still experience delays in concrete deliveries and increased costs associated with transporting sand from farther away.
“The owner is just caught paying for it, and they take it out of other things, like finishes,” he said.
On Long Island, local shortages have led to consolidation among material providers, with firms seizing what resources are left, according to Tim Stroud, chief operating officer at Suffolk Construction, who said many New York projects are now relying on concrete from New Jersey. In 2020, Texas-based U.S. Concrete acquired Coram Materials, citing Coram’s 50 million tons of reserves “in the quickly depleting Long Island sand market,” according to Long Island Business News. Last year, Alabama-based Vulcan Materials Company scooped up U.S. Concrete.
California and New York are still among the top producers, by tons, of construction sand in the country, according to the 2022 geological survey. But in some parts of those states, builders are increasingly ordering aggregate from out of town. Marc Herbst, executive director of the Long Island Contractors’ Association, said Long Island once had 78 permitted sand mines. Now it has 23.
“A lot of the mines are reaching their depletion point,” he said. “It is conceivable that over the next couple of decades, there will be no mines in the region.”
Replacing sand
There is not much urgency among U.S. construction managers and developers to find alternatives to sand: It’s still cheap and relatively available. But experts say the industry should be thinking long-term if it wants to ensure that the material remains within reach. There is also the destruction of farmland, forests, coastlines and ecosystems to consider. Some experts believe flooding in Houston during Hurricane Harvey was made worse by sand mining in the San Jacinto River.
The reduction of global carbon emissions, of which concrete accounts for 8 percent, hinges on how cities shape their built environments in the future. But as an industry, construction has traditionally been slow to adopt new technologies.
A June 2022 study by Northeastern University concluded that there is a “low level of awareness of substitutes for sand in the construction industry in the United States and Canada.”
These substitutes include various kinds of ground construction debris, including slag, a waste product of refining and smelting ore to get copper and other metals. In Zurich, Switzerland, all public buildings must be constructed with recycled concrete. In recent years, many countries have turned to mass timber as an alternative to traditional steel and concrete construction, but the material is just starting to take off in parts of the U.S.
Turner & Townsend’s Robbins hopes the Inflation Reduction Act may incentivize developers to seek out concrete alternatives to qualify for carbon credits.
“Concrete is by no means the most expensive material,” he said. “If you look at it from a pure financial sense, from the perspective of a developer, you may think concrete is not first on their agenda.”
He said that the private sector has taken steps to build more sustainably. JPMorgan Chase’s new 2.5 million-square-foot Midtown Manhattan headquarters at 270 Park Avenue will be all-electric. Some 97 percent of the construction materials from the building demolished to make way for the new headquarters were recycled, though it could perhaps be argued that the more sustainable option would have been to simply keep the existing 60-year-old building on the site.
Eamonn Connolly, director of engineering at McHugh Engineering Group, which is working on what may be Chicago’s first building constructed using low-carbon concrete, said it is also up to local governments to ensure their building codes allow for environmentally friendly innovations in construction.
“Engineers and builders are bound by very strict rules and regulations,” he said. “Until that code gets updated, a lot of technologies and methods are banned.”
Mette Bendixen, a geography professor at McGill University, noted that sand is so cheap, builders often find it economical to just buy new material. It will take action from local governments for the widespread recycling of construction materials or alternatives to sand and concrete to gain traction.
“That requires political will,” she said. “We don’t have that one quick fix, that one solution that solves everything.”